USB设备驱动程序（三）

Linux2.6内核

　#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>　　/* for apple IDs */　#ifdef CONFIG_USB_HID_MODULE　#include "../hid-ids.h"　#endif　　MODULE_AUTHOR(DRIVER_AUTHOR);　MODULE_DESCRIPTION(DRIVER_DESC);　MODULE_LICENSE(DRIVER_LICENSE);　　struct usb_mouse {　char name[128];　char phys[64];　struct usb_device *usbdev;　struct input_dev *dev;　struct urb *irq;　　signed char *data;　dma_addr_t data_dma;　};　　static void usb_mouse_irq(struct urb *urb)　{　struct usb_mouse *mouse = urb->context;　signed char *data = mouse->data;　struct input_dev *dev = mouse->dev;　int 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;　}　　input_report_key(dev, BTN_LEFT,   data[0] & 0x01);　input_report_key(dev, BTN_RIGHT,  data[0] & 0x02);　input_report_key(dev, BTN_MIDDLE, data[0] & 0x04);　input_report_key(dev, BTN_SIDE,   data[0] & 0x08);　input_report_key(dev, BTN_EXTRA,  data[0] & 0x10);　　input_report_rel(dev, REL_X,     data[1]);　input_report_rel(dev, REL_Y,     data[2]);　input_report_rel(dev, REL_WHEEL, data[3]);　　input_sync(dev);　resubmit:　status = usb_submit_urb (urb, GFP_ATOMIC);　if (status)　err ("can't resubmit intr, %s-%s/input0, status %d",　mouse->usbdev->bus->bus_name,　mouse->usbdev->devpath, status);　}　　static int usb_mouse_open(struct input_dev *dev)　{　struct usb_mouse *mouse = input_get_drvdata(dev);　　mouse->irq->dev = mouse->usbdev;　if (usb_submit_urb(mouse->irq, GFP_KERNEL))　return -EIO;　　return 0;　}　　static void usb_mouse_close(struct input_dev *dev)　{　struct usb_mouse *mouse = input_get_drvdata(dev);　　usb_kill_urb(mouse->irq);　}　　static int usb_mouse_probe(struct usb_interface *intf, const struct usb_device_id *id)　{　/* 设备描述 usb_device */　/* 接口描述 usb_interface */　struct usb_device *dev = interface_to_usbdev(intf); 　　/* 接口设置描述 */　struct usb_host_interface *interface;　　/* 端点描述符 */　struct usb_endpoint_descriptor *endpoint;　　　struct usb_mouse *mouse;　struct input_dev *input_dev;　int pipe, maxp;　int error = -ENOMEM;　　/* 获取当前接口设置 */　interface = intf->cur_altsetting;　　　　   /* 根据HID规范，鼠标只有一个端点（不包含0号控制端点）*/　if (interface->desc.bNumEndpoints != 1)　return -ENODEV;　　/* 获取端点0描述符 */　endpoint = &interface->endpoint[0].desc;　　/* 根据HID规范，鼠标唯一的端点应为中断端点 */　if (!usb_endpoint_is_int_in(endpoint))　return -ENODEV;　　/* 生成中断管道 */　pipe = usb_rcvintpipe(dev, endpoint->bEndpointAddress);　　/* 返回该端点能够传输的最大的包长度，鼠标的返回的最大数据包为4个字节。*/  　maxp = usb_maxpacket(dev, pipe, usb_pipeout(pipe));　　/* 创建input设备 */　mouse = kzalloc(sizeof(struct usb_mouse), GFP_KERNEL);　input_dev = input_allocate_device();　if (!mouse || !input_dev)　goto fail1;　　   /* 申请内存空间用于数据传输，data 为指向该空间的地址*/　mouse->data = usb_buffer_alloc(dev, 8, GFP_ATOMIC, &mouse->data_dma);　if (!mouse->data)　goto fail1;　　/* 分配URB */　mouse->irq = usb_alloc_urb(0, GFP_KERNEL);　if (!mouse->irq)　goto fail2;　　mouse->usbdev = dev;　mouse->dev = input_dev;　　if (dev->manufacturer)　strlcpy(mouse->name, dev->manufacturer, sizeof(mouse->name));　　if (dev->product) {　if (dev->manufacturer)　strlcat(mouse->name, " ", sizeof(mouse->name));　strlcat(mouse->name, dev->product, sizeof(mouse->name));　}　　if (!strlen(mouse->name))　snprintf(mouse->name, sizeof(mouse->name),　 "USB HIDBP Mouse %04x:%04x",　 le16_to_cpu(dev->descriptor.idVendor),　 le16_to_cpu(dev->descriptor.idProduct));　　usb_make_path(dev, mouse->phys, sizeof(mouse->phys));　strlcat(mouse->phys, "/input0", sizeof(mouse->phys));　　input_dev->name = mouse->name;　input_dev->phys = mouse->phys;　usb_to_input_id(dev, &input_dev->id);　input_dev->dev.parent = &intf->dev;　　input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);　input_dev->keybit[BIT_WORD(BTN_MOUSE)] = BIT_MASK(BTN_LEFT) |　BIT_MASK(BTN_RIGHT) | BIT_MASK(BTN_MIDDLE);　input_dev->relbit[0] = BIT_MASK(REL_X) | BIT_MASK(REL_Y);　input_dev->keybit[BIT_WORD(BTN_MOUSE)] |= BIT_MASK(BTN_SIDE) |　BIT_MASK(BTN_EXTRA);　input_dev->relbit[0] |= BIT_MASK(REL_WHEEL);　　input_set_drvdata(input_dev, mouse);　　input_dev->open = usb_mouse_open;　input_dev->close = usb_mouse_close;　　/* 初始化中断URB */　usb_fill_int_urb(mouse->irq, dev, pipe, mouse->data,　 (maxp > 8 ? 8 : maxp),　 usb_mouse_irq, mouse, endpoint->bInterval);　mouse->irq->transfer_dma = mouse->data_dma;　mouse->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;　　error = input_register_device(mouse->dev);　if (error)　goto fail3;　　usb_set_intfdata(intf, mouse);　return 0;　　fail3:　usb_free_urb(mouse->irq);　fail2:　usb_buffer_free(dev, 8, mouse->data, mouse->data_dma);　fail1:　input_free_device(input_dev);　kfree(mouse);　return error;　}　　static void usb_mouse_disconnect(struct usb_interface *intf)　{　struct usb_mouse *mouse = usb_get_intfdata (intf);　　usb_set_intfdata(intf, NULL);　if (mouse) {　usb_kill_urb(mouse->irq);　input_unregister_device(mouse->dev);　usb_free_urb(mouse->irq);　usb_buffer_free(interface_to_usbdev(intf), 8, mouse->data, mouse->data_dma);　kfree(mouse);　}　}　　static struct usb_device_id usb_mouse_id_table [] = {　{ USB_INTERFACE_INFO(USB_INTERFACE_CLASS_HID, USB_INTERFACE_SUBCLASS_BOOT,　USB_INTERFACE_PROTOCOL_MOUSE) },　{ }/* Terminating entry */　};　　MODULE_DEVICE_TABLE (usb, usb_mouse_id_table);　　static struct usb_driver usb_mouse_driver = {　.name= "usbmouse",   /* 驱动名 */　.probe= usb_mouse_probe, /* 捕获函数 */　.disconnect= usb_mouse_disconnect, /* 卸载函数 */　.id_table= usb_mouse_id_table, /* 设备列表 */　};　　static int __init usb_mouse_init(void)　{　/* 注册鼠标驱动程序 */　int retval = usb_register(&usb_mouse_driver);　if (retval == 0)　printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"　DRIVER_DESC "\n");　return retval;　}　　static void __exit usb_mouse_exit(void)　{　usb_deregister(&usb_mouse_driver);　}　　module_init(usb_mouse_init);　module_exit(usb_mouse_exit);