1 files changed, 130 insertions, 14 deletions

diff --git a/drivers/input/input-polldev.c b/drivers/input/input-polldev.c
index 0d3ce7a50fb1..10c9b0a845f0 100644
--- a/drivers/input/input-polldev.c
+++ b/drivers/input/input-polldev.c
@@ -9,6 +9,7 @@
  */
 
 #include <linux/jiffies.h>
+#include <linux/slab.h>
 #include <linux/mutex.h>
 #include <linux/input-polldev.h>
 
@@ -56,14 +57,10 @@ 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 +68,15 @@ 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);
@@ -80,11 +86,12 @@ static int input_open_polled_device(struct input_dev *input)
         if (error)
                 return error;
 
-        if (dev->flush)
-                dev->flush(dev);
+        if (dev->open)
+                dev->open(dev);
 
-        queue_delayed_work(polldev_wq, &dev->work,
-                           msecs_to_jiffies(dev->poll_interval));
+        /* Only start polling if polling is enabled */
+        if (dev->poll_interval > 0)
+                queue_delayed_work(polldev_wq, &dev->work, 0);
 
         return 0;
 }
@@ -94,9 +101,95 @@ 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);
+        /*
+         * Clean up work struct to remove references to the workqueue.
+         * It may be destroyed by the next call. This causes problems
+         * at next device open-close in case of poll_interval == 0.
+         */
+        INIT_DELAYED_WORK(&dev->work, dev->work.work.func);
         input_polldev_stop_workqueue();
+
+        if (dev->close)
+                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
  *
@@ -126,7 +219,7 @@ EXPORT_SYMBOL(input_allocate_polled_device);
  * @dev: device to free
  *
  * The function frees memory allocated for polling device and drops
- * reference to the associated input device (if present).
+ * reference to the associated input device.
  */
 void input_free_polled_device(struct input_polled_dev *dev)
 {
@@ -150,15 +243,38 @@ 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;
+        }
+
+        /*
+         * Take extra reference to the underlying input device so
+         * that it survives call to input_unregister_polled_device()
+         * and is deleted only after input_free_polled_device()
+         * has been invoked. This is needed to ease task of freeing
+         * sparse keymaps.
+         */
+        input_get_device(input);
+
+        return 0;
 }
 EXPORT_SYMBOL(input_register_polled_device);
 
@@ -169,13 +285,13 @@ EXPORT_SYMBOL(input_register_polled_device);
  * The function unregisters previously registered polled input
  * device from input layer. Polling is stopped and device is
  * ready to be freed with call to input_free_polled_device().
- * Callers should not attempt to access dev->input pointer
- * after calling this function.
  */
 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;
 }
 EXPORT_SYMBOL(input_unregister_polled_device);