diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 65 |
1 files changed, 42 insertions, 23 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 19878bc75e94..0c00ed2ab431 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1025,7 +1025,8 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, } } - ATOMIC_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier); + rwlock_init(&gdev->line_state_lock); + RAW_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier); BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier); ret = init_srcu_struct(&gdev->srcu); @@ -1056,13 +1057,19 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, desc->gdev = gdev; - if (gc->get_direction && gpiochip_line_is_valid(gc, desc_index)) { - assign_bit(FLAG_IS_OUT, - &desc->flags, !gc->get_direction(gc, desc_index)); - } else { + /* + * We would typically want to check the return value of + * get_direction() here but we must not check the return value + * and bail-out as pin controllers can have pins configured to + * alternate functions and return -EINVAL. Also: there's no + * need to take the SRCU lock here. + */ + if (gc->get_direction && gpiochip_line_is_valid(gc, desc_index)) + assign_bit(FLAG_IS_OUT, &desc->flags, + !gc->get_direction(gc, desc_index)); + else assign_bit(FLAG_IS_OUT, &desc->flags, !gc->direction_input); - } } ret = of_gpiochip_add(gc); @@ -2701,7 +2708,7 @@ EXPORT_SYMBOL_GPL(gpiod_direction_input); int gpiod_direction_input_nonotify(struct gpio_desc *desc) { - int ret = 0; + int ret = 0, dir; CLASS(gpio_chip_guard, guard)(desc); if (!guard.gc) @@ -2728,13 +2735,18 @@ int gpiod_direction_input_nonotify(struct gpio_desc *desc) if (guard.gc->direction_input) { ret = guard.gc->direction_input(guard.gc, gpio_chip_hwgpio(desc)); - } else if (guard.gc->get_direction && - (guard.gc->get_direction(guard.gc, - gpio_chip_hwgpio(desc)) != 1)) { - gpiod_warn(desc, - "%s: missing direction_input() operation and line is output\n", - __func__); - return -EIO; + } else if (guard.gc->get_direction) { + dir = guard.gc->get_direction(guard.gc, + gpio_chip_hwgpio(desc)); + if (dir < 0) + return dir; + + if (dir != GPIO_LINE_DIRECTION_IN) { + gpiod_warn(desc, + "%s: missing direction_input() operation and line is output\n", + __func__); + return -EIO; + } } if (ret == 0) { clear_bit(FLAG_IS_OUT, &desc->flags); @@ -2748,7 +2760,7 @@ int gpiod_direction_input_nonotify(struct gpio_desc *desc) static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value) { - int val = !!value, ret = 0; + int val = !!value, ret = 0, dir; CLASS(gpio_chip_guard, guard)(desc); if (!guard.gc) @@ -2771,12 +2783,18 @@ static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value) gpio_chip_hwgpio(desc), val); } else { /* Check that we are in output mode if we can */ - if (guard.gc->get_direction && - guard.gc->get_direction(guard.gc, gpio_chip_hwgpio(desc))) { - gpiod_warn(desc, - "%s: missing direction_output() operation\n", - __func__); - return -EIO; + if (guard.gc->get_direction) { + dir = guard.gc->get_direction(guard.gc, + gpio_chip_hwgpio(desc)); + if (dir < 0) + return dir; + + if (dir != GPIO_LINE_DIRECTION_OUT) { + gpiod_warn(desc, + "%s: missing direction_output() operation\n", + __func__); + return -EIO; + } } /* * If we can't actively set the direction, we are some @@ -4171,8 +4189,9 @@ EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep); void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action) { - atomic_notifier_call_chain(&desc->gdev->line_state_notifier, - action, desc); + guard(read_lock_irqsave)(&desc->gdev->line_state_lock); + + raw_notifier_call_chain(&desc->gdev->line_state_notifier, action, desc); } /** |