de1_drv.c

linux嵌入式课程实践中的一个关于声卡驱动程序 。

/*
 * CY7C67200/300 OTG Design Example Driver
 *
 * Copyright (c) 2002, 2003 by Cypress Semiconductor Inc.
 * 
 *	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.
 *
 *
 *
 * History:
 *
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/fcntl.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/smp_lock.h>
//#include <linux/devfs_fs_kernel.h>
#include <linux/usb.h>
#include "de1_drv.h"

#ifdef CONFIG_USB_DEBUG
	static int debug = 1;
#else
	static int debug;
#endif

/* Use our own dbg macro */
#undef dbg
#define dbg(format, arg...) do { if (debug) printk(KERN_DEBUG __FILE__ ": " format "\n" , ## arg); } while (0)


/* Version Information */
#define DRIVER_VERSION "v0.3"
#define DRIVER_AUTHOR "[e-mail]"
#define DRIVER_DESC "CY7C67200/300 OTG Design Example Driver"
#define DE1_DEVICE_NAME "DE1"

/* Module paramaters */
MODULE_PARM(debug, "i");
MODULE_PARM_DESC(debug, "Debug enabled or not");


/* Define these values to match your device */
#define USB_OTG_DE1_VENDOR_ID	0x04b4
#define USB_OTG_DE1_PRODUCT_ID	0xDE01
#define DEVICE_CONNECTED		1
#define DEVICE_NOTCONNECTED		0
#define DE1_BUFFER_SIZE			64
#define DE1_DEVICE_MAJOR		253
#define A_DEV			0
#define B_DEV 			1

/* table of devices that work with this driver */
static struct usb_device_id otg_de1_table [] = {
	{ USB_DEVICE(USB_OTG_DE1_VENDOR_ID, USB_OTG_DE1_PRODUCT_ID) },
	{ }					/* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, otg_de1_table);

/* Get a minor range for your devices from the usb maintainer */
#define USB_OTG_DE1_MINOR_BASE	200	

/* we can have up to this number of device plugged in at once */
#define MAX_DEVICES		  	1

#define INTERRUPT_REQ_SIZE		4	/* data request size for interrupt endpoint */
#define INTERRUPT_EP_INTERVAL 	100 /* interval for interrupt endpoint in millisecond */
#define DE_REPORT_INVALID	   	0
#define DE_REPORT_VALID			1


/* Structure to hold all of our device specific stuff */
struct USB_OTG_DE1 {
	struct usb_device *	udev;			/* save off the usb device pointer */
	struct usb_interface *	interface;	/* the interface for this device */
	unsigned char		major;			/* the starting minor number for this device */
	unsigned char		connect_state;  /* connect state of the device */

	unsigned char * 	int_in_buffer;	/* the buffer to receive interrupt data */
	int					int_in_size;	/* the size of the receive interrupt buffer */
	struct urb *		int_in_urb;  	/* the urb used to receive interrupt data */
	__u8				int_in_endpointAddr;	/* the address of the interrupt in endpoint */
	__u8				de_rpt_valid;
	unsigned char *		de_rpt_buffer;

	unsigned char * 	int_out_buffer;	/* the buffer to receive interrupt data */
	int					int_out_size;	/* the size of the receive interrupt buffer */
	__u8				int_out_endpointAddr;	/* the address of the interrupt in endpoint */

	unsigned char * 	bulk_in_buffer;	/* the buffer to receive data */
	int					bulk_in_size;	/* the size of the receive buffer */
	__u8				bulk_in_endpointAddr;	/* the address of the bulk in endpoint */

	unsigned char * 	bulk_out_buffer;	/* the buffer to send data */
	int					bulk_out_size;		/* the size of the send buffer */
	struct urb *		bulk_out_urb;  		/* the urb used to send bulk out data */
	__u8				bulk_out_endpointAddr;	/* the address of the bulk in endpoint */

	struct tq_struct	tqueue;			/* task queue for line discipline waking up */
	int					open_count;	 	/* number of times this port has been opened */
	struct semaphore	sem;			/* locks this structure */
};


