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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.c143
1 files changed, 82 insertions, 61 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index fff9786cdc6..c2534d62911 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -88,13 +88,14 @@ static int gpiod_request(struct gpio_desc *desc, const char *label);
static void gpiod_free(struct gpio_desc *desc);
static int gpiod_direction_input(struct gpio_desc *desc);
static int gpiod_direction_output(struct gpio_desc *desc, int value);
+static int gpiod_get_direction(const struct gpio_desc *desc);
static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce);
-static int gpiod_get_value_cansleep(struct gpio_desc *desc);
+static int gpiod_get_value_cansleep(const struct gpio_desc *desc);
static void gpiod_set_value_cansleep(struct gpio_desc *desc, int value);
-static int gpiod_get_value(struct gpio_desc *desc);
+static int gpiod_get_value(const struct gpio_desc *desc);
static void gpiod_set_value(struct gpio_desc *desc, int value);
-static int gpiod_cansleep(struct gpio_desc *desc);
-static int gpiod_to_irq(struct gpio_desc *desc);
+static int gpiod_cansleep(const struct gpio_desc *desc);
+static int gpiod_to_irq(const struct gpio_desc *desc);
static int gpiod_export(struct gpio_desc *desc, bool direction_may_change);
static int gpiod_export_link(struct device *dev, const char *name,
struct gpio_desc *desc);
@@ -171,12 +172,12 @@ static int gpio_ensure_requested(struct gpio_desc *desc)
return 0;
}
-/* caller holds gpio_lock *OR* gpio is marked as requested */
-static struct gpio_chip *gpiod_to_chip(struct gpio_desc *desc)
+static struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
{
- return desc->chip;
+ return desc ? desc->chip : NULL;
}
+/* caller holds gpio_lock *OR* gpio is marked as requested */
struct gpio_chip *gpio_to_chip(unsigned gpio)
{
return gpiod_to_chip(gpio_to_desc(gpio));
@@ -207,7 +208,7 @@ static int gpiochip_find_base(int ngpio)
}
/* caller ensures gpio is valid and requested, chip->get_direction may sleep */
-static int gpiod_get_direction(struct gpio_desc *desc)
+static int gpiod_get_direction(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
unsigned offset;
@@ -223,11 +224,13 @@ static int gpiod_get_direction(struct gpio_desc *desc)
if (status > 0) {
/* GPIOF_DIR_IN, or other positive */
status = 1;
- clear_bit(FLAG_IS_OUT, &desc->flags);
+ /* FLAG_IS_OUT is just a cache of the result of get_direction(),
+ * so it does not affect constness per se */
+ clear_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags);
}
if (status == 0) {
/* GPIOF_DIR_OUT */
- set_bit(FLAG_IS_OUT, &desc->flags);
+ set_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags);
}
return status;
}
@@ -263,7 +266,7 @@ static DEFINE_MUTEX(sysfs_lock);
static ssize_t gpio_direction_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- struct gpio_desc *desc = dev_get_drvdata(dev);
+ const struct gpio_desc *desc = dev_get_drvdata(dev);
ssize_t status;
mutex_lock(&sysfs_lock);
@@ -654,6 +657,11 @@ static ssize_t export_store(struct class *class,
goto done;
desc = gpio_to_desc(gpio);
+ /* reject invalid GPIOs */
+ if (!desc) {
+ pr_warn("%s: invalid GPIO %ld\n", __func__, gpio);
+ return -EINVAL;
+ }
/* No extra locking here; FLAG_SYSFS just signifies that the
* request and export were done by on behalf of userspace, so
@@ -690,12 +698,14 @@ static ssize_t unexport_store(struct class *class,
if (status < 0)
goto done;
- status = -EINVAL;
-
desc = gpio_to_desc(gpio);
