diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index aa6a11b452e2..8fbc67a88465 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1458,26 +1458,14 @@ EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges); * on each other, and help provide better diagnostics in debugfs. * They're called even less than the "set direction" calls. */ -static int gpiod_request(struct gpio_desc *desc, const char *label) +static int __gpiod_request(struct gpio_desc *desc, const char *label) { - struct gpio_chip *chip; - int status = -EPROBE_DEFER; + struct gpio_chip *chip = desc->chip; + int status; unsigned long flags; - if (!desc) { - pr_warn("%s: invalid GPIO\n", __func__); - return -EINVAL; - } - spin_lock_irqsave(&gpio_lock, flags); - chip = desc->chip; - if (chip == NULL) - goto done; - - if (!try_module_get(chip->owner)) - goto done; - /* NOTE: gpio_request() can be called in early boot, * before IRQs are enabled, for non-sleeping (SOC) GPIOs. */ @@ -1487,7 +1475,6 @@ static int gpiod_request(struct gpio_desc *desc, const char *label) status = 0; } else { status = -EBUSY; - module_put(chip->owner); goto done; } @@ -1499,7 +1486,6 @@ static int gpiod_request(struct gpio_desc *desc, const char *label) if (status < 0) { desc_set_label(desc, NULL); - module_put(chip->owner); clear_bit(FLAG_REQUESTED, &desc->flags); goto done; } @@ -1510,10 +1496,35 @@ static int gpiod_request(struct gpio_desc *desc, const char *label) gpiod_get_direction(desc); spin_lock_irqsave(&gpio_lock, flags); } +done: + spin_unlock_irqrestore(&gpio_lock, flags); + return status; +} + +static int gpiod_request(struct gpio_desc *desc, const char *label) +{ + int status = -EPROBE_DEFER; + struct gpio_chip *chip; + + if (!desc) { + pr_warn("%s: invalid GPIO\n", __func__); + return -EINVAL; + } + + chip = desc->chip; + if (!chip) + goto done; + + if (try_module_get(chip->owner)) { + status = __gpiod_request(desc, label); + if (status < 0) + module_put(chip->owner); + } + done: if (status) gpiod_dbg(desc, "%s: status %d\n", __func__, status); - spin_unlock_irqrestore(&gpio_lock, flags); + return status; } @@ -1523,18 +1534,14 @@ int gpio_request(unsigned gpio, const char *label) } EXPORT_SYMBOL_GPL(gpio_request); -static void gpiod_free(struct gpio_desc *desc) +static bool __gpiod_free(struct gpio_desc *desc) { + bool ret = false; unsigned long flags; struct gpio_chip *chip; might_sleep(); - if (!desc) { - WARN_ON(extra_checks); - return; - } - gpiod_unexport(desc); spin_lock_irqsave(&gpio_lock, flags); @@ -1548,15 +1555,23 @@ static void gpiod_free(struct gpio_desc *desc) spin_lock_irqsave(&gpio_lock, flags); } desc_set_label(desc, NULL); - module_put(desc->chip->owner); clear_bit(FLAG_ACTIVE_LOW, &desc->flags); clear_bit(FLAG_REQUESTED, &desc->flags); clear_bit(FLAG_OPEN_DRAIN, &desc->flags); clear_bit(FLAG_OPEN_SOURCE, &desc->flags); - } else - WARN_ON(extra_checks); + ret = true; + } spin_unlock_irqrestore(&gpio_lock, flags); + return ret; +} + +static void gpiod_free(struct gpio_desc *desc) +{ + if (desc && __gpiod_free(desc)) + module_put(desc->chip->owner); + else + WARN_ON(extra_checks); } void gpio_free(unsigned gpio) @@ -1678,6 +1693,37 @@ const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) } EXPORT_SYMBOL_GPL(gpiochip_is_requested); +/** + * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor + * @desc: GPIO descriptor to request + * @label: label for the GPIO + * + * Function allows GPIO chip drivers to request and use their own GPIO + * descriptors via gpiolib API. Difference to gpiod_request() is that this + * function will not increase reference count of the GPIO chip module. This + * allows the GPIO chip module to be unloaded as needed (we assume that the + * GPIO chip driver handles freeing the GPIOs it has requested). + */ +int gpiochip_request_own_desc(struct gpio_desc *desc, const char *label) +{ + if (!desc || !desc->chip) + return -EINVAL; + + return __gpiod_request(desc, label); +} + +/** + * gpiochip_free_own_desc - Free GPIO requested by the chip driver + * @desc: GPIO descriptor to free + * + * Function frees the given GPIO requested previously with + * gpiochip_request_own_desc(). + */ +void gpiochip_free_own_desc(struct gpio_desc *desc) +{ + if (desc) + __gpiod_free(desc); +} /* Drivers MUST set GPIO direction before making get/set calls. In * some cases this is done in early boot, before IRQs are enabled. diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index 82be586c1f90..cf092941a9fd 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -43,4 +43,7 @@ acpi_get_gpiod_by_index(struct device *dev, int index, } #endif +int gpiochip_request_own_desc(struct gpio_desc *desc, const char *label); +void gpiochip_free_own_desc(struct gpio_desc *desc); + #endif /* GPIOLIB_H */