diff options
Diffstat (limited to 'drivers/gpio/gpiolib-sysfs.c')
| -rw-r--r-- | drivers/gpio/gpiolib-sysfs.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c index 7722ed5..af3bc7a 100644 --- a/drivers/gpio/gpiolib-sysfs.c +++ b/drivers/gpio/gpiolib-sysfs.c @@ -551,6 +551,7 @@ static struct class gpio_class = { */ int gpiod_export(struct gpio_desc *desc, bool direction_may_change) { + struct gpio_chip *chip; unsigned long flags; int status; const char *ioname = NULL; @@ -568,8 +569,16 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change) return -EINVAL; } + chip = desc->chip; + mutex_lock(&sysfs_lock); + /* check if chip is being removed */ + if (!chip || !chip->exported) { + status = -ENODEV; + goto fail_unlock; + } + spin_lock_irqsave(&gpio_lock, flags); if (!test_bit(FLAG_REQUESTED, &desc->flags) || test_bit(FLAG_EXPORT, &desc->flags)) { @@ -783,12 +792,15 @@ void gpiochip_unexport(struct gpio_chip *chip) { int status; struct device *dev; + struct gpio_desc *desc; + unsigned int i; mutex_lock(&sysfs_lock); dev = class_find_device(&gpio_class, NULL, chip, match_export); if (dev) { put_device(dev); device_unregister(dev); + /* prevent further gpiod exports */ chip->exported = false; status = 0; } else @@ -797,6 +809,13 @@ void gpiochip_unexport(struct gpio_chip *chip) if (status) chip_dbg(chip, "%s: status %d\n", __func__, status); + + /* unregister gpiod class devices owned by sysfs */ + for (i = 0; i < chip->ngpio; i++) { + desc = &chip->desc[i]; + if (test_and_clear_bit(FLAG_SYSFS, &desc->flags)) + gpiod_free(desc); + } } static int __init gpiolib_sysfs_init(void) |