diff options
author | Olof Johansson <olof@lixom.net> | 2013-11-15 15:17:59 -0800 |
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committer | Olof Johansson <olof@lixom.net> | 2013-11-15 15:17:59 -0800 |
commit | 6886059f2ef5d62c73e87a905e84fa4f87d56074 (patch) | |
tree | dfe6e1611d7c50057df52db7b55eafbfb8e33a93 /Documentation/acpi/enumeration.txt | |
parent | ca439c9b983ffa14e9eae6030e3ee80ad039388f (diff) | |
parent | 26273e02a0cf18eb72416559310d3294390a9024 (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.txt | 26 |
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. |