diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 143 |
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)) |