基于Linux内核的USB鼠标驱动的简单实现

#include <linux/kernel.h>

#include <linux/slab.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/usb/input.h>

#include <linux/hid.h>

static struct input_dev *uk_dev;

static char *usb_buf;

static dma_addr_t usb_buf_phys;

static int len;

static struct urb *uk_urb;

static struct usb_device_id usbmouse_as_key_id_table [] = {

{ USB_INTERFACE_INFO(USB_INTERFACE_CLASS_HID, USB_INTERFACE_SUBCLASS_BOOT,

USB_INTERFACE_PROTOCOL_MOUSE) },

//{USB_DEVICE(0x1234,0x5678)},

{ }
/* Terminating entry */

};

static void usbmouse_as_key_irq(struct urb *urb)

{

static unsigned char pre_val;

#if 0

int i;

static int cnt = 0;

printk("data cnt %d: ", ++cnt);

for (i = 0; i < len; i++)

{

printk("%02x ", usb_buf[i]);

}

printk("\n");

#endif

/* USB鼠标数据含义

* data[0]: bit0-左键, 1-按下, 0-松开

* bit1-右键, 1-按下, 0-松开

* bit2-中键, 1-按下, 0-松开

*

*/

if ((pre_val & (1<<0)) != (usb_buf[0] & (1<<0)))

{

/* 左键发生了变化 */

input_event(uk_dev, EV_KEY, KEY_L, (usb_buf[0] & (1<<0)) ? 1 : 0);

input_sync(uk_dev);

}

if ((pre_val & (1<<1)) != (usb_buf[0] & (1<<1)))

{

/* 右键发生了变化 */

input_event(uk_dev, EV_KEY, KEY_S, (usb_buf[0] & (1<<1)) ? 1 : 0);

input_sync(uk_dev);

}

if ((pre_val & (1<<2)) != (usb_buf[0] & (1<<2)))

{

/* 中键发生了变化 */

input_event(uk_dev, EV_KEY, KEY_ENTER, (usb_buf[0] & (1<<2)) ? 1 : 0);

input_sync(uk_dev);

}

pre_val = usb_buf[0];

/* 重新提交urb */

usb_submit_urb(uk_urb, GFP_KERNEL);

}

static int usbmouse_as_key_probe(struct usb_interface *intf,

const struct usb_device_id *id)

{

struct usb_device *dev = interface_to_usbdev(intf);

struct usb_host_interface *interface;

struct usb_endpoint_descriptor *endpoint;

int pipe;

interface = intf->cur_altsetting;

endpoint = &interface->endpoint[0].desc;

/* a. 分配一个input_dev */

uk_dev = input_allocate_device();

/* b. 设置 */

/* b.1 能产生哪类事件 */

set_bit(EV_KEY, uk_dev->evbit);

set_bit(EV_REP, uk_dev->evbit);

/* b.2 能产生哪些事件 */

set_bit(KEY_L, uk_dev->keybit);

set_bit(KEY_S, uk_dev->keybit);

set_bit(KEY_ENTER, uk_dev->keybit);

/* c. 注册 */

input_register_device(uk_dev);

/* d. 硬件相关操作 */

/* 数据传输3要素: 源,目的,长度 */

/* 源: USB设备的某个端点 */

pipe = usb_rcvintpipe(dev, endpoint->bEndpointAddress);

/* 长度: */

len = endpoint->wMaxPacketSize;

/* 目的: */

usb_buf = usb_buffer_alloc(dev, len, GFP_ATOMIC, &usb_buf_phys);

/* 使用"3要素" */

/* 分配usb request block */

uk_urb = usb_alloc_urb(0, GFP_KERNEL);

/* 使用"3要素设置urb" */

usb_fill_int_urb(uk_urb, dev, pipe, usb_buf, len, usbmouse_as_key_irq,

NULL, endpoint->bInterval);

uk_urb->transfer_dma = usb_buf_phys;

uk_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

/* 使用URB */

usb_submit_urb(uk_urb, GFP_KERNEL);

return 0;

}

static void usbmouse_as_key_disconnect(struct usb_interface *intf)

{

struct usb_device *dev = interface_to_usbdev(intf);

//printk("disconnect usbmouse!\n");

usb_kill_urb(uk_urb);

usb_free_urb(uk_urb);

usb_buffer_free(dev, len, usb_buf, usb_buf_phys);

input_unregister_device(uk_dev);

input_free_device(uk_dev);

}

/* 1. 分配/设置usb_driver */

static struct usb_driver usbmouse_as_key_driver = {

.name
= "usbmouse_as_key_",

.probe
= usbmouse_as_key_probe,

.disconnect
= usbmouse_as_key_disconnect,

.id_table
= usbmouse_as_key_id_table,

};

static int usbmouse_as_key_init(void)

{

/* 2. 注册 */

usb_register(&usbmouse_as_key_driver);

return 0;

}

static void usbmouse_as_key_exit(void)

{

usb_deregister(&usbmouse_as_key_driver);

}

module_init(usbmouse_as_key_init);

module_exit(usbmouse_as_key_exit);

MODULE_LICENSE("GPL");