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authorChris Wilson <chris@chris-wilson.co.uk>2010-11-22 08:51:36 +0000
committerChris Wilson <chris@chris-wilson.co.uk>2010-11-22 08:51:36 +0000
commite624ae8e0d4243e71daedce7570e91290438eaca (patch)
treee2b9804379a6aab3d2471898d257fe5590feb70c /Documentation/gpio.txt
parentc4a1d9e4dc5d5313cfec2cc0c9d630efe8a6f287 (diff)
parent4ab0fbd3a29067e1540f05093ae4ed07645d18c8 (diff)
downloadtalos-op-linux-e624ae8e0d4243e71daedce7570e91290438eaca.tar.gz
talos-op-linux-e624ae8e0d4243e71daedce7570e91290438eaca.zip
Merge branch 'drm-intel-fixes' into drm-intel-next
Conflicts: drivers/gpu/drm/i915/i915_gem.c
Diffstat (limited to 'Documentation/gpio.txt')
-rw-r--r--Documentation/gpio.txt10
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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.
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