Tomasz Figa f6a8249f9e pinctrl: exynos: Lock GPIOs as interrupts when used as EINTs ... 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>		2014-08-21 07:24:29 -05:00
..
Kconfig
Makefile
pinctrl-exynos5440.c
pinctrl-exynos.c	pinctrl: exynos: Lock GPIOs as interrupts when used as EINTs	2014-08-21 07:24:29 -05:00
pinctrl-exynos.h
pinctrl-s3c24xx.c
pinctrl-s3c64xx.c
pinctrl-samsung.c
pinctrl-samsung.h	pinctrl: exynos: Lock GPIOs as interrupts when used as EINTs	2014-08-21 07:24:29 -05:00