gpio: flush direction status in gpiochip_lock_as_irq()
As irqchip and gpiochip functions are orthogonal, the IRQ
set-up or something else can have changed the direction of
the GPIO line from what the GPIO descriptor knows when we
get into gpiochip_lock_as_irq(). Make sure to re-read the
direction setting if we have the .get_direction() callback
enabled for the chip.
Else we get problems like this:
iio iio:device2: interrupts on the rising edge
gpio gpiochip2: (8012e080.gpio): gpiochip_lock_as_irq:
tried to flag a GPIO set as output for IRQ
gpio gpiochip2: (8012e080.gpio): unable to lock HW IRQ 0 for IRQ
genirq: Failed to request resources for l3g4200d-trigger
(irq 111) on irqchip nmk1-32-63
iio iio:device2: failed to request trigger IRQ.
st-gyro-i2c: probe of 2-0068 failed with error -22
Fixes: 72d320006177 ("gpio: set up initial state from .get_direction()")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index d407f904..e901d26 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2066,17 +2066,30 @@
*/
int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
{
- if (offset >= chip->ngpio)
- return -EINVAL;
+ struct gpio_desc *desc;
- if (test_bit(FLAG_IS_OUT, &chip->gpiodev->descs[offset].flags)) {
+ desc = gpiochip_get_desc(chip, offset);
+ if (IS_ERR(desc))
+ return PTR_ERR(desc);
+
+ /* Flush direction if something changed behind our back */
+ if (chip->get_direction) {
+ int dir = chip->get_direction(chip, offset);
+
+ if (dir)
+ clear_bit(FLAG_IS_OUT, &desc->flags);
+ else
+ set_bit(FLAG_IS_OUT, &desc->flags);
+ }
+
+ if (test_bit(FLAG_IS_OUT, &desc->flags)) {
chip_err(chip,
"%s: tried to flag a GPIO set as output for IRQ\n",
__func__);
return -EIO;
}
- set_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
+ set_bit(FLAG_USED_AS_IRQ, &desc->flags);
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);