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author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2008-10-14 20:31:54 -0400 |
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committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2008-10-14 20:31:54 -0400 |
commit | 6dc6472581f693b5fc95aebedf67b4960fb85cf0 (patch) | |
tree | 06a5a9a08519950575505273eabced331ed51405 /Documentation/ABI/testing/sysfs-gpio | |
parent | ee673eaa72d8d185012b1027a05e25aba18c267f (diff) | |
parent | 8acd3a60bcca17c6d89c73cee3ad6057eb83ba1e (diff) |
Merge commit 'origin'
Manual fixup of conflicts on:
arch/powerpc/include/asm/dcr-regs.h
drivers/net/ibm_newemac/core.h
Diffstat (limited to 'Documentation/ABI/testing/sysfs-gpio')
-rw-r--r-- | Documentation/ABI/testing/sysfs-gpio | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-gpio b/Documentation/ABI/testing/sysfs-gpio new file mode 100644 index 000000000000..8aab8092ad35 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-gpio | |||
@@ -0,0 +1,26 @@ | |||
1 | What: /sys/class/gpio/ | ||
2 | Date: July 2008 | ||
3 | KernelVersion: 2.6.27 | ||
4 | Contact: David Brownell <dbrownell@users.sourceforge.net> | ||
5 | Description: | ||
6 | |||
7 | As a Kconfig option, individual GPIO signals may be accessed from | ||
8 | userspace. GPIOs are only made available to userspace by an explicit | ||
9 | "export" operation. If a given GPIO is not claimed for use by | ||
10 | kernel code, it may be exported by userspace (and unexported later). | ||
11 | Kernel code may export it for complete or partial access. | ||
12 | |||
13 | GPIOs are identified as they are inside the kernel, using integers in | ||
14 | the range 0..INT_MAX. See Documentation/gpio.txt for more information. | ||
15 | |||
16 | /sys/class/gpio | ||
17 | /export ... asks the kernel to export a GPIO to userspace | ||
18 | /unexport ... to return a GPIO to the kernel | ||
19 | /gpioN ... for each exported GPIO #N | ||
20 | /value ... always readable, writes fail for input GPIOs | ||
21 | /direction ... r/w as: in, out (default low); write: high, low | ||
22 | /gpiochipN ... for each gpiochip; #N is its first GPIO | ||
23 | /base ... (r/o) same as N | ||
24 | /label ... (r/o) descriptive, not necessarily unique | ||
25 | /ngpio ... (r/o) number of GPIOs; numbered N to N + (ngpio - 1) | ||
26 | |||