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-rw-r--r--Documentation/arm/Samsung-S3C24XX/GPIO.txt81
-rw-r--r--Documentation/arm/Samsung-S3C24XX/Overview.txt15
-rw-r--r--Documentation/arm/Samsung/GPIO.txt42
-rw-r--r--Documentation/arm/Samsung/Overview.txt33
4 files changed, 158 insertions, 13 deletions
diff --git a/Documentation/arm/Samsung-S3C24XX/GPIO.txt b/Documentation/arm/Samsung-S3C24XX/GPIO.txt
index 2af2cf39915..816d6071669 100644
--- a/Documentation/arm/Samsung-S3C24XX/GPIO.txt
+++ b/Documentation/arm/Samsung-S3C24XX/GPIO.txt
@@ -12,6 +12,8 @@ Introduction
of the s3c2410 GPIO system, please read the Samsung provided
data-sheet/users manual to find out the complete list.
+ See Documentation/arm/Samsung/GPIO.txt for the core implemetation.
+
GPIOLIB
-------
@@ -24,8 +26,60 @@ GPIOLIB
listed below will be removed (they may be marked as __deprecated
in the near future).
- - s3c2410_gpio_getpin
- - s3c2410_gpio_setpin
+ The following functions now either have a s3c_ specific variant
+ or are merged into gpiolib. See the definitions in
+ arch/arm/plat-samsung/include/plat/gpio-cfg.h:
+
+ s3c2410_gpio_setpin() gpio_set_value() or gpio_direction_output()
+ s3c2410_gpio_getpin() gpio_get_value() or gpio_direction_input()
+ s3c2410_gpio_getirq() gpio_to_irq()
+ s3c2410_gpio_cfgpin() s3c_gpio_cfgpin()
+ s3c2410_gpio_getcfg() s3c_gpio_getcfg()
+ s3c2410_gpio_pullup() s3c_gpio_setpull()
+
+
+GPIOLIB conversion
+------------------
+
+If you need to convert your board or driver to use gpiolib from the exiting
+s3c2410 api, then here are some notes on the process.
+
+1) If your board is exclusively using an GPIO, say to control peripheral
+ power, then it will require to claim the gpio with gpio_request() before
+ it can use it.
+
+ It is recommended to check the return value, with at least WARN_ON()
+ during initialisation.
+
+2) The s3c2410_gpio_cfgpin() can be directly replaced with s3c_gpio_cfgpin()
+ as they have the same arguments, and can either take the pin specific
+ values, or the more generic special-function-number arguments.
+
+3) s3c2410_gpio_pullup() changs have the problem that whilst the
+ s3c2410_gpio_pullup(x, 1) can be easily translated to the
+ s3c_gpio_setpull(x, S3C_GPIO_PULL_NONE), the s3c2410_gpio_pullup(x, 0)
+ are not so easy.
+
+ The s3c2410_gpio_pullup(x, 0) case enables the pull-up (or in the case
+ of some of the devices, a pull-down) and as such the new API distinguishes
+ between the UP and DOWN case. There is currently no 'just turn on' setting
+ which may be required if this becomes a problem.
+
+4) s3c2410_gpio_setpin() can be replaced by gpio_set_value(), the old call
+ does not implicitly configure the relevant gpio to output. The gpio
+ direction should be changed before using gpio_set_value().
+
+5) s3c2410_gpio_getpin() is replaceable by gpio_get_value() if the pin
+ has been set to input. It is currently unknown what the behaviour is
+ when using gpio_get_value() on an output pin (s3c2410_gpio_getpin
+ would return the value the pin is supposed to be outputting).
+
+6) s3c2410_gpio_getirq() should be directly replacable with the
+ gpio_to_irq() call.
+
+The s3c2410_gpio and gpio_ calls have always operated on the same gpio
+numberspace, so there is no problem with converting the gpio numbering
+between the calls.
