Like the Spreadtrum EIC driver[1], this driver needs to emulate edge
triggered interrupts to support the generic gpio-keys driver.
[1]: https://www.spinics.net/lists/kernel/msg2764576.html
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This patch implements level-triggered IRQs in the Hollywood GPIO driver.
Edge triggered interrupts are not supported in this GPIO controller, so
I moved their emulation into a separate patch.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The Nintendo Wii's chipset (called "Hollywood") has a GPIO controller
that supports a configurable number of pins (up to 32), interrupts, and
some special mechanisms to share the controller between the system's
security processor (an ARM926) and the PowerPC CPU. Pin multiplexing is
not supported.
This patch adds a basic driver for this GPIO controller. Interrupt
support will come in a later patch.
This patch is based on code developed by Albert Herranz and the GameCube
Linux Team, file arch/powerpc/platforms/embedded6xx/hlwd-gpio.c,
available at https://github.com/DeltaResero/GC-Wii-Linux-Kernels, but
has grown quite dissimilar.
v3:
- Do some style cleanups, as suggest by Andy Shevchenko
v2:
- Change hlwd_gpio_driver.driver.name to "gpio-hlwd" to match the
filename (was "hlwd_gpio")
- Remove unnecessary include of linux/of_gpio.h, as suggested by Linus
Walleij.
- Add struct device pointer to context struct to make it possible to use
dev_info(hlwd->dev, "..."), as suggested by Linus Walleij
- Use the GPIO_GENERIC library to reduce code size, as suggested by
Linus Walleij
- Use iowrite32be instead of __raw_writel for big-endian MMIO access, as
suggested by Linus Walleij
- Remove commit message paragraph suggesting to diff against the
original driver, because it's so different now
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Cc: Albert Herranz <albert_herranz@yahoo.es>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
