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/linux/gpio.h | |
| parent | d27e06ac5dcf60d5502269e1875bcb0f05f1b1c1 (diff) | |
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/linux/gpio.h')
| -rw-r--r-- | include/linux/gpio.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/include/linux/gpio.h b/include/linux/gpio.h index 552e3f46e4a3..a06ec3e85ba3 100644 --- a/include/linux/gpio.h +++ b/include/linux/gpio.h @@ -204,6 +204,18 @@ static inline int gpio_to_irq(unsigned gpio) return -EINVAL; } +static inline int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset) +{ + WARN_ON(1); + return -EINVAL; +} + +static inline void gpio_unlock_as_irq(struct gpio_chip *chip, + unsigned int offset) +{ + WARN_ON(1); +} + static inline int irq_to_gpio(unsigned irq) { /* irq can never have been returned from gpio_to_irq() */ |