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-rw-r--r--drivers/hid/uhid.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c
index 5b02d6cb0e60..05ef4b05a63e 100644
--- a/drivers/hid/uhid.c
+++ b/drivers/hid/uhid.c
@@ -25,16 +25,81 @@
#include <linux/wait.h>
#define UHID_NAME "uhid"
+#define UHID_BUFSIZE 32
+
+struct uhid_device {
+ struct hid_device *hid;
+
+ 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_char_open(struct inode *inode, struct file *file)
{
+ struct uhid_device *uhid;
+
+ uhid = kzalloc(sizeof(*uhid), GFP_KERNEL);
+ if (!uhid)
+ return -ENOMEM;
+
+ spin_lock_init(&uhid->qlock);
+ init_waitqueue_head(&uhid->waitq);
+
+ 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;
+
+ for (i = 0; i < UHID_BUFSIZE; ++i)
+ kfree(uhid->outq[i]);
+
+ kfree(uhid);
+
return 0;
}

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