/* reject bogus commands (gpio_unexport ignores them) */
- if (!desc)
- goto done;
+ if (!desc) {
+ pr_warn("%s: invalid GPIO %ld\n", __func__, gpio);
+ return -EINVAL;
+ }
+
+ status = -EINVAL;
/* No extra locking here; FLAG_SYSFS just signifies that the
* request and export were done by on behalf of userspace, so
@@ -846,8 +856,10 @@ static int gpiod_export_link(struct device *dev, const char *name,
{
int status = -EINVAL;
- if (!desc)
- goto done;
+ if (!desc) {
+ pr_warn("%s: invalid GPIO\n", __func__);
+ return -EINVAL;
+ }
mutex_lock(&sysfs_lock);
@@ -865,7 +877,6 @@ static int gpiod_export_link(struct device *dev, const char *name,
mutex_unlock(&sysfs_lock);
-done:
if (status)
pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc),
status);
@@ -896,8 +907,10 @@ static int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value)
struct device *dev = NULL;
int status = -EINVAL;
- if (!desc)
- goto done;
+ if (!desc) {
+ pr_warn("%s: invalid GPIO\n", __func__);
+ return -EINVAL;
+ }
mutex_lock(&sysfs_lock);
@@ -914,7 +927,6 @@ static int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value)
unlock:
mutex_unlock(&sysfs_lock);
-done:
if (status)
pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc),
status);
@@ -940,8 +952,8 @@ static void gpiod_unexport(struct gpio_desc *desc)
struct device *dev = NULL;
if (!desc) {
- status = -EINVAL;
- goto done;
+ pr_warn("%s: invalid GPIO\n", __func__);
+ return;
}
mutex_lock(&sysfs_lock);
@@ -962,7 +974,7 @@ static void gpiod_unexport(struct gpio_desc *desc)
device_unregister(dev);
put_device(dev);
}
-done:
+
if (status)
pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc),
status);
@@ -1384,12 +1396,13 @@ static int gpiod_request(struct gpio_desc *desc, const char *label)
int status = -EPROBE_DEFER;
unsigned long flags;
- spin_lock_irqsave(&gpio_lock, flags);
-
if (!desc) {
- status = -EINVAL;
- goto done;
+ pr_warn("%s: invalid GPIO\n", __func__);
+ return -EINVAL;
}
+
+ spin_lock_irqsave(&gpio_lock, flags);
+
chip = desc->chip;
if (chip == NULL)
goto done;
@@ -1432,8 +1445,7 @@ static int gpiod_request(struct gpio_desc *desc, const char *label)
done:
if (status)
pr_debug("_gpio_request: gpio-%d (%s) status %d\n",
- desc ? desc_to_gpio(desc) : -1,
- label ? : "?", status);
+ desc_to_gpio(desc), label ? : "?", status);
spin_unlock_irqrestore(&gpio_lock, flags);
return status;
}
@@ -1616,10 +1628,13 @@ static int gpiod_direction_input(struct gpio_desc *desc)
int status = -EINVAL;
int offset;
+ if (!desc) {
+ pr_warn("%s: invalid GPIO\n", __func__);
+ return -EINVAL;
+ }
+
spin_lock_irqsave(&gpio_lock, flags);
- if (!desc)
- goto fail;
chip = desc->chip;
if (!chip || !chip->get || !chip->direction_input)
goto fail;
@@ -1655,13 +1670,9 @@ lose:
return status;
fail:
spin_unlock_irqrestore(&gpio_lock, flags);
- if (status) {
- int gpio = -1;
- if (desc)
- gpio = desc_to_gpio(desc);
- pr_debug("%s: gpio-%d status %d\n",
- __func__, gpio, status);
- }
+ if (status)
+ pr_debug("%s: gpio-%d status %d\n", __func__,
+ desc_to_gpio(desc), status);
return status;
}
@@ -1678,6 +1689,11 @@ static int gpiod_direction_output(struct gpio_desc *desc, int value)
int status = -EINVAL;
int offset;
+ if (!desc) {
+ pr_warn("%s: invalid GPIO\n", __func__);
+ return -EINVAL;
+ }
+
/* Open drain pin should not be driven to 1 */
if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags))
return gpiod_direction_input(desc);
@@ -1688,8 +1704,6 @@ static int gpiod_direction_output(struct gpio_desc *desc, int value)
