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-rw-r--r--Documentation/driver-api/gpio/board.rst21
-rw-r--r--Documentation/firmware-guide/acpi/enumeration.rst111
-rw-r--r--Documentation/firmware-guide/acpi/gpio-properties.rst26
3 files changed, 67 insertions, 91 deletions
diff --git a/Documentation/driver-api/gpio/board.rst b/Documentation/driver-api/gpio/board.rst
index 191fa867826a..4e3adf31c8d1 100644
--- a/Documentation/driver-api/gpio/board.rst
+++ b/Documentation/driver-api/gpio/board.rst
@@ -71,14 +71,14 @@ with the help of _DSD (Device Specific Data), introduced in ACPI 5.1::
Device (FOO) {
Name (_CRS, ResourceTemplate () {
- GpioIo (Exclusive, ..., IoRestrictionOutputOnly,
- "\\_SB.GPI0") {15} // red
- GpioIo (Exclusive, ..., IoRestrictionOutputOnly,
- "\\_SB.GPI0") {16} // green
- GpioIo (Exclusive, ..., IoRestrictionOutputOnly,
- "\\_SB.GPI0") {17} // blue
- GpioIo (Exclusive, ..., IoRestrictionOutputOnly,
- "\\_SB.GPI0") {1} // power
+ GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionOutputOnly,
+ "\\_SB.GPI0", 0, ResourceConsumer) { 15 } // red
+ GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionOutputOnly,
+ "\\_SB.GPI0", 0, ResourceConsumer) { 16 } // green
+ GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionOutputOnly,
+ "\\_SB.GPI0", 0, ResourceConsumer) { 17 } // blue
+ GpioIo (Exclusive, PullNone, 0, 0, IoRestrictionOutputOnly,
+ "\\_SB.GPI0", 0, ResourceConsumer) { 1 } // power
})
Name (_DSD, Package () {
@@ -92,10 +92,7 @@ with the help of _DSD (Device Specific Data), introduced in ACPI 5.1::
^FOO, 2, 0, 1,
}
},
- Package () {
- "power-gpios",
- Package () {^FOO, 3, 0, 0},
- },
+ Package () { "power-gpios", Package () { ^FOO, 3, 0, 0 } },
}
})
}
diff --git a/Documentation/firmware-guide/acpi/enumeration.rst b/Documentation/firmware-guide/acpi/enumeration.rst
index 74b830b2fd59..c414646a1bb4 100644
--- a/Documentation/firmware-guide/acpi/enumeration.rst
+++ b/Documentation/firmware-guide/acpi/enumeration.rst
@@ -19,16 +19,17 @@ possible we decided to do following:
platform devices.
- Devices behind real busses where there is a connector resource
- are represented as struct spi_device or struct i2c_device
- (standard UARTs are not busses so there is no struct uart_device).
+ are represented as struct spi_device or struct i2c_device. Note
+ that standard UARTs are not busses so there is no struct uart_device,
+ although some of them may be represented by sturct serdev_device.
As both ACPI and Device Tree represent a tree of devices (and their
resources) this implementation follows the Device Tree way as much as
possible.
-The ACPI implementation enumerates devices behind busses (platform, SPI and
-I2C), creates the physical devices and binds them to their ACPI handle in
-the ACPI namespace.
+The ACPI implementation enumerates devices behind busses (platform, SPI,
+I2C, and in some cases UART), creates the physical devices and binds them
+to their ACPI handle in the ACPI namespace.
This means that when ACPI_HANDLE(dev) returns non-NULL the device was
enumerated from ACPI namespace. This handle can be used to extract other
@@ -46,18 +47,16 @@ some minor changes.
Adding ACPI support for an existing driver should be pretty
straightforward. Here is the simplest example::
- #ifdef CONFIG_ACPI
static const struct acpi_device_id mydrv_acpi_match[] = {
/* ACPI IDs here */
{ }
};
MODULE_DEVICE_TABLE(acpi, mydrv_acpi_match);
- #endif
static struct platform_driver my_driver = {
...
