Commit d870e5ad authored by Zephaniah E. Hull's avatar Zephaniah E. Hull Committed by Vojtech Pavlik

input: Implement input device grabbing so that it is possible to steal

an input device from other handlers and have an exclusive access
to events.
parent 5b29b6f3
......@@ -29,6 +29,7 @@ struct evdev {
char name[16];
struct input_handle handle;
wait_queue_head_t wait;
struct evdev_list *grab;
struct list_head list;
};
......@@ -48,6 +49,17 @@ static void evdev_event(struct input_handle *handle, unsigned int type, unsigned
struct evdev *evdev = handle->private;
struct evdev_list *list;
if (evdev->grab) {
list = evdev->grab;
do_gettimeofday(&list->buffer[list->head].time);
list->buffer[list->head].type = type;
list->buffer[list->head].code = code;
list->buffer[list->head].value = value;
list->head = (list->head + 1) & (EVDEV_BUFFER_SIZE - 1);
kill_fasync(&list->fasync, SIGIO, POLL_IN);
} else
list_for_each_entry(list, &evdev->list, node) {
do_gettimeofday(&list->buffer[list->head].time);
......@@ -88,6 +100,11 @@ static int evdev_release(struct inode * inode, struct file * file)
{
struct evdev_list *list = file->private_data;
if (list->evdev->grab == list) {
input_release_device(&list->evdev->handle);
list->evdev->grab = NULL;
}
evdev_fasync(-1, file, 0);
list_del(&list->node);
......@@ -257,6 +274,22 @@ static int evdev_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
return -EFAULT;
return 0;
case EVIOCGRAB:
if (arg) {
if (evdev->grab)
return -EBUSY;
if (input_grab_device(&evdev->handle))
return -EBUSY;
evdev->grab = list;
return 0;
} else {
if (evdev->grab != list)
return -EINVAL;
input_release_device(&evdev->handle);
evdev->grab = NULL;
return 0;
}
default:
if (_IOC_TYPE(cmd) != 'E' || _IOC_DIR(cmd) != _IOC_READ)
......
......@@ -33,6 +33,8 @@ EXPORT_SYMBOL(input_register_device);
EXPORT_SYMBOL(input_unregister_device);
EXPORT_SYMBOL(input_register_handler);
EXPORT_SYMBOL(input_unregister_handler);
EXPORT_SYMBOL(input_grab_device);
EXPORT_SYMBOL(input_release_device);
EXPORT_SYMBOL(input_open_device);
EXPORT_SYMBOL(input_close_device);
EXPORT_SYMBOL(input_accept_process);
......@@ -175,6 +177,9 @@ void input_event(struct input_dev *dev, unsigned int type, unsigned int code, in
if (type != EV_SYN)
dev->sync = 0;
if (dev->grab)
dev->grab->handler->event(dev->grab, type, code, value);
else
list_for_each_entry(handle, &dev->h_list, d_node)
if (handle->open)
handle->handler->event(handle, type, code, value);
......@@ -201,6 +206,21 @@ int input_accept_process(struct input_handle *handle, struct file *file)
return 0;
}
int input_grab_device(struct input_handle *handle)
{
if (handle->dev->grab)
return -EBUSY;
handle->dev->grab = handle;
return 0;
}
void input_release_device(struct input_handle *handle)
{
if (handle->dev->grab == handle)
handle->dev->grab = NULL;
}
int input_open_device(struct input_handle *handle)
{
if (handle->dev->pm_dev)
......@@ -221,6 +241,7 @@ int input_flush_device(struct input_handle* handle, struct file* file)
void input_close_device(struct input_handle *handle)
{
input_release_device(handle);
if (handle->dev->pm_dev)
pm_dev_idle(handle->dev->pm_dev);
if (handle->dev->close)
......
......@@ -77,6 +77,8 @@ struct input_absinfo {
#define EVIOCRMFF _IOW('E', 0x81, int) /* Erase a force effect */
#define EVIOCGEFFECTS _IOR('E', 0x84, int) /* Report number of effects playable at the same time */
#define EVIOCGRAB _IOW('E', 0x90, int) /* Grab/Release device */
/*
* Event types
*/
......@@ -798,6 +800,8 @@ struct input_dev {
int (*upload_effect)(struct input_dev *dev, struct ff_effect *effect);
int (*erase_effect)(struct input_dev *dev, int effect_id);
struct input_handle *grab;
struct list_head h_list;
struct list_head node;
};
......@@ -888,6 +892,9 @@ void input_unregister_device(struct input_dev *);
void input_register_handler(struct input_handler *);
void input_unregister_handler(struct input_handler *);
int input_grab_device(struct input_handle *);
void input_release_device(struct input_handle *);
int input_open_device(struct input_handle *);
void input_close_device(struct input_handle *);
......
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