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authorFathi Boudra <fathi.boudra@linaro.org>2013-04-28 09:33:08 +0300
committerFathi Boudra <fathi.boudra@linaro.org>2013-04-28 09:33:08 +0300
commit3b4bd47f8f4ed3aaf7c81c9b5d2d37ad79fadf4a (patch)
treeb9996006addfd7ae70a39672b76843b49aebc189 /Documentation/i2c
downloadlinux-linaro-highbank-3b4bd47f8f4ed3aaf7c81c9b5d2d37ad79fadf4a.tar.gz
Imported Upstream version 3.9.0HEADupstream/3.9.0upstreammaster
Diffstat (limited to 'Documentation/i2c')
-rw-r--r--Documentation/i2c/busses/i2c-ali153542
-rw-r--r--Documentation/i2c/busses/i2c-ali156327
-rw-r--r--Documentation/i2c/busses/i2c-ali15x3112
-rw-r--r--Documentation/i2c/busses/i2c-amd75625
-rw-r--r--Documentation/i2c/busses/i2c-amd811141
-rw-r--r--Documentation/i2c/busses/i2c-diolan-u2c26
-rw-r--r--Documentation/i2c/busses/i2c-i801158
-rw-r--r--Documentation/i2c/busses/i2c-ismt36
-rw-r--r--Documentation/i2c/busses/i2c-nforce250
-rw-r--r--Documentation/i2c/busses/i2c-ocores68
-rw-r--r--Documentation/i2c/busses/i2c-parport177
-rw-r--r--Documentation/i2c/busses/i2c-parport-light22
-rw-r--r--Documentation/i2c/busses/i2c-pca-isa23
-rw-r--r--Documentation/i2c/busses/i2c-piix4109
-rw-r--r--Documentation/i2c/busses/i2c-sis559559
-rw-r--r--Documentation/i2c/busses/i2c-sis63058
-rw-r--r--Documentation/i2c/busses/i2c-sis96x73
-rw-r--r--Documentation/i2c/busses/i2c-taos-evm46
-rw-r--r--Documentation/i2c/busses/i2c-via34
-rw-r--r--Documentation/i2c/busses/i2c-viapro73
-rw-r--r--Documentation/i2c/busses/scx200_acb32
-rw-r--r--Documentation/i2c/dev-interface214
-rw-r--r--Documentation/i2c/fault-codes127
-rw-r--r--Documentation/i2c/functionality148
-rw-r--r--Documentation/i2c/i2c-protocol83
-rw-r--r--Documentation/i2c/i2c-stub53
-rw-r--r--Documentation/i2c/instantiating-devices211
-rw-r--r--Documentation/i2c/muxes/i2c-mux-gpio83
-rw-r--r--Documentation/i2c/old-module-parameters44
-rw-r--r--Documentation/i2c/smbus-protocol273
-rw-r--r--Documentation/i2c/summary47
-rw-r--r--Documentation/i2c/ten-bit-addresses24
-rw-r--r--Documentation/i2c/upgrading-clients281
-rw-r--r--Documentation/i2c/writing-clients403
34 files changed, 3282 insertions, 0 deletions
diff --git a/Documentation/i2c/busses/i2c-ali1535 b/Documentation/i2c/busses/i2c-ali1535
new file mode 100644
index 00000000..5d46342e
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-ali1535
@@ -0,0 +1,42 @@
+Kernel driver i2c-ali1535
+
+Supported adapters:
+ * Acer Labs, Inc. ALI 1535 (south bridge)
+ Datasheet: Now under NDA
+ http://www.ali.com.tw/
+
+Authors:
+ Frodo Looijaard <frodol@dds.nl>,
+ Philip Edelbrock <phil@netroedge.com>,
+ Mark D. Studebaker <mdsxyz123@yahoo.com>,
+ Dan Eaton <dan.eaton@rocketlogix.com>,
+ Stephen Rousset<stephen.rousset@rocketlogix.com>
+
+Description
+-----------
+
+This is the driver for the SMB Host controller on Acer Labs Inc. (ALI)
+M1535 South Bridge.
+
+The M1535 is a South bridge for portable systems. It is very similar to the
+M15x3 South bridges also produced by Acer Labs Inc. Some of the registers
+within the part have moved and some have been redefined slightly.
+Additionally, the sequencing of the SMBus transactions has been modified to
+be more consistent with the sequencing recommended by the manufacturer and
+observed through testing. These changes are reflected in this driver and
+can be identified by comparing this driver to the i2c-ali15x3 driver. For
+an overview of these chips see http://www.acerlabs.com
+
+The SMB controller is part of the M7101 device, which is an ACPI-compliant
+Power Management Unit (PMU).
+
+The whole M7101 device has to be enabled for the SMB to work. You can't
+just enable the SMB alone. The SMB and the ACPI have separate I/O spaces.
+We make sure that the SMB is enabled. We leave the ACPI alone.
+
+
+Features
+--------
+
+This driver controls the SMB Host only. This driver does not use
+interrupts.
diff --git a/Documentation/i2c/busses/i2c-ali1563 b/Documentation/i2c/busses/i2c-ali1563
new file mode 100644
index 00000000..41b1a077
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-ali1563
@@ -0,0 +1,27 @@
+Kernel driver i2c-ali1563
+
+Supported adapters:
+ * Acer Labs, Inc. ALI 1563 (south bridge)
+ Datasheet: Now under NDA
+ http://www.ali.com.tw/
+
+Author: Patrick Mochel <mochel@digitalimplant.org>
+
+Description
+-----------
+
+This is the driver for the SMB Host controller on Acer Labs Inc. (ALI)
+M1563 South Bridge.
+
+For an overview of these chips see http://www.acerlabs.com
+
+The M1563 southbridge is deceptively similar to the M1533, with a few
+notable exceptions. One of those happens to be the fact they upgraded the
+i2c core to be SMBus 2.0 compliant, and happens to be almost identical to
+the i2c controller found in the Intel 801 south bridges.
+
+Features
+--------
+
+This driver controls the SMB Host only. This driver does not use
+interrupts.
diff --git a/Documentation/i2c/busses/i2c-ali15x3 b/Documentation/i2c/busses/i2c-ali15x3
new file mode 100644
index 00000000..42888d8a
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-ali15x3
@@ -0,0 +1,112 @@
+Kernel driver i2c-ali15x3
+
+Supported adapters:
+ * Acer Labs, Inc. ALI 1533 and 1543C (south bridge)
+ Datasheet: Now under NDA
+ http://www.ali.com.tw/
+
+Authors:
+ Frodo Looijaard <frodol@dds.nl>,
+ Philip Edelbrock <phil@netroedge.com>,
+ Mark D. Studebaker <mdsxyz123@yahoo.com>
+
+Module Parameters
+-----------------
+
+* force_addr: int
+ Initialize the base address of the i2c controller
+
+
+Notes
+-----
+
+The force_addr parameter is useful for boards that don't set the address in
+the BIOS. Does not do a PCI force; the device must still be present in
+lspci. Don't use this unless the driver complains that the base address is
+not set.
+
+Example: 'modprobe i2c-ali15x3 force_addr=0xe800'
+
+SMBus periodically hangs on ASUS P5A motherboards and can only be cleared
+by a power cycle. Cause unknown (see Issues below).
+
+
+Description
+-----------
+
+This is the driver for the SMB Host controller on Acer Labs Inc. (ALI)
+M1541 and M1543C South Bridges.
+
+The M1543C is a South bridge for desktop systems.
+The M1541 is a South bridge for portable systems.
+They are part of the following ALI chipsets:
+
+ * "Aladdin Pro 2" includes the M1621 Slot 1 North bridge with AGP and
+ 100MHz CPU Front Side bus
+ * "Aladdin V" includes the M1541 Socket 7 North bridge with AGP and 100MHz
+ CPU Front Side bus
+ Some Aladdin V motherboards:
+ Asus P5A
+ Atrend ATC-5220
+ BCM/GVC VP1541
+ Biostar M5ALA
+ Gigabyte GA-5AX (** Generally doesn't work because the BIOS doesn't
+ enable the 7101 device! **)
+ Iwill XA100 Plus
+ Micronics C200
+ Microstar (MSI) MS-5169
+
+ * "Aladdin IV" includes the M1541 Socket 7 North bridge
+ with host bus up to 83.3 MHz.
+
+For an overview of these chips see http://www.acerlabs.com. At this time the
+full data sheets on the web site are password protected, however if you
+contact the ALI office in San Jose they may give you the password.
+
+The M1533/M1543C devices appear as FOUR separate devices on the PCI bus. An
+output of lspci will show something similar to the following:
+
+ 00:02.0 USB Controller: Acer Laboratories Inc. M5237 (rev 03)
+ 00:03.0 Bridge: Acer Laboratories Inc. M7101 <= THIS IS THE ONE WE NEED
+ 00:07.0 ISA bridge: Acer Laboratories Inc. M1533 (rev c3)
+ 00:0f.0 IDE interface: Acer Laboratories Inc. M5229 (rev c1)
+
+** IMPORTANT **
+** If you have a M1533 or M1543C on the board and you get
+** "ali15x3: Error: Can't detect ali15x3!"
+** then run lspci.
+** If you see the 1533 and 5229 devices but NOT the 7101 device,
+** then you must enable ACPI, the PMU, SMB, or something similar
+** in the BIOS.
+** The driver won't work if it can't find the M7101 device.
+
+The SMB controller is part of the M7101 device, which is an ACPI-compliant
+Power Management Unit (PMU).
+
+The whole M7101 device has to be enabled for the SMB to work. You can't
+just enable the SMB alone. The SMB and the ACPI have separate I/O spaces.
+We make sure that the SMB is enabled. We leave the ACPI alone.
+
+Features
+--------
+
+This driver controls the SMB Host only. The SMB Slave
+controller on the M15X3 is not enabled. This driver does not use
+interrupts.
+
+
+Issues
+------
+
+This driver requests the I/O space for only the SMB
+registers. It doesn't use the ACPI region.
+
+On the ASUS P5A motherboard, there are several reports that
+the SMBus will hang and this can only be resolved by
+powering off the computer. It appears to be worse when the board
+gets hot, for example under heavy CPU load, or in the summer.
+There may be electrical problems on this board.
+On the P5A, the W83781D sensor chip is on both the ISA and
+SMBus. Therefore the SMBus hangs can generally be avoided
+by accessing the W83781D on the ISA bus only.
+
diff --git a/Documentation/i2c/busses/i2c-amd756 b/Documentation/i2c/busses/i2c-amd756
new file mode 100644
index 00000000..67f30874
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-amd756
@@ -0,0 +1,25 @@
+Kernel driver i2c-amd756
+
+Supported adapters:
+ * AMD 756
+ * AMD 766
+ * AMD 768
+ * AMD 8111
+ Datasheets: Publicly available on AMD website
+
+ * nVidia nForce
+ Datasheet: Unavailable
+
+Authors:
+ Frodo Looijaard <frodol@dds.nl>,
+ Philip Edelbrock <phil@netroedge.com>
+
+Description
+-----------
+
+This driver supports the AMD 756, 766, 768 and 8111 Peripheral Bus
+Controllers, and the nVidia nForce.
+
+Note that for the 8111, there are two SMBus adapters. The SMBus 1.0 adapter
+is supported by this driver, and the SMBus 2.0 adapter is supported by the
+i2c-amd8111 driver.
diff --git a/Documentation/i2c/busses/i2c-amd8111 b/Documentation/i2c/busses/i2c-amd8111
new file mode 100644
index 00000000..460dd663
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-amd8111
@@ -0,0 +1,41 @@
+Kernel driver i2c-adm8111
+
+Supported adapters:
+ * AMD-8111 SMBus 2.0 PCI interface
+
+Datasheets:
+ AMD datasheet not yet available, but almost everything can be found
+ in the publicly available ACPI 2.0 specification, which the adapter
+ follows.
+
+Author: Vojtech Pavlik <vojtech@suse.cz>
+
+Description
+-----------
+
+If you see something like this:
+
+00:07.2 SMBus: Advanced Micro Devices [AMD] AMD-8111 SMBus 2.0 (rev 02)
+ Subsystem: Advanced Micro Devices [AMD] AMD-8111 SMBus 2.0
+ Flags: medium devsel, IRQ 19
+ I/O ports at d400 [size=32]
+
+in your 'lspci -v', then this driver is for your chipset.
+
+Process Call Support
+--------------------
+
+Supported.
+
+SMBus 2.0 Support
+-----------------
+
+Supported. Both PEC and block process call support is implemented. Slave
+mode or host notification are not yet implemented.
+
+Notes
+-----
+
+Note that for the 8111, there are two SMBus adapters. The SMBus 2.0 adapter
+is supported by this driver, and the SMBus 1.0 adapter is supported by the
+i2c-amd756 driver.
diff --git a/Documentation/i2c/busses/i2c-diolan-u2c b/Documentation/i2c/busses/i2c-diolan-u2c
new file mode 100644
index 00000000..30fe4bb9
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-diolan-u2c
@@ -0,0 +1,26 @@
+Kernel driver i2c-diolan-u2c
+
+Supported adapters:
+ * Diolan U2C-12 I2C-USB adapter
+ Documentation:
+ http://www.diolan.com/i2c/u2c12.html
+
+Author: Guenter Roeck <guenter.roeck@ericsson.com>
+
+Description
+-----------
+
+This is the driver for the Diolan U2C-12 USB-I2C adapter.
+
+The Diolan U2C-12 I2C-USB Adapter provides a low cost solution to connect
+a computer to I2C slave devices using a USB interface. It also supports
+connectivity to SPI devices.
+
+This driver only supports the I2C interface of U2C-12. The driver does not use
+interrupts.
+
+
+Module parameters
+-----------------
+
+* frequency: I2C bus frequency
diff --git a/Documentation/i2c/busses/i2c-i801 b/Documentation/i2c/busses/i2c-i801
new file mode 100644
index 00000000..d55b8ab2
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-i801
@@ -0,0 +1,158 @@
+Kernel driver i2c-i801
+
+Supported adapters:
+ * Intel 82801AA and 82801AB (ICH and ICH0 - part of the
+ '810' and '810E' chipsets)
+ * Intel 82801BA (ICH2 - part of the '815E' chipset)
+ * Intel 82801CA/CAM (ICH3)
+ * Intel 82801DB (ICH4) (HW PEC supported)
+ * Intel 82801EB/ER (ICH5) (HW PEC supported)
+ * Intel 6300ESB
+ * Intel 82801FB/FR/FW/FRW (ICH6)
+ * Intel 82801G (ICH7)
+ * Intel 631xESB/632xESB (ESB2)
+ * Intel 82801H (ICH8)
+ * Intel 82801I (ICH9)
+ * Intel EP80579 (Tolapai)
+ * Intel 82801JI (ICH10)
+ * Intel 5/3400 Series (PCH)
+ * Intel 6 Series (PCH)
+ * Intel Patsburg (PCH)
+ * Intel DH89xxCC (PCH)
+ * Intel Panther Point (PCH)
+ * Intel Lynx Point (PCH)
+ * Intel Lynx Point-LP (PCH)
+ * Intel Avoton (SOC)
+ * Intel Wellsburg (PCH)
+ Datasheets: Publicly available at the Intel website
+
+On Intel Patsburg and later chipsets, both the normal host SMBus controller
+and the additional 'Integrated Device Function' controllers are supported.
+
+Authors:
+ Mark Studebaker <mdsxyz123@yahoo.com>
+ Jean Delvare <khali@linux-fr.org>
+
+
+Module Parameters
+-----------------
+
+* disable_features (bit vector)
+Disable selected features normally supported by the device. This makes it
+possible to work around possible driver or hardware bugs if the feature in
+question doesn't work as intended for whatever reason. Bit values:
+ 0x01 disable SMBus PEC
+ 0x02 disable the block buffer
+ 0x08 disable the I2C block read functionality
+ 0x10 don't use interrupts
+
+
+Description
+-----------
+
+The ICH (properly known as the 82801AA), ICH0 (82801AB), ICH2 (82801BA),
+ICH3 (82801CA/CAM) and later devices (PCH) are Intel chips that are a part of
+Intel's '810' chipset for Celeron-based PCs, '810E' chipset for
+Pentium-based PCs, '815E' chipset, and others.
