gpio: move sysfs mock device to the gpio_device

Since gpio_device is the struct that survives if the backing
gpio_chip is removed, move the sysfs mock device to this state
container so it becomes part of the dangling state of the
GPIO device on removal.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

4 files changed, 21 insertions, 19 deletions

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 28d3bf2328aa..94ba4bb8b4f8 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -572,7 +572,7 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
         mutex_lock(&sysfs_lock);
 
         /* check if chip is being removed */
-        if (!chip || !chip->cdev) {
+        if (!chip || !gdev->mockdev) {
                 status = -ENODEV;
                 goto err_unlock;
         }
@@ -718,9 +718,10 @@ err_unlock:
 }
 EXPORT_SYMBOL_GPL(gpiod_unexport);
 
-int gpiochip_sysfs_register(struct gpio_chip *chip)
+int gpiochip_sysfs_register(struct gpio_device *gdev)
 {
         struct device   *dev;
+        struct gpio_chip *chip = gdev->chip;
 
         /*
          * Many systems add gpio chips for SOC support very early,
@@ -732,7 +733,7 @@ int gpiochip_sysfs_register(struct gpio_chip *chip)
                 return 0;
 
         /* use chip->base for the ID; it's already known to be unique */
-        dev = device_create_with_groups(&gpio_class, chip->parent,
+        dev = device_create_with_groups(&gpio_class, &gdev->dev,
                                         MKDEV(0, 0),
                                         chip, gpiochip_groups,
                                         "gpiochip%d", chip->base);
@@ -740,25 +741,26 @@ int gpiochip_sysfs_register(struct gpio_chip *chip)
                 return PTR_ERR(dev);
 
         mutex_lock(&sysfs_lock);
-        chip->cdev = dev;
+        gdev->mockdev = dev;
         mutex_unlock(&sysfs_lock);
 
         return 0;
 }
 
-void gpiochip_sysfs_unregister(struct gpio_chip *chip)
+void gpiochip_sysfs_unregister(struct gpio_device *gdev)
 {
         struct gpio_desc *desc;
+        struct gpio_chip *chip = gdev->chip;
         unsigned int i;
 
-        if (!chip->cdev)
+        if (!gdev->mockdev)
                 return;
 
-        device_unregister(chip->cdev);
+        device_unregister(gdev->mockdev);
 
         /* prevent further gpiod exports */
         mutex_lock(&sysfs_lock);
-        chip->cdev = NULL;
+        gdev->mockdev = NULL;
         mutex_unlock(&sysfs_lock);
 
         /* unregister gpiod class devices owned by sysfs */
@@ -787,7 +789,7 @@ static int __init gpiolib_sysfs_init(void)
          */
         spin_lock_irqsave(&gpio_lock, flags);
         list_for_each_entry(gdev, &gpio_devices, list) {
-                if (gdev->chip->cdev)
+                if (gdev->mockdev)
                         continue;
 
                 /*
@@ -800,12 +802,11 @@ static int __init gpiolib_sysfs_init(void)
                  * gpio_lock prevents us from doing this.
                  */
                 spin_unlock_irqrestore(&gpio_lock, flags);
-                status = gpiochip_sysfs_register(gdev->chip);
+                status = gpiochip_sysfs_register(gdev);
                 spin_lock_irqsave(&gpio_lock, flags);
         }
         spin_unlock_irqrestore(&gpio_lock, flags);
 
-
         return status;
 }
 postcore_initcall(gpiolib_sysfs_init);
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 36f8be3f910b..5763290f777c 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -558,7 +558,7 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data)
         if (status)
                 goto err_remove_chardev;
 
-        status = gpiochip_sysfs_register(chip);
+        status = gpiochip_sysfs_register(gdev);
         if (status)
                 goto err_remove_device;
 
@@ -615,7 +615,7 @@ void gpiochip_remove(struct gpio_chip *chip)
         gdev->chip = NULL;
 
         /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
-        gpiochip_sysfs_unregister(chip);
+        gpiochip_sysfs_unregister(gdev);
         gpiochip_irqchip_remove(chip);
         acpi_gpiochip_remove(chip);
         gpiochip_remove_pin_ranges(chip);
diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index 1524ba0ca99d..c5a5b57463c7 100644
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -27,6 +27,8 @@ struct acpi_device;
  * @id: numerical ID number for the GPIO chip
  * @dev: the GPIO device struct
  * @chrdev: character device for the GPIO device
+ * @mockdev: class device used by the deprecated sysfs interface (may be
+ * NULL)
  * @owner: helps prevent removal of modules exporting active GPIOs
  * @chip: pointer to the corresponding gpiochip, holding static
  * data for this device
@@ -41,6 +43,7 @@ struct gpio_device {
         int                     id;
         struct device           dev;
         struct cdev             chrdev;
+        struct device           *mockdev;
         struct module           *owner;
         struct gpio_chip        *chip;
         struct list_head        list;
@@ -190,17 +193,17 @@ static int __maybe_unused gpio_chip_hwgpio(const struct gpio_desc *desc)
 
 #ifdef CONFIG_GPIO_SYSFS
 
-int gpiochip_sysfs_register(struct gpio_chip *chip);
-void gpiochip_sysfs_unregister(struct gpio_chip *chip);
+int gpiochip_sysfs_register(struct gpio_device *gdev);
+void gpiochip_sysfs_unregister(struct gpio_device *gdev);
 
 #else
 
-static inline int gpiochip_sysfs_register(struct gpio_chip *chip)
+static inline int gpiochip_sysfs_register(struct gpio_device *gdev)
 {
         return 0;
 }
 
-static inline void gpiochip_sysfs_unregister(struct gpio_chip *chip)
+static inline void gpiochip_sysfs_unregister(struct gpio_device *gdev)
 {
 }
 
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index f3f1dbd43c9b..4db64ab534ef 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -24,7 +24,6 @@ struct gpio_device;
  * @label: for diagnostics
  * @gpiodev: the internal state holder, opaque struct
  * @parent: optional parent device providing the GPIOs
- * @cdev: class device used by sysfs interface (may be NULL)
  * @owner: helps prevent removal of modules exporting active GPIOs
  * @data: per-instance data assigned by the driver
  * @request: optional hook for chip-specific activation, such as
@@ -110,7 +109,6 @@ struct gpio_chip {
         const char              *label;
         struct gpio_device      *gpiodev;