Merge tag 'gpio-v4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux...

[cascardo/linux.git] / drivers / gpio / gpiolib.c

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index d2ba286..53ff25a 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -947,7 +947,6 @@ static void gpiodevice_release(struct device *dev)
 {
        struct gpio_device *gdev = dev_get_drvdata(dev);
 
-       cdev_del(&gdev->chrdev);
        list_del(&gdev->list);
        ida_simple_remove(&gpio_ida, gdev->id);
        kfree(gdev->label);
@@ -980,7 +979,6 @@ static int gpiochip_setup_dev(struct gpio_device *gdev)
 
        /* From this point, the .release() function cleans up gpio_device */
        gdev->dev.release = gpiodevice_release;
-       get_device(&gdev->dev);
        pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
                 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
                 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
@@ -1269,6 +1267,8 @@ void gpiochip_remove(struct gpio_chip *chip)
         * be removed, else it will be dangling until the last user is
         * gone.
         */
+       cdev_del(&gdev->chrdev);
+       device_del(&gdev->dev);
        put_device(&gdev->dev);
 }
 EXPORT_SYMBOL_GPL(gpiochip_remove);
@@ -1368,7 +1368,7 @@ struct gpio_chip *gpiochip_find(void *data,
 
        spin_lock_irqsave(&gpio_lock, flags);
        list_for_each_entry(gdev, &gpio_devices, list)
-               if (match(gdev->chip, data))
+               if (gdev->chip && match(gdev->chip, data))
                        break;
 
        /* No match? */
@@ -1851,14 +1851,6 @@ static int __gpiod_request(struct gpio_desc *desc, const char *label)
                spin_lock_irqsave(&gpio_lock, flags);
        }
 done:
-       if (status < 0) {
-               /* Clear flags that might have been set by the caller before
-                * requesting the GPIO.
-                */
-               clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
-               clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
-               clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
-       }
        spin_unlock_irqrestore(&gpio_lock, flags);
        return status;
 }
@@ -1872,8 +1864,12 @@ done:
 #define VALIDATE_DESC(desc) do { \
        if (!desc) \
                return 0; \
+       if (IS_ERR(desc)) {                                             \
+               pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
+               return PTR_ERR(desc); \
+       } \
        if (!desc->gdev) { \
-               pr_warn("%s: invalid GPIO\n", __func__); \
+               pr_warn("%s: invalid GPIO (no device)\n", __func__); \
                return -EINVAL; \
        } \
        if ( !desc->gdev->chip ) { \
@@ -1885,8 +1881,12 @@ done:
 #define VALIDATE_DESC_VOID(desc) do { \
        if (!desc) \
                return; \
+       if (IS_ERR(desc)) {                                             \
+               pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
+               return; \
+       } \
        if (!desc->gdev) { \
-               pr_warn("%s: invalid GPIO\n", __func__); \
+               pr_warn("%s: invalid GPIO (no device)\n", __func__); \
                return; \
        } \
        if (!desc->gdev->chip) { \
@@ -2555,7 +2555,14 @@ int gpiod_to_irq(const struct gpio_desc *desc)
        struct gpio_chip *chip;
        int offset;
 
-       VALIDATE_DESC(desc);
+       /*
+        * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
+        * requires this function to not return zero on an invalid descriptor
+        * but rather a negative error number.
+        */
+       if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
+               return -EINVAL;
+
        chip = desc->gdev->chip;
        offset = gpio_chip_hwgpio(desc);
        if (chip->to_irq) {
@@ -3071,28 +3078,13 @@ struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(gpiod_get_optional);
 
-/**
- * gpiod_parse_flags - helper function to parse GPIO lookup flags
- * @desc:      gpio to be setup
- * @lflags:    gpio_lookup_flags - returned from of_find_gpio() or
- *             of_get_gpio_hog()
- *
- * Set the GPIO descriptor flags based on the given GPIO lookup flags.
- */
-static void gpiod_parse_flags(struct gpio_desc *desc, unsigned long lflags)
-{
-       if (lflags & GPIO_ACTIVE_LOW)
-               set_bit(FLAG_ACTIVE_LOW, &desc->flags);
-       if (lflags & GPIO_OPEN_DRAIN)
-               set_bit(FLAG_OPEN_DRAIN, &desc->flags);
-       if (lflags & GPIO_OPEN_SOURCE)
-               set_bit(FLAG_OPEN_SOURCE, &desc->flags);
-}
 
 /**
  * gpiod_configure_flags - helper function to configure a given GPIO
  * @desc:      gpio whose value will be assigned
  * @con_id:    function within the GPIO consumer
+ * @lflags:    gpio_lookup_flags - returned from of_find_gpio() or
+ *             of_get_gpio_hog()
  * @dflags:    gpiod_flags - optional GPIO initialization flags
  *
  * Return 0 on success, -ENOENT if no GPIO has been assigned to the
@@ -3100,10 +3092,17 @@ static void gpiod_parse_flags(struct gpio_desc *desc, unsigned long lflags)
  * occurred while trying to acquire the GPIO.
  */
 static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
-                                enum gpiod_flags dflags)
+               unsigned long lflags, enum gpiod_flags dflags)
 {
        int status;
 
+       if (lflags & GPIO_ACTIVE_LOW)
+               set_bit(FLAG_ACTIVE_LOW, &desc->flags);
+       if (lflags & GPIO_OPEN_DRAIN)
+               set_bit(FLAG_OPEN_DRAIN, &desc->flags);
+       if (lflags & GPIO_OPEN_SOURCE)
+               set_bit(FLAG_OPEN_SOURCE, &desc->flags);
+
        /* No particular flag request, return here... */
        if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
                pr_debug("no flags found for %s\n", con_id);
@@ -3170,13 +3169,11 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
                return desc;
        }
 
-       gpiod_parse_flags(desc, lookupflags);
-
        status = gpiod_request(desc, con_id);
        if (status < 0)
                return ERR_PTR(status);
 
-       status = gpiod_configure_flags(desc, con_id, flags);
+       status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
        if (status < 0) {
                dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
                gpiod_put(desc);
@@ -3232,6 +3229,10 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
        if (IS_ERR(desc))
                return desc;
 
+       ret = gpiod_request(desc, NULL);
+       if (ret)
+               return ERR_PTR(ret);
+
        if (active_low)
                set_bit(FLAG_ACTIVE_LOW, &desc->flags);
 
@@ -3242,10 +3243,6 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
                        set_bit(FLAG_OPEN_SOURCE, &desc->flags);
        }
 
-       ret = gpiod_request(desc, NULL);
-       if (ret)
-               return ERR_PTR(ret);
-
        return desc;
 }
 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
@@ -3298,8 +3295,6 @@ int gpiod_hog(struct gpio_desc *desc, const char *name,
        chip = gpiod_to_chip(desc);
        hwnum = gpio_chip_hwgpio(desc);
 
-       gpiod_parse_flags(desc, lflags);
-
        local_desc = gpiochip_request_own_desc(chip, hwnum, name);
        if (IS_ERR(local_desc)) {
                status = PTR_ERR(local_desc);
@@ -3308,7 +3303,7 @@ int gpiod_hog(struct gpio_desc *desc, const char *name,
                return status;
        }
 
-       status = gpiod_configure_flags(desc, name, dflags);
+       status = gpiod_configure_flags(desc, name, lflags, dflags);
        if (status < 0) {
                pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
                       name, chip->label, hwnum, status);