+
+The ICH chips contain at least SEVEN separate PCI functions in TWO logical
+PCI devices. An output of lspci will show something similar to the
+following:
+
+ 00:1e.0 PCI bridge: Intel Corporation: Unknown device 2418 (rev 01)
+ 00:1f.0 ISA bridge: Intel Corporation: Unknown device 2410 (rev 01)
+ 00:1f.1 IDE interface: Intel Corporation: Unknown device 2411 (rev 01)
+ 00:1f.2 USB Controller: Intel Corporation: Unknown device 2412 (rev 01)
+ 00:1f.3 Unknown class [0c05]: Intel Corporation: Unknown device 2413 (rev 01)
+
+The SMBus controller is function 3 in device 1f. Class 0c05 is SMBus Serial
+Controller.
+
+The ICH chips are quite similar to Intel's PIIX4 chip, at least in the
+SMBus controller.
+
+
+Process Call Support
+--------------------
+
+Not supported.
+
+
+I2C Block Read Support
+----------------------
+
+I2C block read is supported on the 82801EB (ICH5) and later chips.
+
+
+SMBus 2.0 Support
+-----------------
+
+The 82801DB (ICH4) and later chips support several SMBus 2.0 features.
+
+
+Interrupt Support
+-----------------
+
+PCI interrupt support is supported on the 82801EB (ICH5) and later chips.
+
+
+Hidden ICH SMBus
+----------------
+
+If your system has an Intel ICH south bridge, but you do NOT see the
+SMBus device at 00:1f.3 in lspci, and you can't figure out any way in the
+BIOS to enable it, it means it has been hidden by the BIOS code. Asus is
+well known for first doing this on their P4B motherboard, and many other
+boards after that. Some vendor machines are affected as well.
+
+The first thing to try is the "i2c_ec" ACPI driver. It could be that the
+SMBus was hidden on purpose because it'll be driven by ACPI. If the
+i2c_ec driver works for you, just forget about the i2c-i801 driver and
+don't try to unhide the ICH SMBus. Even if i2c_ec doesn't work, you
+better make sure that the SMBus isn't used by the ACPI code. Try loading
+the "fan" and "thermal" drivers, and check in /proc/acpi/fan and
+/proc/acpi/thermal_zone. If you find anything there, it's likely that
+the ACPI is accessing the SMBus and it's safer not to unhide it. Only
+once you are certain that ACPI isn't using the SMBus, you can attempt
+to unhide it.
+
+In order to unhide the SMBus, we need to change the value of a PCI
+register before the kernel enumerates the PCI devices. This is done in
+drivers/pci/quirks.c, where all affected boards must be listed (see
+function asus_hides_smbus_hostbridge.) If the SMBus device is missing,
+and you think there's something interesting on the SMBus (e.g. a
+hardware monitoring chip), you need to add your board to the list.
+
+The motherboard is identified using the subvendor and subdevice IDs of the
+host bridge PCI device. Get yours with "lspci -n -v -s 00:00.0":
+
+00:00.0 Class 0600: 8086:2570 (rev 02)
+ Subsystem: 1043:80f2
+ Flags: bus master, fast devsel, latency 0
+ Memory at fc000000 (32-bit, prefetchable) [size=32M]
+ Capabilities: [e4] #09 [2106]
+ Capabilities: [a0] AGP version 3.0
+
+Here the host bridge ID is 2570 (82865G/PE/P), the subvendor ID is 1043
+(Asus) and the subdevice ID is 80f2 (P4P800-X). You can find the symbolic
+names for the bridge ID and the subvendor ID in include/linux/pci_ids.h,
+and then add a case for your subdevice ID at the right place in
+drivers/pci/quirks.c. Then please give it very good testing, to make sure
+that the unhidden SMBus doesn't conflict with e.g. ACPI.
+
+If it works, proves useful (i.e. there are usable chips on the SMBus)
+and seems safe, please submit a patch for inclusion into the kernel.
+
+Note: There's a useful script in lm_sensors 2.10.2 and later, named
+unhide_ICH_SMBus (in prog/hotplug), which uses the fakephp driver to
+temporarily unhide the SMBus without having to patch and recompile your
+kernel. It's very convenient if you just want to check if there's
+anything interesting on your hidden ICH SMBus.
+
+
+**********************
+The lm_sensors project gratefully acknowledges the support of Texas
+Instruments in the initial development of this driver.
+
+The lm_sensors project gratefully acknowledges the support of Intel in the
+development of SMBus 2.0 / ICH4 features of this driver.
diff --git a/Documentation/i2c/busses/i2c-ismt b/Documentation/i2c/busses/i2c-ismt
new file mode 100644
index 00000000..73735582
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-ismt
@@ -0,0 +1,36 @@
+Kernel driver i2c-ismt
+
+Supported adapters:
+ * Intel S12xx series SOCs
+
+Authors:
+ Bill Brown <bill.e.brown@intel.com>
+
+
+Module Parameters
+-----------------
+
+* bus_speed (unsigned int)
+Allows changing of the bus speed. Normally, the bus speed is set by the BIOS
+and never needs to be changed. However, some SMBus analyzers are too slow for
+monitoring the bus during debug, thus the need for this module parameter.
+Specify the bus speed in kHz.
+Available bus frequency settings:
+ 0 no change
+ 80 kHz
+ 100 kHz
+ 400 kHz
+ 1000 kHz
+
+
+Description
+-----------
+
+The S12xx series of SOCs have a pair of integrated SMBus 2.0 controllers
+targeted primarily at the microserver and storage markets.
+
+The S12xx series contain a pair of PCI functions. An output of lspci will show
+something similar to the following:
+
+ 00:13.0 System peripheral: Intel Corporation Centerton SMBus 2.0 Controller 0
+ 00:13.1 System peripheral: Intel Corporation Centerton SMBus 2.0 Controller 1
diff --git a/Documentation/i2c/busses/i2c-nforce2 b/Documentation/i2c/busses/i2c-nforce2
new file mode 100644
index 00000000..9698c396
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-nforce2
@@ -0,0 +1,50 @@
+Kernel driver i2c-nforce2
+
+Supported adapters:
+ * nForce2 MCP 10de:0064
+ * nForce2 Ultra 400 MCP 10de:0084
+ * nForce3 Pro150 MCP 10de:00D4
+ * nForce3 250Gb MCP 10de:00E4
+ * nForce4 MCP 10de:0052
+ * nForce4 MCP-04 10de:0034
+ * nForce MCP51 10de:0264
+ * nForce MCP55 10de:0368
+ * nForce MCP61 10de:03EB
+ * nForce MCP65 10de:0446
+ * nForce MCP67 10de:0542
+ * nForce MCP73 10de:07D8
+ * nForce MCP78S 10de:0752
+ * nForce MCP79 10de:0AA2
+
+Datasheet: not publicly available, but seems to be similar to the
+ AMD-8111 SMBus 2.0 adapter.
+
+Authors:
+ Hans-Frieder Vogt <hfvogt@gmx.net>,
+ Thomas Leibold <thomas@plx.com>,
+ Patrick Dreker <patrick@dreker.de>
+
+Description
+-----------
+
+i2c-nforce2 is a driver for the SMBuses included in the nVidia nForce2 MCP.
+
+If your 'lspci -v' listing shows something like the following,
+
+00:01.1 SMBus: nVidia Corporation: Unknown device 0064 (rev a2)
+ Subsystem: Asustek Computer, Inc.: Unknown device 0c11
+ Flags: 66Mhz, fast devsel, IRQ 5
+ I/O ports at c000 [size=32]
+ Capabilities: <available only to root>
+
+then this driver should support the SMBuses of your motherboard.
+
+
+Notes
+-----
+
+The SMBus adapter in the nForce2 chipset seems to be very similar to the
+SMBus 2.0 adapter in the AMD-8111 south bridge. However, I could only get
+the driver to work with direct I/O access, which is different to the EC
+interface of the AMD-8111. Tested on Asus A7N8X. The ACPI DSDT table of the
+Asus A7N8X lists two SMBuses, both of which are supported by this driver.
diff --git a/Documentation/i2c/busses/i2c-ocores b/Documentation/i2c/busses/i2c-ocores
new file mode 100644
index 00000000..c269aaa2
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-ocores
@@ -0,0 +1,68 @@
+Kernel driver i2c-ocores
+
+Supported adapters:
+ * OpenCores.org I2C controller by Richard Herveille (see datasheet link)
+ Datasheet: http://www.opencores.org/projects.cgi/web/i2c/overview
+
+Author: Peter Korsgaard <jacmet@sunsite.dk>
+
+Description
+-----------
+
+i2c-ocores is an i2c bus driver for the OpenCores.org I2C controller
+IP core by Richard Herveille.
+
+Usage
+-----
+
+i2c-ocores uses the platform bus, so you need to provide a struct
+platform_device with the base address and interrupt number. The
+dev.platform_data of the device should also point to a struct
+ocores_i2c_platform_data (see linux/i2c-ocores.h) describing the
+distance between registers and the input clock speed.
+There is also a possibility to attach a list of i2c_board_info which
+the i2c-ocores driver will add to the bus upon creation.
+
+E.G. something like:
+
+static struct resource ocores_resources[] = {
+ [0] = {
+ .start = MYI2C_BASEADDR,
+ .end = MYI2C_BASEADDR + 8,
+ .flags = IORESOURCE_MEM,
+ },
+ [1] = {
+ .start = MYI2C_IRQ,
+ .end = MYI2C_IRQ,
+ .flags = IORESOURCE_IRQ,
+ },
+};
+
+/* optional board info */
+struct i2c_board_info ocores_i2c_board_info[] = {
+ {
+ I2C_BOARD_INFO("tsc2003", 0x48),
+ .platform_data = &tsc2003_platform_data,
+ .irq = TSC_IRQ
+ },
+ {
+ I2C_BOARD_INFO("adv7180", 0x42 >> 1),
+ .irq = ADV_IRQ
+ }
+};
+
+static struct ocores_i2c_platform_data myi2c_data = {
+ .regstep = 2, /* two bytes between registers */
+ .clock_khz = 50000, /* input clock of 50MHz */
+ .devices = ocores_i2c_board_info, /* optional table of devices */
+ .num_devices = ARRAY_SIZE(ocores_i2c_board_info), /* table size */
+};
+
+static struct platform_device myi2c = {
+ .name = "ocores-i2c",
+ .dev = {
+ .platform_data = &myi2c_data,
+ },
+ .num_resources = ARRAY_SIZE(ocores_resources),
+ .resource = ocores_resources,
+};
diff --git a/Documentation/i2c/busses/i2c-parport b/Documentation/i2c/busses/i2c-parport
new file mode 100644
index 00000000..2461c7b5
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-parport
@@ -0,0 +1,177 @@
+Kernel driver i2c-parport
+
+Author: Jean Delvare <khali@linux-fr.org>
+
+This is a unified driver for several i2c-over-parallel-port adapters,
+such as the ones made by Philips, Velleman or ELV. This driver is
+meant as a replacement for the older, individual drivers:
+ * i2c-philips-par
+ * i2c-elv
+ * i2c-velleman
+ * video/i2c-parport (NOT the same as this one, dedicated to home brew
+ teletext adapters)
+
+It currently supports the following devices:
+ * (type=0) Philips adapter
+ * (type=1) home brew teletext adapter
+ * (type=2) Velleman K8000 adapter
+ * (type=3) ELV adapter
+ * (type=4) Analog Devices ADM1032 evaluation board
+ * (type=5) Analog Devices evaluation boards: ADM1025, ADM1030, ADM1031
+ * (type=6) Barco LPT->DVI (K5800236) adapter
+ * (type=7) One For All JP1 parallel port adapter
+
+These devices use different pinout configurations, so you have to tell
+the driver what you have, using the type module parameter. There is no
+way to autodetect the devices. Support for different pinout configurations
+can be easily added when needed.
+
+Earlier kernels defaulted to type=0 (Philips). But now, if the type
+parameter is missing, the driver will simply fail to initialize.
+
+SMBus alert support is available on adapters which have this line properly
+connected to the parallel port's interrupt pin.
+
+
+Building your own adapter
+-------------------------
+
+If you want to build you own i2c-over-parallel-port adapter, here is
+a sample electronics schema (credits go to Sylvain Munaut):
+
+Device PC
+Side ___________________Vdd (+) Side
+ | | |
+ --- --- ---
+ | | | | | |
+ |R| |R| |R|
+ | | | | | |
+ --- --- ---
+ | | |
+ | | /| |
+SCL ----------x--------o |-----------x------------------- pin 2
+ | \| | |
+ | | |
+ | |\ | |
+SDA ----------x----x---| o---x--------------------------- pin 13
+ | |/ |
+ | |
+ | /| |
+ ---------o |----------------x-------------- pin 3
+ \| | |
+ | |
+ --- ---
+ | | | |
+ |R| |R|
+ | | | |
+ --- ---
+ | |
+ ### ###
+ GND GND
+
+Remarks:
+ - This is the exact pinout and electronics used on the Analog Devices
+ evaluation boards.
+ /|
+ - All inverters -o |- must be 74HC05, they must be open collector output.
+ \|
+ - All resitors are 10k.
+ - Pins 18-25 of the parallel port connected to GND.
+ - Pins 4-9 (D2-D7) could be used as VDD is the driver drives them high.
+ The ADM1032 evaluation board uses D4-D7. Beware that the amount of
+ current you can draw from the parallel port is limited. Also note that
+ all connected lines MUST BE driven at the same state, else you'll short
+ circuit the output buffers! So plugging the I2C adapter after loading
+ the i2c-parport module might be a good safety since data line state
+ prior to init may be unknown.
+ - This is 5V!
+ - Obviously you cannot read SCL (so it's not really standard-compliant).
+ Pretty easy to add, just copy the SDA part and use another input pin.
+ That would give (ELV compatible pinout):
+
+
+Device PC
+Side ______________________________Vdd (+) Side
+ | | | |
+ --- --- --- ---
+ | | | | | | | |
+ |R| |R| |R| |R|
+ | | | | | | | |
+ --- --- --- ---
+ | | | |
+ | | |\ | |
+SCL ----------x--------x--| o---x------------------------ pin 15
+ | | |/ |
+ | | |
+ | | /| |
+ | ---o |-------------x-------------- pin 2
+ | \| | |
+ | | |
+ | | |
+ | |\ | |
+SDA ---------------x---x--| o--------x------------------- pin 10
+ | |/ |
+ | |
+ | /| |
+ ---o |------------------x--------- pin 3
+ \| | |
+ | |
+ --- ---
+ | | | |
+ |R| |R|
+ | | | |
+ --- ---
+ | |
+ ### ###
+ GND GND
+
+
+If possible, you should use the same pinout configuration as existing
+adapters do, so you won't even have to change the code.
+
+
+Similar (but different) drivers
+-------------------------------
+
+This driver is NOT the same as the i2c-pport driver found in the i2c
+package. The i2c-pport driver makes use of modern parallel port features so
+that you don't need additional electronics. It has other restrictions
+however, and was not ported to Linux 2.6 (yet).
+
+This driver is also NOT the same as the i2c-pcf-epp driver found in the
+lm_sensors package. The i2c-pcf-epp driver doesn't use the parallel port as
+an I2C bus directly. Instead, it uses it to control an external I2C bus
+master. That driver was not ported to Linux 2.6 (yet) either.
+
+
+Legacy documentation for Velleman adapter
+-----------------------------------------
+
+Useful links:
+Velleman http://www.velleman.be/
+Velleman K8000 Howto http://howto.htlw16.ac.at/k8000-howto.html
+
+The project has lead to new libs for the Velleman K8000 and K8005:
+ LIBK8000 v1.99.1 and LIBK8005 v0.21
+With these libs, you can control the K8000 interface card and the K8005
+stepper motor card with the simple commands which are in the original
+Velleman software, like SetIOchannel, ReadADchannel, SendStepCCWFull and
+many more, using /dev/velleman.
