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authorOlof Johansson <olof@lixom.net>2013-11-15 15:17:59 -0800
committerOlof Johansson <olof@lixom.net>2013-11-15 15:17:59 -0800
commit6886059f2ef5d62c73e87a905e84fa4f87d56074 (patch)
treedfe6e1611d7c50057df52db7b55eafbfb8e33a93 /Documentation/acpi/enumeration.txt
parentca439c9b983ffa14e9eae6030e3ee80ad039388f (diff)
parent26273e02a0cf18eb72416559310d3294390a9024 (diff)
Merge tag 'omap-for-v3.13/fixes-for-merge-window-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes
Few clock fixes, a runtime PM fix, and pinctrl-single fix along with few other fixes that popped up during the merge window. * tag 'omap-for-v3.13/fixes-for-merge-window-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap: ARM: OMAP2+: Fix build for dra7xx without omap4 and 5 ARM: OMAP2+: omap_device: maintain sane runtime pm status around suspend/resume doc: devicetree: Add bindings documentation for omap-des driver ARM: dts: doc: Document missing compatible property for omap-sham driver ARM: OMAP3: Beagle: fix return value check in beagle_opp_init() ARM: OMAP: devicetree: fix SPI node compatible property syntax items pinctrl: single: call pcs_soc->rearm() whenever IRQ mask is changed ARM: OMAP2+: smsc911x: fix return value check in gpmc_smsc911x_init() + sync with newer trunk
Diffstat (limited to 'Documentation/acpi/enumeration.txt')
-rw-r--r--Documentation/acpi/enumeration.txt26
1 files changed, 22 insertions, 4 deletions
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.