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| author | David S. Miller <davem@davemloft.net> | 2010-12-26 22:37:05 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-12-26 22:37:05 -0800 |
| commit | 17f7f4d9fcce8f1b75b5f735569309dee7665968 (patch) | |
| tree | 14d7e49ca0053a0fcab3c33b5023bf3f90c5c08a /Documentation/gpio.txt | |
| parent | 041110a439e21cd40709ead4ffbfa8034619ad77 (diff) | |
| parent | d7c1255a3a21e98bdc64df8ccf005a174d7e6289 (diff) | |
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
net/ipv4/fib_frontend.c
Diffstat (limited to 'Documentation/gpio.txt')
| -rw-r--r-- | Documentation/gpio.txt | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt index 9633da01ff4..792faa3c06c 100644 --- a/Documentation/gpio.txt +++ b/Documentation/gpio.txt @@ -617,6 +617,16 @@ and have the following read/write attributes: is configured as an output, this value may be written; any nonzero value is treated as high. + If the pin can be configured as interrupt-generating interrupt + and if it has been configured to generate interrupts (see the + description of "edge"), you can poll(2) on that file and + poll(2) will return whenever the interrupt was triggered. If + you use poll(2), set the events POLLPRI and POLLERR. If you + use select(2), set the file descriptor in exceptfds. After + poll(2) returns, either lseek(2) to the beginning of the sysfs + file and read the new value or close the file and re-open it + to read the value. + "edge" ... reads as either "none", "rising", "falling", or "both". Write these strings to select the signal edge(s) that will make poll(2) on the "value" file return. |