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| author | Thierry Reding <treding@nvidia.com> | 2014-04-25 17:10:06 +0200 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2014-05-09 13:48:30 +0200 |
| commit | 29a1f2333e07bbbecb920cc78fd035fe8f53207a (patch) | |
| tree | b2cb50d4c41ff4d1337cca888da3840f6f0d4d84 /Documentation/driver-model | |
| parent | 91329132c909bbeb27699556b98b7f745ddb2ed9 (diff) | |
| download | lwn-29a1f2333e07bbbecb920cc78fd035fe8f53207a.tar.gz lwn-29a1f2333e07bbbecb920cc78fd035fe8f53207a.zip | |
gpio: Add helpers for optional GPIOs
Introduce gpiod_get_optional() and gpiod_get_index_optional() helpers
that make it easier for drivers to handle optional GPIOs.
Currently in order to handle optional GPIOs, a driver needs to special
case error handling for -ENOENT, such as this:
gpio = gpiod_get(dev, "foo");
if (IS_ERR(gpio)) {
if (PTR_ERR(gpio) != -ENOENT)
return PTR_ERR(gpio);
gpio = NULL;
}
if (gpio) {
/* set up GPIO */
}
With these new helpers the above is reduced to:
gpio = gpiod_get_optional(dev, "foo");
if (IS_ERR(gpio))
return PTR_ERR(gpio);
if (gpio) {
/* set up GPIO */
}
While at it, device-managed variants of these functions are also
provided.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'Documentation/driver-model')
| -rw-r--r-- | Documentation/driver-model/devres.txt | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index 8ff1167cfedf..10b8c5d2c797 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -312,4 +312,6 @@ SPI GPIO devm_gpiod_get() devm_gpiod_get_index() + devm_gpiod_get_optional() + devm_gpiod_get_index_optional() devm_gpiod_put() |