+ http://home.wanadoo.nl/hihihi/libk8000.htm
+ http://home.wanadoo.nl/hihihi/libk8005.htm
+ http://struyve.mine.nu:8080/index.php?block=k8000
+ http://sourceforge.net/projects/libk8005/
+
+
+One For All JP1 parallel port adapter
+-------------------------------------
+
+The JP1 project revolves around a set of remote controls which expose
+the I2C bus their internal configuration EEPROM lives on via a 6 pin
+jumper in the battery compartment. More details can be found at:
+
+http://www.hifi-remote.com/jp1/
+
+Details of the simple parallel port hardware can be found at:
+
+http://www.hifi-remote.com/jp1/hardware.shtml
diff --git a/Documentation/i2c/busses/i2c-parport-light b/Documentation/i2c/busses/i2c-parport-light
new file mode 100644
index 00000000..c22ee063
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-parport-light
@@ -0,0 +1,22 @@
+Kernel driver i2c-parport-light
+
+Author: Jean Delvare <khali@linux-fr.org>
+
+This driver is a light version of i2c-parport. It doesn't depend
+on the parport driver, and uses direct I/O access instead. This might be
+preferred on embedded systems where wasting memory for the clean but heavy
+parport handling is not an option. The drawback is a reduced portability
+and the impossibility to daisy-chain other parallel port devices.
+
+Please see i2c-parport for documentation.
+
+Module parameters:
+
+* type: type of adapter (see i2c-parport or modinfo)
+
+* base: base I/O address
+ Default is 0x378 which is fairly common for parallel ports, at least on PC.
+
+* irq: optional IRQ
+ This must be passed if you want SMBus alert support, assuming your adapter
+ actually supports this.
diff --git a/Documentation/i2c/busses/i2c-pca-isa b/Documentation/i2c/busses/i2c-pca-isa
new file mode 100644
index 00000000..b044e526
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-pca-isa
@@ -0,0 +1,23 @@
+Kernel driver i2c-pca-isa
+
+Supported adapters:
+This driver supports ISA boards using the Philips PCA 9564
+Parallel bus to I2C bus controller
+
+Author: Ian Campbell <icampbell@arcom.com>, Arcom Control Systems
+
+Module Parameters
+-----------------
+
+* base int
+ I/O base address
+* irq int
+ IRQ interrupt
+* clock int
+ Clock rate as described in table 1 of PCA9564 datasheet
+
+Description
+-----------
+
+This driver supports ISA boards using the Philips PCA 9564
+Parallel bus to I2C bus controller
diff --git a/Documentation/i2c/busses/i2c-piix4 b/Documentation/i2c/busses/i2c-piix4
new file mode 100644
index 00000000..1e6634f5
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-piix4
@@ -0,0 +1,109 @@
+Kernel driver i2c-piix4
+
+Supported adapters:
+ * Intel 82371AB PIIX4 and PIIX4E
+ * Intel 82443MX (440MX)
+ Datasheet: Publicly available at the Intel website
+ * ServerWorks OSB4, CSB5, CSB6, HT-1000 and HT-1100 southbridges
+ Datasheet: Only available via NDA from ServerWorks
+ * ATI IXP200, IXP300, IXP400, SB600, SB700 and SB800 southbridges
+ Datasheet: Not publicly available
+ SB700 register reference available at:
+ http://support.amd.com/us/Embedded_TechDocs/43009_sb7xx_rrg_pub_1.00.pdf
+ * AMD SP5100 (SB700 derivative found on some server mainboards)
+ Datasheet: Publicly available at the AMD website
+ http://support.amd.com/us/Embedded_TechDocs/44413.pdf
+ * AMD Hudson-2
+ Datasheet: Not publicly available
+ * Standard Microsystems (SMSC) SLC90E66 (Victory66) southbridge
+ Datasheet: Publicly available at the SMSC website http://www.smsc.com
+
+Authors:
+ Frodo Looijaard <frodol@dds.nl>
+ Philip Edelbrock <phil@netroedge.com>
+
+
+Module Parameters
+-----------------
+
+* force: int
+ Forcibly enable the PIIX4. DANGEROUS!
+* force_addr: int
+ Forcibly enable the PIIX4 at the given address. EXTREMELY DANGEROUS!
+
+
+Description
+-----------
+
+The PIIX4 (properly known as the 82371AB) is an Intel chip with a lot of
+functionality. Among other things, it implements the PCI bus. One of its
+minor functions is implementing a System Management Bus. This is a true
+SMBus - you can not access it on I2C levels. The good news is that it
+natively understands SMBus commands and you do not have to worry about
+timing problems. The bad news is that non-SMBus devices connected to it can
+confuse it mightily. Yes, this is known to happen...
+
+Do 'lspci -v' and see whether it contains an entry like this:
+
+0000:00:02.3 Bridge: Intel Corp. 82371AB/EB/MB PIIX4 ACPI (rev 02)
+ Flags: medium devsel, IRQ 9
+
+Bus and device numbers may differ, but the function number must be
+identical (like many PCI devices, the PIIX4 incorporates a number of
+different 'functions', which can be considered as separate devices). If you
+find such an entry, you have a PIIX4 SMBus controller.
+
+On some computers (most notably, some Dells), the SMBus is disabled by
+default. If you use the insmod parameter 'force=1', the kernel module will
+try to enable it. THIS IS VERY DANGEROUS! If the BIOS did not set up a
+correct address for this module, you could get in big trouble (read:
+crashes, data corruption, etc.). Try this only as a last resort (try BIOS
+updates first, for example), and backup first! An even more dangerous
+option is 'force_addr=<IOPORT>'. This will not only enable the PIIX4 like
+'force' foes, but it will also set a new base I/O port address. The SMBus
+parts of the PIIX4 needs a range of 8 of these addresses to function
+correctly. If these addresses are already reserved by some other device,
+you will get into big trouble! DON'T USE THIS IF YOU ARE NOT VERY SURE
+ABOUT WHAT YOU ARE DOING!
+
+The PIIX4E is just an new version of the PIIX4; it is supported as well.
+The PIIX/PIIX3 does not implement an SMBus or I2C bus, so you can't use
+this driver on those mainboards.
+
+The ServerWorks Southbridges, the Intel 440MX, and the Victory66 are
+identical to the PIIX4 in I2C/SMBus support.
+
+The AMD SB700 and SP5100 chipsets implement two PIIX4-compatible SMBus
+controllers. If your BIOS initializes the secondary controller, it will
+be detected by this driver as an "Auxiliary SMBus Host Controller".
+
+If you own Force CPCI735 motherboard or other OSB4 based systems you may need
+to change the SMBus Interrupt Select register so the SMBus controller uses
+the SMI mode.
+
+1) Use lspci command and locate the PCI device with the SMBus controller:
+ 00:0f.0 ISA bridge: ServerWorks OSB4 South Bridge (rev 4f)
+ The line may vary for different chipsets. Please consult the driver source
+ for all possible PCI ids (and lspci -n to match them). Lets assume the
+ device is located at 00:0f.0.
+2) Now you just need to change the value in 0xD2 register. Get it first with
+ command: lspci -xxx -s 00:0f.0
+ If the value is 0x3 then you need to change it to 0x1
+ setpci -s 00:0f.0 d2.b=1
+
+Please note that you don't need to do that in all cases, just when the SMBus is
+not working properly.
+
+
+Hardware-specific issues
+------------------------
+
+This driver will refuse to load on IBM systems with an Intel PIIX4 SMBus.
+Some of these machines have an RFID EEPROM (24RF08) connected to the SMBus,
+which can easily get corrupted due to a state machine bug. These are mostly
+Thinkpad laptops, but desktop systems may also be affected. We have no list
+of all affected systems, so the only safe solution was to prevent access to
+the SMBus on all IBM systems (detected using DMI data.)
+
+For additional information, read:
+http://www.lm-sensors.org/browser/lm-sensors/trunk/README
diff --git a/Documentation/i2c/busses/i2c-sis5595 b/Documentation/i2c/busses/i2c-sis5595
new file mode 100644
index 00000000..ecd21fb4
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-sis5595
@@ -0,0 +1,59 @@
+Kernel driver i2c-sis5595
+
+Authors:
+ Frodo Looijaard <frodol@dds.nl>,
+ Mark D. Studebaker <mdsxyz123@yahoo.com>,
+ Philip Edelbrock <phil@netroedge.com>
+
+Supported adapters:
+ * Silicon Integrated Systems Corp. SiS5595 Southbridge
+ Datasheet: Publicly available at the Silicon Integrated Systems Corp. site.
+
+Note: all have mfr. ID 0x1039.
+
+ SUPPORTED PCI ID
+ 5595 0008
+
+ Note: these chips contain a 0008 device which is incompatible with the
+ 5595. We recognize these by the presence of the listed
+ "blacklist" PCI ID and refuse to load.
+
+ NOT SUPPORTED PCI ID BLACKLIST PCI ID
+ 540 0008 0540
+ 550 0008 0550
+ 5513 0008 5511
+ 5581 0008 5597
+ 5582 0008 5597
+ 5597 0008 5597
+ 5598 0008 5597/5598
+ 630 0008 0630
+ 645 0008 0645
+ 646 0008 0646
+ 648 0008 0648
+ 650 0008 0650
+ 651 0008 0651
+ 730 0008 0730
+ 735 0008 0735
+ 745 0008 0745
+ 746 0008 0746
+
+Module Parameters
+-----------------
+
+* force_addr=0xaddr Set the I/O base address. Useful for boards
+ that don't set the address in the BIOS. Does not do a
+ PCI force; the device must still be present in lspci.
+ Don't use this unless the driver complains that the
+ base address is not set.
+
+Description
+-----------
+
+i2c-sis5595 is a true SMBus host driver for motherboards with the SiS5595
+southbridges.
+
+WARNING: If you are trying to access the integrated sensors on the SiS5595
+chip, you want the sis5595 driver for those, not this driver. This driver
+is a BUS driver, not a CHIP driver. A BUS driver is used by other CHIP
+drivers to access chips on the bus.
+
diff --git a/Documentation/i2c/busses/i2c-sis630 b/Documentation/i2c/busses/i2c-sis630
new file mode 100644
index 00000000..ee794363
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-sis630
@@ -0,0 +1,58 @@
+Kernel driver i2c-sis630
+
+Supported adapters:
+ * Silicon Integrated Systems Corp (SiS)
+ 630 chipset (Datasheet: available at http://www.sfr-fresh.com/linux)
+ 730 chipset
+ 964 chipset
+ * Possible other SiS chipsets ?
+
+Author: Alexander Malysh <amalysh@web.de>
+ Amaury Decrême <amaury.decreme@gmail.com> - SiS964 support
+
+Module Parameters
+-----------------
+
+* force = [1|0] Forcibly enable the SIS630. DANGEROUS!
+ This can be interesting for chipsets not named
+ above to check if it works for you chipset, but DANGEROUS!
+
+* high_clock = [1|0] Forcibly set Host Master Clock to 56KHz (default,
+ what your BIOS use). DANGEROUS! This should be a bit
+ faster, but freeze some systems (i.e. my Laptop).
+ SIS630/730 chip only.
+
+
+Description
+-----------
+
+This SMBus only driver is known to work on motherboards with the above
+named chipsets.
+
+If you see something like this:
+
+00:00.0 Host bridge: Silicon Integrated Systems [SiS] 630 Host (rev 31)
+00:01.0 ISA bridge: Silicon Integrated Systems [SiS] 85C503/5513
+
+or like this:
+
+00:00.0 Host bridge: Silicon Integrated Systems [SiS] 730 Host (rev 02)
+00:01.0 ISA bridge: Silicon Integrated Systems [SiS] 85C503/5513
+
+or like this:
+
+00:00.0 Host bridge: Silicon Integrated Systems [SiS] 760/M760 Host (rev 02)
+00:02.0 ISA bridge: Silicon Integrated Systems [SiS] SiS964 [MuTIOL Media IO]
+ LPC Controller (rev 36)
+
+in your 'lspci' output , then this driver is for your chipset.
+
+Thank You
+---------
+Philip Edelbrock <phil@netroedge.com>
+- testing SiS730 support
+Mark M. Hoffman <mhoffman@lightlink.com>
+- bug fixes
+
+To anyone else which I forgot here ;), thanks!
+
diff --git a/Documentation/i2c/busses/i2c-sis96x b/Documentation/i2c/busses/i2c-sis96x
new file mode 100644
index 00000000..0b979f32
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-sis96x
@@ -0,0 +1,73 @@
+Kernel driver i2c-sis96x
+
+Replaces 2.4.x i2c-sis645
+
+Supported adapters:
+ * Silicon Integrated Systems Corp (SiS)
+ Any combination of these host bridges:
+ 645, 645DX (aka 646), 648, 650, 651, 655, 735, 745, 746
+ and these south bridges:
+ 961, 962, 963(L)
+
+Author: Mark M. Hoffman <mhoffman@lightlink.com>
+
+Description
+-----------
+
+This SMBus only driver is known to work on motherboards with the above
+named chipset combinations. The driver was developed without benefit of a
+proper datasheet from SiS. The SMBus registers are assumed compatible with
+those of the SiS630, although they are located in a completely different
+place. Thanks to Alexander Malysh <amalysh@web.de> for providing the
+SiS630 datasheet (and driver).
+
+The command "lspci" as root should produce something like these lines:
+
+00:00.0 Host bridge: Silicon Integrated Systems [SiS]: Unknown device 0645
+00:02.0 ISA bridge: Silicon Integrated Systems [SiS] 85C503/5513
+00:02.1 SMBus: Silicon Integrated Systems [SiS]: Unknown device 0016
+
+or perhaps this...
+
+00:00.0 Host bridge: Silicon Integrated Systems [SiS]: Unknown device 0645
+00:02.0 ISA bridge: Silicon Integrated Systems [SiS]: Unknown device 0961
+00:02.1 SMBus: Silicon Integrated Systems [SiS]: Unknown device 0016
+
+(kernel versions later than 2.4.18 may fill in the "Unknown"s)
+
+If you can't see it please look on quirk_sis_96x_smbus
+(drivers/pci/quirks.c) (also if southbridge detection fails)
+
+I suspect that this driver could be made to work for the following SiS
+chipsets as well: 635, and 635T. If anyone owns a board with those chips
+AND is willing to risk crashing & burning an otherwise well-behaved kernel
+in the name of progress... please contact me at <mhoffman@lightlink.com> or
+via the linux-i2c mailing list: <linux-i2c@vger.kernel.org>. Please send bug
+reports and/or success stories as well.
+
+
+TO DOs
+------
+
+* The driver does not support SMBus block reads/writes; I may add them if a
+scenario is found where they're needed.
+
+
+Thank You
+---------
+
+Mark D. Studebaker <mdsxyz123@yahoo.com>
+ - design hints and bug fixes
+Alexander Maylsh <amalysh@web.de>
+ - ditto, plus an important datasheet... almost the one I really wanted
+Hans-Günter Lütke Uphues <hg_lu@t-online.de>
+ - patch for SiS735
+Robert Zwerus <arzie@dds.nl>
+ - testing for SiS645DX
+Kianusch Sayah Karadji <kianusch@sk-tech.net>
+ - patch for SiS645DX/962
+Ken Healy
+ - patch for SiS655
+
+To anyone else who has written w/ feedback, thanks!
+
diff --git a/Documentation/i2c/busses/i2c-taos-evm b/Documentation/i2c/busses/i2c-taos-evm
new file mode 100644
index 00000000..63f62bcb
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-taos-evm
@@ -0,0 +1,46 @@
+Kernel driver i2c-taos-evm
+
+Author: Jean Delvare <khali@linux-fr.org>
+
+This is a driver for the evaluation modules for TAOS I2C/SMBus chips.
+The modules include an SMBus master with limited capabilities, which can
+be controlled over the serial port. Virtually all evaluation modules
+are supported, but a few lines of code need to be added for each new
+module to instantiate the right I2C chip on the bus. Obviously, a driver
+for the chip in question is also needed.
