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Commit 6664ef72 authored by David Herrmann's avatar David Herrmann Committed by Jiri Kosina
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HID: uhid: implement write() on uhid devices 



Similar to read() you can only write() a single event with one call to an
uhid device. To write multiple events use writev() which is supported by
uhid.

We currently always return -EOPNOTSUPP but other events will be added in
later patches.

Signed-off-by: default avatarDavid Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent d937ae5f

drivers/hid/uhid.c

+30 −1
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
struct uhid_device {

	struct mutex devlock;

	struct hid_device *hid;

	struct uhid_event input_buf;



	wait_queue_head_t waitq;

	spinlock_t qlock;
@@ -156,7 +157,35 @@ static ssize_t uhid_char_read(struct file *file, char __user *buffer, 
static ssize_t uhid_char_write(struct file *file, const char __user *buffer,

				size_t count, loff_t *ppos)

{

	return 0;

	struct uhid_device *uhid = file->private_data;

	int ret;

	size_t len;



	/* we need at least the "type" member of uhid_event */

	if (count < sizeof(__u32))

		return -EINVAL;



	ret = mutex_lock_interruptible(&uhid->devlock);

	if (ret)

		return ret;



	memset(&uhid->input_buf, 0, sizeof(uhid->input_buf));

	len = min(count, sizeof(uhid->input_buf));

	if (copy_from_user(&uhid->input_buf, buffer, len)) {

		ret = -EFAULT;

		goto unlock;

	}



	switch (uhid->input_buf.type) {

	default:

		ret = -EOPNOTSUPP;

	}



unlock:

	mutex_unlock(&uhid->devlock);



	/* return "count" not "len" to not confuse the caller */

	return ret ? ret : count;

}



static unsigned int uhid_char_poll(struct file *file, poll_table *wait)