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author | Eric Paris <eparis@redhat.com> | 2014-03-07 11:41:32 -0500 |
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committer | Eric Paris <eparis@redhat.com> | 2014-03-07 11:41:32 -0500 |
commit | b7d3622a39fde7658170b7f3cf6c6889bb8db30d (patch) | |
tree | 64f4e781ecb2a85d675e234072b988560bcd25f1 /Documentation/acpi/enumeration.txt | |
parent | audit: whitespace fix in kernel-parameters.txt (diff) | |
parent | Linux 3.13 (diff) | |
download | linux-dev-b7d3622a39fde7658170b7f3cf6c6889bb8db30d.tar.xz linux-dev-b7d3622a39fde7658170b7f3cf6c6889bb8db30d.zip |
Merge tag 'v3.13' into for-3.15
Linux 3.13
Conflicts:
include/net/xfrm.h
Simple merge where v3.13 removed 'extern' from definitions and the audit
tree did s/u32/unsigned int/ to the same definitions.
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. |