/* 参考: drivers\hid\usbhid\usbmouse.c */
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/usb.h>
#include <linux/input.h>
#include <linux/hid.h>
struct usb_mouse_as_key_desc {
struct usb_device *dev;
struct usb_interface *intf;
const struct usb_device_id *id;
int pipe, maxp;
int bInterval;
void *data_buffer;
dma_addr_t data_dma;
struct urb *urb;
};
/* 1. 构造usb_driver
* 1.1 id_table : 能支持哪些设备
* 1.2 probe : 记录某些信息, 分配/设置/注册input_dev, 也许也可以在probe里面做"分配/填充/提交URB"
*/
static struct usb_device_id usb_mouse_as_key_id_table [] = {
{ USB_INTERFACE_INFO(USB_INTERFACE_CLASS_HID, USB_INTERFACE_SUBCLASS_BOOT,
USB_INTERFACE_PROTOCOL_MOUSE), .driver_info = (kernel_ulong_t)"it is a mouse", },/*.driver_info = (kernel_ulong_t)"it is a mouse" 可以增加一些probe需要的驱动信息，probe里面会自动得到这些信息*/
{ } /* Terminating entry */
};
static void usb_mouse_as_key_irq(struct urb *urb)
{
struct input_dev *dev = urb->context;
struct usb_mouse_as_key_desc *desc = input_get_drvdata(dev);
signed char *data = desc->data_buffer;
int status;
//printk("%s %s %d, urb->status = %d\n", __FILE__, __FUNCTION__, __LINE__, urb->status);
switch (urb->status) {
case 0: /* success */
break;
case -ECONNRESET: /* unlink */
case -ENOENT:
case -ESHUTDOWN:
return;
/* -EPIPE: should clear the halt */
default: /* error */
goto resubmit; /*如果错误，重新提交*/
}
// printk("data[0] = 0x%x\n", data[1]);
input_report_key(dev, KEY_L, data[1] & 0x01); /*查看鼠标数据格式可知data[1]代表 按键状态 见 07_使用libusb读取鼠标数据.md*/
input_report_key(dev, KEY_S, data[1] & 0x02);
input_report_key(dev, KEY_ENTER, data[1] & 0x04);
input_sync(dev);
resubmit:
status = usb_submit_urb (urb, GFP_ATOMIC);
//printk("%s %s %d, status = %d\n", __FILE__, __FUNCTION__, __LINE__, status);
}
static int usb_mouse_as_key_open(struct input_dev *dev)
{
struct urb *urb;
struct usb_mouse_as_key_desc *desc = input_get_drvdata(dev); /*获取我们之前存入的驱动信息*/
int err;
urb= desc->urb;
printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
err = usb_submit_urb (urb, GFP_KERNEL);
printk("%s %s %d, err = %d\n", __FILE__, __FUNCTION__, __LINE__, err);
return err;
}
static void usb_mouse_as_key_close(struct input_dev *dev)
{
struct usb_mouse_as_key_desc *desc = input_get_drvdata(dev); /*获取我们之前存入的驱动信息*/
/* 取消/释放 URB */
usb_kill_urb(desc->urb);
usb_free_urb(desc->urb);
}
static int usb_mouse_as_key_probe(struct usb_interface *intf, const struct usb_device_id *id)
{
struct usb_device *dev = interface_to_usbdev(intf);
struct input_dev *input_dev;
struct usb_mouse_as_key_desc *desc;
int error;
struct usb_host_interface *interface;
struct usb_endpoint_descriptor *endpoint;
int pipe, maxp;
printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
/* 1. 记录设备信息: intf */
/*判断是不是真正的鼠标*/
interface = intf->cur_altsetting;
if (interface->desc.bNumEndpoints != 1)
return -ENODEV;
endpoint = &interface->endpoint[0].desc;
if (!usb_endpoint_is_int_in(endpoint)) /*如果不是输入端口，说明不是真正的鼠标设备*/
return -ENODEV;
pipe = usb_rcvintpipe(dev, endpoint->bEndpointAddress);
