pinctrl: samsung: Decouple direction setting from pinctrl
This patch makes the pinctrl-samsung driver configure GPIO direction on
its own, without using the pinctrl_gpio_direction_*() "helpers". The
rationale behind this change is as follows:
- pinctrl-samsung does not need translation from GPIO namespace to
pinctrl namespace to handle GPIO operations - GPIO chip and offset
therein are enough to calculate necessary offsets and bit masks in
constant time,
- the pinctrl_gpio_direction_*() functions do not do anything useful
other than translating the pin into pinctrl namespace and calling the
.gpio_set_direction() from pinmux_ops of the controller,
- the undesirable side effect of using those helpers is losing the
ability to change GPIO direction in atomic context, because they
explicitly use a mutex for synchronization,
Results of this patch are:
- fixed warnings about scheduling while atomic in code that needs to
set GPIO direction in atomic context (e.g. interrupt handler),
- reduced overhead of bitbanging drivers that use gpio_direction_*(),
e.g. i2c-gpio.
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
1 file changed