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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: David Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
David Herrmann 2012-06-10 15:16:17 +02:00 committed by Jiri Kosina
parent d937ae5fae
commit 6664ef72a4
1 changed files with 30 additions and 1 deletions
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31
drivers/hid/uhid.c
View File

@ -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 @@ try_again:
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)