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| author | Linus Walleij <linus.walleij@linaro.org> | 2023-10-02 10:12:47 +0200 |
|---|---|---|
| committer | Bartosz Golaszewski <bartosz.golaszewski@linaro.org> | 2023-10-04 13:40:44 +0200 |
| commit | 7691ba064b71ffa03bbaefcb2af7ec1e2131eeed (patch) | |
| tree | 8cb5f6c9b54997dde5a1fe0efbbcaf20f3382a20 /Documentation/driver-api | |
| parent | gpio: sysfs: drop the mention of gpiochip_find() from sysfs code (diff) | |
| download | linux-7691ba064b71ffa03bbaefcb2af7ec1e2131eeed.tar.xz linux-7691ba064b71ffa03bbaefcb2af7ec1e2131eeed.zip | |
gpio: Further document optional GPIOLIB
Optional GPIOLIB as in not depended on or selected by a driver
should NOT use any *_optional() calls, this becomes paradoxical.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Diffstat (limited to 'Documentation/driver-api')
| -rw-r--r-- | Documentation/driver-api/gpio/consumer.rst | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/driver-api/gpio/consumer.rst b/Documentation/driver-api/gpio/consumer.rst index de6fc79ad6f0..3e588b9d678c 100644 --- a/Documentation/driver-api/gpio/consumer.rst +++ b/Documentation/driver-api/gpio/consumer.rst @@ -29,6 +29,10 @@ warnings. These stubs are used for two use cases: will use it under other compile-time configurations. In this case the consumer must make sure not to call into these functions, or the user will be met with console warnings that may be perceived as intimidating. + Combining truly optional GPIOLIB usage with calls to + ``[devm_]gpiod_get_optional()`` is a *bad idea*, and will result in weird + error messages. Use the ordinary getter functions with optional GPIOLIB: + some open coding of error handling should be expected when you do this. All the functions that work with the descriptor-based GPIO interface are prefixed with ``gpiod_``. The ``gpio_`` prefix is used for the legacy |