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| author | Paul Mundt <lethal@linux-sh.org> | 2010-11-24 16:21:08 +0900 |
|---|---|---|
| committer | Paul Mundt <lethal@linux-sh.org> | 2010-11-24 16:21:08 +0900 |
| commit | 540565257101f7c52b6fc5a57651f7505f8d20fe (patch) | |
| tree | 7adee0bc65a02fead0dd9cae4f2d4632b227ac56 /Documentation/gpio.txt | |
| parent | 4d048435e9864998f6a6ad16422393d42322716d (diff) | |
| parent | 421b446abeec55bed1251fab80cb5c12be58b773 (diff) | |
| download | linux-540565257101f7c52b6fc5a57651f7505f8d20fe.tar.gz linux-540565257101f7c52b6fc5a57651f7505f8d20fe.tar.bz2 linux-540565257101f7c52b6fc5a57651f7505f8d20fe.zip | |
Merge branch 'rmobile/fsi-despair' into rmobile-fixes-for-linus
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 9633da01ff46..792faa3c06cf 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. |