.driver = {
- .acpi_match_table = ACPI_PTR(mydrv_acpi_match),
+ .acpi_match_table = mydrv_acpi_match,
},
};
@@ -155,7 +154,7 @@ Here is what the ACPI namespace for a SPI slave might look like::
Device (EEP0)
{
Name (_ADR, 1)
- Name (_CID, Package() {
+ Name (_CID, Package () {
"ATML0025",
"AT25",
})
@@ -172,59 +171,51 @@ The SPI device drivers only need to add ACPI IDs in a similar way than with
the platform device drivers. Below is an example where we add ACPI support
to at25 SPI eeprom driver (this is meant for the above ACPI snippet)::
- #ifdef CONFIG_ACPI
static const struct acpi_device_id at25_acpi_match[] = {
{ "AT25", 0 },
- { },
+ { }
};
MODULE_DEVICE_TABLE(acpi, at25_acpi_match);
- #endif
static struct spi_driver at25_driver = {
.driver = {
...
- .acpi_match_table = ACPI_PTR(at25_acpi_match),
+ .acpi_match_table = at25_acpi_match,
},
};
Note that this driver actually needs more information like page size of the
-eeprom etc. but at the time writing this there is no standard way of
-passing those. One idea is to return this in _DSM method like::
+eeprom, etc. This information can be passed via _DSD method like::
Device (EEP0)
{
...
- Method (_DSM, 4, NotSerialized)
+ Name (_DSD, Package ()
{
- Store (Package (6)
+ ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ Package ()
{
- "byte-len", 1024,
- "addr-mode", 2,
- "page-size, 32
- }, Local0)
-
- // Check UUIDs etc.
-
- Return (Local0)
- }
-
-Then the at25 SPI driver can get this configuration by calling _DSM on its
-ACPI handle like::
-
- struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
- struct acpi_object_list input;
- acpi_status status;
+ Package () { "size", 1024 },
+ Package () { "pagesize", 32 },
+ Package () { "address-width", 16 },
+ }
+ })
+ }
- /* Fill in the input buffer */
+Then the at25 SPI driver can get this configuration by calling device property
+APIs during ->probe() phase like::
- status = acpi_evaluate_object(ACPI_HANDLE(&spi->dev), "_DSM",
- &input, &output);
- if (ACPI_FAILURE(status))
- /* Handle the error */
+ err = device_property_read_u32(dev, "size", &size);
+ if (err)
+ ...error handling...
- /* Extract the data here */
+ err = device_property_read_u32(dev, "pagesize", &page_size);
+ if (err)
+ ...error handling...
- kfree(output.pointer);
+ err = device_property_read_u32(dev, "address-width", &addr_width);
+ if (err)
+ ...error handling...
I2C serial bus support
======================
@@ -237,26 +228,24 @@ registered.
Below is an example of how to add ACPI support to the existing mpu3050
input driver::
- #ifdef CONFIG_ACPI
static const struct acpi_device_id mpu3050_acpi_match[] = {
{ "MPU3050", 0 },
- { },
+ { }
};
MODULE_DEVICE_TABLE(acpi, mpu3050_acpi_match);
- #endif
static struct i2c_driver mpu3050_i2c_driver = {
.driver = {
.name = "mpu3050",
- .owner = THIS_MODULE,
.pm = &mpu3050_pm,
.of_match_table = mpu3050_of_match,
- .acpi_match_table = ACPI_PTR(mpu3050_acpi_match),
+ .acpi_match_table = mpu3050_acpi_match,
},
.probe = mpu3050_probe,
.remove = mpu3050_remove,
.id_table = mpu3050_ids,
};
+ module_i2c_driver(mpu3050_i2c_driver);
Reference to PWM device
=======================
@@ -282,9 +271,9 @@ introduced, i.e.::
}
}
}
-
})
...
+ }
In the above example the PWM-based LED driver references to the PWM channel 0
of \_SB.PCI0.PWM device with initial period setting equal to 600 ms (note that
@@ -306,26 +295,13 @@ For example::
{
Name (SBUF, ResourceTemplate()
{
- ...
// Used to power on/off the device
- GpioIo (Exclusive, PullDefault, 0x0000, 0x0000,
- IoRestrictionOutputOnly, "\\_SB.PCI0.GPI0",
- 0x00, ResourceConsumer,,)
- {
- // Pin List
- 0x0055
- }
+ GpioIo (Exclusive, PullNone, 0, 0, IoRestrictionOutputOnly,
+ "\\_SB.PCI0.GPI0", 0, ResourceConsumer) { 85 }
// Interrupt for the device
- GpioInt (Edge, ActiveHigh, ExclusiveAndWake, PullNone,
- 0x0000, "\\_SB.PCI0.GPI0", 0x00, ResourceConsumer,,)
- {
- // Pin list
- 0x0058
- }
-
- ...
