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path: root/drivers/gpio/gpiolib-sysfs.c
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Diffstat (limited to 'drivers/gpio/gpiolib-sysfs.c')
-rw-r--r--drivers/gpio/gpiolib-sysfs.c19
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)