+
+Currently supported devices are:
+
+* TAOS TSL2550 EVM
+
+For additional information on TAOS products, please see
+ http://www.taosinc.com/
+
+
+Using this driver
+-----------------
+
+In order to use this driver, you'll need the serport driver, and the
+inputattach tool, which is part of the input-utils package. The following
+commands will tell the kernel that you have a TAOS EVM on the first
+serial port:
+
+# modprobe serport
+# inputattach --taos-evm /dev/ttyS0
+
+
+Technical details
+-----------------
+
+Only 4 SMBus transaction types are supported by the TAOS evaluation
+modules:
+* Receive Byte
+* Send Byte
+* Read Byte
+* Write Byte
+
+The communication protocol is text-based and pretty simple. It is
+described in a PDF document on the CD which comes with the evaluation
+module. The communication is rather slow, because the serial port has
+to operate at 1200 bps. However, I don't think this is a big concern in
+practice, as these modules are meant for evaluation and testing only.
diff --git a/Documentation/i2c/busses/i2c-via b/Documentation/i2c/busses/i2c-via
new file mode 100644
index 00000000..34387066
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-via
@@ -0,0 +1,34 @@
+Kernel driver i2c-via
+
+Supported adapters:
+ * VIA Technologies, InC. VT82C586B
+ Datasheet: Publicly available at the VIA website
+
+Author: Kyösti Mälkki <kmalkki@cc.hut.fi>
+
+Description
+-----------
+
+i2c-via is an i2c bus driver for motherboards with VIA chipset.
+
+The following VIA pci chipsets are supported:
+ - MVP3, VP3, VP2/97, VPX/97
+ - others with South bridge VT82C586B
+
+Your lspci listing must show this :
+
+ Bridge: VIA Technologies, Inc. VT82C586B ACPI (rev 10)
+
+ Problems?
+
+ Q: You have VT82C586B on the motherboard, but not in the listing.
+
+ A: Go to your BIOS setup, section PCI devices or similar.
+ Turn USB support on, and try again.
+
+ Q: No error messages, but still i2c doesn't seem to work.
+
+ A: This can happen. This driver uses the pins VIA recommends in their
+ datasheets, but there are several ways the motherboard manufacturer
+ can actually wire the lines.
+
diff --git a/Documentation/i2c/busses/i2c-viapro b/Documentation/i2c/busses/i2c-viapro
new file mode 100644
index 00000000..b88f91ae
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-viapro
@@ -0,0 +1,73 @@
+Kernel driver i2c-viapro
+
+Supported adapters:
+ * VIA Technologies, Inc. VT82C596A/B
+ Datasheet: Sometimes available at the VIA website
+
+ * VIA Technologies, Inc. VT82C686A/B
+ Datasheet: Sometimes available at the VIA website
+
+ * VIA Technologies, Inc. VT8231, VT8233, VT8233A
+ Datasheet: available on request from VIA
+
+ * VIA Technologies, Inc. VT8235, VT8237R, VT8237A, VT8237S, VT8251
+ Datasheet: available on request and under NDA from VIA
+
+ * VIA Technologies, Inc. CX700
+ Datasheet: available on request and under NDA from VIA
+
+ * VIA Technologies, Inc. VX800/VX820
+ Datasheet: available on http://linux.via.com.tw
+
+ * VIA Technologies, Inc. VX855/VX875
+ Datasheet: available on http://linux.via.com.tw
+
+ * VIA Technologies, Inc. VX900
+ Datasheet: available on http://linux.via.com.tw
+
+Authors:
+ Kyösti Mälkki <kmalkki@cc.hut.fi>,
+ Mark D. Studebaker <mdsxyz123@yahoo.com>,
+ Jean Delvare <khali@linux-fr.org>
+
+Module Parameters
+-----------------
+
+* force: int
+ Forcibly enable the SMBus controller. DANGEROUS!
+* force_addr: int
+ Forcibly enable the SMBus at the given address. EXTREMELY DANGEROUS!
+
+Description
+-----------
+
+i2c-viapro is a true SMBus host driver for motherboards with one of the
+supported VIA south bridges.
+
+Your lspci -n listing must show one of these :
+
+ device 1106:3050 (VT82C596A function 3)
+ device 1106:3051 (VT82C596B function 3)
+ device 1106:3057 (VT82C686 function 4)
+ device 1106:3074 (VT8233)
+ device 1106:3147 (VT8233A)
+ device 1106:8235 (VT8231 function 4)
+ device 1106:3177 (VT8235)
+ device 1106:3227 (VT8237R)
+ device 1106:3337 (VT8237A)
+ device 1106:3372 (VT8237S)
+ device 1106:3287 (VT8251)
+ device 1106:8324 (CX700)
+ device 1106:8353 (VX800/VX820)
+ device 1106:8409 (VX855/VX875)
+ device 1106:8410 (VX900)
+
+If none of these show up, you should look in the BIOS for settings like
+enable ACPI / SMBus or even USB.
+
+Except for the oldest chips (VT82C596A/B, VT82C686A and most probably
+VT8231), this driver supports I2C block transactions. Such transactions
+are mainly useful to read from and write to EEPROMs.
+
+The CX700/VX800/VX820 additionally appears to support SMBus PEC, although
+this driver doesn't implement it yet.
diff --git a/Documentation/i2c/busses/scx200_acb b/Documentation/i2c/busses/scx200_acb
new file mode 100644
index 00000000..ce83c871
--- /dev/null
+++ b/Documentation/i2c/busses/scx200_acb
@@ -0,0 +1,32 @@
+Kernel driver scx200_acb
+
+Author: Christer Weinigel <wingel@nano-system.com>
+
+The driver supersedes the older, never merged driver named i2c-nscacb.
+
+Module Parameters
+-----------------
+
+* base: up to 4 ints
+ Base addresses for the ACCESS.bus controllers on SCx200 and SC1100 devices
+
+ By default the driver uses two base addresses 0x820 and 0x840.
+ If you want only one base address, specify the second as 0 so as to
+ override this default.
+
+Description
+-----------
+
+Enable the use of the ACCESS.bus controller on the Geode SCx200 and
+SC1100 processors and the CS5535 and CS5536 Geode companion devices.
+
+Device-specific notes
+---------------------
+
+The SC1100 WRAP boards are known to use base addresses 0x810 and 0x820.
+If the scx200_acb driver is built into the kernel, add the following
+parameter to your boot command line:
+ scx200_acb.base=0x810,0x820
+If the scx200_acb driver is built as a module, add the following line to
+a configuration file in /etc/modprobe.d/ instead:
+ options scx200_acb base=0x810,0x820
diff --git a/Documentation/i2c/dev-interface b/Documentation/i2c/dev-interface
new file mode 100644
index 00000000..3e742ba2
--- /dev/null
+++ b/Documentation/i2c/dev-interface
@@ -0,0 +1,214 @@
+Usually, i2c devices are controlled by a kernel driver. But it is also
+possible to access all devices on an adapter from userspace, through
+the /dev interface. You need to load module i2c-dev for this.
+
+Each registered i2c adapter gets a number, counting from 0. You can
+examine /sys/class/i2c-dev/ to see what number corresponds to which adapter.
+Alternatively, you can run "i2cdetect -l" to obtain a formated list of all
+i2c adapters present on your system at a given time. i2cdetect is part of
+the i2c-tools package.
+
+I2C device files are character device files with major device number 89
+and a minor device number corresponding to the number assigned as
+explained above. They should be called "i2c-%d" (i2c-0, i2c-1, ...,
+i2c-10, ...). All 256 minor device numbers are reserved for i2c.
+
+
+C example
+=========
+
+So let's say you want to access an i2c adapter from a C program. The
+first thing to do is "#include <linux/i2c-dev.h>". Please note that
+there are two files named "i2c-dev.h" out there, one is distributed
+with the Linux kernel and is meant to be included from kernel
+driver code, the other one is distributed with i2c-tools and is
+meant to be included from user-space programs. You obviously want
+the second one here.
+
+Now, you have to decide which adapter you want to access. You should
+inspect /sys/class/i2c-dev/ or run "i2cdetect -l" to decide this.
+Adapter numbers are assigned somewhat dynamically, so you can not
+assume much about them. They can even change from one boot to the next.
+
+Next thing, open the device file, as follows:
+
+ int file;
+ int adapter_nr = 2; /* probably dynamically determined */
+ char filename[20];
+
+ snprintf(filename, 19, "/dev/i2c-%d", adapter_nr);
+ file = open(filename, O_RDWR);
+ if (file < 0) {
+ /* ERROR HANDLING; you can check errno to see what went wrong */
+ exit(1);
+ }
+
+When you have opened the device, you must specify with what device
+address you want to communicate:
+
+ int addr = 0x40; /* The I2C address */
+
+ if (ioctl(file, I2C_SLAVE, addr) < 0) {
+ /* ERROR HANDLING; you can check errno to see what went wrong */
+ exit(1);
+ }
+
+Well, you are all set up now. You can now use SMBus commands or plain
+I2C to communicate with your device. SMBus commands are preferred if
+the device supports them. Both are illustrated below.
+
+ __u8 register = 0x10; /* Device register to access */
+ __s32 res;
+ char buf[10];
+
+ /* Using SMBus commands */
+ res = i2c_smbus_read_word_data(file, register);
+ if (res < 0) {
+ /* ERROR HANDLING: i2c transaction failed */
+ } else {
+ /* res contains the read word */
+ }
+
+ /* Using I2C Write, equivalent of
+ i2c_smbus_write_word_data(file, register, 0x6543) */
+ buf[0] = register;
+ buf[1] = 0x43;
+ buf[2] = 0x65;
+ if (write(file, buf, 3) ! =3) {
+ /* ERROR HANDLING: i2c transaction failed */
+ }
+
+ /* Using I2C Read, equivalent of i2c_smbus_read_byte(file) */
+ if (read(file, buf, 1) != 1) {
+ /* ERROR HANDLING: i2c transaction failed */
+ } else {
+ /* buf[0] contains the read byte */
+ }
+
+Note that only a subset of the I2C and SMBus protocols can be achieved by
+the means of read() and write() calls. In particular, so-called combined
+transactions (mixing read and write messages in the same transaction)
+aren't supported. For this reason, this interface is almost never used by
+user-space programs.
+
+IMPORTANT: because of the use of inline functions, you *have* to use
+'-O' or some variation when you compile your program!
+
+
+Full interface description
+==========================
+
+The following IOCTLs are defined:
+
+ioctl(file, I2C_SLAVE, long addr)
+ Change slave address. The address is passed in the 7 lower bits of the
+ argument (except for 10 bit addresses, passed in the 10 lower bits in this
+ case).
+
+ioctl(file, I2C_TENBIT, long select)
+ Selects ten bit addresses if select not equals 0, selects normal 7 bit
+ addresses if select equals 0. Default 0. This request is only valid
+ if the adapter has I2C_FUNC_10BIT_ADDR.
+
+ioctl(file, I2C_PEC, long select)
+ Selects SMBus PEC (packet error checking) generation and verification
+ if select not equals 0, disables if select equals 0. Default 0.
+ Used only for SMBus transactions. This request only has an effect if the
+ the adapter has I2C_FUNC_SMBUS_PEC; it is still safe if not, it just
+ doesn't have any effect.
+
+ioctl(file, I2C_FUNCS, unsigned long *funcs)
+ Gets the adapter functionality and puts it in *funcs.
+
+ioctl(file, I2C_RDWR, struct i2c_rdwr_ioctl_data *msgset)
+ Do combined read/write transaction without stop in between.
+ Only valid if the adapter has I2C_FUNC_I2C. The argument is
+ a pointer to a
+
+ struct i2c_rdwr_ioctl_data {
+ struct i2c_msg *msgs; /* ptr to array of simple messages */
+ int nmsgs; /* number of messages to exchange */
+ }
+
+ The msgs[] themselves contain further pointers into data buffers.
+ The function will write or read data to or from that buffers depending
+ on whether the I2C_M_RD flag is set in a particular message or not.
+ The slave address and whether to use ten bit address mode has to be
+ set in each message, overriding the values set with the above ioctl's.
+
+ioctl(file, I2C_SMBUS, struct i2c_smbus_ioctl_data *args)
+ Not meant to be called directly; instead, use the access functions
+ below.
+
+You can do plain i2c transactions by using read(2) and write(2) calls.
+You do not need to pass the address byte; instead, set it through
+ioctl I2C_SLAVE before you try to access the device.
+
+You can do SMBus level transactions (see documentation file smbus-protocol
+for details) through the following functions:
+ __s32 i2c_smbus_write_quick(int file, __u8 value);
+ __s32 i2c_smbus_read_byte(int file);
+ __s32 i2c_smbus_write_byte(int file, __u8 value);
+ __s32 i2c_smbus_read_byte_data(int file, __u8 command);
+ __s32 i2c_smbus_write_byte_data(int file, __u8 command, __u8 value);
+ __s32 i2c_smbus_read_word_data(int file, __u8 command);
+ __s32 i2c_smbus_write_word_data(int file, __u8 command, __u16 value);
+ __s32 i2c_smbus_process_call(int file, __u8 command, __u16 value);
+ __s32 i2c_smbus_read_block_data(int file, __u8 command, __u8 *values);
+ __s32 i2c_smbus_write_block_data(int file, __u8 command, __u8 length,
+ __u8 *values);
+All these transactions return -1 on failure; you can read errno to see
+what happened. The 'write' transactions return 0 on success; the
+'read' transactions return the read value, except for read_block, which
+returns the number of values read. The block buffers need not be longer
+than 32 bytes.
+
+The above functions are all inline functions, that resolve to calls to
+the i2c_smbus_access function, that on its turn calls a specific ioctl
+with the data in a specific format. Read the source code if you
+want to know what happens behind the screens.
+
+
+Implementation details
+======================
+
+For the interested, here's the code flow which happens inside the kernel
+when you use the /dev interface to I2C:
+
+1* Your program opens /dev/i2c-N and calls ioctl() on it, as described in
+section "C example" above.
+
+2* These open() and ioctl() calls are handled by the i2c-dev kernel
+driver: see i2c-dev.c:i2cdev_open() and i2c-dev.c:i2cdev_ioctl(),
+respectively. You can think of i2c-dev as a generic I2C chip driver
+that can be programmed from user-space.
+
+3* Some ioctl() calls are for administrative tasks and are handled by
+i2c-dev directly. Examples include I2C_SLAVE (set the address of the
+device you want to access) and I2C_PEC (enable or disable SMBus error
+checking on future transactions.)
+
+4* Other ioctl() calls are converted to in-kernel function calls by
+i2c-dev. Examples include I2C_FUNCS, which queries the I2C adapter
+functionality using i2c.h:i2c_get_functionality(), and I2C_SMBUS, which
+performs an SMBus transaction using i2c-core.c:i2c_smbus_xfer().
+
+The i2c-dev driver is responsible for checking all the parameters that
+come from user-space for validity. After this point, there is no
+difference between these calls that came from user-space through i2c-dev
+and calls that would have been performed by kernel I2C chip drivers
+directly. This means that I2C bus drivers don't need to implement
+anything special to support access from user-space.
+
+5* These i2c-core.c/i2c.h functions are wrappers to the actual
+implementation of your I2C bus driver. Each adapter must declare
+callback functions implementing these standard calls.
+i2c.h:i2c_get_functionality() calls i2c_adapter.algo->functionality(),
+while i2c-core.c:i2c_smbus_xfer() calls either
+adapter.algo->smbus_xfer() if it is implemented, or if not,
+i2c-core.c:i2c_smbus_xfer_emulated() which in turn calls
+i2c_adapter.algo->master_xfer().
+
+After your I2C bus driver has processed these requests, execution runs
+up the call chain, with almost no processing done, except by i2c-dev to
+package the returned data, if any, in suitable format for the ioctl.
diff --git a/Documentation/i2c/fault-codes b/Documentation/i2c/fault-codes
new file mode 100644
index 00000000..045765c0
--- /dev/null
+++ b/Documentation/i2c/fault-codes
@@ -0,0 +1,127 @@
+This is a summary of the most important conventions for use of fault
+codes in the I2C/SMBus stack.
+
+
+A "Fault" is not always an "Error"
+----------------------------------
+Not all fault reports imply errors; "page faults" should be a familiar
+example. Software often retries idempotent operations after transient
+faults. There may be fancier recovery schemes that are appropriate in
+some cases, such as re-initializing (and maybe resetting). After such
+recovery, triggered by a fault report, there is no error.
