HID: uhid: forward raw output reports to user-space
[linux-2.6.git] / drivers / hid / uhid.c
index 5b02d6c..421c492 100644 (file)
 #include <linux/wait.h>
 
 #define UHID_NAME      "uhid"
+#define UHID_BUFSIZE   32
+
+struct uhid_device {
+       struct mutex devlock;
+       bool running;
+
+       __u8 *rd_data;
+       uint rd_size;
+
+       struct hid_device *hid;
+       struct uhid_event input_buf;
+
+       wait_queue_head_t waitq;
+       spinlock_t qlock;
+       __u8 head;
+       __u8 tail;
+       struct uhid_event *outq[UHID_BUFSIZE];
+};
 
 static struct miscdevice uhid_misc;
 
+static void uhid_queue(struct uhid_device *uhid, struct uhid_event *ev)
+{
+       __u8 newhead;
+
+       newhead = (uhid->head + 1) % UHID_BUFSIZE;
+
+       if (newhead != uhid->tail) {
+               uhid->outq[uhid->head] = ev;
+               uhid->head = newhead;
+               wake_up_interruptible(&uhid->waitq);
+       } else {
+               hid_warn(uhid->hid, "Output queue is full\n");
+               kfree(ev);
+       }
+}
+
+static int uhid_queue_event(struct uhid_device *uhid, __u32 event)
+{
+       unsigned long flags;
+       struct uhid_event *ev;
+
+       ev = kzalloc(sizeof(*ev), GFP_KERNEL);
+       if (!ev)
+               return -ENOMEM;
+
+       ev->type = event;
+
+       spin_lock_irqsave(&uhid->qlock, flags);
+       uhid_queue(uhid, ev);
+       spin_unlock_irqrestore(&uhid->qlock, flags);
+
+       return 0;
+}
+
+static int uhid_hid_start(struct hid_device *hid)
+{
+       struct uhid_device *uhid = hid->driver_data;
+
+       return uhid_queue_event(uhid, UHID_START);
+}
+
+static void uhid_hid_stop(struct hid_device *hid)
+{
+       struct uhid_device *uhid = hid->driver_data;
+
+       hid->claimed = 0;
+       uhid_queue_event(uhid, UHID_STOP);
+}
+
+static int uhid_hid_open(struct hid_device *hid)
+{
+       struct uhid_device *uhid = hid->driver_data;
+
+       return uhid_queue_event(uhid, UHID_OPEN);
+}
+
+static void uhid_hid_close(struct hid_device *hid)
+{
+       struct uhid_device *uhid = hid->driver_data;
+
+       uhid_queue_event(uhid, UHID_CLOSE);
+}
+
+static int uhid_hid_input(struct input_dev *input, unsigned int type,
+                         unsigned int code, int value)
+{
+       struct hid_device *hid = input_get_drvdata(input);
+       struct uhid_device *uhid = hid->driver_data;
+       unsigned long flags;
+       struct uhid_event *ev;
+
+       ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
+       if (!ev)
+               return -ENOMEM;
+
+       ev->type = UHID_OUTPUT_EV;
+       ev->u.output_ev.type = type;
+       ev->u.output_ev.code = code;
+       ev->u.output_ev.value = value;
+
+       spin_lock_irqsave(&uhid->qlock, flags);
+       uhid_queue(uhid, ev);
+       spin_unlock_irqrestore(&uhid->qlock, flags);
+
+       return 0;
+}
+
+static int uhid_hid_parse(struct hid_device *hid)
+{
+       struct uhid_device *uhid = hid->driver_data;
+
+       return hid_parse_report(hid, uhid->rd_data, uhid->rd_size);
+}
+
+static int uhid_hid_get_raw(struct hid_device *hid, unsigned char rnum,
+                           __u8 *buf, size_t count, unsigned char rtype)
+{
+       return 0;
+}
+
+static int uhid_hid_output_raw(struct hid_device *hid, __u8 *buf, size_t count,
+                              unsigned char report_type)
+{
+       struct uhid_device *uhid = hid->driver_data;
+       __u8 rtype;
+       unsigned long flags;
+       struct uhid_event *ev;
+
+       switch (report_type) {
+       case HID_FEATURE_REPORT:
+               rtype = UHID_FEATURE_REPORT;
+               break;
+       case HID_OUTPUT_REPORT:
+               rtype = UHID_OUTPUT_REPORT;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       if (count < 1 || count > UHID_DATA_MAX)
+               return -EINVAL;
+
+       ev = kzalloc(sizeof(*ev), GFP_KERNEL);
+       if (!ev)
+               return -ENOMEM;
+
+       ev->type = UHID_OUTPUT;
+       ev->u.output.size = count;
+       ev->u.output.rtype = rtype;
+       memcpy(ev->u.output.data, buf, count);
+
+       spin_lock_irqsave(&uhid->qlock, flags);
+       uhid_queue(uhid, ev);
+       spin_unlock_irqrestore(&uhid->qlock, flags);
+
+       return count;
+}
+
+static struct hid_ll_driver uhid_hid_driver = {
+       .start = uhid_hid_start,
+       .stop = uhid_hid_stop,
+       .open = uhid_hid_open,
+       .close = uhid_hid_close,
+       .hidinput_input_event = uhid_hid_input,
+       .parse = uhid_hid_parse,
+};
+
+static int uhid_dev_create(struct uhid_device *uhid,
+                          const struct uhid_event *ev)
+{
+       struct hid_device *hid;
+       int ret;
+
+       if (uhid->running)
+               return -EALREADY;
+
+       uhid->rd_size = ev->u.create.rd_size;
+       if (uhid->rd_size <= 0 || uhid->rd_size > HID_MAX_DESCRIPTOR_SIZE)
+               return -EINVAL;
+
+       uhid->rd_data = kmalloc(uhid->rd_size, GFP_KERNEL);
+       if (!uhid->rd_data)
+               return -ENOMEM;
+
+       if (copy_from_user(uhid->rd_data, ev->u.create.rd_data,
+                          uhid->rd_size)) {
+               ret = -EFAULT;
+               goto err_free;
+       }
+
+       hid = hid_allocate_device();
+       if (IS_ERR(hid)) {
+               ret = PTR_ERR(hid);
+               goto err_free;
+       }
+
+       strncpy(hid->name, ev->u.create.name, 127);
+       hid->name[127] = 0;
+       strncpy(hid->phys, ev->u.create.phys, 63);
+       hid->phys[63] = 0;
+       strncpy(hid->uniq, ev->u.create.uniq, 63);
+       hid->uniq[63] = 0;
+
+       hid->ll_driver = &uhid_hid_driver;
+       hid->hid_get_raw_report = uhid_hid_get_raw;
+       hid->hid_output_raw_report = uhid_hid_output_raw;
+       hid->bus = ev->u.create.bus;
+       hid->vendor = ev->u.create.vendor;
+       hid->product = ev->u.create.product;
+       hid->version = ev->u.create.version;
+       hid->country = ev->u.create.country;
+       hid->driver_data = uhid;
+       hid->dev.parent = uhid_misc.this_device;
+
+       uhid->hid = hid;
+       uhid->running = true;
+
+       ret = hid_add_device(hid);
+       if (ret) {
+               hid_err(hid, "Cannot register HID device\n");
+               goto err_hid;
+       }
+
+       return 0;
+
+err_hid:
+       hid_destroy_device(hid);
+       uhid->hid = NULL;
+       uhid->running = false;
+err_free:
+       kfree(uhid->rd_data);
+       return ret;
+}
+
+static int uhid_dev_destroy(struct uhid_device *uhid)
+{
+       if (!uhid->running)
+               return -EINVAL;
+
+       uhid->running = false;
+
+       hid_destroy_device(uhid->hid);
+       kfree(uhid->rd_data);
+
+       return 0;
+}
+
+static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev)
+{
+       if (!uhid->running)
+               return -EINVAL;
+
+       hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input.data,
+                        min_t(size_t, ev->u.input.size, UHID_DATA_MAX), 0);
+
+       return 0;
+}
+
 static int uhid_char_open(struct inode *inode, struct file *file)
 {
+       struct uhid_device *uhid;
+
+       uhid = kzalloc(sizeof(*uhid), GFP_KERNEL);
+       if (!uhid)
+               return -ENOMEM;
+
+       mutex_init(&uhid->devlock);
+       spin_lock_init(&uhid->qlock);
+       init_waitqueue_head(&uhid->waitq);
+       uhid->running = false;
+
+       file->private_data = uhid;
+       nonseekable_open(inode, file);
+
        return 0;
 }
 