maxp = usb_maxpacket(dev, pipe, usb_pipeout(pipe)); /*管道一次性能够传输的数据*/
desc = kmalloc(sizeof(struct usb_mouse_as_key_desc), GFP_KERNEL);
desc->dev = dev;
desc->intf = intf;
desc->id = id;
desc->pipe = pipe;
desc->maxp = maxp;
desc->bInterval = endpoint->bInterval;
desc->data_buffer = usb_alloc_coherent(dev, maxp, GFP_ATOMIC, &desc->data_dma); /*分配dma*/
//printk("%s %s %d, desc->data_buffer = 0x%x\n", __FILE__, __FUNCTION__, __LINE__, desc->data_buffer);
/* 2. 分配/设置/注册input_dev
* 2.1 能产生哪类事件
* 2.2 能产生这类事件里哪些些事件: L/S/ENTER ,可见 input 框架
* 2.3 设置函数, 比如open
* 2.4 在open函数里: 分配/填充/提交 URB
* 2.5 URB的回调函数: 解析数据, 上报input_event
*/
input_dev = devm_input_allocate_device(&intf->dev); /*里面自带free ，一般带前缀的allocate，里面都自带free*/
input_set_drvdata(input_dev, desc); /*存入一些我们想要的驱动描述信息*/
/* set 1: which type event ? */
__set_bit(EV_KEY, input_dev->evbit);
/* set 2: which event ? */
__set_bit(KEY_L, input_dev->keybit);
__set_bit(KEY_S, input_dev->keybit);
__set_bit(KEY_ENTER, input_dev->keybit);
/* set 3: open */
input_dev->open = usb_mouse_as_key_open;
input_dev->close = usb_mouse_as_key_close;
/* 分配/填充 URB */
desc->urb = usb_alloc_urb(0, GFP_KERNEL);
usb_fill_int_urb(desc->urb,
desc->dev,
desc->pipe,
desc->data_buffer,
(desc->maxp > 8 ? 8 : desc->maxp),
usb_mouse_as_key_irq,
dev, /*context参数会传入回调函数*/
desc->bInterval);
/**如果URB使用DMA Buffer，需要如下的设置**/
desc->urb->transfer_dma = desc->data_dma;
desc->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
error = input_register_device(input_dev);
usb_set_intfdata(intf, input_dev);
return 0;
}
static void usb_mouse_as_key_disconnect(struct usb_interface *intf)
{
struct input_dev *input_dev = usb_get_intfdata (intf);
struct usb_mouse_as_key_desc *desc = input_get_drvdata(input_dev);
usb_free_coherent(desc->dev, desc->maxp, desc->data_buffer, desc->data_dma);
kfree(desc);
input_unregister_device(input_dev);
usb_set_intfdata(intf, NULL);
}
static struct usb_driver usb_mouse_as_key_driver = {
.name = "usbmouse_as_key",
.probe = usb_mouse_as_key_probe,
.disconnect = usb_mouse_as_key_disconnect,
.id_table = usb_mouse_as_key_id_table,
};
/* 入口函数 / 出口函数 */
// module_usb_driver(usb_mouse_as_key_driver);可以使用这个宏一键完成入口函数 / 出口函数 等同于196:208行代码
static int __init usb_mouse_as_key__init(void)
{
printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
return usb_register(&usb_mouse_as_key_driver);
}
static void __exit usb_mouse_as_key__init_exit(void)
{
usb_deregister(&usb_mouse_as_key_driver);
}
module_init(usb_mouse_as_key__init);
module_exit(usb_mouse_as_key__init_exit);
/* 2. 注册usb_driver */
MODULE_LICENSE("GPL");装载该驱动时，首先要卸载原本内核自带的驱动程序
把USB鼠标查到开发板上
先看看原来有哪些设备节点
ls /dev/input/event*
安装驱动程序
insmod usbmouse_as_key.ko
再看看新得到了哪个设备节点
ls /dev/input/event*
执行命令, 假设event4是新节点
hexdump /dev/input/event4
点击鼠标按键即可观察输出信息
第2种测试方法: 执行以下命令，按鼠标左键、右键，再按中键就有输出"ls"
cat /dev/tty0
第3种测试方法: 执行以下命令(注意"<"号前后没有空格)，就可以使用鼠标按键在控制台输入字符
exec 0</dev/tty0
打印内核input信息：
hexdump /dev/input/event* /*具体对应 event几 要自己判断*/