+
+In a similar way, sometimes a "fault" code just reports one defined
+result for an operation ... it doesn't indicate that anything is wrong
+at all, just that the outcome wasn't on the "golden path".
+
+In short, your I2C driver code may need to know these codes in order
+to respond correctly. Other code may need to rely on YOUR code reporting
+the right fault code, so that it can (in turn) behave correctly.
+
+
+I2C and SMBus fault codes
+-------------------------
+These are returned as negative numbers from most calls, with zero or
+some positive number indicating a non-fault return. The specific
+numbers associated with these symbols differ between architectures,
+though most Linux systems use <asm-generic/errno*.h> numbering.
+
+Note that the descriptions here are not exhaustive. There are other
+codes that may be returned, and other cases where these codes should
+be returned. However, drivers should not return other codes for these
+cases (unless the hardware doesn't provide unique fault reports).
+
+Also, codes returned by adapter probe methods follow rules which are
+specific to their host bus (such as PCI, or the platform bus).
+
+
+EAGAIN
+ Returned by I2C adapters when they lose arbitration in master
+ transmit mode: some other master was transmitting different
+ data at the same time.
+
+ Also returned when trying to invoke an I2C operation in an
+ atomic context, when some task is already using that I2C bus
+ to execute some other operation.
+
+EBADMSG
+ Returned by SMBus logic when an invalid Packet Error Code byte
+ is received. This code is a CRC covering all bytes in the
+ transaction, and is sent before the terminating STOP. This
+ fault is only reported on read transactions; the SMBus slave
+ may have a way to report PEC mismatches on writes from the
+ host. Note that even if PECs are in use, you should not rely
+ on these as the only way to detect incorrect data transfers.
+
+EBUSY
+ Returned by SMBus adapters when the bus was busy for longer
+ than allowed. This usually indicates some device (maybe the
+ SMBus adapter) needs some fault recovery (such as resetting),
+ or that the reset was attempted but failed.
+
+EINVAL
+ This rather vague error means an invalid parameter has been
+ detected before any I/O operation was started. Use a more
+ specific fault code when you can.
+
+ One example would be a driver trying an SMBus Block Write
+ with block size outside the range of 1-32 bytes.
+
+EIO
+ This rather vague error means something went wrong when
+ performing an I/O operation. Use a more specific fault
+ code when you can.
+
+ENODEV
+ Returned by driver probe() methods. This is a bit more
+ specific than ENXIO, implying the problem isn't with the
+ address, but with the device found there. Driver probes
+ may verify the device returns *correct* responses, and
+ return this as appropriate. (The driver core will warn
+ about probe faults other than ENXIO and ENODEV.)
+
+ENOMEM
+ Returned by any component that can't allocate memory when
+ it needs to do so.
+
+ENXIO
+ Returned by I2C adapters to indicate that the address phase
+ of a transfer didn't get an ACK. While it might just mean
+ an I2C device was temporarily not responding, usually it
+ means there's nothing listening at that address.
+
+ Returned by driver probe() methods to indicate that they
+ found no device to bind to. (ENODEV may also be used.)
+
+EOPNOTSUPP
+ Returned by an adapter when asked to perform an operation
+ that it doesn't, or can't, support.
+
+ For example, this would be returned when an adapter that
+ doesn't support SMBus block transfers is asked to execute
+ one. In that case, the driver making that request should
+ have verified that functionality was supported before it
+ made that block transfer request.
+
+ Similarly, if an I2C adapter can't execute all legal I2C
+ messages, it should return this when asked to perform a
+ transaction it can't. (These limitations can't be seen in
+ the adapter's functionality mask, since the assumption is
+ that if an adapter supports I2C it supports all of I2C.)
+
+EPROTO
+ Returned when slave does not conform to the relevant I2C
+ or SMBus (or chip-specific) protocol specifications. One
+ case is when the length of an SMBus block data response
+ (from the SMBus slave) is outside the range 1-32 bytes.
+
+ETIMEDOUT
+ This is returned by drivers when an operation took too much
+ time, and was aborted before it completed.
+
+ SMBus adapters may return it when an operation took more
+ time than allowed by the SMBus specification; for example,
+ when a slave stretches clocks too far. I2C has no such
+ timeouts, but it's normal for I2C adapters to impose some
+ arbitrary limits (much longer than SMBus!) too.
+
diff --git a/Documentation/i2c/functionality b/Documentation/i2c/functionality
new file mode 100644
index 00000000..b0ff2ab5
--- /dev/null
+++ b/Documentation/i2c/functionality
@@ -0,0 +1,148 @@
+INTRODUCTION
+------------
+
+Because not every I2C or SMBus adapter implements everything in the
+I2C specifications, a client can not trust that everything it needs
+is implemented when it is given the option to attach to an adapter:
+the client needs some way to check whether an adapter has the needed
+functionality.
+
+
+FUNCTIONALITY CONSTANTS
+-----------------------
+
+For the most up-to-date list of functionality constants, please check
+<linux/i2c.h>!
+
+ I2C_FUNC_I2C Plain i2c-level commands (Pure SMBus
+ adapters typically can not do these)
+ I2C_FUNC_10BIT_ADDR Handles the 10-bit address extensions
+ I2C_FUNC_PROTOCOL_MANGLING Knows about the I2C_M_IGNORE_NAK,
+ I2C_M_REV_DIR_ADDR and I2C_M_NO_RD_ACK
+ flags (which modify the I2C protocol!)
+ I2C_FUNC_NOSTART Can skip repeated start sequence
+ I2C_FUNC_SMBUS_QUICK Handles the SMBus write_quick command
+ I2C_FUNC_SMBUS_READ_BYTE Handles the SMBus read_byte command
+ I2C_FUNC_SMBUS_WRITE_BYTE Handles the SMBus write_byte command
+ I2C_FUNC_SMBUS_READ_BYTE_DATA Handles the SMBus read_byte_data command
+ I2C_FUNC_SMBUS_WRITE_BYTE_DATA Handles the SMBus write_byte_data command
+ I2C_FUNC_SMBUS_READ_WORD_DATA Handles the SMBus read_word_data command
+ I2C_FUNC_SMBUS_WRITE_WORD_DATA Handles the SMBus write_byte_data command
+ I2C_FUNC_SMBUS_PROC_CALL Handles the SMBus process_call command
+ I2C_FUNC_SMBUS_READ_BLOCK_DATA Handles the SMBus read_block_data command
+ I2C_FUNC_SMBUS_WRITE_BLOCK_DATA Handles the SMBus write_block_data command
+ I2C_FUNC_SMBUS_READ_I2C_BLOCK Handles the SMBus read_i2c_block_data command
+ I2C_FUNC_SMBUS_WRITE_I2C_BLOCK Handles the SMBus write_i2c_block_data command
+
+A few combinations of the above flags are also defined for your convenience:
+
+ I2C_FUNC_SMBUS_BYTE Handles the SMBus read_byte
+ and write_byte commands
+ I2C_FUNC_SMBUS_BYTE_DATA Handles the SMBus read_byte_data
+ and write_byte_data commands
+ I2C_FUNC_SMBUS_WORD_DATA Handles the SMBus read_word_data
+ and write_word_data commands
+ I2C_FUNC_SMBUS_BLOCK_DATA Handles the SMBus read_block_data
+ and write_block_data commands
+ I2C_FUNC_SMBUS_I2C_BLOCK Handles the SMBus read_i2c_block_data
+ and write_i2c_block_data commands
+ I2C_FUNC_SMBUS_EMUL Handles all SMBus commands than can be
+ emulated by a real I2C adapter (using
+ the transparent emulation layer)
+
+In kernel versions prior to 3.5 I2C_FUNC_NOSTART was implemented as
+part of I2C_FUNC_PROTOCOL_MANGLING.
+
+
+ADAPTER IMPLEMENTATION
+----------------------
+
+When you write a new adapter driver, you will have to implement a
+function callback `functionality'. Typical implementations are given
+below.
+
+A typical SMBus-only adapter would list all the SMBus transactions it
+supports. This example comes from the i2c-piix4 driver:
+
+ static u32 piix4_func(struct i2c_adapter *adapter)
+ {
+ return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
+ I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
+ I2C_FUNC_SMBUS_BLOCK_DATA;
+ }
+
+A typical full-I2C adapter would use the following (from the i2c-pxa
+driver):
+
+ static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
+ {
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+ }
+
+I2C_FUNC_SMBUS_EMUL includes all the SMBus transactions (with the
+addition of I2C block transactions) which i2c-core can emulate using
+I2C_FUNC_I2C without any help from the adapter driver. The idea is
+to let the client drivers check for the support of SMBus functions
+without having to care whether the said functions are implemented in
+hardware by the adapter, or emulated in software by i2c-core on top
+of an I2C adapter.
+
+
+CLIENT CHECKING
+---------------
+
+Before a client tries to attach to an adapter, or even do tests to check
+whether one of the devices it supports is present on an adapter, it should
+check whether the needed functionality is present. The typical way to do
+this is (from the lm75 driver):
+
+ static int lm75_detect(...)
+ {
+ (...)
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
+ I2C_FUNC_SMBUS_WORD_DATA))
+ goto exit;
+ (...)
+ }
+
+Here, the lm75 driver checks if the adapter can do both SMBus byte data
+and SMBus word data transactions. If not, then the driver won't work on
+this adapter and there's no point in going on. If the check above is
+successful, then the driver knows that it can call the following
+functions: i2c_smbus_read_byte_data(), i2c_smbus_write_byte_data(),
+i2c_smbus_read_word_data() and i2c_smbus_write_word_data(). As a rule of
+thumb, the functionality constants you test for with
+i2c_check_functionality() should match exactly the i2c_smbus_* functions
+which you driver is calling.
+
+Note that the check above doesn't tell whether the functionalities are
+implemented in hardware by the underlying adapter or emulated in
+software by i2c-core. Client drivers don't have to care about this, as
+i2c-core will transparently implement SMBus transactions on top of I2C
+adapters.
+
+
+CHECKING THROUGH /DEV
+---------------------
+
+If you try to access an adapter from a userspace program, you will have
+to use the /dev interface. You will still have to check whether the
+functionality you need is supported, of course. This is done using
+the I2C_FUNCS ioctl. An example, adapted from the i2cdetect program, is
+below:
+
+ int file;
+ if (file = open("/dev/i2c-0", O_RDWR) < 0) {
+ /* Some kind of error handling */
+ exit(1);
+ }
+ if (ioctl(file, I2C_FUNCS, &funcs) < 0) {
+ /* Some kind of error handling */
+ exit(1);
+ }
+ if (!(funcs & I2C_FUNC_SMBUS_QUICK)) {
+ /* Oops, the needed functionality (SMBus write_quick function) is
+ not available! */
+ exit(1);
+ }
+ /* Now it is safe to use the SMBus write_quick command */
diff --git a/Documentation/i2c/i2c-protocol b/Documentation/i2c/i2c-protocol
new file mode 100644
index 00000000..0b3e62d1
--- /dev/null
+++ b/Documentation/i2c/i2c-protocol
@@ -0,0 +1,83 @@
+This document describes the i2c protocol. Or will, when it is finished :-)
+
+Key to symbols
+==============
+
+S (1 bit) : Start bit
+P (1 bit) : Stop bit
+Rd/Wr (1 bit) : Read/Write bit. Rd equals 1, Wr equals 0.
+A, NA (1 bit) : Accept and reverse accept bit.
+Addr (7 bits): I2C 7 bit address. Note that this can be expanded as usual to
+ get a 10 bit I2C address.
+Comm (8 bits): Command byte, a data byte which often selects a register on
+ the device.
+Data (8 bits): A plain data byte. Sometimes, I write DataLow, DataHigh
+ for 16 bit data.
+Count (8 bits): A data byte containing the length of a block operation.
+
+[..]: Data sent by I2C device, as opposed to data sent by the host adapter.
+
+
+Simple send transaction
+======================
+
+This corresponds to i2c_master_send.
+
+ S Addr Wr [A] Data [A] Data [A] ... [A] Data [A] P
+
+
+Simple receive transaction
+===========================
+
+This corresponds to i2c_master_recv
+
+ S Addr Rd [A] [Data] A [Data] A ... A [Data] NA P
+
+
+Combined transactions
+====================
+
+This corresponds to i2c_transfer
+
+They are just like the above transactions, but instead of a stop bit P
+a start bit S is sent and the transaction continues. An example of
+a byte read, followed by a byte write:
+
+ S Addr Rd [A] [Data] NA S Addr Wr [A] Data [A] P
+
+
+Modified transactions
+=====================
+
+The following modifications to the I2C protocol can also be generated,
+with the exception of I2C_M_NOSTART these are usually only needed to
+work around device issues:
+
+ Flag I2C_M_NOSTART:
+ In a combined transaction, no 'S Addr Wr/Rd [A]' is generated at some
+ point. For example, setting I2C_M_NOSTART on the second partial message
+ generates something like:
+ S Addr Rd [A] [Data] NA Data [A] P
+ If you set the I2C_M_NOSTART variable for the first partial message,
+ we do not generate Addr, but we do generate the startbit S. This will
+ probably confuse all other clients on your bus, so don't try this.
+
+ This is often used to gather transmits from multiple data buffers in
+ system memory into something that appears as a single transfer to the
+ I2C device but may also be used between direction changes by some
+ rare devices.
+
+ Flags I2C_M_REV_DIR_ADDR
+ This toggles the Rd/Wr flag. That is, if you want to do a write, but
+ need to emit an Rd instead of a Wr, or vice versa, you set this
+ flag. For example:
+ S Addr Rd [A] Data [A] Data [A] ... [A] Data [A] P
+
+ Flags I2C_M_IGNORE_NAK
+ Normally message is interrupted immediately if there is [NA] from the
+ client. Setting this flag treats any [NA] as [A], and all of
+ message is sent.
+ These messages may still fail to SCL lo->hi timeout.
+
+ Flags I2C_M_NO_RD_ACK
+ In a read message, master A/NA bit is skipped.
diff --git a/Documentation/i2c/i2c-stub b/Documentation/i2c/i2c-stub
new file mode 100644
index 00000000..fa4b669c
--- /dev/null
+++ b/Documentation/i2c/i2c-stub
@@ -0,0 +1,53 @@
+MODULE: i2c-stub
+
+DESCRIPTION:
+
+This module is a very simple fake I2C/SMBus driver. It implements five
+types of SMBus commands: write quick, (r/w) byte, (r/w) byte data, (r/w)
+word data, and (r/w) I2C block data.
+
+You need to provide chip addresses as a module parameter when loading this
+driver, which will then only react to SMBus commands to these addresses.
+
+No hardware is needed nor associated with this module. It will accept write
+quick commands to the specified addresses; it will respond to the other
+commands (also to the specified addresses) by reading from or writing to
+arrays in memory. It will also spam the kernel logs for every command it
+handles.
+
+A pointer register with auto-increment is implemented for all byte
+operations. This allows for continuous byte reads like those supported by
+EEPROMs, among others.
+
+The typical use-case is like this:
+ 1. load this module
+ 2. use i2cset (from the i2c-tools project) to pre-load some data
+ 3. load the target chip driver module
+ 4. observe its behavior in the kernel log
+
+There's a script named i2c-stub-from-dump in the i2c-tools package which
+can load register values automatically from a chip dump.
+
+PARAMETERS:
+
+int chip_addr[10]:
+ The SMBus addresses to emulate chips at.
+
+unsigned long functionality:
+ Functionality override, to disable some commands. See I2C_FUNC_*
+ constants in <linux/i2c.h> for the suitable values. For example,
+ value 0x1f0000 would only enable the quick, byte and byte data
+ commands.
+
+CAVEATS:
+
+If your target driver polls some byte or word waiting for it to change, the
+stub could lock it up. Use i2cset to unlock it.
+
+If the hardware for your driver has banked registers (e.g. Winbond sensors
+chips) this module will not work well - although it could be extended to
+support that pretty easily.
