《Linux总线、设备与驱动》USBHID设备驱动

转载： http://blog.csdn.net/tankai19880619/article/details/17447791
说明：本分析基于mstar801平台Linux2.6.35.11内核，其他内核版本仅供参考。

一、HID虚拟总线驱动加载

drivers/hid/hid-core.c

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module_init(hid_init);

static int __init hid_init(void){

ret = bus_register(&hid_bus_type); //注册HID虚拟总线

ret = hidraw_init();

}

static struct bus_type hid_bus_type = {

.name = "hid",

.match = hid_bus_match,

.probe = hid_device_probe,

.remove = hid_device_remove,

.uevent = hid_uevent,

};

二、USBHID驱动加载

USBHID驱动同时包含USB总线设备驱动和HID总线设备驱动。

drivers/hid/usbhid/hid-core.c

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static int __init hid_init(void){

retval = hid_register_driver(&hid_usb_driver); //注册HID总线设备驱动

retval = usb_register(&hid_driver); //注册USB总线设备驱动

}

module_init(hid_init);

static struct hid_driver hid_usb_driver = { //一般HID驱动都不实现probe方法

.name = "generic-usb",

.id_table = hid_usb_table,

};

static struct usb_driver hid_driver = { //USB设备驱动方法

.name = "usbhid",

.probe = usbhid_probe,

.disconnect = usbhid_disconnect,

#ifdef CONFIG_PM

.suspend = hid_suspend,

.resume = hid_resume,

.reset_resume = hid_reset_resume,

#endif

.pre_reset = hid_pre_reset,

.post_reset = hid_post_reset,

.id_table = hid_usb_ids,

.supports_autosuspend = 1,

};

三、USBHID设备探测

1.USB总线的设备探测并注册HID设备

USB设备发现机制看如下链接：

《Linux总线、设备与驱动》USB设备发现机制

drivers/hid/usbhid/hid-core.c

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static int usbhid_probe(struct usb_interface *intf, const struct usb_device_id *id){

hid = hid_allocate_device(); //申请HID设备

hid->ll_driver = &usb_hid_driver; //重要！

/*

static struct hid_ll_driver usb_hid_driver = {

.parse = usbhid_parse,

.start = usbhid_start,

.stop = usbhid_stop,

.open = usbhid_open,

.close = usbhid_close,

.power = usbhid_power,

.hidinput_input_event = usb_hidinput_input_event,

};

*/

hid->hiddev_connect = hiddev_connect;

hid->hiddev_disconnect = hiddev_disconnect;

hid->hiddev_hid_event = hiddev_hid_event;

hid->hiddev_report_event = hiddev_report_event;

usb_make_path(dev, hid->phys, sizeof(hid->phys));

strlcat(hid->phys, "/input", sizeof(hid->phys));

if (len < sizeof(hid->phys) - 1)

snprintf(hid->phys + len, sizeof(hid->phys) - len, "%d", intf->altsetting[0].desc.bInterfaceNumber);

ret = hid_add_device(hid); //注册HID设备

}

申请HID设备：

drivers/hid/hid-core.c

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struct hid_device *hid_allocate_device(void){

struct hid_device *hdev;

device_initialize(&hdev->dev);

hdev->dev.release = hid_device_release;

hdev->dev.bus = &hid_bus_type;

}

static struct bus_type hid_bus_type = {

.name = "hid",

.match = hid_bus_match,

.probe = hid_device_probe,

.remove = hid_device_remove,

.uevent = hid_uevent,

};

注册HID设备：

drivers/hid/hid-core.c

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int hid_add_device(struct hid_device *hdev){

ret = device_add(&hdev->dev); //该函数的调用将导致总线对应match和probe的调用

}

2.HID总线的设备探测

参考USB总线探测：/article/2476581.html

drivers/hid/hid-core.c

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//HID总线match函数

static int hid_bus_match(struct device *dev, struct device_driver *drv){

if (!hid_match_device(hdev, hdrv)) //匹配VID和PID

return 0;

if (!strncmp(hdrv->name, "generic-", 8)) //名字为generic-都匹配

return !hid_match_id(hdev, hid_have_special_driver);

}

//HID总线的probe函数

static int hid_device_probe(struct device *dev){

if (hdrv->probe) { //一般HID驱动都没有实现probe方法

ret = hdrv->probe(hdev, id);

} else { /* default probe */

ret = hid_parse(hdev);

/*

include/linux/hid.h

static inline int __must_check hid_parse(struct hid_device *hdev){

ret = hdev->ll_driver->parse(hdev);

if (!ret)

hdev->status |= HID_STAT_PARSED;

return ret;

}

drivers/hid/usbhid/hid-core.c

static int usbhid_parse(struct hid_device *hid){

ret = hid_parse_report(hid, rdesc, rsize);

}

*/

if (!ret)

ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);

/*

include/linux/hid.h

static inline int __must_check hid_hw_start(struct hid_device *hdev,

unsigned int connect_mask){

int ret = hdev->ll_driver->start(hdev);

ret = hid_connect(hdev, connect_mask);

if (ret)

hdev->ll_driver->stop(hdev);

}

drivers/hid/usbhid/hid-core.c

static int usbhid_start(struct hid_device *hid){

}

*/

}

}

int hid_connect(struct hid_device *hdev, unsigned int connect_mask){

static const char *types[] = { "Device", "Pointer", "Mouse", "Device",

"Joystick", "Gamepad", "Keyboard", "Keypad",

"Multi-Axis Controller"

};

//HIDINPUT设备

if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev,connect_mask & HID_CONNECT_HIDINPUT_FORCE))

hdev->claimed |= HID_CLAIMED_INPUT;

