cpia_usb.c

cpia usb摄像头的驱动程序源码。需要video4linux和i2c-core支持

/*
 * cpia_usb CPiA USB driver
 *
 * Supports CPiA based parallel port Video Camera's.
 *
 * Copyright (C) 1999        Jochen Scharrlach <[e-mail]>
 * Copyright (C) 1999, 2000  Johannes Erdfelt <[e-mail]>
 *
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/* define _CPIA_DEBUG_ for verbose debug output (see cpia.h) */
/* #define _CPIA_DEBUG_  1 */  

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/usb.h>

#include "cpia.h"

#define USB_REQ_CPIA_GRAB_FRAME			0xC1
#define USB_REQ_CPIA_UPLOAD_FRAME		0xC2
#define  WAIT_FOR_NEXT_FRAME			0
#define  FORCE_FRAME_UPLOAD			1

#define FRAMES_PER_DESC		10
#define CPIA_NUMSBUF		2
#define STREAM_BUF_SIZE		(PAGE_SIZE * 4)
#define SCRATCH_BUF_SIZE	(STREAM_BUF_SIZE * 2)

struct cpia_sbuf {
	char *data;
#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,4,20))
	urb_t *urb;
#else
	struct urb *urb;
#endif
};

#define FRAMEBUF_LEN (CPIA_MAX_FRAME_SIZE+100)
enum framebuf_status {
	FRAME_EMPTY,
	FRAME_READING,
	FRAME_READY,
	FRAME_ERROR,
};

struct framebuf {
	int length;
	enum framebuf_status status;
	u8 data[FRAMEBUF_LEN];
	struct framebuf *next;
};

struct usb_cpia {
	/* Device structure */
	struct usb_device *dev;

	unsigned char iface;
	unsigned int alt;
	wait_queue_head_t wq_stream;

	int cursbuf;		/* Current receiving sbuf */
	struct cpia_sbuf sbuf[CPIA_NUMSBUF];		/* Double buffering */

	int streaming;
	int open;
	int present;
	struct framebuf *buffers[3];
	struct framebuf *curbuff, *workbuff;
};

static int cpia_usb_open(void *privdata, int alt);
static int cpia_usb_registerCallback(void *privdata, void (*cb) (void *cbdata),
			             void *cbdata);
static int cpia_usb_transferCmd(void *privdata, u8 *command, u8 *data);
static int cpia_usb_streamStart(void *privdata);
static int cpia_usb_streamStop(void *privdata);
static int cpia_usb_streamRead(void *privdata, u8 *frame, int noblock);
static int cpia_usb_close(void *privdata);
static int cpia_usb_upload_mode(void *privdata);

#define ABOUT "USB driver for Vision CPiA based cameras"

static struct cpia_camera_ops cpia_usb_ops = {
	cpia_usb_open,
	cpia_usb_registerCallback,
	cpia_usb_transferCmd,
	cpia_usb_streamStart,
	cpia_usb_streamStop,
	cpia_usb_streamRead,
	cpia_usb_close,
	CAM_TYPE_USB,
	cpia_usb_upload_mode,
	0,
	THIS_MODULE
};

static LIST_HEAD(cam_list);
static spinlock_t cam_list_lock_usb;

#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
static void cpia_usb_complete(struct urb *urb)
#else
static void cpia_usb_complete(struct urb *urb, struct pt_regs *regs)
#endif
{
	int i;
	char *cdata;
	struct usb_cpia *ucpia;

	if (!urb || !urb->context)
		return;

	ucpia = (struct usb_cpia *) urb->context;

	if (!ucpia->dev || !ucpia->streaming || !ucpia->present || !ucpia->open)
		return;

	if (ucpia->workbuff->status == FRAME_EMPTY) {
		ucpia->workbuff->status = FRAME_READING;
		ucpia->workbuff->length = 0;
	}
 		  
	for (i = 0; i < urb->number_of_packets; i++) {
		int n = urb->iso_frame_desc[i].actual_length;
		int st = urb->iso_frame_desc[i].status;

		cdata = urb->transfer_buffer + urb->iso_frame_desc[i].offset;

		if (st)
			printk(KERN_DEBUG "cpia data error: [%d] len=%d, status=%X\n", i, n, st);

		if (FRAMEBUF_LEN < ucpia->workbuff->length + n) {
			printk(KERN_DEBUG "cpia: scratch buf overflow!scr_len: %d, n: %d\n", ucpia->workbuff->length, n);
			return;
		}
	    
		if (n) {
			if ((ucpia->workbuff->length > 0) || 
			    (0x19 == cdata[0] && 0x68 == cdata[1])) {
				memcpy(ucpia->workbuff->data + ucpia->workbuff->length, cdata, n);
				ucpia->workbuff->length += n;
			} else
				DBG("Ignoring packet!\n");
		} else {
			if (ucpia->workbuff->length > 4 &&
			    0xff == ucpia->workbuff->data[ucpia->workbuff->length-1] &&
			    0xff == ucpia->workbuff->data[ucpia->workbuff->length-2] &&
			    0xff == ucpia->workbuff->data[ucpia->workbuff->length-3] &&
			    0xff == ucpia->workbuff->data[ucpia->workbuff->length-4]) {
				ucpia->workbuff->status = FRAME_READY;
				ucpia->curbuff = ucpia->workbuff;
				ucpia->workbuff = ucpia->workbuff->next;
				ucpia->workbuff->status = FRAME_EMPTY;
				ucpia->workbuff->length = 0;
		  
				if (waitqueue_active(&ucpia->wq_stream))
					wake_up_interruptible(&ucpia->wq_stream);
			}
		}
	}
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,0))
	/* resubmit */
	urb->dev = ucpia->dev;
	if ((i = usb_submit_urb(urb, GFP_ATOMIC)) != 0)
		printk(KERN_ERR "%s: usb_submit_urb ret %d\n", __FUNCTION__,  i);
#endif
}

static int cpia_usb_upload_mode (void *privdata )
{
	struct usb_cpia *ucpia = (struct usb_cpia *) privdata;
	return ucpia->alt;
}


static int cpia_usb_open(void *privdata, int usb_alt_interface_setting )
{
	struct usb_cpia *ucpia = (struct usb_cpia *) privdata;
#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,4,20))
	urb_t *urb;
#else
	struct urb *urb;
#endif
	int ret, retval = 0, fx, err;
	int alt, frame_size_per_desc;
	
	if (!ucpia)
		return -EINVAL;
	