+
+If you spam it hard enough, printk can be lossy. This module really wants
+something like relayfs.
+
diff --git a/Documentation/i2c/instantiating-devices b/Documentation/i2c/instantiating-devices
new file mode 100644
index 00000000..22182660
--- /dev/null
+++ b/Documentation/i2c/instantiating-devices
@@ -0,0 +1,211 @@
+How to instantiate I2C devices
+==============================
+
+Unlike PCI or USB devices, I2C devices are not enumerated at the hardware
+level. Instead, the software must know which devices are connected on each
+I2C bus segment, and what address these devices are using. For this
+reason, the kernel code must instantiate I2C devices explicitly. There are
+several ways to achieve this, depending on the context and requirements.
+
+
+Method 1: Declare the I2C devices by bus number
+-----------------------------------------------
+
+This method is appropriate when the I2C bus is a system bus as is the case
+for many embedded systems. On such systems, each I2C bus has a number
+which is known in advance. It is thus possible to pre-declare the I2C
+devices which live on this bus. This is done with an array of struct
+i2c_board_info which is registered by calling i2c_register_board_info().
+
+Example (from omap2 h4):
+
+static struct i2c_board_info __initdata h4_i2c_board_info[] = {
+ {
+ I2C_BOARD_INFO("isp1301_omap", 0x2d),
+ .irq = OMAP_GPIO_IRQ(125),
+ },
+ { /* EEPROM on mainboard */
+ I2C_BOARD_INFO("24c01", 0x52),
+ .platform_data = &m24c01,
+ },
+ { /* EEPROM on cpu card */
+ I2C_BOARD_INFO("24c01", 0x57),
+ .platform_data = &m24c01,
+ },
+};
+
+static void __init omap_h4_init(void)
+{
+ (...)
+ i2c_register_board_info(1, h4_i2c_board_info,
+ ARRAY_SIZE(h4_i2c_board_info));
+ (...)
+}
+
+The above code declares 3 devices on I2C bus 1, including their respective
+addresses and custom data needed by their drivers. When the I2C bus in
+question is registered, the I2C devices will be instantiated automatically
+by i2c-core.
+
+The devices will be automatically unbound and destroyed when the I2C bus
+they sit on goes away (if ever.)
+
+
+Method 2: Instantiate the devices explicitly
+--------------------------------------------
+
+This method is appropriate when a larger device uses an I2C bus for
+internal communication. A typical case is TV adapters. These can have a
+tuner, a video decoder, an audio decoder, etc. usually connected to the
+main chip by the means of an I2C bus. You won't know the number of the I2C
+bus in advance, so the method 1 described above can't be used. Instead,
+you can instantiate your I2C devices explicitly. This is done by filling
+a struct i2c_board_info and calling i2c_new_device().
+
+Example (from the sfe4001 network driver):
+
+static struct i2c_board_info sfe4001_hwmon_info = {
+ I2C_BOARD_INFO("max6647", 0x4e),
+};
+
+int sfe4001_init(struct efx_nic *efx)
+{
+ (...)
+ efx->board_info.hwmon_client =
+ i2c_new_device(&efx->i2c_adap, &sfe4001_hwmon_info);
+
+ (...)
+}
+
+The above code instantiates 1 I2C device on the I2C bus which is on the
+network adapter in question.
+
+A variant of this is when you don't know for sure if an I2C device is
+present or not (for example for an optional feature which is not present
+on cheap variants of a board but you have no way to tell them apart), or
+it may have different addresses from one board to the next (manufacturer
+changing its design without notice). In this case, you can call
+i2c_new_probed_device() instead of i2c_new_device().
+
+Example (from the nxp OHCI driver):
+
+static const unsigned short normal_i2c[] = { 0x2c, 0x2d, I2C_CLIENT_END };
+
+static int usb_hcd_nxp_probe(struct platform_device *pdev)
+{
+ (...)
+ struct i2c_adapter *i2c_adap;
+ struct i2c_board_info i2c_info;
+
+ (...)
+ i2c_adap = i2c_get_adapter(2);
+ memset(&i2c_info, 0, sizeof(struct i2c_board_info));
+ strlcpy(i2c_info.type, "isp1301_nxp", I2C_NAME_SIZE);
+ isp1301_i2c_client = i2c_new_probed_device(i2c_adap, &i2c_info,
+ normal_i2c, NULL);
+ i2c_put_adapter(i2c_adap);
+ (...)
+}
+
+The above code instantiates up to 1 I2C device on the I2C bus which is on
+the OHCI adapter in question. It first tries at address 0x2c, if nothing
+is found there it tries address 0x2d, and if still nothing is found, it
+simply gives up.
+
+The driver which instantiated the I2C device is responsible for destroying
+it on cleanup. This is done by calling i2c_unregister_device() on the
+pointer that was earlier returned by i2c_new_device() or
+i2c_new_probed_device().
+
+
+Method 3: Probe an I2C bus for certain devices
+----------------------------------------------
+
+Sometimes you do not have enough information about an I2C device, not even
+to call i2c_new_probed_device(). The typical case is hardware monitoring
+chips on PC mainboards. There are several dozen models, which can live
+at 25 different addresses. Given the huge number of mainboards out there,
+it is next to impossible to build an exhaustive list of the hardware
+monitoring chips being used. Fortunately, most of these chips have
+manufacturer and device ID registers, so they can be identified by
+probing.
+
+In that case, I2C devices are neither declared nor instantiated
+explicitly. Instead, i2c-core will probe for such devices as soon as their
+drivers are loaded, and if any is found, an I2C device will be
+instantiated automatically. In order to prevent any misbehavior of this
+mechanism, the following restrictions apply:
+* The I2C device driver must implement the detect() method, which
+ identifies a supported device by reading from arbitrary registers.
+* Only buses which are likely to have a supported device and agree to be
+ probed, will be probed. For example this avoids probing for hardware
+ monitoring chips on a TV adapter.
+
+Example:
+See lm90_driver and lm90_detect() in drivers/hwmon/lm90.c
+
+I2C devices instantiated as a result of such a successful probe will be
+destroyed automatically when the driver which detected them is removed,
+or when the underlying I2C bus is itself destroyed, whichever happens
+first.
+
+Those of you familiar with the i2c subsystem of 2.4 kernels and early 2.6
+kernels will find out that this method 3 is essentially similar to what
+was done there. Two significant differences are:
+* Probing is only one way to instantiate I2C devices now, while it was the
+ only way back then. Where possible, methods 1 and 2 should be preferred.
+ Method 3 should only be used when there is no other way, as it can have
+ undesirable side effects.
+* I2C buses must now explicitly say which I2C driver classes can probe
+ them (by the means of the class bitfield), while all I2C buses were
+ probed by default back then. The default is an empty class which means
+ that no probing happens. The purpose of the class bitfield is to limit
+ the aforementioned undesirable side effects.
+
+Once again, method 3 should be avoided wherever possible. Explicit device
+instantiation (methods 1 and 2) is much preferred for it is safer and
+faster.
+
+
+Method 4: Instantiate from user-space
+-------------------------------------
+
+In general, the kernel should know which I2C devices are connected and
+what addresses they live at. However, in certain cases, it does not, so a
+sysfs interface was added to let the user provide the information. This
+interface is made of 2 attribute files which are created in every I2C bus
+directory: new_device and delete_device. Both files are write only and you
+must write the right parameters to them in order to properly instantiate,
+respectively delete, an I2C device.
+
+File new_device takes 2 parameters: the name of the I2C device (a string)
+and the address of the I2C device (a number, typically expressed in
+hexadecimal starting with 0x, but can also be expressed in decimal.)
+
+File delete_device takes a single parameter: the address of the I2C
+device. As no two devices can live at the same address on a given I2C
+segment, the address is sufficient to uniquely identify the device to be
+deleted.
+
+Example:
+# echo eeprom 0x50 > /sys/bus/i2c/devices/i2c-3/new_device
+
+While this interface should only be used when in-kernel device declaration
+can't be done, there is a variety of cases where it can be helpful:
+* The I2C driver usually detects devices (method 3 above) but the bus
+ segment your device lives on doesn't have the proper class bit set and
+ thus detection doesn't trigger.
+* The I2C driver usually detects devices, but your device lives at an
+ unexpected address.
+* The I2C driver usually detects devices, but your device is not detected,
+ either because the detection routine is too strict, or because your
+ device is not officially supported yet but you know it is compatible.
+* You are developing a driver on a test board, where you soldered the I2C
+ device yourself.
+
+This interface is a replacement for the force_* module parameters some I2C
+drivers implement. Being implemented in i2c-core rather than in each
+device driver individually, it is much more efficient, and also has the
+advantage that you do not have to reload the driver to change a setting.
+You can also instantiate the device before the driver is loaded or even
+available, and you don't need to know what driver the device needs.
diff --git a/Documentation/i2c/muxes/i2c-mux-gpio b/Documentation/i2c/muxes/i2c-mux-gpio
new file mode 100644
index 00000000..d4d91a53
--- /dev/null
+++ b/Documentation/i2c/muxes/i2c-mux-gpio
@@ -0,0 +1,83 @@
+Kernel driver i2c-gpio-mux
+
+Author: Peter Korsgaard <peter.korsgaard@barco.com>
+
+Description
+-----------
+
+i2c-gpio-mux is an i2c mux driver providing access to I2C bus segments
+from a master I2C bus and a hardware MUX controlled through GPIO pins.
+
+E.G.:
+
+ ---------- ---------- Bus segment 1 - - - - -
+ | | SCL/SDA | |-------------- | |
+ | |------------| |
+ | | | | Bus segment 2 | |
+ | Linux | GPIO 1..N | MUX |--------------- Devices
+ | |------------| | | |
+ | | | | Bus segment M
+ | | | |---------------| |
+ ---------- ---------- - - - - -
+
+SCL/SDA of the master I2C bus is multiplexed to bus segment 1..M
+according to the settings of the GPIO pins 1..N.
+
+Usage
+-----
+
+i2c-gpio-mux uses the platform bus, so you need to provide a struct
+platform_device with the platform_data pointing to a struct
+gpio_i2cmux_platform_data with the I2C adapter number of the master
+bus, the number of bus segments to create and the GPIO pins used
+to control it. See include/linux/i2c-gpio-mux.h for details.
+
+E.G. something like this for a MUX providing 4 bus segments
+controlled through 3 GPIO pins:
+
+#include <linux/i2c-gpio-mux.h>
+#include <linux/platform_device.h>
+
+static const unsigned myboard_gpiomux_gpios[] = {
+ AT91_PIN_PC26, AT91_PIN_PC25, AT91_PIN_PC24
+};
+
+static const unsigned myboard_gpiomux_values[] = {
+ 0, 1, 2, 3
+};
+
+static struct gpio_i2cmux_platform_data myboard_i2cmux_data = {
+ .parent = 1,
+ .base_nr = 2, /* optional */
+ .values = myboard_gpiomux_values,
+ .n_values = ARRAY_SIZE(myboard_gpiomux_values),
+ .gpios = myboard_gpiomux_gpios,
+ .n_gpios = ARRAY_SIZE(myboard_gpiomux_gpios),
+ .idle = 4, /* optional */
+};
+
+static struct platform_device myboard_i2cmux = {
+ .name = "i2c-gpio-mux",
+ .id = 0,
+ .dev = {
+ .platform_data = &myboard_i2cmux_data,
+ },
+};
+
+If you don't know the absolute GPIO pin numbers at registration time,
+you can instead provide a chip name (.chip_name) and relative GPIO pin
+numbers, and the i2c-gpio-mux driver will do the work for you,
+including deferred probing if the GPIO chip isn't immediately
+available.
+
+Device Registration
+-------------------
+
+When registering your i2c-gpio-mux device, you should pass the number
+of any GPIO pin it uses as the device ID. This guarantees that every
+instance has a different ID.
+
+Alternatively, if you don't need a stable device name, you can simply
+pass PLATFORM_DEVID_AUTO as the device ID, and the platform core will
+assign a dynamic ID to your device. If you do not know the absolute
+GPIO pin numbers at registration time, this is even the only option.
diff --git a/Documentation/i2c/old-module-parameters b/Documentation/i2c/old-module-parameters
new file mode 100644
index 00000000..8e2b629d
--- /dev/null
+++ b/Documentation/i2c/old-module-parameters
@@ -0,0 +1,44 @@
+I2C device driver binding control from user-space
+=================================================
+
+Up to kernel 2.6.32, many i2c drivers used helper macros provided by
+<linux/i2c.h> which created standard module parameters to let the user
+control how the driver would probe i2c buses and attach to devices. These
+parameters were known as "probe" (to let the driver probe for an extra
+address), "force" (to forcibly attach the driver to a given device) and
+"ignore" (to prevent a driver from probing a given address).
+
+With the conversion of the i2c subsystem to the standard device driver
+binding model, it became clear that these per-module parameters were no
+longer needed, and that a centralized implementation was possible. The new,
+sysfs-based interface is described in the documentation file
+"instantiating-devices", section "Method 4: Instantiate from user-space".
+
+Below is a mapping from the old module parameters to the new interface.
+
+Attaching a driver to an I2C device
+-----------------------------------
+
+Old method (module parameters):
+# modprobe <driver> probe=1,0x2d
+# modprobe <driver> force=1,0x2d
+# modprobe <driver> force_<device>=1,0x2d
+
+New method (sysfs interface):
+# echo <device> 0x2d > /sys/bus/i2c/devices/i2c-1/new_device
+
+Preventing a driver from attaching to an I2C device
+---------------------------------------------------
+
+Old method (module parameters):
+# modprobe <driver> ignore=1,0x2f
+
+New method (sysfs interface):
+# echo dummy 0x2f > /sys/bus/i2c/devices/i2c-1/new_device
+# modprobe <driver>
+
+Of course, it is important to instantiate the "dummy" device before loading
+the driver. The dummy device will be handled by i2c-core itself, preventing
+other drivers from binding to it later on. If there is a real device at the
+problematic address, and you want another driver to bind to it, then simply
+pass the name of the device in question instead of "dummy".
diff --git a/Documentation/i2c/smbus-protocol b/Documentation/i2c/smbus-protocol
new file mode 100644
index 00000000..6012b12b
--- /dev/null
+++ b/Documentation/i2c/smbus-protocol
@@ -0,0 +1,273 @@
+SMBus Protocol Summary
+======================
+
+The following is a summary of the SMBus protocol. It applies to
+all revisions of the protocol (1.0, 1.1, and 2.0).
+Certain protocol features which are not supported by
+this package are briefly described at the end of this document.
+
+Some adapters understand only the SMBus (System Management Bus) protocol,
+which is a subset from the I2C protocol. Fortunately, many devices use
+only the same subset, which makes it possible to put them on an SMBus.
+
+If you write a driver for some I2C device, please try to use the SMBus
+commands if at all possible (if the device uses only that subset of the
+I2C protocol). This makes it possible to use the device driver on both
+SMBus adapters and I2C adapters (the SMBus command set is automatically
+translated to I2C on I2C adapters, but plain I2C commands can not be
+handled at all on most pure SMBus adapters).
+
+Below is a list of SMBus protocol operations, and the functions executing
+them. Note that the names used in the SMBus protocol specifications usually
+don't match these function names. For some of the operations which pass a
+single data byte, the functions using SMBus protocol operation names execute
+a different protocol operation entirely.
+
+Each transaction type corresponds to a functionality flag. Before calling a
+transaction function, a device driver should always check (just once) for
+the corresponding functionality flag to ensure that the underlying I2C
+adapter supports the transaction in question. See
+<file:Documentation/i2c/functionality> for the details.
+
+
+Key to symbols
+==============
+
+S (1 bit) : Start bit
+P (1 bit) : Stop bit
+Rd/Wr (1 bit) : Read/Write bit. Rd equals 1, Wr equals 0.
+A, NA (1 bit) : Accept and reverse accept bit.
+Addr (7 bits): I2C 7 bit address. Note that this can be expanded as usual to
+ get a 10 bit I2C address.
+Comm (8 bits): Command byte, a data byte which often selects a register on
+ the device.
+Data (8 bits): A plain data byte. Sometimes, I write DataLow, DataHigh
+ for 16 bit data.