/* local function prototypes */
static ssize_t 	otg_de1_read	(struct file *file, char *buffer, size_t count, loff_t *ppos);
static ssize_t 	otg_de1_write	(struct file *file, const char *buffer, size_t count, loff_t *ppos);
static int 		otg_de1_ioctl  	(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg);
static int 		otg_de1_open   	(struct inode *inode, struct file *file);
static int 		otg_de1_release	(struct inode *inode, struct file *file);
	
static void * 	otg_de1_probe	(struct usb_device *dev, unsigned int ifnum, const struct usb_device_id *id);
static void 	otg_de1_disconnect	(struct usb_device *dev, void *ptr);

static void 	otg_de1_write_bulk_callback	(struct urb *urb);
static void 	otg_de1_int_in_callback (struct urb *urb);

/* DE1 structure */
static struct USB_OTG_DE1 		*dev = NULL;

/*
 * File operations needed when we register this driver.
 */
static struct file_operations otg_de1_fops = {
	/*
	 * The owner field is part of the module-locking
	 * mechanism. The idea is that the kernel knows
	 * which module to increment the use-counter of
	 * BEFORE it calls the device's open() function.
	 * This also means that the kernel can decrement
	 * the use-counter again before calling release()
	 * or should the open() function fail.
	 *
	 * Not all device structures have an "owner" field
	 * yet. "struct file_operations" and "struct net_device"
	 * do, while "struct tty_driver" does not. If the struct
	 * has an "owner" field, then initialize it to the value
	 * THIS_MODULE and the kernel will handle all module
	 * locking for you automatically. Otherwise, you must
	 * increment the use-counter in the open() function
	 * and decrement it again in the release() function
	 * yourself.
	 */
	owner:		THIS_MODULE,

	read:		otg_de1_read,
	write:		otg_de1_write,
	ioctl:		otg_de1_ioctl,
	open:		otg_de1_open,
	release:	otg_de1_release,
};      


/* usb specific object needed to register this driver with the usb subsystem */
static struct usb_driver otg_de1_driver = {
	name:		"otg_de1",
	probe:		otg_de1_probe,
	disconnect:	otg_de1_disconnect,
	fops:		&otg_de1_fops,
	minor:		USB_OTG_DE1_MINOR_BASE,
	id_table:	otg_de1_table,
};


/**
 *	USB_OTG_DE1_debug_data
 */
static inline void USB_OTG_DE1_debug_data (const char *function, int size, const unsigned char *data)
{
	int i;

	if (!debug)
		return;
	
	printk (KERN_DEBUG __FILE__": %s - length = %d, data = ", 
		function, size);
	for (i = 0; i < size; ++i) {
		printk ("%.2x ", data[i]);
	}
	printk ("\n");
}


/**
 *	otg_de1_delete
 */
static inline void otg_de1_delete (struct USB_OTG_DE1 *dev)
{
	/* Release buffers and URB(s) */

	if (dev != NULL) {
		/* Free bulk in buffer */
		if (dev->bulk_in_buffer != NULL)
			kfree (dev->bulk_in_buffer);

		/* Free bulk out buffer and urb */
		if (dev->bulk_out_buffer != NULL)
			kfree (dev->bulk_out_buffer);
		if (dev->bulk_out_urb != NULL)
			usb_free_urb(dev->bulk_out_urb);

		/* Free interrupt buffer and urb */
		if (dev->int_in_buffer != NULL)
			kfree (dev->int_in_buffer);
		if (dev->int_in_urb != NULL)
			usb_free_urb(dev->int_in_urb);

		/* Free interrupt out buffer */
		if (dev->int_out_buffer != NULL)
			kfree (dev->int_out_buffer);

		/* Free report buffer */
		if (dev->de_rpt_buffer != NULL)
			kfree (dev->de_rpt_buffer);

		/* Free device structure */
		kfree (dev);
	}	
}


/**
 *	otg_de1_open
 */
static int otg_de1_open (struct inode *inode, struct file *file)
{
	int retval = 0;
	
