usb鼠标驱动(一)

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
usb鼠标驱动(一)_第1张图片

//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 , or by paper mail:
 * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
 */

#include 
#include 
#include 
#include 
#include 
#include 

/* 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 "
#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);

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