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path: root/drivers/gpio/gpiolib.c
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Diffstat (limited to 'drivers/gpio/gpiolib.c')
-rw-r--r--drivers/gpio/gpiolib.c55
1 files changed, 26 insertions, 29 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index fc19df5a64c2..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);
@@ -1056,24 +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)) {
- ret = gc->get_direction(gc, desc_index);
- if (ret < 0)
- /*
- * FIXME: Bail-out here once all GPIO drivers
- * are updated to not return errors in
- * situations that can be considered normal
- * operation.
- */
- dev_warn(&gdev->dev,
- "%s: get_direction failed: %d\n",
- __func__, ret);
-
- assign_bit(FLAG_IS_OUT, &desc->flags, !ret);
- } 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);
@@ -2712,7 +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)
@@ -2740,12 +2736,12 @@ int gpiod_direction_input_nonotify(struct gpio_desc *desc)
ret = guard.gc->direction_input(guard.gc,
gpio_chip_hwgpio(desc));
} else if (guard.gc->get_direction) {
- ret = guard.gc->get_direction(guard.gc,
+ dir = guard.gc->get_direction(guard.gc,
gpio_chip_hwgpio(desc));
- if (ret < 0)
- return ret;
+ if (dir < 0)
+ return dir;
- if (ret != GPIO_LINE_DIRECTION_IN) {
+ if (dir != GPIO_LINE_DIRECTION_IN) {
gpiod_warn(desc,
"%s: missing direction_input() operation and line is output\n",
__func__);
@@ -2764,7 +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)
@@ -2788,12 +2784,12 @@ static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
} else {
/* Check that we are in output mode if we can */
if (guard.gc->get_direction) {
- ret = guard.gc->get_direction(guard.gc,
+ dir = guard.gc->get_direction(guard.gc,
gpio_chip_hwgpio(desc));
- if (ret < 0)
- return ret;
+ if (dir < 0)
+ return dir;
- if (ret != GPIO_LINE_DIRECTION_OUT) {
+ if (dir != GPIO_LINE_DIRECTION_OUT) {
gpiod_warn(desc,
"%s: missing direction_output() operation\n",
__func__);
@@ -4193,8 +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);
}
/**