usb_device_drv.c

usb设备的Linux驱动程序

/*********************************************
*  Purpose: implement a USB driver for fps2000
*  Scope:   suitable to Linux OS
*  Author:  ZhengKarl
*  History: None
*  Version: 0.1
*/


#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/kref.h>
#include <linux/smp_lock.h>
#include <linux/usb.h>
#include <asm/uaccess.h>


/* Define these values to match your devices */
#define USB_SKEL_VENDOR_ID 0x61a
#define USB_SKEL_PRODUCT_ID 0x200

#define fdbg(format, arg...) printk(KERN_DEBUG __FILE__ ": "  format "\n" , ## arg)

/* table of devices that work with this driver */
static struct usb_device_id skel_table [] = {
	{ USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) },
	{ }     /* Terminating entry */
};
MODULE_DEVICE_TABLE (usb, skel_table);


/* Get a minor range for your devices from the usb maintainer */
#define USB_SKEL_MINOR_BASE 192

/* Structure to hold all of our device specific stuff */
struct usb_skel {
	struct usb_device * udev;   /* the usb device for this device */
	struct usb_interface * interface;  /* the interface for this device */
	unsigned char *  bulk_in_buffer;  /* the buffer to receive data */
	size_t   bulk_in_size;  /* the size of the receive buffer */
	__u8   bulk_in_endpointAddr; /* the address of the bulk in endpoint */
	__u8   bulk_out_endpointAddr; /* the address of the bulk out endpoint */
	struct kref  kref;
};
#define to_skel_dev(d) container_of(d, struct usb_skel, kref)

static struct usb_driver skel_driver;

static int fps200_usb_writeRegister(struct usb_device *usbdev,
									int reg, unsigned char data){
	int i;
	i = usb_control_msg(usbdev, /* the device */
		usb_sndctrlpipe(usbdev, 0),  /* pipe */
		0xc2,   /*  FPS200_USB_WRITE_REQUEST,  request */ 
		USB_TYPE_VENDOR | USB_DIR_OUT |
		USB_RECIP_DEVICE,/* bmRequestType */
		(data << 8) | reg, /* value */
		0, /* index */
		NULL,
		0,
		(100*HZ));
	if(i<0)
	{
		fdbg("write register error!error code:%d,0x%x",i,i);
		fdbg("\nENODEV = %d,0x%x",ENODEV, -ENODEV);
	}
	
	i = usb_control_msg(usbdev, /* the device */
		usb_sndctrlpipe(usbdev, 128),  /* pipe */
		0xc2,   /*  FPS200_USB_WRITE_REQUEST,  request */ 
		USB_TYPE_VENDOR | USB_DIR_OUT |
		USB_RECIP_DEVICE,/* bmRequestType */
		(data << 8) | reg, /* value */
		0, /* index */
		NULL,
		0,
		(100*HZ));
	if(i<0)
	{
		fdbg("write register error at Endpoint 128!error code:%d,0x%x",i,i);
	}
	else
	{
		fdbg("write register secceed at Endpoint 128!!");
	}
	i = usb_control_msg(usbdev, /* the device */
		usb_sndctrlpipe(usbdev, 129),  /* pipe */
		0xc2,   /*  FPS200_USB_WRITE_REQUEST,  request */ 
		USB_TYPE_VENDOR | USB_DIR_OUT |
		USB_RECIP_DEVICE,/* bmRequestType */
		(data << 8) | reg, /* value */
		0, /* index */
		NULL,
		0,
		(100*HZ));
	if(i<0)
	{
		fdbg("write register error at Endpoint 129!error code:%d,0x%x",i,i);
	}
	else
	{
		fdbg("write register secceed at Endpoint 129!!");
		
	}
	
	return i;
	
}


static void skel_delete(struct kref *kref)
{ 
	struct usb_skel *dev = to_skel_dev(kref);
	
	usb_put_dev(dev->udev);
	kfree (dev->bulk_in_buffer);
	kfree (dev);
}

static int skel_open(struct inode *inode, struct file *file)
{
	struct usb_skel *dev;
	struct usb_interface *interface;
	int subminor;
	int retval = 0;
	
	subminor = iminor(inode);
	
	interface = usb_find_interface(&skel_driver, subminor);
	if (!interface) {
		err ("%s - error, can't find device for minor %d",
			__FUNCTION__, subminor);
		retval = -ENODEV;
		goto exit;
	}
	
	dev = usb_get_intfdata(interface);
	if (!dev) {
		retval = -ENODEV;
		goto exit;
	}
	
