summaryrefslogtreecommitdiffstats
path: root/Documentation/ABI/testing/gpio-cdev
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/ABI/testing/gpio-cdev')
-rw-r--r--Documentation/ABI/testing/gpio-cdev27
1 files changed, 27 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/gpio-cdev b/Documentation/ABI/testing/gpio-cdev
new file mode 100644
index 000000000..66bdcd188
--- /dev/null
+++ b/Documentation/ABI/testing/gpio-cdev
@@ -0,0 +1,27 @@
+What: /dev/gpiochip[0-9]+
+Date: November 2015
+KernelVersion: 4.4
+Contact: linux-gpio@vger.kernel.org
+Description:
+ The character device files /dev/gpiochip* are the interface
+ between GPIO chips and userspace.
+
+ The ioctl(2)-based ABI is defined and documented in
+ [include/uapi]<linux/gpio.h>.
+
+ The following file operations are supported:
+
+ open(2)
+ Currently the only useful flags are O_RDWR.
+
+ ioctl(2)
+ Initiate various actions.
+
+ See the inline documentation in [include/uapi]<linux/gpio.h>
+ for descriptions of all ioctls.
+
+ close(2)
+ Stops and free up the I/O contexts that was associated
+ with the file descriptor.
+
+Users: TBD