 static int uhid_char_release(struct inode *inode, struct file *file)
 {
+       struct uhid_device *uhid = file->private_data;
+       unsigned int i;
+
+       uhid_dev_destroy(uhid);
+
+       for (i = 0; i < UHID_BUFSIZE; ++i)
+               kfree(uhid->outq[i]);
+
+       kfree(uhid);
+
        return 0;
 }
 
 static ssize_t uhid_char_read(struct file *file, char __user *buffer,
                                size_t count, loff_t *ppos)
 {
-       return 0;
+       struct uhid_device *uhid = file->private_data;
+       int ret;
+       unsigned long flags;
+       size_t len;
+
+       /* they need at least the "type" member of uhid_event */
+       if (count < sizeof(__u32))
+               return -EINVAL;
+
+try_again:
+       if (file->f_flags & O_NONBLOCK) {
+               if (uhid->head == uhid->tail)
+                       return -EAGAIN;
+       } else {
+               ret = wait_event_interruptible(uhid->waitq,
+                                               uhid->head != uhid->tail);
+               if (ret)
+                       return ret;
+       }
+
+       ret = mutex_lock_interruptible(&uhid->devlock);
+       if (ret)
+               return ret;
+
+       if (uhid->head == uhid->tail) {
+               mutex_unlock(&uhid->devlock);
+               goto try_again;
+       } else {
+               len = min(count, sizeof(**uhid->outq));
+               if (copy_to_user(buffer, &uhid->outq[uhid->tail], len)) {
+                       ret = -EFAULT;
+               } else {
+                       kfree(uhid->outq[uhid->tail]);
+                       uhid->outq[uhid->tail] = NULL;
+
+                       spin_lock_irqsave(&uhid->qlock, flags);
+                       uhid->tail = (uhid->tail + 1) % UHID_BUFSIZE;
+                       spin_unlock_irqrestore(&uhid->qlock, flags);
+               }
+       }
+
+       mutex_unlock(&uhid->devlock);
+       return ret ? ret : len;
 }
 
 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) {
+       case UHID_CREATE:
+               ret = uhid_dev_create(uhid, &uhid->input_buf);
+               break;
+       case UHID_DESTROY:
+               ret = uhid_dev_destroy(uhid);
+               break;
+       case UHID_INPUT:
+               ret = uhid_dev_input(uhid, &uhid->input_buf);
+               break;
+       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)
 {
+       struct uhid_device *uhid = file->private_data;
+
+       poll_wait(file, &uhid->waitq, wait);
+
+       if (uhid->head != uhid->tail)
+               return POLLIN | POLLRDNORM;
+
        return 0;
 }