	/* increment our usage count for the device */
	kref_get(&dev->kref);
	
	/* save our object in the file's private structure */
	file->private_data = dev;
	
exit:
	return retval;
}

static int skel_release(struct inode *inode, struct file *file)
{
	struct usb_skel *dev;
	
	dev = (struct usb_skel *)file->private_data;
	if (dev == NULL)
		return -ENODEV;
	
	/* decrement the count on our device */
	kref_put(&dev->kref, skel_delete);
	return 0;
}

static ssize_t skel_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
{
	struct usb_skel *dev;
	int retval = 0;
	
	dev = (struct usb_skel *)file->private_data;
	
	/* do a blocking bulk read to get data from the device */
	retval = usb_bulk_msg(dev->udev,
		usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr),
		dev->bulk_in_buffer,
		min(dev->bulk_in_size, count),
		&count, HZ*10);
	
	/* if the read was successful, copy the data to userspace */
	if (!retval) {
		if (copy_to_user(buffer, dev->bulk_in_buffer, count))
			retval = -EFAULT;
		else
			retval = count;
	}
	
	return retval;
}

static void skel_write_bulk_callback(struct urb *urb, struct pt_regs *regs)
{
	/* sync/async unlink faults aren't errors */
	if (urb->status &&
		!(urb->status == -ENOENT ||
		urb->status == -ECONNRESET ||
		urb->status == -ESHUTDOWN)) {
		dbg("%s - nonzero write bulk status received: %d",
			__FUNCTION__, urb->status);
	}
	
	/* free up our allocated buffer */
	usb_buffer_free(urb->dev, urb->transfer_buffer_length,
		urb->transfer_buffer, urb->transfer_dma);
}

static ssize_t skel_write(struct file *file, const char __user *user_buffer, size_t count, loff_t *ppos)
{
	struct usb_skel *dev;
	int retval = 0;
	struct urb *urb = NULL;
	char *buf = NULL;
	
	dev = (struct usb_skel *)file->private_data;
	
	/* verify that we actually have some data to write */
	if (count == 0)
		goto exit;
	
	/* create a urb, and a buffer for it, and copy the data to the urb */
	urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!urb) {
		retval = -ENOMEM;
		goto error;
	}
	
	buf = usb_buffer_alloc(dev->udev, count, GFP_KERNEL, &urb->transfer_dma);
	if (!buf) {
		retval = -ENOMEM;
		goto error;
	}
	if (copy_from_user(buf, user_buffer, count)) {
		retval = -EFAULT;
		goto error;
	}
	
	/* initialize the urb properly */
	usb_fill_bulk_urb(urb, dev->udev,
		usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr),
		buf, count, skel_write_bulk_callback, dev);
	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
	
	/* send the data out the bulk port */
	retval = usb_submit_urb(urb, GFP_KERNEL);
	if (retval) {
		err("%s - failed submitting write urb, error %d", __FUNCTION__, retval);
		goto error;
	}
	
	/* release our reference to this urb, the USB core will eventually free it entirely */
	usb_free_urb(urb);
	
exit:
	return count;
	
error:
	usb_buffer_free(dev->udev, count, buf, urb->transfer_dma);
	usb_free_urb(urb);
	kfree(buf);
	return retval;
}

static struct file_operations skel_fops = {
	.owner = THIS_MODULE,
		.read =  skel_read,
		.write = skel_write,
		.open =  skel_open,
		.release = skel_release,
};

/*
* usb class driver info in order to get a minor number from the usb core,
* and to have the device registered with devfs and the driver core
*/
static struct usb_class_driver skel_class = {
	.name = "usb/skel%d",
		.fops = &skel_fops,
		.mode = S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH,
		.minor_base = USB_SKEL_MINOR_BASE,
};

static int skel_probe(struct usb_interface *interface, const struct usb_device_id *id)
{
	struct usb_skel *dev = NULL;
	struct usb_host_interface *iface_desc;
	struct usb_endpoint_descriptor *endpoint;
	size_t buffer_size;
	int i;
	int retval = -ENOMEM;
	
	int errorcode;
	