+Count (8 bits): A data byte containing the length of a block operation.
+
+[..]: Data sent by I2C device, as opposed to data sent by the host adapter.
+
+
+SMBus Quick Command
+===================
+
+This sends a single bit to the device, at the place of the Rd/Wr bit.
+
+A Addr Rd/Wr [A] P
+
+Functionality flag: I2C_FUNC_SMBUS_QUICK
+
+
+SMBus Receive Byte: i2c_smbus_read_byte()
+==========================================
+
+This reads a single byte from a device, without specifying a device
+register. Some devices are so simple that this interface is enough; for
+others, it is a shorthand if you want to read the same register as in
+the previous SMBus command.
+
+S Addr Rd [A] [Data] NA P
+
+Functionality flag: I2C_FUNC_SMBUS_READ_BYTE
+
+
+SMBus Send Byte: i2c_smbus_write_byte()
+========================================
+
+This operation is the reverse of Receive Byte: it sends a single byte
+to a device. See Receive Byte for more information.
+
+S Addr Wr [A] Data [A] P
+
+Functionality flag: I2C_FUNC_SMBUS_WRITE_BYTE
+
+
+SMBus Read Byte: i2c_smbus_read_byte_data()
+============================================
+
+This reads a single byte from a device, from a designated register.
+The register is specified through the Comm byte.
+
+S Addr Wr [A] Comm [A] S Addr Rd [A] [Data] NA P
+
+Functionality flag: I2C_FUNC_SMBUS_READ_BYTE_DATA
+
+
+SMBus Read Word: i2c_smbus_read_word_data()
+============================================
+
+This operation is very like Read Byte; again, data is read from a
+device, from a designated register that is specified through the Comm
+byte. But this time, the data is a complete word (16 bits).
+
+S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
+
+Functionality flag: I2C_FUNC_SMBUS_READ_WORD_DATA
+
+Note the convenience function i2c_smbus_read_word_swapped is
+available for reads where the two data bytes are the other way
+around (not SMBus compliant, but very popular.)
+
+
+SMBus Write Byte: i2c_smbus_write_byte_data()
+==============================================
+
+This writes a single byte to a device, to a designated register. The
+register is specified through the Comm byte. This is the opposite of
+the Read Byte operation.
+
+S Addr Wr [A] Comm [A] Data [A] P
+
+Functionality flag: I2C_FUNC_SMBUS_WRITE_BYTE_DATA
+
+
+SMBus Write Word: i2c_smbus_write_word_data()
+==============================================
+
+This is the opposite of the Read Word operation. 16 bits
+of data is written to a device, to the designated register that is
+specified through the Comm byte.
+
+S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A] P
+
+Functionality flag: I2C_FUNC_SMBUS_WRITE_WORD_DATA
+
+Note the convenience function i2c_smbus_write_word_swapped is
+available for writes where the two data bytes are the other way
+around (not SMBus compliant, but very popular.)
+
+
+SMBus Process Call:
+===================
+
+This command selects a device register (through the Comm byte), sends
+16 bits of data to it, and reads 16 bits of data in return.
+
+S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A]
+ S Addr Rd [A] [DataLow] A [DataHigh] NA P
+
+Functionality flag: I2C_FUNC_SMBUS_PROC_CALL
+
+
+SMBus Block Read: i2c_smbus_read_block_data()
+==============================================
+
+This command reads a block of up to 32 bytes from a device, from a
+designated register that is specified through the Comm byte. The amount
+of data is specified by the device in the Count byte.
+
+S Addr Wr [A] Comm [A]
+ S Addr Rd [A] [Count] A [Data] A [Data] A ... A [Data] NA P
+
+Functionality flag: I2C_FUNC_SMBUS_READ_BLOCK_DATA
+
+
+SMBus Block Write: i2c_smbus_write_block_data()
+================================================
+
+The opposite of the Block Read command, this writes up to 32 bytes to
+a device, to a designated register that is specified through the
+Comm byte. The amount of data is specified in the Count byte.
+
+S Addr Wr [A] Comm [A] Count [A] Data [A] Data [A] ... [A] Data [A] P
+
+Functionality flag: I2C_FUNC_SMBUS_WRITE_BLOCK_DATA
+
+
+SMBus Block Write - Block Read Process Call
+===========================================
+
+SMBus Block Write - Block Read Process Call was introduced in
+Revision 2.0 of the specification.
+
+This command selects a device register (through the Comm byte), sends
+1 to 31 bytes of data to it, and reads 1 to 31 bytes of data in return.
+
+S Addr Wr [A] Comm [A] Count [A] Data [A] ...
+ S Addr Rd [A] [Count] A [Data] ... A P
+
+Functionality flag: I2C_FUNC_SMBUS_BLOCK_PROC_CALL
+
+
+SMBus Host Notify
+=================
+
+This command is sent from a SMBus device acting as a master to the
+SMBus host acting as a slave.
+It is the same form as Write Word, with the command code replaced by the
+alerting device's address.
+
+[S] [HostAddr] [Wr] A [DevAddr] A [DataLow] A [DataHigh] A [P]
+
+
+Packet Error Checking (PEC)
+===========================
+
+Packet Error Checking was introduced in Revision 1.1 of the specification.
+
+PEC adds a CRC-8 error-checking byte to transfers using it, immediately
+before the terminating STOP.
+
+
+Address Resolution Protocol (ARP)
+=================================
+
+The Address Resolution Protocol was introduced in Revision 2.0 of
+the specification. It is a higher-layer protocol which uses the
+messages above.
+
+ARP adds device enumeration and dynamic address assignment to
+the protocol. All ARP communications use slave address 0x61 and
+require PEC checksums.
+
+
+SMBus Alert
+===========
+
+SMBus Alert was introduced in Revision 1.0 of the specification.
+
+The SMBus alert protocol allows several SMBus slave devices to share a
+single interrupt pin on the SMBus master, while still allowing the master
+to know which slave triggered the interrupt.
+
+This is implemented the following way in the Linux kernel:
+* I2C bus drivers which support SMBus alert should call
+ i2c_setup_smbus_alert() to setup SMBus alert support.
+* I2C drivers for devices which can trigger SMBus alerts should implement
+ the optional alert() callback.
+
+
+I2C Block Transactions
+======================
+
+The following I2C block transactions are supported by the
+SMBus layer and are described here for completeness.
+They are *NOT* defined by the SMBus specification.
+
+I2C block transactions do not limit the number of bytes transferred
+but the SMBus layer places a limit of 32 bytes.
+
+
+I2C Block Read: i2c_smbus_read_i2c_block_data()
+================================================
+
+This command reads a block of bytes from a device, from a
+designated register that is specified through the Comm byte.
+
+S Addr Wr [A] Comm [A]
+ S Addr Rd [A] [Data] A [Data] A ... A [Data] NA P
+
+Functionality flag: I2C_FUNC_SMBUS_READ_I2C_BLOCK
+
+
+I2C Block Write: i2c_smbus_write_i2c_block_data()
+==================================================
+
+The opposite of the Block Read command, this writes bytes to
+a device, to a designated register that is specified through the
+Comm byte. Note that command lengths of 0, 2, or more bytes are
+supported as they are indistinguishable from data.
+
+S Addr Wr [A] Comm [A] Data [A] Data [A] ... [A] Data [A] P
+
+Functionality flag: I2C_FUNC_SMBUS_WRITE_I2C_BLOCK
diff --git a/Documentation/i2c/summary b/Documentation/i2c/summary
new file mode 100644
index 00000000..13ab076d
--- /dev/null
+++ b/Documentation/i2c/summary
@@ -0,0 +1,47 @@
+I2C and SMBus
+=============
+
+I2C (pronounce: I squared C) is a protocol developed by Philips. It is a
+slow two-wire protocol (variable speed, up to 400 kHz), with a high speed
+extension (3.4 MHz). It provides an inexpensive bus for connecting many
+types of devices with infrequent or low bandwidth communications needs.
+I2C is widely used with embedded systems. Some systems use variants that
+don't meet branding requirements, and so are not advertised as being I2C.
+
+SMBus (System Management Bus) is based on the I2C protocol, and is mostly
+a subset of I2C protocols and signaling. Many I2C devices will work on an
+SMBus, but some SMBus protocols add semantics beyond what is required to
+achieve I2C branding. Modern PC mainboards rely on SMBus. The most common
+devices connected through SMBus are RAM modules configured using I2C EEPROMs,
+and hardware monitoring chips.
+
+Because the SMBus is mostly a subset of the generalized I2C bus, we can
+use its protocols on many I2C systems. However, there are systems that don't
+meet both SMBus and I2C electrical constraints; and others which can't
+implement all the common SMBus protocol semantics or messages.
+
+
+Terminology
+===========
+
+When we talk about I2C, we use the following terms:
+ Bus -> Algorithm
+ Adapter
+ Device -> Driver
+ Client
+
+An Algorithm driver contains general code that can be used for a whole class
+of I2C adapters. Each specific adapter driver either depends on one algorithm
+driver, or includes its own implementation.
+
+A Driver driver (yes, this sounds ridiculous, sorry) contains the general
+code to access some type of device. Each detected device gets its own
+data in the Client structure. Usually, Driver and Client are more closely
+integrated than Algorithm and Adapter.
+
+For a given configuration, you will need a driver for your I2C bus, and
+drivers for your I2C devices (usually one driver for each device).
+
+At this time, Linux only operates I2C (or SMBus) in master mode; you can't
+use these APIs to make a Linux system behave as a slave/device, either to
+speak a custom protocol or to emulate some other device.
diff --git a/Documentation/i2c/ten-bit-addresses b/Documentation/i2c/ten-bit-addresses
new file mode 100644
index 00000000..cdfe1390
--- /dev/null
+++ b/Documentation/i2c/ten-bit-addresses
@@ -0,0 +1,24 @@
+The I2C protocol knows about two kinds of device addresses: normal 7 bit
+addresses, and an extended set of 10 bit addresses. The sets of addresses
+do not intersect: the 7 bit address 0x10 is not the same as the 10 bit
+address 0x10 (though a single device could respond to both of them).
+
+I2C messages to and from 10-bit address devices have a different format.
+See the I2C specification for the details.
+
+The current 10 bit address support is minimal. It should work, however
+you can expect some problems along the way:
+* Not all bus drivers support 10-bit addresses. Some don't because the
+ hardware doesn't support them (SMBus doesn't require 10-bit address
+ support for example), some don't because nobody bothered adding the
+ code (or it's there but not working properly.) Software implementation
+ (i2c-algo-bit) is known to work.
+* Some optional features do not support 10-bit addresses. This is the
+ case of automatic detection and instantiation of devices by their,
+ drivers, for example.
+* Many user-space packages (for example i2c-tools) lack support for
+ 10-bit addresses.
+
+Note that 10-bit address devices are still pretty rare, so the limitations
+listed above could stay for a long time, maybe even forever if nobody
+needs them to be fixed.
diff --git a/Documentation/i2c/upgrading-clients b/Documentation/i2c/upgrading-clients
new file mode 100644
index 00000000..d6991625
--- /dev/null
+++ b/Documentation/i2c/upgrading-clients
@@ -0,0 +1,281 @@
+Upgrading I2C Drivers to the new 2.6 Driver Model
+=================================================
+
+Ben Dooks <ben-linux@fluff.org>
+
+Introduction
+------------
+
+This guide outlines how to alter existing Linux 2.6 client drivers from
+the old to the new new binding methods.
+
+
+Example old-style driver
+------------------------
+
+
+struct example_state {
+ struct i2c_client client;
+ ....
+};
+
+static struct i2c_driver example_driver;
+
+static unsigned short ignore[] = { I2C_CLIENT_END };
+static unsigned short normal_addr[] = { OUR_ADDR, I2C_CLIENT_END };
+
+I2C_CLIENT_INSMOD;
+
+static int example_attach(struct i2c_adapter *adap, int addr, int kind)
+{
+ struct example_state *state;
+ struct device *dev = &adap->dev; /* to use for dev_ reports */
+ int ret;
+
+ state = kzalloc(sizeof(struct example_state), GFP_KERNEL);
+ if (state == NULL) {
+ dev_err(dev, "failed to create our state\n");
+ return -ENOMEM;
+ }
+
+ example->client.addr = addr;
+ example->client.flags = 0;
+ example->client.adapter = adap;
+
+ i2c_set_clientdata(&state->i2c_client, state);
+ strlcpy(client->i2c_client.name, "example", I2C_NAME_SIZE);
+
+ ret = i2c_attach_client(&state->i2c_client);
+ if (ret < 0) {
+ dev_err(dev, "failed to attach client\n");
+ kfree(state);
+ return ret;
+ }
+
+ dev = &state->i2c_client.dev;
+
+ /* rest of the initialisation goes here. */
+
+ dev_info(dev, "example client created\n");
+
+ return 0;
+}
+
+static int example_detach(struct i2c_client *client)
+{
+ struct example_state *state = i2c_get_clientdata(client);
+
+ i2c_detach_client(client);
+ kfree(state);
+ return 0;
+}
+
+static int example_attach_adapter(struct i2c_adapter *adap)
+{
+ return i2c_probe(adap, &addr_data, example_attach);
+}
+
+static struct i2c_driver example_driver = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "example",
+ },
+ .attach_adapter = example_attach_adapter,
+ .detach_client = example_detach,
+ .suspend = example_suspend,
+ .resume = example_resume,
+};
+
+
+Updating the client
+-------------------
+
+The new style binding model will check against a list of supported
+devices and their associated address supplied by the code registering
+the busses. This means that the driver .attach_adapter and
+.detach_client methods can be removed, along with the addr_data,
+as follows:
+
+- static struct i2c_driver example_driver;
+
+- static unsigned short ignore[] = { I2C_CLIENT_END };
+- static unsigned short normal_addr[] = { OUR_ADDR, I2C_CLIENT_END };
+
+- I2C_CLIENT_INSMOD;
+
+- static int example_attach_adapter(struct i2c_adapter *adap)
+- {
+- return i2c_probe(adap, &addr_data, example_attach);
+- }
+
+ static struct i2c_driver example_driver = {
+- .attach_adapter = example_attach_adapter,
+- .detach_client = example_detach,
+ }
+
+Add the probe and remove methods to the i2c_driver, as so:
+
+ static struct i2c_driver example_driver = {
++ .probe = example_probe,
++ .remove = example_remove,
+ }
+
+Change the example_attach method to accept the new parameters
+which include the i2c_client that it will be working with:
+
+- static int example_attach(struct i2c_adapter *adap, int addr, int kind)
++ static int example_probe(struct i2c_client *client,
++ const struct i2c_device_id *id)
+
+Change the name of example_attach to example_probe to align it with the
+i2c_driver entry names. The rest of the probe routine will now need to be
+changed as the i2c_client has already been setup for use.
+
+The necessary client fields have already been setup before
+the probe function is called, so the following client setup
+can be removed:
+
+- example->client.addr = addr;
+- example->client.flags = 0;
+- example->client.adapter = adap;
+-
+- strlcpy(client->i2c_client.name, "example", I2C_NAME_SIZE);
+
+The i2c_set_clientdata is now:
+
+- i2c_set_clientdata(&state->client, state);
++ i2c_set_clientdata(client, state);
+
+The call to i2c_attach_client is no longer needed, if the probe
+routine exits successfully, then the driver will be automatically
+attached by the core. Change the probe routine as so:
+
+- ret = i2c_attach_client(&state->i2c_client);
+- if (ret < 0) {
+- dev_err(dev, "failed to attach client\n");
+- kfree(state);
+- return ret;
+- }
+
+
+Remove the storage of 'struct i2c_client' from the 'struct example_state'
+as we are provided with the i2c_client in our example_probe. Instead we
+store a pointer to it for when it is needed.
