2 files changed, 115 insertions, 7 deletions

diff --git a/drivers/input/input-polldev.c b/drivers/input/input-polldev.c
index 910220c127c..31874275fed 100644
--- a/drivers/input/input-polldev.c
+++ b/drivers/input/input-polldev.c
@@ -56,14 +56,10 @@ static void input_polldev_stop_workqueue(void)
 	mutex_unlock(&polldev_mutex);
 }
 
-static void input_polled_device_work(struct work_struct *work)
+static void input_polldev_queue_work(struct input_polled_dev *dev)
 {
-	struct input_polled_dev *dev =
-		container_of(work, struct input_polled_dev, work.work);
 	unsigned long delay;
 
-	dev->poll(dev);
-
 	delay = msecs_to_jiffies(dev->poll_interval);
 	if (delay >= HZ)
 		delay = round_jiffies_relative(delay);
@@ -71,6 +67,15 @@ static void input_polled_device_work(struct work_struct *work)
 	queue_delayed_work(polldev_wq, &dev->work, delay);
 }
 
+static void input_polled_device_work(struct work_struct *work)
+{
+	struct input_polled_dev *dev =
+		container_of(work, struct input_polled_dev, work.work);
+
+	dev->poll(dev);
+	input_polldev_queue_work(dev);
+}
+
 static int input_open_polled_device(struct input_dev *input)
 {
 	struct input_polled_dev *dev = input_get_drvdata(input);
@@ -100,6 +105,83 @@ static void input_close_polled_device(struct input_dev *input)
 		dev->close(dev);
 }
 
+/* SYSFS interface */
+
+static ssize_t input_polldev_get_poll(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	struct input_polled_dev *polldev = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", polldev->poll_interval);
+}
+
+static ssize_t input_polldev_set_poll(struct device *dev,
+				struct device_attribute *attr, const char *buf,
+				size_t count)
+{
+	struct input_polled_dev *polldev = dev_get_drvdata(dev);
+	struct input_dev *input = polldev->input;
+	unsigned long interval;
+
+	if (strict_strtoul(buf, 0, &interval))
+		return -EINVAL;
+
+	if (interval < polldev->poll_interval_min)
+		return -EINVAL;
+
+	if (interval > polldev->poll_interval_max)
+		return -EINVAL;
+
+	mutex_lock(&input->mutex);
+
+	polldev->poll_interval = interval;
+
+	if (input->users) {
+		cancel_delayed_work_sync(&polldev->work);
+		if (polldev->poll_interval > 0)
+			input_polldev_queue_work(polldev);
+	}
+
+	mutex_unlock(&input->mutex);
+
+	return count;
+}
+
+static DEVICE_ATTR(poll, S_IRUGO | S_IWUSR, input_polldev_get_poll,
+					    input_polldev_set_poll);
+
+
+static ssize_t input_polldev_get_max(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct input_polled_dev *polldev = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", polldev->poll_interval_max);
+}
+
+static DEVICE_ATTR(max, S_IRUGO, input_polldev_get_max, NULL);
+
+static ssize_t input_polldev_get_min(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct input_polled_dev *polldev = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", polldev->poll_interval_min);
+}
+
+static DEVICE_ATTR(min, S_IRUGO, input_polldev_get_min, NULL);
+
+static struct attribute *sysfs_attrs[] = {
+	&dev_attr_poll.attr,
+	&dev_attr_max.attr,
+	&dev_attr_min.attr,
+	NULL
+};
+
+static struct attribute_group input_polldev_attribute_group = {
+	.attrs = sysfs_attrs
+};
+
 /**
  * input_allocate_polled_device - allocated memory polled device
  *
@@ -153,15 +235,29 @@ EXPORT_SYMBOL(input_free_polled_device);
 int input_register_polled_device(struct input_polled_dev *dev)
 {
 	struct input_dev *input = dev->input;
+	int error;
 
 	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;
 
-	return input_register_device(input);
+	error = input_register_device(input);
+	if (error)
+		return error;
+
+	error = sysfs_create_group(&input->dev.kobj,
+				   &input_polldev_attribute_group);
+	if (error) {
+		input_unregister_device(input);
+		return error;
+	}
+
+	return 0;
 }
 EXPORT_SYMBOL(input_register_polled_device);
 
@@ -177,6 +273,9 @@ 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);
+
 	input_unregister_device(dev->input);
 	dev->input = NULL;
 }
diff --git a/include/linux/input-polldev.h b/include/linux/input-polldev.h
index 5c0ec68a965..5e3dddf8f56 100644
--- a/include/linux/input-polldev.h
+++ b/include/linux/input-polldev.h
@@ -21,7 +21,12 @@
  *	longer being polled. Used to put device into low power mode.
  * @poll: driver-supplied method that polls the device and posts
  *	input events (mandatory).
- * @poll_interval: specifies how often the poll() method shoudl be called.
+ * @poll_interval: specifies how often the poll() method should be called.
+ *	Defaults to 500 msec unless overriden when registering the device.
+ * @poll_interval_max: specifies upper bound for the poll interval.
+ *	Defaults to the initial value of @poll_interval.
+ * @poll_interval_min: specifies lower bound for the poll interval.
+ *	Defaults to 0.
  * @input: input device structire associated with the polled device.
  *	Must be properly initialized by the driver (id, name, phys, bits).
  *
@@ -36,8 +41,12 @@ struct input_polled_dev {
 	void (*close)(struct input_polled_dev *dev);
 	void (*poll)(struct input_polled_dev *dev);
 	unsigned int poll_interval; /* msec */
+	unsigned int poll_interval_max; /* msec */
+	unsigned int poll_interval_min; /* msec */
 
 	struct input_dev *input;
+
+/* private: */
 	struct delayed_work work;
 };