	/* allocate memory for our device state and initialize it */
	dev = kmalloc(sizeof(struct usb_skel), GFP_KERNEL);
	if (dev == NULL) {
		err("Out of memory");
		goto error;
	}
	memset(dev, 0x00, sizeof (*dev));
	kref_init(&dev->kref);
	
	dev->udev = usb_get_dev(interface_to_usbdev(interface));
	dev->interface = interface;
	
	fdbg("Now usbdev = %x\n", dev->udev);
	
	/* set up the endpoint information */
	/* use only the first bulk-in and bulk-out endpoints */
	iface_desc = interface->cur_altsetting;
	
	fdbg("There are %d Endpoints in the interface\n", iface_desc->desc.bNumEndpoints);
	
	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i)
	{
		endpoint = &iface_desc->endpoint[i].desc;
		
		fdbg("endpoint %d bmAttributes: 0x%x\n", i, endpoint->bmAttributes);
		
		if (!dev->bulk_in_endpointAddr &&
			(endpoint->bEndpointAddress & USB_DIR_IN) &&
			((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
			== USB_ENDPOINT_XFER_BULK))
		{
			/* we found a bulk in endpoint */
			fdbg("We find an bulk in Endpoint at %d", endpoint->bEndpointAddress);
			buffer_size = endpoint->wMaxPacketSize;
			dev->bulk_in_size = buffer_size;
			dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
			dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
			if (!dev->bulk_in_buffer)
			{
				err("Could not allocate bulk_in_buffer");
				goto error;
			}
		}
		
		if((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
			== USB_ENDPOINT_XFER_CONTROL)
		{
			fdbg("We find an control Endpoint at %d", endpoint->bEndpointAddress);
		}
		
		if (!dev->bulk_out_endpointAddr &&
			!(endpoint->bEndpointAddress & USB_DIR_IN) &&
			((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
			== USB_ENDPOINT_XFER_BULK)) {
			/* we found a bulk out endpoint */
			fdbg("We find an bulk in Endpoint at %d", endpoint->bEndpointAddress);
			dev->bulk_out_endpointAddr = endpoint->bEndpointAddress;
		}
	}
	
	/* save our data pointer in this interface device */
	usb_set_intfdata(interface, dev);
	
	/* we can register the device now, as it is ready */
	retval = usb_register_dev(interface, &skel_class);
	if (retval) {
		/* something prevented us from registering this driver */
		err("Not able to get a minor for this device.");
		usb_set_intfdata(interface, NULL);
		goto error;
	}
	
	/* let the user know what node this device is now attached to */
	info("USB Skeleton device now attached to USBSkel-%d", interface->minor);
	errorcode = fps200_usb_writeRegister(dev->udev, 0x06, 10);
	if (errorcode < 0)
	{
		fdbg("write register erro code:%d", errorcode);
	}
    fdbg("usb device state: %d", dev->udev->state);
	
	return 0;
	
error:
	if (dev)
		kref_put(&dev->kref, skel_delete);
	return retval;
}

static void skel_disconnect(struct usb_interface *interface)
{
	struct usb_skel *dev;
	int minor = interface->minor;
	
	/* prevent skel_open() from racing skel_disconnect() */
	lock_kernel();
	
	dev = usb_get_intfdata(interface);
	usb_set_intfdata(interface, NULL);
	
	/* give back our minor */
	usb_deregister_dev(interface, &skel_class);
	
	unlock_kernel();
	
	/* decrement our usage count */
	kref_put(&dev->kref, skel_delete);
	
	info("USB Skeleton #%d now disconnected", minor);
}

static struct usb_driver skel_driver = {
	.owner = THIS_MODULE,
		.name = "skeleton",
		.id_table = skel_table,
		.probe = skel_probe,
		.disconnect = skel_disconnect,
};

static int __init usb_skel_init(void)
{
	int result;
	
	/* register this driver with the USB subsystem */
	result = usb_register(&skel_driver);
	if (result)
		err("usb_register failed. Error number %d", result);
	
	return result;
}

static void __exit usb_skel_exit(void)
{
	/* deregister this driver with the USB subsystem */
	usb_deregister(&skel_driver);
}

module_init (usb_skel_init);
module_exit (usb_skel_exit);

MODULE_LICENSE("GPL");