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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.c119
1 files changed, 78 insertions, 41 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 679ed764cb14..0c00ed2ab431 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -904,13 +904,13 @@ int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev)
}
if (gc->ngpio == 0) {
- chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
+ dev_err(dev, "tried to insert a GPIO chip with zero lines\n");
return -EINVAL;
}
if (gc->ngpio > FASTPATH_NGPIO)
- chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n",
- gc->ngpio, FASTPATH_NGPIO);
+ dev_warn(dev, "line cnt %u is greater than fast path cnt %u\n",
+ gc->ngpio, FASTPATH_NGPIO);
return 0;
}
@@ -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
@@ -3129,6 +3147,8 @@ static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
static int gpio_chip_get_multiple(struct gpio_chip *gc,
unsigned long *mask, unsigned long *bits)
{
+ lockdep_assert_held(&gc->gpiodev->srcu);
+
if (gc->get_multiple)
return gc->get_multiple(gc, mask, bits);
if (gc->get) {
@@ -3159,6 +3179,7 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
+ struct gpio_chip *gc;
int ret, i = 0;
/*
@@ -3170,10 +3191,15 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep,
array_size <= array_info->size &&
(void *)array_info == desc_array + array_info->size) {
if (!can_sleep)
- WARN_ON(array_info->chip->can_sleep);
+ WARN_ON(array_info->gdev->can_sleep);
- ret = gpio_chip_get_multiple(array_info->chip,
- array_info->get_mask,
+ guard(srcu)(&array_info->gdev->srcu);
+ gc = srcu_dereference(array_info->gdev->chip,
+ &array_info->gdev->srcu);
+ if (!gc)
+ return -ENODEV;
+
+ ret = gpio_chip_get_multiple(gc, array_info->get_mask,
value_bitmap);
if (ret)
return ret;
@@ -3454,6 +3480,8 @@ static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
static void gpio_chip_set_multiple(struct gpio_chip *gc,
unsigned long *mask, unsigned long *bits)
{
+ lockdep_assert_held(&gc->gpiodev->srcu);
+
if (gc->set_multiple) {
gc->set_multiple(gc, mask, bits);
} else {
@@ -3471,6 +3499,7 @@ int gpiod_set_array_value_complex(bool raw, bool can_sleep,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
+ struct gpio_chip *gc;
int i = 0;
/*
@@ -3482,14 +3511,19 @@ int gpiod_set_array_value_complex(bool raw, bool can_sleep,
array_size <= array_info->size &&
(void *)array_info == desc_array + array_info->size) {
if (!can_sleep)
- WARN_ON(array_info->chip->can_sleep);
+ WARN_ON(array_info->gdev->can_sleep);
+
+ guard(srcu)(&array_info->gdev->srcu);
+ gc = srcu_dereference(array_info->gdev->chip,
+ &array_info->gdev->srcu);
+ if (!gc)
+ return -ENODEV;
if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
bitmap_xor(value_bitmap, value_bitmap,
array_info->invert_mask, array_size);
- gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
- value_bitmap);
+ gpio_chip_set_multiple(gc, array_info->set_mask, value_bitmap);
i = find_first_zero_bit(array_info->set_mask, array_size);
if (i == array_size)
@@ -4155,8 +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);
}
/**
@@ -4751,9 +4786,10 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
{
struct gpio_desc *desc;
struct gpio_descs *descs;
+ struct gpio_device *gdev;
struct gpio_array *array_info = NULL;
- struct gpio_chip *gc;
int count, bitmap_size;
+ unsigned long dflags;
size_t descs_size;
count = gpiod_count(dev, con_id);
@@ -4774,7 +4810,7 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
descs->desc[descs->ndescs] = desc;
- gc = gpiod_to_chip(desc);
+ gdev = gpiod_to_gpio_device(desc);
/*
* If pin hardware number of array member 0 is also 0, select
* its chip as a candidate for fast bitmap processing path.
@@ -4782,8 +4818,8 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
struct gpio_descs *array;
- bitmap_size = BITS_TO_LONGS(gc->ngpio > count ?
- gc->ngpio : count);
+ bitmap_size = BITS_TO_LONGS(gdev->ngpio > count ?
+ gdev->ngpio : count);
array = krealloc(descs, descs_size +
struct_size(array_info, invert_mask, 3 * bitmap_size),
@@ -4803,7 +4839,7 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
array_info->desc = descs->desc;
array_info->size = count;
- array_info->chip = gc;
+ array_info->gdev = gdev;
bitmap_set(array_info->get_mask, descs->ndescs,
count - descs->ndescs);
bitmap_set(array_info->set_mask, descs->ndescs,
@@ -4816,7 +4852,7 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
continue;
/* Unmark array members which don't belong to the 'fast' chip */
- if (array_info->chip != gc) {
+ if (array_info->gdev != gdev) {
__clear_bit(descs->ndescs, array_info->get_mask);
__clear_bit(descs->ndescs, array_info->set_mask);
}
@@ -4839,9 +4875,10 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
array_info->set_mask);
}
} else {
+ dflags = READ_ONCE(desc->flags);
/* Exclude open drain or open source from fast output */
- if (gpiochip_line_is_open_drain(gc, descs->ndescs) ||
- gpiochip_line_is_open_source(gc, descs->ndescs))
+ if (test_bit(FLAG_OPEN_DRAIN, &dflags) ||
+ test_bit(FLAG_OPEN_SOURCE, &dflags))
__clear_bit(descs->ndescs,
array_info->set_mask);
/* Identify 'fast' pins which require invertion */
@@ -4853,7 +4890,7 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
if (array_info)
dev_dbg(dev,
"GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
- array_info->chip->label, array_info->size,
+ array_info->gdev->label, array_info->size,
*array_info->get_mask, *array_info->set_mask,
*array_info->invert_mask);
return descs;
generated by cgit v1.2.3 (git 2.46.0) at 2025-07-02 00:02:02 +0000