Currently the driver mixes constant init data with runtime data, which
is far from being elegant and can invite potential hard to track issues.
This patch intends to solve this by introducing a new
samsung_pin_bank_data structure to hold only constant data known at
compile time, which can be copied to main samsung_pin_bank struct used
at runtime.
In addition, thanks to this change, all per-bank initdata can be marked
with const and __initconst keywords and dropped after init completes.
Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
In order to separate initialization constants from runtime data, this
patch modifies the driver to store only constant data in
samsung_pin_ctrl struct and copy data required at runtime to
samsung_pinctrl_drv_data struct. This makes it possible to mark all
existing instances of samsung_pin_ctrl struct as const and __initconst.
Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
This structure is not intended to be modified at runtime and functions
as constant data shared between multiple pin banks. This patch makes all
instances of it constant across the driver.
Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
There is no code using it and in fact there are pin controller variants
that do not even have this field initialized in their init data. This
patch removes it completely.
Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
Currently after configuring a GPIO pin as an interrupt related pinmux
registers are changed, but there is no protection from calling
gpio_direction_*() in a badly written driver, which would cause the same
pinmux register to be reconfigured for regular input/output and this
disabling interrupt capability of the pin.
This patch addresses this issue by moving pinmux reconfiguration to
.irq_{request,release}_resources() callback of irq_chip and calling
gpio_lock_as_irq() helper to prevent reconfiguration of pin direction.
Setting up a GPIO interrupt on Samsung SoCs is a two-step operation -
in addition to trigger configuration in a dedicated register, the pinmux
must be also reconfigured to GPIO interrupt, which is a different function
than normal GPIO input, although I/O-wise they both behave in the same way
and gpio_get_value() can be used on a pin configured as IRQ as well.
Such design implies subtleties such as gpio_direction_input() not having
to fail if a pin is already configured as an interrupt nor change the
configuration to normal input. But the FLAG_USED_AS_IRQ set in gpiolib by
gpio_lock_as_irq() is only used to check that gpio_direction_output() is
not called, it's not used to prevent gpio_direction_input() to be called.
So this is not a complete solution for Samsung SoCs but it's definitely a
move in the right direction.
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
[javier: use request resources instead of startup and expand commit message]
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Group all pin control drivers of Samsung platform together in
a sub-directory for easy maintenance.
Signed-off-by: Sachin Kamat <sachin.kamat@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Tomasz Figa