HID: uhid: introduce user-space I/O driver support for HID

This adds a dummy driver that will support user-space I/O drivers for the
HID subsystem. This allows to write transport-level drivers like USB-HID
and Bluetooth-HID in user-space.

Low-Energy Bluetooth needs this to feed HID data that is parsed in
user-space back into the kernel.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 88 insertions, 0 deletions

diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c
new file mode 100644
index 000000000000..5b02d6cb0e60
--- /dev/null
+++ b/drivers/hid/uhid.c
@@ -0,0 +1,88 @@
+/*
+ * User-space I/O driver support for HID subsystem
+ * Copyright (c) 2012 David Herrmann
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ */
+
+#include <linux/atomic.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/hid.h>
+#include <linux/input.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/uhid.h>
+#include <linux/wait.h>
+
+#define UHID_NAME       "uhid"
+
+static struct miscdevice uhid_misc;
+
+static int uhid_char_open(struct inode *inode, struct file *file)
+{
+        return 0;
+}
+
+static int uhid_char_release(struct inode *inode, struct file *file)
+{
+        return 0;
+}
+
+static ssize_t uhid_char_read(struct file *file, char __user *buffer,
+                                size_t count, loff_t *ppos)
+{
+        return 0;
+}
+
+static ssize_t uhid_char_write(struct file *file, const char __user *buffer,
+                                size_t count, loff_t *ppos)
+{
+        return 0;
+}
+
+static unsigned int uhid_char_poll(struct file *file, poll_table *wait)
+{
+        return 0;
+}
+
+static const struct file_operations uhid_fops = {
+        .owner          = THIS_MODULE,
+        .open           = uhid_char_open,
+        .release        = uhid_char_release,
+        .read           = uhid_char_read,
+        .write          = uhid_char_write,
+        .poll           = uhid_char_poll,
+        .llseek         = no_llseek,
+};
+
+static struct miscdevice uhid_misc = {
+        .fops           = &uhid_fops,
+        .minor          = MISC_DYNAMIC_MINOR,
+        .name           = UHID_NAME,
+};
+
+static int __init uhid_init(void)
+{
+        return misc_register(&uhid_misc);
+}
+
+static void __exit uhid_exit(void)
+{
+        misc_deregister(&uhid_misc);
+}
+
+module_init(uhid_init);
+module_exit(uhid_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Herrmann <dh.herrmann@gmail.com>");
+MODULE_DESCRIPTION("User-space I/O driver support for HID subsystem");