	//info ("Cypress OTG device open");
	dbg(__FUNCTION__);

	if (dev == NULL) {
		dbg(__FUNCTION__ " - object is NULL");
		return -ENODEV;
	}

	if (dev->open_count > 0) {
		err(__FUNCTION__ " - Device already open!");
		return -ENODEV;
	}

	/* Increment our usage count for the module.
	 * This is redundant here, because "struct file_operations"
	 * has an "owner" field. This line is included here soley as
	 * a reference for drivers using lesser structures... ;-)
	 */
	MOD_INC_USE_COUNT;

	/* lock this device */
	down (&dev->sem);

	/* increment our usage count for the driver */
	++dev->open_count;

	/* save our object in the file's private structure */
	file->private_data = dev;

	/* unlock this device */
	up (&dev->sem);

	return retval;
}


/**
 *	otg_de1_release
 */
static int otg_de1_release (struct inode *inode, struct file *file)
{
	int retval = 0;

	if (dev == NULL) {
		dbg (__FUNCTION__ " - object is NULL");
		return -ENODEV;
	}

	/* lock our device */
	down (&dev->sem);

	if (dev->open_count <= 0) {
		dbg (__FUNCTION__ " - device not opened");
		retval = -ENODEV;
		goto exit_not_opened;
	}

	/* decrement our usage count for the device */
	--dev->open_count;
	if (dev->open_count <= 0) {
		/* shutdown any bulk writes that might be going on */
		usb_unlink_urb (dev->bulk_out_urb);

		dev->open_count = 0;
	}

	/* decrement our usage count for the module */
	MOD_DEC_USE_COUNT;

exit_not_opened:
	up (&dev->sem);

	return retval;
}


/**
 *	otg_de1_read
 */
static ssize_t otg_de1_read (struct file *file, char *buffer, size_t count, loff_t *ppos)
{
	int retval = 0;

	if (dev == NULL) {
		dbg (__FUNCTION__ " - object is NULL");
		return -ENODEV;
	}

//	dbg(__FUNCTION__ " - count = %d", count);

	/* lock this object */
	down (&dev->sem);

	/* verify that the device wasn't unplugged */
	if ((dev->udev == NULL) || (dev->connect_state != DEVICE_CONNECTED)){
		up (&dev->sem);
		return -ENODEV;
	}
	
	if (count > 0) {
		/* Do an immediate 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, dev->bulk_in_size,
							&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;
		}
	} else {
  	    dbg(__FUNCTION__ " - read negative or zero bytes");
	}

	/* unlock the device */
	up (&dev->sem);
	return retval;
}


/**
 *	otg_de1_write
 */
static ssize_t otg_de1_write (struct file *file, const char *buffer, size_t count, loff_t *ppos)
{
	ssize_t bytes_written = 0;
	int retval = 0;

	if (dev == NULL) {
		dbg (__FUNCTION__ " - object is NULL");
		return -ENODEV;
	}

//	dbg(__FUNCTION__ " - count = %d", count);

	/* lock this object */
	down (&dev->sem);

	/* verify that the device wasn't unplugged */
	if ((dev->udev == NULL) || (dev->connect_state != DEVICE_CONNECTED)) {
		retval = -ENODEV;
		goto exit;
	}

	/* verify that we actually have some data to write */
	if (count == 0) {
		dbg(__FUNCTION__ " - write request of 0 bytes");
		goto exit;
	}

	/* see if we are already in the middle of a write */
	if (dev->bulk_out_urb->status == -EINPROGRESS) {
		dbg (__FUNCTION__ " - already writing");
		goto exit;
	}
   
	/* we can only write as much as 1 urb will hold */
	bytes_written = (ssize_t) min(count, dev->bulk_out_size);

	/* copy the data from userspace into our urb */
	if (copy_from_user(dev->bulk_out_buffer, buffer, 
			   		   bytes_written)) {
		retval = -EFAULT;
		goto exit;
	}

	/* set up our urb */
	FILL_BULK_URB(dev->bulk_out_urb, dev->udev,