Headers
@@ -54,6 +108,11 @@ PIN Numbers
eg S3C2410_GPA(0) or S3C2410_GPF(1). These defines are used to tell
the GPIO functions which pin is to be used.
+ With the conversion to gpiolib, there is no longer a direct conversion
+ from gpio pin number to register base address as in earlier kernels. This
+ is due to the number space required for newer SoCs where the later
+ GPIOs are not contiguous.
+
Configuring a pin
-----------------
@@ -71,6 +130,8 @@ Configuring a pin
which would turn GPA(0) into the lowest Address line A0, and set
GPE(8) to be connected to the SDIO/MMC controller's SDDAT1 line.
+ The s3c_gpio_cfgpin() call is a functional replacement for this call.
+
Reading the current configuration
---------------------------------
@@ -82,6 +143,9 @@ Reading the current configuration
The return value will be from the same set of values which can be
passed to s3c2410_gpio_cfgpin().
+ The s3c_gpio_getcfg() call should be a functional replacement for
+ this call.
+
Configuring a pull-up resistor
------------------------------
@@ -95,6 +159,10 @@ Configuring a pull-up resistor
Where the to value is zero to set the pull-up off, and 1 to enable
the specified pull-up. Any other values are currently undefined.
+ The s3c_gpio_setpull() offers similar functionality, but with the
+ ability to encode whether the pull is up or down. Currently there
+ is no 'just on' state, so up or down must be selected.
+
Getting the state of a PIN
--------------------------
@@ -106,6 +174,9 @@ Getting the state of a PIN
This will return either zero or non-zero. Do not count on this
function returning 1 if the pin is set.
+ This call is now implemented by the relevant gpiolib calls, convert
+ your board or driver to use gpiolib.
+
Setting the state of a PIN
--------------------------
@@ -117,6 +188,9 @@ Setting the state of a PIN
Which sets the given pin to the value. Use 0 to write 0, and 1 to
set the output to 1.
+ This call is now implemented by the relevant gpiolib calls, convert
+ your board or driver to use gpiolib.
+
Getting the IRQ number associated with a PIN
--------------------------------------------
@@ -128,6 +202,9 @@ Getting the IRQ number associated with a PIN
Note, not all pins have an IRQ.
+ This call is now implemented by the relevant gpiolib calls, convert
+ your board or driver to use gpiolib.
+
Authour
-------
diff --git a/Documentation/arm/Samsung-S3C24XX/Overview.txt b/Documentation/arm/Samsung-S3C24XX/Overview.txt
index 081892df4fd..c12bfc1a00c 100644
--- a/Documentation/arm/Samsung-S3C24XX/Overview.txt
+++ b/Documentation/arm/Samsung-S3C24XX/Overview.txt
@@ -8,10 +8,16 @@ Introduction
The Samsung S3C24XX range of ARM9 System-on-Chip CPUs are supported
by the 's3c2410' architecture of ARM Linux. Currently the S3C2410,
- S3C2412, S3C2413, S3C2440, S3C2442 and S3C2443 devices are supported.
+ S3C2412, S3C2413, S3C2416 S3C2440, S3C2442, S3C2443 and S3C2450 devices
+ are supported.
Support for the S3C2400 and S3C24A0 series are in progress.
+ The S3C2416 and S3C2450 devices are very similar and S3C2450 support is
+ included under the arch/arm/mach-s3c2416 directory. Note, whilst core
+ support for these SoCs is in, work on some of the extra peripherals
+ and extra interrupts is still ongoing.
+
Configuration
-------------
@@ -209,6 +215,13 @@ GPIO
Newer kernels carry GPIOLIB, and support is being moved towards
this with some of the older support in line to be removed.
+ As of v2.6.34, the move towards using gpiolib support is almost
+ complete, and very little of the old calls are left.
+
+ See Documentation/arm/Samsung-S3C24XX/GPIO.txt for the S3C24XX specific
+ support and Documentation/arm/Samsung/GPIO.txt for the core Samsung
+ implementation.
