1 files changed, 122 insertions, 9 deletions

diff --git a/drivers/input/input-polldev.c b/drivers/input/input-polldev.c
index 7f161d93203c..3664f81655ca 100644
--- a/drivers/input/input-polldev.c
+++ b/drivers/input/input-polldev.c
@@ -147,6 +147,11 @@ static struct attribute_group input_polldev_attribute_group = {
         .attrs = sysfs_attrs
 };
 
+static const struct attribute_group *input_polldev_attribute_groups[] = {
+        &input_polldev_attribute_group,
+        NULL
+};
+
 /**
  * input_allocate_polled_device - allocate memory for polled device
  *
@@ -171,6 +176,91 @@ struct input_polled_dev *input_allocate_polled_device(void)
 }
 EXPORT_SYMBOL(input_allocate_polled_device);
 
+struct input_polled_devres {
+        struct input_polled_dev *polldev;
+};
+
+static int devm_input_polldev_match(struct device *dev, void *res, void *data)
+{
+        struct input_polled_devres *devres = res;
+
+        return devres->polldev == data;
+}
+
+static void devm_input_polldev_release(struct device *dev, void *res)
+{
+        struct input_polled_devres *devres = res;
+        struct input_polled_dev *polldev = devres->polldev;
+
+        dev_dbg(dev, "%s: dropping reference/freeing %s\n",
+                __func__, dev_name(&polldev->input->dev));
+
+        input_put_device(polldev->input);
+        kfree(polldev);
+}
+
+static void devm_input_polldev_unregister(struct device *dev, void *res)
+{
+        struct input_polled_devres *devres = res;
+        struct input_polled_dev *polldev = devres->polldev;
+
+        dev_dbg(dev, "%s: unregistering device %s\n",
+                __func__, dev_name(&polldev->input->dev));
+        input_unregister_device(polldev->input);
+
+        /*
+         * Note that we are still holding extra reference to the input
+         * device so it will stick around until devm_input_polldev_release()
+         * is called.
+         */
+}
+
+/**
+ * devm_input_allocate_polled_device - allocate managed polled device
+ * @dev: device owning the polled device being created
+ *
+ * Returns prepared &struct input_polled_dev or %NULL.
+ *
+ * Managed polled input devices do not need to be explicitly unregistered
+ * or freed as it will be done automatically when owner device unbinds
+ * from * its driver (or binding fails). Once such managed polled device
+ * is allocated, it is ready to be set up and registered in the same
+ * fashion as regular polled input devices (using
+ * input_register_polled_device() function).
+ *
+ * If you want to manually unregister and free such managed polled devices,
+ * it can be still done by calling input_unregister_polled_device() and
+ * input_free_polled_device(), although it is rarely needed.
+ *
+ * NOTE: the owner device is set up as parent of input device and users
+ * should not override it.
+ */
+struct input_polled_dev *devm_input_allocate_polled_device(struct device *dev)
+{
+        struct input_polled_dev *polldev;
+        struct input_polled_devres *devres;
+
+        devres = devres_alloc(devm_input_polldev_release, sizeof(*devres),
+                              GFP_KERNEL);
+        if (!devres)
+                return NULL;
+
+        polldev = input_allocate_polled_device();
+        if (!polldev) {
+                devres_free(devres);
+                return NULL;
+        }
+
+        polldev->input->dev.parent = dev;
+        polldev->devres_managed = true;
+
+        devres->polldev = polldev;
+        devres_add(dev, devres);
+
+        return polldev;
+}
+EXPORT_SYMBOL(devm_input_allocate_polled_device);
+
 /**
  * input_free_polled_device - free memory allocated for polled device
  * @dev: device to free
@@ -181,7 +271,12 @@ EXPORT_SYMBOL(input_allocate_polled_device);
 void input_free_polled_device(struct input_polled_dev *dev)
 {
         if (dev) {
-                input_free_device(dev->input);
+                if (dev->devres_managed)
+                        WARN_ON(devres_destroy(dev->input->dev.parent,
+                                                devm_input_polldev_release,
+                                                devm_input_polldev_match,
+                                                dev));
+                input_put_device(dev->input);
                 kfree(dev);
         }
 }
@@ -199,26 +294,35 @@ EXPORT_SYMBOL(input_free_polled_device);
  */
 int input_register_polled_device(struct input_polled_dev *dev)
 {
+        struct input_polled_devres *devres = NULL;
         struct input_dev *input = dev->input;
         int error;
 
+        if (dev->devres_managed) {
+                devres = devres_alloc(devm_input_polldev_unregister,
+                                      sizeof(*devres), GFP_KERNEL);
+                if (!devres)
+                        return -ENOMEM;
+
+                devres->polldev = dev;
+        }
+
         input_set_drvdata(input, dev);
         INIT_DELAYED_WORK(&dev->work, input_polled_device_work);
+
         if (!dev->poll_interval)
                 dev->poll_interval = 500;
         if (!dev->poll_interval_max)
                 dev->poll_interval_max = dev->poll_interval;
+
         input->open = input_open_polled_device;
         input->close = input_close_polled_device;
 
-        error = input_register_device(input);
-        if (error)
-                return error;
+        input->dev.groups = input_polldev_attribute_groups;
 
-        error = sysfs_create_group(&input->dev.kobj,
-                                   &input_polldev_attribute_group);
+        error = input_register_device(input);
         if (error) {
-                input_unregister_device(input);
+                devres_free(devres);
                 return error;
         }
 
@@ -231,6 +335,12 @@ int input_register_polled_device(struct input_polled_dev *dev)
          */
         input_get_device(input);
 
+        if (dev->devres_managed) {
+                dev_dbg(input->dev.parent, "%s: registering %s with devres.\n",
+                        __func__, dev_name(&input->dev));
+                devres_add(input->dev.parent, devres);
+        }
+
         return 0;
 }
 EXPORT_SYMBOL(input_register_polled_device);
@@ -245,8 +355,11 @@ EXPORT_SYMBOL(input_register_polled_device);
  */
 void input_unregister_polled_device(struct input_polled_dev *dev)
 {
-        sysfs_remove_group(&dev->input->dev.kobj,
-                           &input_polldev_attribute_group);
+        if (dev->devres_managed)
+                WARN_ON(devres_destroy(dev->input->dev.parent,
+                                        devm_input_polldev_unregister,
+                                        devm_input_polldev_match,
+                                        dev));
 
         input_unregister_device(dev->input);
 }