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authorJ. Bruce Fields <bfields@redhat.com>2010-12-17 13:29:07 -0500
committerJ. Bruce Fields <bfields@redhat.com>2010-12-17 13:29:07 -0500
commitec66ee3797e5848356cf593c6ec7aabf30a00cf1 (patch)
tree7ed5c84cc914644ffa1cd1b6a2b45db53fc224e8 /Documentation/gpio.txt
parent1205065764f2eda3216ebe213143f69891ee3460 (diff)
parentb0c3844d8af6b9f3f18f31e1b0502fbefa2166be (diff)
downloadop-kernel-dev-ec66ee3797e5848356cf593c6ec7aabf30a00cf1.zip
op-kernel-dev-ec66ee3797e5848356cf593c6ec7aabf30a00cf1.tar.gz
Merge commit 'v2.6.37-rc6' into for-2.6.38
Diffstat (limited to 'Documentation/gpio.txt')
-rw-r--r--Documentation/gpio.txt10
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt
index 9633da0..792faa3 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.
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