diff options
| author | Linus Walleij <linus.walleij@linaro.org> | 2013-09-24 11:54:38 +0200 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2013-10-16 09:59:54 +0200 |
| commit | d468bf9ecaabd3bf3a6134e5a369ced82b1d1ca1 (patch) | |
| tree | 452eaf82c5c50a4673ccd5fccdc1407b1243d03d /include/asm-generic | |
| parent | d27e06ac5dcf60d5502269e1875bcb0f05f1b1c1 (diff) | |
| download | linux-d468bf9ecaabd3bf3a6134e5a369ced82b1d1ca1.tar.bz2 | |
gpio: add API to be strict about GPIO IRQ usage
It is currently often possible in many GPIO drivers to request
a GPIO line to be used as IRQ after calling gpio_to_irq() and,
as the gpiolib is not aware of this, set the same line to
output and start driving it, with undesired side effects.
As it is a bogus usage scenario to request a line flagged as
output to used as IRQ, we introduce APIs to let gpiolib track
the use of a line as IRQ, and also set this flag from the
userspace ABI.
The API is symmetric so that lines can also be flagged from
.irq_enable() and unflagged from IRQ by .irq_disable().
The debugfs file is altered so that we see if a line is
reserved for IRQ.
Cc: Enric Balletbo i Serra <eballetbo@gmail.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'include/asm-generic')
| -rw-r--r-- | include/asm-generic/gpio.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index bde646995d10..b309a5c0019e 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -192,6 +192,9 @@ extern int __gpio_cansleep(unsigned gpio); extern int __gpio_to_irq(unsigned gpio); +extern int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset); +extern void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset); + extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label); extern int gpio_request_array(const struct gpio *array, size_t num); extern void gpio_free_array(const struct gpio *array, size_t num); |