Linux USB 鼠标驱动程序详解
注册一个usb driver，这个drvier不是usb设备driver，而是接口driver。
/* use a define to avoid include chaining to get THIS_MODULE & friends */
#define usb_register(driver) \
usb_register_driver(driver, THIS_MODULE, KBUILD_MODNAME)
retval = driver_register(&new_driver->drvwrap.driver);
if (retval)
goto out;
这个probe参数1是一个接口数据结构，表示注册的时接口驱动不是设备驱动，设备驱动在在系统中已经注册好了，是一个通用设备驱动，用来读取设备的描述符，做一些解析。所以我们真正实现的时一个usb接口驱动。
static int usb_mouse_probe(struct usb_interface *intf,const struct usb_device_id *id)；
//表示一个接口
struct usb_interface {
/* array of alternate settings for this interface,
* stored in no particular order */
struct usb_host_interface *altsetting;
struct usb_host_interface *cur_altsetting; /* the currently
* active alternate setting */
unsigned num_altsetting; /* number of alternate settings */
/* If there is an interface association descriptor then it will list
* the associated interfaces */
struct usb_interface_assoc_descriptor *intf_assoc;
int minor; /* minor number this interface is
* bound to */
enum usb_interface_condition condition; /* state of binding */
unsigned sysfs_files_created:1; /* the sysfs attributes exist */
unsigned ep_devs_created:1; /* endpoint "devices" exist */
unsigned unregistering:1; /* unregistration is in progress */
unsigned needs_remote_wakeup:1; /* driver requires remote wakeup */
unsigned needs_altsetting0:1; /* switch to altsetting 0 is pending */
unsigned needs_binding:1; /* needs delayed unbind/rebind */
unsigned resetting_device:1; /* true: bandwidth alloc after reset */
unsigned authorized:1; /* used for interface authorization */
struct device dev; /* interface specific device info */
struct device *usb_dev;
struct work_struct reset_ws; /* for resets in atomic context */
};
#define to_usb_interface(d) container_of(d, struct usb_interface, dev)
usb设备结构体
struct usb_device {
int devnum;
char devpath[16];
u32 route;
enum usb_device_state state;
enum usb_device_speed speed;
unsigned int rx_lanes;
unsigned int tx_lanes;
struct usb_tt *tt;
int ttport;
unsigned int toggle[2];
struct usb_device *parent;
struct usb_bus *bus;
struct usb_host_endpoint ep0;
struct device dev;
struct usb_device_descriptor descriptor;
struct usb_host_bos *bos;
struct usb_host_config *config;
struct usb_host_config *actconfig;
struct usb_host_endpoint *ep_in[16];
struct usb_host_endpoint *ep_out[16];
char **rawdescriptors;
unsigned short bus_mA;
u8 portnum;
u8 level;
unsigned can_submit:1;
unsigned persist_enabled:1;
unsigned have_langid:1;
unsigned authorized:1;
unsigned authenticated:1;
unsigned wusb:1;
unsigned lpm_capable:1;
unsigned usb2_hw_lpm_capable:1;
unsigned usb2_hw_lpm_besl_capable:1;
unsigned usb2_hw_lpm_enabled:1;
unsigned usb2_hw_lpm_allowed:1;
unsigned usb3_lpm_u1_enabled:1;
unsigned usb3_lpm_u2_enabled:1;
int string_langid;
/* static strings from the device */
char *product;
char *manufacturer;
char *serial;
struct list_head filelist;
int maxchild;
u32 quirks;
atomic_t urbnum;
unsigned long active_duration;
#ifdef CONFIG_PM
unsigned long connect_time;
unsigned do_remote_wakeup:1;
unsigned reset_resume:1;
unsigned port_is_suspended:1;
#endif
struct wusb_dev *wusb_dev;
int slot_id;
enum usb_device_removable removable;
struct usb2_lpm_parameters l1_params;
struct usb3_lpm_parameters u1_params;
struct usb3_lpm_parameters u2_params;
unsigned lpm_disable_count;
u16 hub_delay;
};
#define to_usb_device(d) container_of(d, struct usb_device, dev)
int devnum; //usb总线上的一个地址
struct usb_device_descriptor descriptor; //设备描述符
配置描述符，可以有多个配置描述。
struct usb_host_config {
struct usb_config_descriptor desc;
char *string; /* iConfiguration string, if present */
/* List of any Interface Association Descriptors in this
* configuration. */
struct usb_interface_assoc_descriptor *intf_assoc[USB_MAXIADS];
/* the interfaces associated with this configuration,
* stored in no particular order */
struct usb_interface *interface[USB_MAXINTERFACES];
/* Interface information available even when this is not the
* active configuration */
struct usb_interface_cache *intf_cache[USB_MAXINTERFACES];
unsigned char *extra; /* Extra descriptors */
int extralen;
};
/* host-side wrapper for one interface setting’s parsed descriptors */
一个接口设置的解析描述符的主机端包装器
/* host-side wrapper for one interface setting's parsed descriptors */
struct usb_host_interface {
struct usb_interface_descriptor desc;
int extralen;
unsigned char *extra; /* Extra descriptors */
/* array of desc.bNumEndpoints endpoints associated with this
* interface setting. these will be in no particular order.
*/
struct usb_host_endpoint *endpoint;
char *string; /* iInterface string, if present */
};
端点结构体：表示一个端点
//鼠标驱动代码学习。
/*
* Copyright (c) 1999-2001 Vojtech Pavlik
*
* USB HIDBP Mouse support
*/
/*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Should you need to contact me, the author, you can do so either by
* e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
* Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
*/
#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
/*
* Version Information
*/
#define DRIVER_VERSION "v1.6"
#define DRIVER_AUTHOR "Vojtech Pavlik <vojtech@ucw.cz>"
#define DRIVER_DESC "USB HID Boot Protocol mouse driver"
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
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)
dev_err(&mouse->usbdev->dev,
"can't resubmit intr, %s-%s/input0, status %d\n",
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)
{
struct usb_device *dev = interface_to_usbdev(intf);
struct usb_host_interface *interface;
struct usb_endpoint_descriptor *endpoint;
struct usb_mouse *mouse;
struct input_dev *input_dev;
int pipe, maxp;
int error = -ENOMEM;
interface = intf->cur_altsetting;
if (interface->desc.bNumEndpoints != 1)
return -ENODEV;
endpoint = &interface->endpoint[0].desc;
if (!usb_endpoint_is_int_in(endpoint))
return -ENODEV;
pipe = usb_rcvintpipe(dev, endpoint->bEndpointAddress);
maxp = usb_maxpacket(dev, pipe, usb_pipeout(pipe));
mouse = kzalloc(sizeof(struct usb_mouse), GFP_KERNEL);
input_dev = input_allocate_device();
if (!mouse || !input_dev)
goto fail1;
mouse->data = usb_alloc_coherent(dev, 8, GFP_ATOMIC, &mouse->data_dma);
if (!mouse->data)
goto fail1;
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;
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_free_coherent(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_free_coherent(interface_to_usbdev(intf), 8, mouse->data, mouse->data_dma);
kfree(mouse);
}
}
static const 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",
.probe = usb_mouse_probe,
.disconnect = usb_mouse_disconnect,
.id_table = usb_mouse_id_table,
};
module_usb_driver(usb_mouse_driver);