diff options
| author | Geert Uytterhoeven <geert+renesas@glider.be> | 2020-05-11 12:18:28 +0200 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2020-05-16 11:37:35 +0200 |
| commit | 582838ea5bea41258d136c82a6c493a95cda652c (patch) | |
| tree | 1e79ffd92747744ab3717b63289f702af28ce7ea /drivers/gpio | |
| parent | ed43f2b4e78069ee02687e5a562e1ecd15cbef4f (diff) | |
| download | linux-582838ea5bea41258d136c82a6c493a95cda652c.tar.bz2 | |
gpiolib: Document that GPIO line names are not globally unique
gpiochip_set_desc_names() no longer rejects GPIO line name collisions.
Hence GPIO line names are not guaranteed to be globally unique.
In case of multiple GPIO lines with the same name, gpio_name_to_desc()
will return the first match found.
Update the comments for gpio_name_to_desc() and
gpiochip_set_desc_names() to match reality.
Fixes: f881bab038c9667d ("gpio: keep the GPIO line names internal")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200511101828.30046-1-geert+renesas@glider.be
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 48b4f70e2898..fe5f14a417bd 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -296,6 +296,9 @@ static int gpiodev_add_to_list(struct gpio_device *gdev) /* * Convert a GPIO name to its descriptor + * Note that there is no guarantee that GPIO names are globally unique! + * Hence this function will return, if it exists, a reference to the first GPIO + * line found that matches the given name. */ static struct gpio_desc *gpio_name_to_desc(const char * const name) { @@ -329,10 +332,12 @@ static struct gpio_desc *gpio_name_to_desc(const char * const name) } /* - * Takes the names from gc->names and checks if they are all unique. If they - * are, they are assigned to their gpio descriptors. + * Take the names from gc->names and assign them to their GPIO descriptors. + * Warn if a name is already used for a GPIO line on a different GPIO chip. * - * Warning if one of the names is already used for a different GPIO. + * Note that: + * 1. Non-unique names are still accepted, + * 2. Name collisions within the same GPIO chip are not reported. */ static int gpiochip_set_desc_names(struct gpio_chip *gc) { |