+
+struct example_state {
+- struct i2c_client client;
++ struct i2c_client *client;
+
+the new i2c client as so:
+
+- struct device *dev = &adap->dev; /* to use for dev_ reports */
++ struct device *dev = &i2c_client->dev; /* to use for dev_ reports */
+
+And remove the change after our client is attached, as the driver no
+longer needs to register a new client structure with the core:
+
+- dev = &state->i2c_client.dev;
+
+In the probe routine, ensure that the new state has the client stored
+in it:
+
+static int example_probe(struct i2c_client *i2c_client,
+ const struct i2c_device_id *id)
+{
+ struct example_state *state;
+ struct device *dev = &i2c_client->dev;
+ int ret;
+
+ state = kzalloc(sizeof(struct example_state), GFP_KERNEL);
+ if (state == NULL) {
+ dev_err(dev, "failed to create our state\n");
+ return -ENOMEM;
+ }
+
++ state->client = i2c_client;
+
+Update the detach method, by changing the name to _remove and
+to delete the i2c_detach_client call. It is possible that you
+can also remove the ret variable as it is not not needed for
+any of the core functions.
+
+- static int example_detach(struct i2c_client *client)
++ static int example_remove(struct i2c_client *client)
+{
+ struct example_state *state = i2c_get_clientdata(client);
+
+- i2c_detach_client(client);
+
+And finally ensure that we have the correct ID table for the i2c-core
+and other utilities:
+
++ struct i2c_device_id example_idtable[] = {
++ { "example", 0 },
++ { }
++};
++
++MODULE_DEVICE_TABLE(i2c, example_idtable);
+
+static struct i2c_driver example_driver = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "example",
+ },
++ .id_table = example_ids,
+
+
+Our driver should now look like this:
+
+struct example_state {
+ struct i2c_client *client;
+ ....
+};
+
+static int example_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct example_state *state;
+ struct device *dev = &client->dev;
+
+ state = kzalloc(sizeof(struct example_state), GFP_KERNEL);
+ if (state == NULL) {
+ dev_err(dev, "failed to create our state\n");
+ return -ENOMEM;
+ }
+
+ state->client = client;
+ i2c_set_clientdata(client, state);
+
+ /* rest of the initialisation goes here. */
+
+ dev_info(dev, "example client created\n");
+
+ return 0;
+}
+
+static int example_remove(struct i2c_client *client)
+{
+ struct example_state *state = i2c_get_clientdata(client);
+
+ kfree(state);
+ return 0;
+}
+
+static struct i2c_device_id example_idtable[] = {
+ { "example", 0 },
+ { }
+};
+
+MODULE_DEVICE_TABLE(i2c, example_idtable);
+
+static struct i2c_driver example_driver = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "example",
+ },
+ .id_table = example_idtable,
+ .probe = example_probe,
+ .remove = example_remove,
+ .suspend = example_suspend,
+ .resume = example_resume,
+};
diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients
new file mode 100644
index 00000000..6b344b51
--- /dev/null
+++ b/Documentation/i2c/writing-clients
@@ -0,0 +1,403 @@
+This is a small guide for those who want to write kernel drivers for I2C
+or SMBus devices, using Linux as the protocol host/master (not slave).
+
+To set up a driver, you need to do several things. Some are optional, and
+some things can be done slightly or completely different. Use this as a
+guide, not as a rule book!
+
+
+General remarks
+===============
+
+Try to keep the kernel namespace as clean as possible. The best way to
+do this is to use a unique prefix for all global symbols. This is
+especially important for exported symbols, but it is a good idea to do
+it for non-exported symbols too. We will use the prefix `foo_' in this
+tutorial.
+
+
+The driver structure
+====================
+
+Usually, you will implement a single driver structure, and instantiate
+all clients from it. Remember, a driver structure contains general access
+routines, and should be zero-initialized except for fields with data you
+provide. A client structure holds device-specific information like the
+driver model device node, and its I2C address.
+
+static struct i2c_device_id foo_idtable[] = {
+ { "foo", my_id_for_foo },
+ { "bar", my_id_for_bar },
+ { }
+};
+
+MODULE_DEVICE_TABLE(i2c, foo_idtable);
+
+static struct i2c_driver foo_driver = {
+ .driver = {
+ .name = "foo",
+ },
+
+ .id_table = foo_idtable,
+ .probe = foo_probe,
+ .remove = foo_remove,
+ /* if device autodetection is needed: */
+ .class = I2C_CLASS_SOMETHING,
+ .detect = foo_detect,
+ .address_list = normal_i2c,
+
+ .shutdown = foo_shutdown, /* optional */
+ .suspend = foo_suspend, /* optional */
+ .resume = foo_resume, /* optional */
+ .command = foo_command, /* optional, deprecated */
+}
+
+The name field is the driver name, and must not contain spaces. It
+should match the module name (if the driver can be compiled as a module),
+although you can use MODULE_ALIAS (passing "foo" in this example) to add
+another name for the module. If the driver name doesn't match the module
+name, the module won't be automatically loaded (hotplug/coldplug).
+
+All other fields are for call-back functions which will be explained
+below.
+
+
+Extra client data
+=================
+
+Each client structure has a special `data' field that can point to any
+structure at all. You should use this to keep device-specific data.
+
+ /* store the value */
+ void i2c_set_clientdata(struct i2c_client *client, void *data);
+
+ /* retrieve the value */
+ void *i2c_get_clientdata(const struct i2c_client *client);
+
+Note that starting with kernel 2.6.34, you don't have to set the `data' field
+to NULL in remove() or if probe() failed anymore. The i2c-core does this
+automatically on these occasions. Those are also the only times the core will
+touch this field.
+
+
+Accessing the client
+====================
+
+Let's say we have a valid client structure. At some time, we will need
+to gather information from the client, or write new information to the
+client.
+
+I have found it useful to define foo_read and foo_write functions for this.
+For some cases, it will be easier to call the i2c functions directly,
+but many chips have some kind of register-value idea that can easily
+be encapsulated.
+
+The below functions are simple examples, and should not be copied
+literally.
+
+int foo_read_value(struct i2c_client *client, u8 reg)
+{
+ if (reg < 0x10) /* byte-sized register */
+ return i2c_smbus_read_byte_data(client, reg);
+ else /* word-sized register */
+ return i2c_smbus_read_word_data(client, reg);
+}
+
+int foo_write_value(struct i2c_client *client, u8 reg, u16 value)
+{
+ if (reg == 0x10) /* Impossible to write - driver error! */
+ return -EINVAL;
+ else if (reg < 0x10) /* byte-sized register */
+ return i2c_smbus_write_byte_data(client, reg, value);
+ else /* word-sized register */
+ return i2c_smbus_write_word_data(client, reg, value);
+}
+
+
+Probing and attaching
+=====================
+
+The Linux I2C stack was originally written to support access to hardware
+monitoring chips on PC motherboards, and thus used to embed some assumptions
+that were more appropriate to SMBus (and PCs) than to I2C. One of these
+assumptions was that most adapters and devices drivers support the SMBUS_QUICK
+protocol to probe device presence. Another was that devices and their drivers
+can be sufficiently configured using only such probe primitives.
+
+As Linux and its I2C stack became more widely used in embedded systems
+and complex components such as DVB adapters, those assumptions became more
+problematic. Drivers for I2C devices that issue interrupts need more (and
+different) configuration information, as do drivers handling chip variants
+that can't be distinguished by protocol probing, or which need some board
+specific information to operate correctly.
+
+
+Device/Driver Binding
+---------------------
+
+System infrastructure, typically board-specific initialization code or
+boot firmware, reports what I2C devices exist. For example, there may be
+a table, in the kernel or from the boot loader, identifying I2C devices
+and linking them to board-specific configuration information about IRQs
+and other wiring artifacts, chip type, and so on. That could be used to
+create i2c_client objects for each I2C device.
+
+I2C device drivers using this binding model work just like any other
+kind of driver in Linux: they provide a probe() method to bind to
+those devices, and a remove() method to unbind.
+
+ static int foo_probe(struct i2c_client *client,
+ const struct i2c_device_id *id);
+ static int foo_remove(struct i2c_client *client);
+
+Remember that the i2c_driver does not create those client handles. The
+handle may be used during foo_probe(). If foo_probe() reports success
+(zero not a negative status code) it may save the handle and use it until
+foo_remove() returns. That binding model is used by most Linux drivers.
+
+The probe function is called when an entry in the id_table name field
+matches the device's name. It is passed the entry that was matched so
+the driver knows which one in the table matched.
+
+
+Device Creation
+---------------
+
+If you know for a fact that an I2C device is connected to a given I2C bus,
+you can instantiate that device by simply filling an i2c_board_info
+structure with the device address and driver name, and calling
+i2c_new_device(). This will create the device, then the driver core will
+take care of finding the right driver and will call its probe() method.
+If a driver supports different device types, you can specify the type you
+want using the type field. You can also specify an IRQ and platform data
+if needed.
+
+Sometimes you know that a device is connected to a given I2C bus, but you
+don't know the exact address it uses. This happens on TV adapters for
+example, where the same driver supports dozens of slightly different
+models, and I2C device addresses change from one model to the next. In
+that case, you can use the i2c_new_probed_device() variant, which is
+similar to i2c_new_device(), except that it takes an additional list of
+possible I2C addresses to probe. A device is created for the first
+responsive address in the list. If you expect more than one device to be
+present in the address range, simply call i2c_new_probed_device() that
+many times.
+
+The call to i2c_new_device() or i2c_new_probed_device() typically happens
+in the I2C bus driver. You may want to save the returned i2c_client
+reference for later use.
+
+
+Device Detection
+----------------
+
+Sometimes you do not know in advance which I2C devices are connected to
+a given I2C bus. This is for example the case of hardware monitoring
+devices on a PC's SMBus. In that case, you may want to let your driver
+detect supported devices automatically. This is how the legacy model
+was working, and is now available as an extension to the standard
+driver model.
+
+You simply have to define a detect callback which will attempt to
+identify supported devices (returning 0 for supported ones and -ENODEV
+for unsupported ones), a list of addresses to probe, and a device type
+(or class) so that only I2C buses which may have that type of device
+connected (and not otherwise enumerated) will be probed. For example,
+a driver for a hardware monitoring chip for which auto-detection is
+needed would set its class to I2C_CLASS_HWMON, and only I2C adapters
+with a class including I2C_CLASS_HWMON would be probed by this driver.
+Note that the absence of matching classes does not prevent the use of
+a device of that type on the given I2C adapter. All it prevents is
+auto-detection; explicit instantiation of devices is still possible.
+
+Note that this mechanism is purely optional and not suitable for all
+devices. You need some reliable way to identify the supported devices
+(typically using device-specific, dedicated identification registers),
+otherwise misdetections are likely to occur and things can get wrong
+quickly. Keep in mind that the I2C protocol doesn't include any
+standard way to detect the presence of a chip at a given address, let
+alone a standard way to identify devices. Even worse is the lack of
+semantics associated to bus transfers, which means that the same
+transfer can be seen as a read operation by a chip and as a write
+operation by another chip. For these reasons, explicit device
+instantiation should always be preferred to auto-detection where
+possible.
+
+
+Device Deletion
+---------------
+
+Each I2C device which has been created using i2c_new_device() or
+i2c_new_probed_device() can be unregistered by calling
+i2c_unregister_device(). If you don't call it explicitly, it will be
+called automatically before the underlying I2C bus itself is removed, as a
+device can't survive its parent in the device driver model.
+
+
+Initializing the driver
+=======================
+
+When the kernel is booted, or when your foo driver module is inserted,
+you have to do some initializing. Fortunately, just registering the
+driver module is usually enough.
+
+static int __init foo_init(void)
+{
+ return i2c_add_driver(&foo_driver);
+}
+module_init(foo_init);
+
+static void __exit foo_cleanup(void)
+{
+ i2c_del_driver(&foo_driver);
+}
+module_exit(foo_cleanup);
+
+The module_i2c_driver() macro can be used to reduce above code.
+
+module_i2c_driver(foo_driver);
+
+Note that some functions are marked by `__init'. These functions can
+be removed after kernel booting (or module loading) is completed.
+Likewise, functions marked by `__exit' are dropped by the compiler when
+the code is built into the kernel, as they would never be called.
+
+
+Driver Information
+==================
+
+/* Substitute your own name and email address */
+MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>"
+MODULE_DESCRIPTION("Driver for Barf Inc. Foo I2C devices");
+
+/* a few non-GPL license types are also allowed */
+MODULE_LICENSE("GPL");
+
+
+Power Management
+================
+
+If your I2C device needs special handling when entering a system low
+power state -- like putting a transceiver into a low power mode, or
+activating a system wakeup mechanism -- do that in the suspend() method.
+The resume() method should reverse what the suspend() method does.
+
+These are standard driver model calls, and they work just like they
+would for any other driver stack. The calls can sleep, and can use
+I2C messaging to the device being suspended or resumed (since their
+parent I2C adapter is active when these calls are issued, and IRQs
+are still enabled).
+
+
+System Shutdown
+===============
+
+If your I2C device needs special handling when the system shuts down
+or reboots (including kexec) -- like turning something off -- use a
+shutdown() method.
+
+Again, this is a standard driver model call, working just like it
+would for any other driver stack: the calls can sleep, and can use
+I2C messaging.
+
+
+Command function
+================
+
+A generic ioctl-like function call back is supported. You will seldom
+need this, and its use is deprecated anyway, so newer design should not
+use it.
+
+
+Sending and receiving
+=====================
+
+If you want to communicate with your device, there are several functions
+to do this. You can find all of them in <linux/i2c.h>.
+
+If you can choose between plain I2C communication and SMBus level
+communication, please use the latter. All adapters understand SMBus level
+commands, but only some of them understand plain I2C!
+
+
+Plain I2C communication
+-----------------------
+
+ int i2c_master_send(struct i2c_client *client, const char *buf,
+ int count);
+ int i2c_master_recv(struct i2c_client *client, char *buf, int count);
+
+These routines read and write some bytes from/to a client. The client
+contains the i2c address, so you do not have to include it. The second
+parameter contains the bytes to read/write, the third the number of bytes
+to read/write (must be less than the length of the buffer, also should be
+less than 64k since msg.len is u16.) Returned is the actual number of bytes
+read/written.
+
+ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msg,
+ int num);
+
+This sends a series of messages. Each message can be a read or write,
+and they can be mixed in any way. The transactions are combined: no
+stop bit is sent between transaction. The i2c_msg structure contains
+for each message the client address, the number of bytes of the message
+and the message data itself.
+
+You can read the file `i2c-protocol' for more information about the
+actual I2C protocol.
+
+
+SMBus communication
+-------------------
+
+ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
+ unsigned short flags, char read_write, u8 command,
+ int size, union i2c_smbus_data *data);
+
+This is the generic SMBus function. All functions below are implemented
+in terms of it. Never use this function directly!
+
+ s32 i2c_smbus_read_byte(struct i2c_client *client);
+ s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value);
+ s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command);
+ s32 i2c_smbus_write_byte_data(struct i2c_client *client,
+ u8 command, u8 value);
+ s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command);
+ s32 i2c_smbus_write_word_data(struct i2c_client *client,
+ u8 command, u16 value);
+ s32 i2c_smbus_read_block_data(struct i2c_client *client,
+ u8 command, u8 *values);
+ s32 i2c_smbus_write_block_data(struct i2c_client *client,
+ u8 command, u8 length, const u8 *values);
+ s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client,
+ u8 command, u8 length, u8 *values);
+ s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client,
+ u8 command, u8 length,
+ const u8 *values);
+
+These ones were removed from i2c-core because they had no users, but could
+be added back later if needed:
+
+ s32 i2c_smbus_write_quick(struct i2c_client *client, u8 value);
+ s32 i2c_smbus_process_call(struct i2c_client *client,
+ u8 command, u16 value);
+ s32 i2c_smbus_block_process_call(struct i2c_client *client,
+ u8 command, u8 length, u8 *values);
+
+All these transactions return a negative errno value on failure. The 'write'
+transactions return 0 on success; the 'read' transactions return the read
+value, except for block transactions, which return the number of values
+read. The block buffers need not be longer than 32 bytes.
+
+You can read the file `smbus-protocol' for more information about the
+actual SMBus protocol.
+
+
+General purpose routines
+========================
+
+Below all general purpose routines are listed, that were not mentioned
+before.
+
+ /* Return the adapter number for a specific adapter */
+ int i2c_adapter_id(struct i2c_adapter *adap);