diff options
Diffstat (limited to 'drivers/hid/uhid.c')
| -rw-r--r-- | drivers/hid/uhid.c | 120 |
1 files changed, 119 insertions, 1 deletions
diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c index 421c492dc824..ea560bfa033d 100644 --- a/drivers/hid/uhid.c +++ b/drivers/hid/uhid.c @@ -42,6 +42,12 @@ struct uhid_device { __u8 head; __u8 tail; struct uhid_event *outq[UHID_BUFSIZE]; + + struct mutex report_lock; + wait_queue_head_t report_wait; + atomic_t report_done; + atomic_t report_id; + struct uhid_event report_buf; }; static struct miscdevice uhid_misc; @@ -143,7 +149,84 @@ static int uhid_hid_parse(struct hid_device *hid) static int uhid_hid_get_raw(struct hid_device *hid, unsigned char rnum, __u8 *buf, size_t count, unsigned char rtype) { - return 0; + struct uhid_device *uhid = hid->driver_data; + __u8 report_type; + struct uhid_event *ev; + unsigned long flags; + int ret; + size_t len; + struct uhid_feature_answer_req *req; + + if (!uhid->running) + return -EIO; + + switch (rtype) { + case HID_FEATURE_REPORT: + report_type = UHID_FEATURE_REPORT; + break; + case HID_OUTPUT_REPORT: + report_type = UHID_OUTPUT_REPORT; + break; + case HID_INPUT_REPORT: + report_type = UHID_INPUT_REPORT; + break; + default: + return -EINVAL; + } + + ret = mutex_lock_interruptible(&uhid->report_lock); + if (ret) + return ret; + + ev = kzalloc(sizeof(*ev), GFP_KERNEL); + if (!ev) { + ret = -ENOMEM; + goto unlock; + } + + spin_lock_irqsave(&uhid->qlock, flags); + ev->type = UHID_FEATURE; + ev->u.feature.id = atomic_inc_return(&uhid->report_id); + ev->u.feature.rnum = rnum; + ev->u.feature.rtype = report_type; + + atomic_set(&uhid->report_done, 0); + uhid_queue(uhid, ev); + spin_unlock_irqrestore(&uhid->qlock, flags); + + ret = wait_event_interruptible_timeout(uhid->report_wait, + atomic_read(&uhid->report_done), 5 * HZ); + + /* + * Make sure "uhid->running" is cleared on shutdown before + * "uhid->report_done" is set. + */ + smp_rmb(); + if (!ret || !uhid->running) { + ret = -EIO; + } else if (ret < 0) { + ret = -ERESTARTSYS; + } else { + spin_lock_irqsave(&uhid->qlock, flags); + req = &uhid->report_buf.u.feature_answer; + + if (req->err) { + ret = -EIO; + } else { + ret = 0; + len = min(count, + min_t(size_t, req->size, UHID_DATA_MAX)); + memcpy(buf, req->data, len); + } + + spin_unlock_irqrestore(&uhid->qlock, flags); + } + + atomic_set(&uhid->report_done, 1); + +unlock: + mutex_unlock(&uhid->report_lock); + return ret ? ret : len; } static int uhid_hid_output_raw(struct hid_device *hid, __u8 *buf, size_t count, @@ -265,7 +348,11 @@ static int uhid_dev_destroy(struct uhid_device *uhid) if (!uhid->running) return -EINVAL; + /* clear "running" before setting "report_done" */ uhid->running = false; + smp_wmb(); + atomic_set(&uhid->report_done, 1); + wake_up_interruptible(&uhid->report_wait); hid_destroy_device(uhid->hid); kfree(uhid->rd_data); @@ -284,6 +371,31 @@ static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev) return 0; } +static int uhid_dev_feature_answer(struct uhid_device *uhid, + struct uhid_event *ev) +{ + unsigned long flags; + + if (!uhid->running) + return -EINVAL; + + spin_lock_irqsave(&uhid->qlock, flags); + + /* id for old report; drop it silently */ + if (atomic_read(&uhid->report_id) != ev->u.feature_answer.id) + goto unlock; + if (atomic_read(&uhid->report_done)) + goto unlock; + + memcpy(&uhid->report_buf, ev, sizeof(*ev)); + atomic_set(&uhid->report_done, 1); + wake_up_interruptible(&uhid->report_wait); + +unlock: + spin_unlock_irqrestore(&uhid->qlock, flags); + return 0; +} + static int uhid_char_open(struct inode *inode, struct file *file) { struct uhid_device *uhid; @@ -293,9 +405,12 @@ static int uhid_char_open(struct inode *inode, struct file *file) return -ENOMEM; mutex_init(&uhid->devlock); + mutex_init(&uhid->report_lock); spin_lock_init(&uhid->qlock); init_waitqueue_head(&uhid->waitq); + init_waitqueue_head(&uhid->report_wait); uhid->running = false; + atomic_set(&uhid->report_done, 1); file->private_data = uhid; nonseekable_open(inode, file); @@ -398,6 +513,9 @@ static ssize_t uhid_char_write(struct file *file, const char __user *buffer, case UHID_INPUT: ret = uhid_dev_input(uhid, &uhid->input_buf); break; + case UHID_FEATURE_ANSWER: + ret = uhid_dev_feature_answer(uhid, &uhid->input_buf); + break; default: ret = -EOPNOTSUPP; } |