diff options
author | David S. Miller <davem@davemloft.net> | 2008-10-01 09:12:56 -0400 |
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committer | David S. Miller <davem@davemloft.net> | 2008-10-01 09:12:56 -0400 |
commit | b262e60309e1b0eb25d300c7e739427d5316abb1 (patch) | |
tree | bf319d78c79bb5cb617ff0c8340c73aa349bba15 /Documentation/ABI/testing/sysfs-gpio | |
parent | 93c8b90f01f0dc73891da4e84b26524b61d29d66 (diff) | |
parent | 0523820482dcb42784572ffd2296c2f08c275a2b (diff) |
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
drivers/net/wireless/ath9k/core.c
drivers/net/wireless/ath9k/main.c
net/core/dev.c
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 | |||