[RFC PATCH 3/5] Input: input_reset()

Jason Wessel
2010-11-05T19:05:41Z

From: Dmitry Torokhov <dtor@mail.ru>

Expose part of the logic used to resume from suspend to clear a
keyboard state for use from an exported function called
input_reset_device(). The intended use of the function is allow
reseting the input state after resuming kernel execution from the
kernel debugger.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
---
drivers/input/input.c | 50 ++++++++++++++++++++++++++++++++++--------------
include/linux/input.h | 4 ++-
2 files changed, 38 insertions(+), 16 deletions(-)

diff --git a/drivers/input/input.c b/drivers/input/input.c
index d092ef9..75bed63 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -1565,8 +1565,7 @@ static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env)
} \
} while (0)

-#ifdef CONFIG_PM
-static void input_dev_reset(struct input_dev *dev, bool activate)
+static void input_dev_toggle(struct input_dev *dev, bool activate)
{
if (!dev->event)
return;
@@ -1580,12 +1579,44 @@ static void input_dev_reset(struct input_dev *dev, bool activate)
}
}

+/**
+ * input_reset_device() - reset/restore the state of input device
+ * @dev: input device whose state needs to be reset
+ *
+ * This function tries to reset the state of an opened input device and
+ * bring internal state and state if the hardware in sync with each other.
+ * We mark all keys as released, restore LED state, repeat rate, etc.
+ */
+void input_reset_device(struct input_dev *dev)
+{
+ mutex_lock(&dev->mutex);
+
+ if (dev->users) {
+ input_dev_toggle(dev, true);
+
+ /*
+ * Keys that have been pressed at suspend time are unlikely
+ * to be still pressed when we resume.
+ */
+ spin_lock_irq(&dev->event_lock);
+ input_dev_release_keys(dev);
+ spin_unlock_irq(&dev->event_lock);
+ }
+
+ mutex_unlock(&dev->mutex);
+}
+EXPORT_SYMBOL(input_reset_device);
+
+#ifdef CONFIG_PM
static int input_dev_suspend(struct device *dev)
{
struct input_dev *input_dev = to_input_dev(dev);

mutex_lock(&input_dev->mutex);
- input_dev_reset(input_dev, false);
+
+ if (input_dev->users)
+ input_dev_toggle(input_dev, false);
+
mutex_unlock(&input_dev->mutex);

return 0;
@@ -1595,18 +1626,7 @@ static int input_dev_resume(struct device *dev)
{
struct input_dev *input_dev = to_input_dev(dev);

- mutex_lock(&input_dev->mutex);
- input_dev_reset(input_dev, true);
-
- /*
- * Keys that have been pressed at suspend time are unlikely
- * to be still pressed when we resume.
- */
- spin_lock_irq(&input_dev->event_lock);
- input_dev_release_keys(input_dev);
- spin_unlock_irq(&input_dev->event_lock);
-
- mutex_unlock(&input_dev->mutex);
+ input_reset_device(input_dev);

return 0;
}
diff --git a/include/linux/input.h b/include/linux/input.h
index 51af441..6ef4446 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -1406,6 +1406,8 @@ static inline void input_set_drvdata(struct input_dev *dev, void *data)
int __must_check input_register_device(struct input_dev *);
void input_unregister_device(struct input_dev *);

+void input_reset_device(struct input_dev *);
+
int __must_check input_register_handler(struct input_handler *);
void input_unregister_handler(struct input_handler *);

@@ -1421,7 +1423,7 @@ void input_release_device(struct input_handle *);
int input_open_device(struct input_handle *);
void input_close_device(struct input_handle *);

-int input_flush_device(struct input_handle* handle, struct file* file);
+int input_flush_device(struct input_handle *handle, struct file *file);

void input_event(struct input_dev *dev, unsigned int type, unsigned int code, int value);
void input_inject_event(struct input_handle *handle, unsigned int type, unsigned int code, int value);
--
1.6.3.3