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>

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index e9c68fedfcff0b90222cf6a48886fe5229f53d94..8cca0af2dbd1b8c84233acadb92c3418d730385f 100644 (file)
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -59,6 +59,27 @@ config HIDRAW
 
        If unsure, say Y.
 
+config UHID
+       tristate "User-space I/O driver support for HID subsystem"
+       depends on HID
+       default n
+       ---help---
+       Say Y here if you want to provide HID I/O Drivers from user-space.
+       This allows to write I/O drivers in user-space and feed the data from
+       the device into the kernel. The kernel parses the HID reports, loads the
+       corresponding HID Device Driver or provides input devices on top of your
+       user-space device.
+
+       This driver cannot be used to parse HID-reports in user-space and write
+       special HID-drivers. You should use hidraw for that.
+       Instead, this driver allows to write the transport-layer driver in
+       user-space like USB-HID and Bluetooth-HID do in kernel-space.
+
+       If unsure, say N.
+
+       To compile this driver as a module, choose M here: the
+       module will be called uhid.
+
 source "drivers/hid/usbhid/Kconfig"
 
 menu "Special HID drivers"

diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index ca6cc9f0485c90d22fb11d0c6deeb6560ac36158..d7061928325e30d8bb70d18169ae9b4a89a74de6 100644 (file)
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -8,6 +8,7 @@ ifdef CONFIG_DEBUG_FS
 endif
 
 obj-$(CONFIG_HID)              += hid.o
+obj-$(CONFIG_UHID)             += uhid.o
 
 obj-$(CONFIG_HID_GENERIC)      += hid-generic.o
 

diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c
new file mode 100644 (file)
index 0000000..5b02d6c
--- /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");