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authorMichal Marek <mmarek@suse.cz>2014-01-02 17:02:06 +0400
committerMichal Marek <mmarek@suse.cz>2014-01-02 17:02:06 +0400
commit37e2c2a775fc887acd1432908478dfd532f7f00f (patch)
treee51ebc699d8e262fd47e0913be6a711cb1a7b565 /Documentation/acpi
parent1c8ddae09f4c102b97c9086cc70347e89468a547 (diff)
parent6ce4eac1f600b34f2f7f58f9cd8f0503d79e42ae (diff)
downloadlinux-37e2c2a775fc887acd1432908478dfd532f7f00f.tar.xz
Merge commit v3.13-rc1 into kbuild/misc
Diffstat (limited to 'Documentation/acpi')
-rw-r--r--Documentation/acpi/dsdt-override.txt2
-rw-r--r--Documentation/acpi/enumeration.txt26
2 files changed, 23 insertions, 5 deletions
diff --git a/Documentation/acpi/dsdt-override.txt b/Documentation/acpi/dsdt-override.txt
index febbb1ba4d23..784841caa6e6 100644
--- a/Documentation/acpi/dsdt-override.txt
+++ b/Documentation/acpi/dsdt-override.txt
@@ -4,4 +4,4 @@ CONFIG_ACPI_CUSTOM_DSDT builds the image into the kernel.
When to use this method is described in detail on the
Linux/ACPI home page:
-http://www.lesswatts.org/projects/acpi/overridingDSDT.php
+https://01.org/linux-acpi/documentation/overriding-dsdt
diff --git a/Documentation/acpi/enumeration.txt b/Documentation/acpi/enumeration.txt
index aca4e69121b7..b994bcb32b92 100644
--- a/Documentation/acpi/enumeration.txt
+++ b/Documentation/acpi/enumeration.txt
@@ -295,10 +295,6 @@ 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
we need to translate them to the Linux GPIO numbers.
-The driver can do this by including <linux/acpi_gpio.h> and then calling
-acpi_get_gpio(path, gpio). This will return the Linux GPIO number or
-negative errno if there was no translation found.
-
In a simple case of just getting the Linux GPIO number from device
resources one can use acpi_get_gpio_by_index() helper function. It takes
pointer to the device and index of the GpioIo/GpioInt descriptor in the
@@ -322,3 +318,25 @@ suitable to the gpiolib before passing them.
In case of GpioInt resource an additional call to gpio_to_irq() must be
done before calling request_irq().
+
+Note that the above API is ACPI specific and not recommended for drivers
+that need to support non-ACPI systems. The recommended way is to use
+the descriptor based GPIO interfaces. The above example looks like this
+when converted to the GPIO desc:
+
+ #include <linux/gpio/consumer.h>
+ ...
+
+ struct gpio_desc *irq_desc, *power_desc;
+
+ irq_desc = gpiod_get_index(dev, NULL, 1);
+ if (IS_ERR(irq_desc))
+ /* handle error */
+
+ power_desc = gpiod_get_index(dev, NULL, 0);
+ if (IS_ERR(power_desc))
+ /* handle error */
+
+ /* Now we can use the GPIO descriptors */
+
+See also Documentation/gpio.txt.