spin_lock_irqsave(&gpio_lock, flags);
- if (!desc)
- goto fail;
chip = desc->chip;
if (!chip || !chip->set || !chip->direction_output)
goto fail;
@@ -1725,13 +1739,9 @@ lose:
return status;
fail:
spin_unlock_irqrestore(&gpio_lock, flags);
- if (status) {
- int gpio = -1;
- if (desc)
- gpio = desc_to_gpio(desc);
- pr_debug("%s: gpio-%d status %d\n",
- __func__, gpio, status);
- }
+ if (status)
+ pr_debug("%s: gpio-%d status %d\n", __func__,
+ desc_to_gpio(desc), status);
return status;
}
@@ -1753,10 +1763,13 @@ static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
int status = -EINVAL;
int offset;
+ if (!desc) {
+ pr_warn("%s: invalid GPIO\n", __func__);
+ return -EINVAL;
+ }
+
spin_lock_irqsave(&gpio_lock, flags);
- if (!desc)
- goto fail;
chip = desc->chip;
if (!chip || !chip->set || !chip->set_debounce)
goto fail;
@@ -1776,13 +1789,9 @@ static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
fail:
spin_unlock_irqrestore(&gpio_lock, flags);
- if (status) {
- int gpio = -1;
- if (desc)
- gpio = desc_to_gpio(desc);
- pr_debug("%s: gpio-%d status %d\n",
- __func__, gpio, status);
- }
+ if (status)
+ pr_debug("%s: gpio-%d status %d\n", __func__,
+ desc_to_gpio(desc), status);
return status;
}
@@ -1824,12 +1833,14 @@ EXPORT_SYMBOL_GPL(gpio_set_debounce);
* It returns the zero or nonzero value provided by the associated
* gpio_chip.get() method; or zero if no such method is provided.
*/
-static int gpiod_get_value(struct gpio_desc *desc)
+static int gpiod_get_value(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
int value;
int offset;
+ if (!desc)
+ return 0;
chip = desc->chip;
offset = gpio_chip_hwgpio(desc);
/* Should be using gpio_get_value_cansleep() */
@@ -1912,6 +1923,8 @@ static void gpiod_set_value(struct gpio_desc *desc, int value)
{
struct gpio_chip *chip;
+ if (!desc)
+ return;
chip = desc->chip;
/* Should be using gpio_set_value_cansleep() */
WARN_ON(chip->can_sleep);
@@ -1938,8 +1951,10 @@ EXPORT_SYMBOL_GPL(__gpio_set_value);
* This is used directly or indirectly to implement gpio_cansleep(). It
* returns nonzero if access reading or writing the GPIO value can sleep.
*/
-static int gpiod_cansleep(struct gpio_desc *desc)
+static int gpiod_cansleep(const struct gpio_desc *desc)
{
+ if (!desc)
+ return 0;
/* only call this on GPIOs that are valid! */
return desc->chip->can_sleep;
}
@@ -1959,11 +1974,13 @@ EXPORT_SYMBOL_GPL(__gpio_cansleep);
* It returns the number of the IRQ signaled by this (input) GPIO,
* or a negative errno.
*/
-static int gpiod_to_irq(struct gpio_desc *desc)
+static int gpiod_to_irq(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
int offset;
+ if (!desc)
+ return -EINVAL;
chip = desc->chip;
offset = gpio_chip_hwgpio(desc);
return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO;
@@ -1980,13 +1997,15 @@ EXPORT_SYMBOL_GPL(__gpio_to_irq);
* Common examples include ones connected to I2C or SPI chips.
*/
-static int gpiod_get_value_cansleep(struct gpio_desc *desc)
+static int gpiod_get_value_cansleep(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
int value;
int offset;
might_sleep_if(extra_checks);
+ if (!desc)
+ return 0;
chip = desc->chip;
offset = gpio_chip_hwgpio(desc);
value = chip->get ? chip->get(chip, offset) : 0;
@@ -2005,6 +2024,8 @@ static void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
struct gpio_chip *chip;
might_sleep_if(extra_checks);
+ if (!desc)
+ return;
chip = desc->chip;
trace_gpio_value(desc_to_gpio(desc), 0, value);
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-27 00:08:01 +0000