leds: leds-gpio: set devm_gpio_request_one() flags param correctly
commit a99d76f leds: leds-gpio: use gpio_request_one
changed the leds-gpio driver to use gpio_request_one() instead
of gpio_request() + gpio_direction_output()
Unfortunately, it also made a semantic change that breaks the
leds-gpio driver.
The gpio_request_one() flags parameter was set to:
GPIOF_DIR_OUT | (led_dat->active_low ^ state)
Since GPIOF_DIR_OUT is 0, the final flags value will just be the
XOR'ed value of led_dat->active_low and state.
This value were used to distinguish between HIGH/LOW output initial
level and call gpio_direction_output() accordingly.
With this new semantic gpio_request_one() will take the flags value
of 1 as a configuration of input direction (GPIOF_DIR_IN) and will
call gpio_direction_input() instead of gpio_direction_output().
int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
{
..
if (flags & GPIOF_DIR_IN)
err = gpio_direction_input(gpio);
else
err = gpio_direction_output(gpio,
(flags & GPIOF_INIT_HIGH) ? 1 : 0);
..
}
The right semantic is to evaluate led_dat->active_low ^ state and
set the output initial level explicitly.
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reported-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
1 file changed
