1 files changed, 67 insertions, 31 deletions

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 5ca7c9aa4fab..b747c76fd2b1 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -68,6 +68,7 @@ LIST_HEAD(gpio_devices);
 static void gpiochip_free_hogs(struct gpio_chip *chip);
 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
 
+static bool gpiolib_initialized;
 
 static inline void desc_set_label(struct gpio_desc *d, const char *label)
 {
@@ -445,6 +446,58 @@ static void gpiodevice_release(struct device *dev)
         kfree(gdev);
 }
 
+static int gpiochip_setup_dev(struct gpio_device *gdev)
+{
+        int status;
+
+        cdev_init(&gdev->chrdev, &gpio_fileops);
+        gdev->chrdev.owner = THIS_MODULE;
+        gdev->chrdev.kobj.parent = &gdev->dev.kobj;
+        gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
+        status = cdev_add(&gdev->chrdev, gdev->dev.devt, 1);
+        if (status < 0)
+                chip_warn(gdev->chip, "failed to add char device %d:%d\n",
+                          MAJOR(gpio_devt), gdev->id);
+        else
+                chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
+                         MAJOR(gpio_devt), gdev->id);
+        status = device_add(&gdev->dev);
+        if (status)
+                goto err_remove_chardev;
+
+        status = gpiochip_sysfs_register(gdev);
+        if (status)
+                goto err_remove_device;
+
+        /* 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");
+
+        return 0;
+
+err_remove_device:
+        device_del(&gdev->dev);
+err_remove_chardev:
+        cdev_del(&gdev->chrdev);
+        return status;
+}
+
+static void gpiochip_setup_devs(void)
+{
+        struct gpio_device *gdev;
+        int err;
+
+        list_for_each_entry(gdev, &gpio_devices, list) {
+                err = gpiochip_setup_dev(gdev);
+                if (err)
+                        pr_err("%s: Failed to initialize gpio device (%d)\n",
+                               dev_name(&gdev->dev), err);
+        }
+}
+
 /**
  * gpiochip_add_data() - register a gpio_chip
  * @chip: the chip to register, with chip->base initialized
@@ -459,6 +512,9 @@ static void gpiodevice_release(struct device *dev)
  * the gpio framework's arch_initcall().  Otherwise sysfs initialization
  * for GPIOs will fail rudely.
  *
+ * gpiochip_add_data() must only be called after gpiolib initialization,
+ * ie after core_initcall().
+ *
  * If chip->base is negative, this requests dynamic assignment of
  * a range of valid GPIOs.
  */
@@ -515,7 +571,7 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data)
         if (chip->ngpio == 0) {
                 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
                 status = -EINVAL;
-                goto err_free_gdev;
+                goto err_free_descs;
         }
 
         if (chip->label)
@@ -597,39 +653,16 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data)
          * we get a device node entry in sysfs under
          * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
          * coldplug of device nodes and other udev business.
+         * We can do this only if gpiolib has been initialized.
+         * Otherwise, defer until later.
          */
-        cdev_init(&gdev->chrdev, &gpio_fileops);
-        gdev->chrdev.owner = THIS_MODULE;
-        gdev->chrdev.kobj.parent = &gdev->dev.kobj;
-        gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
-        status = cdev_add(&gdev->chrdev, gdev->dev.devt, 1);
-        if (status < 0)
-                chip_warn(chip, "failed to add char device %d:%d\n",
-                          MAJOR(gpio_devt), gdev->id);
-        else
-                chip_dbg(chip, "added GPIO chardev (%d:%d)\n",
-                         MAJOR(gpio_devt), gdev->id);
-        status = device_add(&gdev->dev);
-        if (status)
-                goto err_remove_chardev;
-
-        status = gpiochip_sysfs_register(gdev);
-        if (status)
-                goto err_remove_device;
-
-        /* 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), chip->label ? : "generic");
-
+        if (gpiolib_initialized) {
+                status = gpiochip_setup_dev(gdev);
+                if (status)
+                        goto err_remove_chip;
+        }
         return 0;
 
-err_remove_device:
-        device_del(&gdev->dev);
-err_remove_chardev:
-        cdev_del(&gdev->chrdev);
 err_remove_chip:
         acpi_gpiochip_remove(chip);
         gpiochip_free_hogs(chip);
@@ -2842,6 +2875,9 @@ static int __init gpiolib_dev_init(void)
         if (ret < 0) {
                 pr_err("gpiolib: failed to allocate char dev region\n");
                 bus_unregister(&gpio_bus_type);
+        } else {
+                gpiolib_initialized = true;
+                gpiochip_setup_devs();
         }
         return ret;
 }