diff options
| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2014-03-18 09:43:56 +0100 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2014-03-18 09:43:56 +0100 |
| commit | e19b9137142988bec5a76c5f8bdf12a77ea802b0 (patch) | |
| tree | b36c83fa93da7f18c1331252fb82a87431697443 /Documentation/gpio/consumer.txt | |
| parent | 2fae6a860ca9adb0c881f6dcd633df775c2520e9 (diff) | |
| parent | e40d641099213145a034981e646dc2180a488152 (diff) | |
Merge remote-tracking branch 'airlied/drm-next' into drm-intel-next
Conflicts:
drivers/gpu/drm/i915/Makefile
Makefile cleanup in drm-intel-next conflicts with a build-fix to move
intel_opregion under CONFIG_ACPI.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'Documentation/gpio/consumer.txt')
| -rw-r--r-- | Documentation/gpio/consumer.txt | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt index 07c74a3765a..e42f77d8d4c 100644 --- a/Documentation/gpio/consumer.txt +++ b/Documentation/gpio/consumer.txt @@ -38,7 +38,11 @@ device that displays digits), an additional index argument can be specified: const char *con_id, unsigned int idx) Both functions return either a valid GPIO descriptor, or an error code checkable -with IS_ERR(). They will never return a NULL pointer. +with IS_ERR() (they will never return a NULL pointer). -ENOENT will be returned +if and only if no GPIO has been assigned to the device/function/index triplet, +other error codes are used for cases where a GPIO has been assigned but an error +occured while trying to acquire it. This is useful to discriminate between mere +errors and an absence of GPIO for optional GPIO parameters. Device-managed variants of these functions are also defined: |