+
Clock Management
----------------
diff --git a/Documentation/arm/Samsung/GPIO.txt b/Documentation/arm/Samsung/GPIO.txt
new file mode 100644
index 00000000000..05850c62abe
--- /dev/null
+++ b/Documentation/arm/Samsung/GPIO.txt
@@ -0,0 +1,42 @@
+ Samsung GPIO implementation
+ ===========================
+
+Introduction
+------------
+
+This outlines the Samsung GPIO implementation and the architecture
+specfic calls provided alongisde the drivers/gpio core.
+
+
+S3C24XX (Legacy)
+----------------
+
+See Documentation/arm/Samsung-S3C24XX/GPIO.txt for more information
+about these devices. Their implementation is being brought into line
+with the core samsung implementation described in this document.
+
+
+GPIOLIB integration
+-------------------
+
+The gpio implementation uses gpiolib as much as possible, only providing
+specific calls for the items that require Samsung specific handling, such
+as pin special-function or pull resistor control.
+
+GPIO numbering is synchronised between the Samsung and gpiolib system.
+
+
+PIN configuration
+-----------------
+
+Pin configuration is specific to the Samsung architecutre, with each SoC
+registering the necessary information for the core gpio configuration
+implementation to configure pins as necessary.
+
+The s3c_gpio_cfgpin() and s3c_gpio_setpull() provide the means for a
+driver or machine to change gpio configuration.
+
+See arch/arm/plat-samsung/include/plat/gpio-cfg.h for more information
+on these functions.
+
+
diff --git a/Documentation/arm/Samsung/Overview.txt b/Documentation/arm/Samsung/Overview.txt
index 7cced1fea9c..c3094ea51aa 100644
--- a/Documentation/arm/Samsung/Overview.txt
+++ b/Documentation/arm/Samsung/Overview.txt
@@ -13,9 +13,10 @@ Introduction
- S3C24XX: See Documentation/arm/Samsung-S3C24XX/Overview.txt for full list
- S3C64XX: S3C6400 and S3C6410
- - S5PC6440
-
- S5PC100 and S5PC110 support is currently being merged
+ - S5P6440
+ - S5P6442
+ - S5PC100
+ - S5PC110 / S5PV210
S3C24XX Systems
@@ -35,7 +36,10 @@ Configuration
unifying all the SoCs into one kernel.
s5p6440_defconfig - S5P6440 specific default configuration
+ s5p6442_defconfig - S5P6442 specific default configuration
s5pc100_defconfig - S5PC100 specific default configuration
+ s5pc110_defconfig - S5PC110 specific default configuration
+ s5pv210_defconfig - S5PV210 specific default configuration
Layout
@@ -50,18 +54,27 @@ Layout
specific information. It contains the base clock, GPIO and device definitions
to get the system running.
- plat-s3c is the s3c24xx/s3c64xx platform directory, although it is currently
- involved in other builds this will be phased out once the relevant code is
- moved elsewhere.
-
plat-s3c24xx is for s3c24xx specific builds, see the S3C24XX docs.
- plat-s3c64xx is for the s3c64xx specific bits, see the S3C24XX docs.
+ plat-s5p is for s5p specific builds, and contains common support for the
+ S5P specific systems. Not all S5Ps use all the features in this directory
+ due to differences in the hardware.
+
+
+Layout changes
+--------------
+
+ The old plat-s3c and plat-s5pc1xx directories have been removed, with
+ support moved to either plat-samsung or plat-s5p as necessary. These moves
+ where to simplify the include and dependency issues involved with having
+ so many different platform directories.
- plat-s5p is for s5p specific builds, more to be added.
+ It was decided to remove plat-s5pc1xx as some of the support was already
+ in plat-s5p or plat-samsung, with the S5PC110 support added with S5PV210
+ the only user was the S5PC100. The S5PC100 specific items where moved to
+ arch/arm/mach-s5pc100.
- [ to finish ]
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