diff options
| author | David Herrmann <dh.herrmann@googlemail.com> | 2012-06-10 15:16:17 +0200 |
|---|---|---|
| committer | Colin Cross <ccross@android.com> | 2012-08-16 12:44:28 -0700 |
| commit | d3444a842acc1113febe0ebade74fe18aa99dfee (patch) | |
| tree | a1469adb09fdd7e32fdbf3a1b53e49509bef2bae /drivers/hid | |
| parent | b8dd3d95cafc815793eb7a380be493eb5382710a (diff) | |
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>
Diffstat (limited to 'drivers/hid')
| -rw-r--r-- | drivers/hid/uhid.c | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c index 93860826d629..31e8379cfd15 100644 --- a/drivers/hid/uhid.c +++ b/drivers/hid/uhid.c @@ -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) |