//HIDDEV设备

if ((connect_mask & HID_CONNECT_HIDDEV) && hdev->hiddev_connect && !hdev->hiddev_connect(hdev,connect_mask & HID_CONNECT_HIDDEV_FORCE))

hdev->claimed |= HID_CLAIMED_HIDDEV;

//HIDRAW设备

if ((connect_mask & HID_CONNECT_HIDRAW) && !hidraw_connect(hdev))

hdev->claimed |= HID_CLAIMED_HIDRAW;

}

四、具体设备驱动

1.HIDINPUT设备，如走2.4G的遥控器

drivers/hid/hid-input.c

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int hidinput_connect(struct hid_device *hid, unsigned int force){

//申请设备

input_dev = input_allocate_device();

input_dev->event = hid->ll_driver->hidinput_input_event;

input_dev->open = hidinput_open;

input_dev->close = hidinput_close;

input_dev->setkeycode = hidinput_setkeycode;

input_dev->getkeycode = hidinput_getkeycode;

input_dev->name = hid->name;

for (i = 0; i < report->maxfield; i++)

for (j = 0; j < report->field[i]->maxusage; j++)

hidinput_configure_usage(hidinput, report->field[i],report->field[i]->usage + j);

/*

static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_field *field,

struct hid_usage *usage){

switch (usage->hid & HID_USAGE_PAGE) {

case HID_UP_KEYBOARD:

set_bit(EV_REP, input->evbit);

if ((usage->hid & HID_USAGE) < 256) {

if (!hid_keyboard[usage->hid & HID_USAGE]) goto ignore;

map_key_clear(hid_keyboard[usage->hid & HID_USAGE]);

/*

static const unsigned char hid_keyboard[256] = {

0, 0, 0, 0, 30, 48, 46, 32, 18, 33, 34, 35, 23, 36, 37, 38,

50, 49, 24, 25, 16, 19, 31, 20, 22, 47, 17, 45, 21, 44, 2, 3,

4, 5, 6, 7, 8, 9, 10, 11, 28, 1, 14, 15, 57, 12, 13, 26,

27, 43, 43, 39, 40, 41, 51, 52, 53, 58, 59, 60, 61, 62, 63, 64,

65, 66, 67, 68, 87, 88, 99, 70,119,110,102,104,111,107,109,106,

105,108,103, 69, 98, 55, 74, 78, 96, 79, 80, 81, 75, 76, 77, 71,

72, 73, 82, 83, 86,127,116,117,183,184,185,186,187,188,189,190,

191,192,193,194,134,138,130,132,128,129,131,137,133,135,136,113,

115,114,unk,172,194,121,229, 89, 93,124, 92, 94, 95,unk,unk,unk,

122,123, 90, 91, 85,unk,unk,unk,unk,unk,unk,unk,111,unk,unk,unk,

unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,

unk,unk,unk,unk,unk,unk,179,180,unk,unk,unk,unk,unk,unk,unk,unk,

unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,

unk,unk,unk,unk,unk,unk,unk,unk,111,unk,unk,unk,unk,unk,unk,unk,

29, 42, 56,125, 97, 54,100,126,164,166,165,163,161,115,114,113,

150,158,159,128,136,177,178,176,142,152,173,140,unk,unk,unk,unk

};

*/

} else

map_key(KEY_UNKNOWN);

break;

}

}

}

*/

//注册设备

if (hidinput && input_register_device(hidinput->input))

goto out_cleanup;

}

2.HIDDEV设备

drivers/hid/usbhid/hiddev.c

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int hiddev_connect(struct hid_device *hid, unsigned int force){

retval = usb_register_dev(usbhid->intf, &hiddev_class);

}

3.HIDRAW设备，用来与设备做原始的通讯

这个驱动中不会解析任何数据，只是简单的将设备产生的数据传给应用层。

drivers/hid/hidraw.c

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int hidraw_connect(struct hid_device *hid){

dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor), NULL, "%s%d", "hidraw", minor);

}

五、设备移除部分

1.USB总线设备移除触发USBHID中USB驱动部分调用

drivers/hid/usbhid/hid-core.c

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retval = usb_register(&hid_driver);

static struct usb_driver hid_driver = {

.disconnect = usbhid_disconnect,

}

static void usbhid_disconnect(struct usb_interface *intf){

hid_destroy_device(hid); //调用HID总线的设备注销函数

}

2.HID总线驱动

drivers/hid/hid-core.c

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void hid_destroy_device(struct hid_device *hdev){

hid_remove_device(hdev);

}

static void hid_remove_device(struct hid_device *hdev){

device_del(&hdev->dev);

}

//总线设备注销触发总线函数调用：

static struct bus_type hid_bus_type = {

.remove = hid_device_remove,

}

static int hid_device_remove(struct device *dev){

if (hdrv) {

if (hdrv->remove)

hdrv->remove(hdev);

else /* default remove */

hid_hw_stop(hdev);

/*

include/linux/hid.h

static inline void hid_hw_stop(struct hid_device *hdev){

hid_disconnect(hdev);

}

*/

hdev->driver = NULL;

}

}

void hid_disconnect(struct hid_device *hdev){

device_remove_bin_file(&hdev->dev, &dev_bin_attr_report_desc);

if (hdev->claimed & HID_CLAIMED_INPUT)

hidinput_disconnect(hdev); //HIDINPUT设备

if (hdev->claimed & HID_CLAIMED_HIDDEV)

hdev->hiddev_disconnect(hdev); //HIDDEV设备

if (hdev->claimed & HID_CLAIMED_HIDRAW)

hidraw_disconnect(hdev); //HIDRAW设备

}