[1/1] Input polldev: Sysfs interface for setting of polling interval

Commit Message

[e-mail] Nov. 9, 2009, 1:03 p.m. UTC

None

Patch

diff --git a/drivers/input/input-polldev.c b/drivers/input/input-polldev.c
index 910220c..5d7fffd 100644
--- a/drivers/input/input-polldev.c
+++ b/drivers/input/input-polldev.c
@@ -46,10 +46,12 @@  static int input_polldev_start_workqueue(void)
 	return retval;
 }
 
-static void input_polldev_stop_workqueue(void)
+static void input_polldev_stop_workqueue(struct input_polled_dev *dev)
 {
 	mutex_lock(&polldev_mutex);
 
+	cancel_delayed_work_sync(&dev->work);
+
 	if (!--polldev_users)
 		destroy_workqueue(polldev_wq);
 
@@ -83,6 +85,8 @@  static int input_open_polled_device(struct input_dev *input)
 	if (dev->open)
 		dev->open(dev);
 
+	dev->is_opened = 1;
+
 	queue_delayed_work(polldev_wq, &dev->work,
 			   msecs_to_jiffies(dev->poll_interval));
 
@@ -93,13 +97,72 @@  static void input_close_polled_device(struct input_dev *input)
 {
 	struct input_polled_dev *dev = input_get_drvdata(input);
 
-	cancel_delayed_work_sync(&dev->work);
-	input_polldev_stop_workqueue();
+	dev->is_opened = 0;
+	input_polldev_stop_workqueue(dev);
 
 	if (dev->close)
 		dev->close(dev);
 }
 
+/* SYSFS interface */
+
+static ssize_t input_polldev_get_interval(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_interval(struct device *dev,
+				struct device_attribute *attr, const char *buf,
+				size_t count)
+{
+	struct input_polled_dev *polldev = dev_get_drvdata(dev);
+	unsigned long delay;
+	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(&polldev_mutex);
+
+	polldev->poll_interval = interval;
+
+	if (polldev->is_opened) {
+		if (polldev->poll_interval > 0) {
+			delay = msecs_to_jiffies(polldev->poll_interval);
+			if (delay >= HZ)
+				delay = round_jiffies_relative(delay);
+
+			queue_delayed_work(polldev_wq, &polldev->work, delay);
+		} else {
+			cancel_delayed_work_sync(&polldev->work);
+		}
+	}
+	mutex_unlock(&polldev_mutex);
+
+	return count;
+}
+
+static DEVICE_ATTR(interval, S_IRUGO | S_IWUSR, input_polldev_get_interval,
+						input_polldev_set_interval);
+
+static struct attribute *sysfs_attrs[] = {
+	&dev_attr_interval.attr,
+	NULL
+};
+
+static struct attribute_group input_polldev_attribute_group = {
+	.attrs = sysfs_attrs
+};
+
 /**
  * input_allocate_polled_device - allocated memory polled device
  *
@@ -153,15 +216,27 @@  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 < 0)
+		goto fail;
+
+	error = sysfs_create_group(&input->dev.kobj,
+				   &input_polldev_attribute_group);
+	if (error < 0)
+		input_unregister_device(input);
+fail:
+	return error;
 }
 EXPORT_SYMBOL(input_register_polled_device);
 
@@ -177,6 +252,9 @@  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 5c0ec68..f2b1e03 100644
--- a/include/linux/input-polldev.h
+++ b/include/linux/input-polldev.h
@@ -36,6 +36,9 @@  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 */
+	int is_opened;
 
 	struct input_dev *input;
 	struct delayed_work work;