-
+ GpioInt (Edge, ActiveHigh, ExclusiveAndWake, PullNone, 0,
+ "\\_SB.PCI0.GPI0", 0, ResourceConsumer) { 88 }
}
Return (SBUF)
@@ -337,11 +313,12 @@ For example::
ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
Package ()
{
- Package () {"power-gpios", Package() {^DEV, 0, 0, 0 }},
- Package () {"irq-gpios", Package() {^DEV, 1, 0, 0 }},
+ Package () { "power-gpios", Package () { ^DEV, 0, 0, 0 } },
+ Package () { "irq-gpios", Package () { ^DEV, 1, 0, 0 } },
}
})
...
+ }
These GPIO numbers are controller relative and path "\\_SB.PCI0.GPI0"
specifies the path to the controller. In order to use these GPIOs in Linux
@@ -460,10 +437,10 @@ namespace link::
Device (TMP0)
{
Name (_HID, "PRP0001")
- Name (_DSD, Package() {
+ Name (_DSD, Package () {
ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
Package () {
- Package (2) { "compatible", "ti,tmp75" },
+ Package () { "compatible", "ti,tmp75" },
}
})
Method (_CRS, 0, Serialized)
diff --git a/Documentation/firmware-guide/acpi/gpio-properties.rst b/Documentation/firmware-guide/acpi/gpio-properties.rst
index df4b711053ee..eaec732cc77c 100644
--- a/Documentation/firmware-guide/acpi/gpio-properties.rst
+++ b/Documentation/firmware-guide/acpi/gpio-properties.rst
@@ -21,18 +21,18 @@ index, like the ASL example below shows::
Name (_CRS, ResourceTemplate ()
{
GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionOutputOnly,
- "\\_SB.GPO0", 0, ResourceConsumer) {15}
+ "\\_SB.GPO0", 0, ResourceConsumer) { 15 }
GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionOutputOnly,
- "\\_SB.GPO0", 0, ResourceConsumer) {27, 31}
+ "\\_SB.GPO0", 0, ResourceConsumer) { 27, 31 }
})
Name (_DSD, Package ()
{
ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
Package ()
- {
- Package () {"reset-gpios", Package() {^BTH, 1, 1, 0 }},
- Package () {"shutdown-gpios", Package() {^BTH, 0, 0, 0 }},
+ {
+ Package () { "reset-gpios", Package () { ^BTH, 1, 1, 0 } },
+ Package () { "shutdown-gpios", Package () { ^BTH, 0, 0, 0 } },
}
})
}
@@ -123,17 +123,17 @@ Example::
// _DSD Hierarchical Properties Extension UUID
ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
Package () {
- Package () {"hog-gpio8", "G8PU"}
+ Package () { "hog-gpio8", "G8PU" }
}
})
Name (G8PU, Package () {
ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
Package () {
- Package () {"gpio-hog", 1},
- Package () {"gpios", Package () {8, 0}},
- Package () {"output-high", 1},
- Package () {"line-name", "gpio8-pullup"},
+ Package () { "gpio-hog", 1 },
+ Package () { "gpios", Package () { 8, 0 } },
+ Package () { "output-high", 1 },
+ Package () { "line-name", "gpio8-pullup" },
}
})
@@ -266,15 +266,17 @@ have a device like below::
Name (_CRS, ResourceTemplate () {
GpioIo (Exclusive, PullNone, 0, 0, IoRestrictionNone,
- "\\_SB.GPO0", 0, ResourceConsumer) {15}
+ "\\_SB.GPO0", 0, ResourceConsumer) { 15 }
GpioIo (Exclusive, PullNone, 0, 0, IoRestrictionNone,
- "\\_SB.GPO0", 0, ResourceConsumer) {27}
+ "\\_SB.GPO0", 0, ResourceConsumer) { 27 }
})
}
The driver might expect to get the right GPIO when it does::
desc = gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+ if (IS_ERR(desc))
+ ...error handling...
but since there is no way to know the mapping between "reset" and
the GpioIo() in _CRS desc will hold ERR_PTR(-ENOENT).
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-10 11:49:00 +0000