diff options
| -rw-r--r-- | drivers/gpio/gpiolib-legacy.c | 106 | ||||
| -rw-r--r-- | drivers/gpio/gpiolib.c | 129 | ||||
| -rw-r--r-- | include/asm-generic/gpio.h | 15 |
3 files changed, 113 insertions, 137 deletions
diff --git a/drivers/gpio/gpiolib-legacy.c b/drivers/gpio/gpiolib-legacy.c index 078ae6c2df79..0f9429b2522a 100644 --- a/drivers/gpio/gpiolib-legacy.c +++ b/drivers/gpio/gpiolib-legacy.c @@ -5,6 +5,64 @@ #include "gpiolib.h" +/* Warn when drivers omit gpio_request() calls -- legal but ill-advised + * when setting direction, and otherwise illegal. Until board setup code + * and drivers use explicit requests everywhere (which won't happen when + * those calls have no teeth) we can't avoid autorequesting. This nag + * message should motivate switching to explicit requests... so should + * the weaker cleanup after faults, compared to gpio_request(). + * + * NOTE: the autorequest mechanism is going away; at this point it's + * only "legal" in the sense that (old) code using it won't break yet, + * but instead only triggers a WARN() stack dump. + */ +static int gpio_ensure_requested(struct gpio_desc *desc) +{ + struct gpio_chip *chip = desc->chip; + unsigned long flags; + bool request = false; + int err = 0; + + spin_lock_irqsave(&gpio_lock, flags); + + if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0, + "autorequest GPIO-%d\n", desc_to_gpio(desc))) { + if (!try_module_get(chip->owner)) { + gpiod_err(desc, "%s: module can't be gotten\n", + __func__); + clear_bit(FLAG_REQUESTED, &desc->flags); + /* lose */ + err = -EIO; + goto end; + } + desc->label = "[auto]"; + /* caller must chip->request() w/o spinlock */ + if (chip->request) + request = true; + } + +end: + spin_unlock_irqrestore(&gpio_lock, flags); + + if (request) { + might_sleep_if(chip->can_sleep); + err = chip->request(chip, gpio_chip_hwgpio(desc)); + + if (err < 0) { + gpiod_dbg(desc, "%s: chip request fail, %d\n", + __func__, err); + spin_lock_irqsave(&gpio_lock, flags); + + desc->label = NULL; + clear_bit(FLAG_REQUESTED, &desc->flags); + + spin_unlock_irqrestore(&gpio_lock, flags); + } + } + + return err; +} + void gpio_free(unsigned gpio) { gpiod_free(gpio_to_desc(gpio)); @@ -100,3 +158,51 @@ void gpio_free_array(const struct gpio *array, size_t num) gpio_free((array++)->gpio); } EXPORT_SYMBOL_GPL(gpio_free_array); + +int gpio_direction_input(unsigned gpio) +{ + struct gpio_desc *desc = gpio_to_desc(gpio); + int err; + + if (!desc) + return -EINVAL; + + err = gpio_ensure_requested(desc); + if (err < 0) + return err; + + return gpiod_direction_input(desc); +} +EXPORT_SYMBOL_GPL(gpio_direction_input); + +int gpio_direction_output(unsigned gpio, int value) +{ + struct gpio_desc *desc = gpio_to_desc(gpio); + int err; + + if (!desc) + return -EINVAL; + + err = gpio_ensure_requested(desc); + if (err < 0) + return err; + + return gpiod_direction_output_raw(desc, value); +} +EXPORT_SYMBOL_GPL(gpio_direction_output); + +int gpio_set_debounce(unsigned gpio, unsigned debounce) +{ + struct gpio_desc *desc = gpio_to_desc(gpio); + int err; + + if (!desc) + return -EINVAL; + + err = gpio_ensure_requested(desc); + if (err < 0) + return err; + + return gpiod_set_debounce(desc, debounce); +} +EXPORT_SYMBOL_GPL(gpio_set_debounce); diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 7582207c92e7..412d64e93cfb 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -95,39 +95,6 @@ int desc_to_gpio(const struct gpio_desc *desc) EXPORT_SYMBOL_GPL(desc_to_gpio); -/* Warn when drivers omit gpio_request() calls -- legal but ill-advised - * when setting direction, and otherwise illegal. Until board setup code - * and drivers use explicit requests everywhere (which won't happen when - * those calls have no teeth) we can't avoid autorequesting. This nag - * message should motivate switching to explicit requests... so should - * the weaker cleanup after faults, compared to gpio_request(). - * - * NOTE: the autorequest mechanism is going away; at this point it's - * only "legal" in the sense that (old) code using it won't break yet, - * but instead only triggers a WARN() stack dump. - */ -static int gpio_ensure_requested(struct gpio_desc *desc) -{ - const struct gpio_chip *chip = desc->chip; - const int gpio = desc_to_gpio(desc); - - if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0, - "autorequest GPIO-%d\n", gpio)) { - if (!try_module_get(chip->owner)) { - gpiod_err(desc, "%s: module can't be gotten\n", - __func__); - clear_bit(FLAG_REQUESTED, &desc->flags); - /* lose */ - return -EIO; - } - desc_set_label(desc, "[auto]"); - /* caller must chip->request() w/o spinlock */ - if (chip->request) - return 1; - } - return 0; -} - /** * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs * @desc: descriptor to return the chip of @@ -964,10 +931,8 @@ void gpiochip_free_own_desc(struct gpio_desc *desc) */ int gpiod_direction_input(struct gpio_desc *desc) { - unsigned long flags; struct gpio_chip *chip; int status = -EINVAL; - int offset; if (!desc || !desc->chip) { pr_warn("%s: invalid GPIO\n", __func__); @@ -982,52 +947,20 @@ int gpiod_direction_input(struct gpio_desc *desc) return -EIO; } - spin_lock_irqsave(&gpio_lock, flags); - - status = gpio_ensure_requested(desc); - if (status < 0) - goto fail; - - /* now we know the gpio is valid and chip won't vanish */ - - spin_unlock_irqrestore(&gpio_lock, flags); - - might_sleep_if(chip->can_sleep); - - offset = gpio_chip_hwgpio(desc); - if (status) { - status = chip->request(chip, offset); - if (status < 0) { - gpiod_dbg(desc, "%s: chip request fail, %d\n", - __func__, status); - /* and it's not available to anyone else ... - * gpio_request() is the fully clean solution. - */ - goto lose; - } - } - - status = chip->direction_input(chip, offset); + status = chip->direction_input(chip, gpio_chip_hwgpio(desc)); if (status == 0) clear_bit(FLAG_IS_OUT, &desc->flags); trace_gpio_direction(desc_to_gpio(desc), 1, status); -lose: - return status; -fail: - spin_unlock_irqrestore(&gpio_lock, flags); - if (status) - gpiod_dbg(desc, "%s: status %d\n", __func__, status); + return status; } EXPORT_SYMBOL_GPL(gpiod_direction_input); static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value) { - unsigned long flags; struct gpio_chip *chip; int status = -EINVAL; - int offset; /* GPIOs used for IRQs shall not be set as output */ if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) { @@ -1053,42 +986,11 @@ static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value) return -EIO; } - spin_lock_irqsave(&gpio_lock, flags); - - status = gpio_ensure_requested(desc); - if (status < 0) - goto fail; - - /* now we know the gpio is valid and chip won't vanish */ - - spin_unlock_irqrestore(&gpio_lock, flags); - - might_sleep_if(chip->can_sleep); - - offset = gpio_chip_hwgpio(desc); - if (status) { - status = chip->request(chip, offset); - if (status < 0) { - gpiod_dbg(desc, "%s: chip request fail, %d\n", - __func__, status); - /* and it's not available to anyone else ... - * gpio_request() is the fully clean solution. - */ - goto lose; - } - } - - status = chip->direction_output(chip, offset, value); + status = chip->direction_output(chip, gpio_chip_hwgpio(desc), value); if (status == 0) set_bit(FLAG_IS_OUT, &desc->flags); trace_gpio_value(desc_to_gpio(desc), 0, value); trace_gpio_direction(desc_to_gpio(desc), 0, status); -lose: - return status; -fail: - spin_unlock_irqrestore(&gpio_lock, flags); - if (status) - gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status); return status; } @@ -1147,10 +1049,7 @@ EXPORT_SYMBOL_GPL(gpiod_direction_output); */ int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) { - unsigned long flags; struct gpio_chip *chip; - int status = -EINVAL; - int offset; if (!desc || !desc->chip) { pr_warn("%s: invalid GPIO\n", __func__); @@ -1165,27 +1064,7 @@ int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) return -ENOTSUPP; } - spin_lock_irqsave(&gpio_lock, flags); - - status = gpio_ensure_requested(desc); - if (status < 0) - goto fail; - - /* now we know the gpio is valid and chip won't vanish */ - - spin_unlock_irqrestore(&gpio_lock, flags); - - might_sleep_if(chip->can_sleep); - - offset = gpio_chip_hwgpio(desc); - return chip->set_debounce(chip, offset, debounce); - -fail: - spin_unlock_irqrestore(&gpio_lock, flags); - if (status) - gpiod_dbg(desc, "%s: status %d\n", __func__, status); - - return status; + return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce); } EXPORT_SYMBOL_GPL(gpiod_set_debounce); diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index c1d4105e1c1d..39a1d06950d9 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -63,19 +63,10 @@ static inline struct gpio_chip *gpio_to_chip(unsigned gpio) extern int gpio_request(unsigned gpio, const char *label); extern void gpio_free(unsigned gpio); -static inline int gpio_direction_input(unsigned gpio) -{ - return gpiod_direction_input(gpio_to_desc(gpio)); -} -static inline int gpio_direction_output(unsigned gpio, int value) -{ - return gpiod_direction_output_raw(gpio_to_desc(gpio), value); -} +extern int gpio_direction_input(unsigned gpio); +extern int gpio_direction_output(unsigned gpio, int value); -static inline int gpio_set_debounce(unsigned gpio, unsigned debounce) -{ - return gpiod_set_debounce(gpio_to_desc(gpio), debounce); -} +extern int gpio_set_debounce(unsigned gpio, unsigned debounce); static inline int gpio_get_value_cansleep(unsigned gpio) { |