	/*select alternate usb interface setting */	
	switch (usb_alt_interface_setting) {
	case 3:
		frame_size_per_desc = CPIA_USB_MAX_PACKET_SIZE_ALT_3;
		alt = 3;
		break;
	case 2:
		frame_size_per_desc = CPIA_USB_MAX_PACKET_SIZE_ALT_2;
		alt = 2;
		break;
	case 1:
		frame_size_per_desc = CPIA_USB_MAX_PACKET_SIZE_ALT_1;
		alt = 1;
		break;
	default:
		return -EINVAL;
		break;
	}
	
	ucpia->sbuf[0].data = kmalloc(FRAMES_PER_DESC * frame_size_per_desc, GFP_KERNEL);
	if (!ucpia->sbuf[0].data)
		return -EINVAL;

	ucpia->sbuf[1].data = kmalloc(FRAMES_PER_DESC * frame_size_per_desc, GFP_KERNEL);
	if (!ucpia->sbuf[1].data) {
		retval = -EINVAL;
		goto error_0;
	}
	
	ret = usb_set_interface(ucpia->dev, ucpia->iface, alt);
	if (ret < 0) {
		printk(KERN_ERR "cpia_usb_open: usb_set_interface error (ret = %d)\n", ret);
		retval = -EBUSY;
		goto error_1;
	}
	ucpia->alt = alt;

	ucpia->buffers[0]->status = FRAME_EMPTY;
	ucpia->buffers[0]->length = 0;
	ucpia->buffers[1]->status = FRAME_EMPTY;
	ucpia->buffers[1]->length = 0;
	ucpia->buffers[2]->status = FRAME_EMPTY;
	ucpia->buffers[2]->length = 0;
	ucpia->curbuff = ucpia->buffers[0];
	ucpia->workbuff = ucpia->buffers[1];

#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
	/* We double buffer the Iso lists */
	urb = usb_alloc_urb(FRAMES_PER_DESC);
#else
	/* We double buffer the Iso lists, and also know the polling
	 * interval is every frame (1 == (1 << (bInterval -1))).
	 */
	urb = usb_alloc_urb(FRAMES_PER_DESC, GFP_KERNEL);
#endif
	if (!urb) {
		printk(KERN_ERR "cpia_init_isoc: usb_alloc_urb 0\n");
		retval = -ENOMEM;
		goto error_1;
	}

	ucpia->sbuf[0].urb = urb;
	urb->dev = ucpia->dev;
	urb->context = ucpia;
	urb->pipe = usb_rcvisocpipe(ucpia->dev, 1);
#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
	urb->transfer_flags = USB_ISO_ASAP;
#else
	urb->transfer_flags = URB_ISO_ASAP;
#endif
	urb->transfer_buffer = ucpia->sbuf[0].data;
	urb->complete = cpia_usb_complete;
	urb->number_of_packets = FRAMES_PER_DESC;
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,0))
	urb->interval = 1;
#endif
	urb->transfer_buffer_length = frame_size_per_desc * FRAMES_PER_DESC;
	for (fx = 0; fx < FRAMES_PER_DESC; fx++) {
		urb->iso_frame_desc[fx].offset = frame_size_per_desc * fx;
		urb->iso_frame_desc[fx].length = frame_size_per_desc;
	}

#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
	urb = usb_alloc_urb(FRAMES_PER_DESC);
#else
	urb = usb_alloc_urb(FRAMES_PER_DESC, GFP_KERNEL);
#endif
	if (!urb) {
		printk(KERN_ERR "cpia_init_isoc: usb_alloc_urb 1\n");
		retval = -ENOMEM;
		goto error_urb0;
	}

	ucpia->sbuf[1].urb = urb;
	urb->dev = ucpia->dev;
	urb->context = ucpia;
	urb->pipe = usb_rcvisocpipe(ucpia->dev, 1);
#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
	urb->transfer_flags = USB_ISO_ASAP;
#else
	urb->transfer_flags = URB_ISO_ASAP;
#endif
	urb->transfer_buffer = ucpia->sbuf[1].data;
	urb->complete = cpia_usb_complete;
	urb->number_of_packets = FRAMES_PER_DESC;
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,0))
	urb->interval = 1;
#endif
	urb->transfer_buffer_length = frame_size_per_desc * FRAMES_PER_DESC;
	for (fx = 0; fx < FRAMES_PER_DESC; fx++) {
		urb->iso_frame_desc[fx].offset = frame_size_per_desc * fx;
		urb->iso_frame_desc[fx].length = frame_size_per_desc;
	}

#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
	ucpia->sbuf[1].urb->next = ucpia->sbuf[0].urb;
	ucpia->sbuf[0].urb->next = ucpia->sbuf[1].urb;
	
	err = usb_submit_urb(ucpia->sbuf[0].urb);
#else
	/* queue the ISO urbs, and resubmit in the completion handler */
	err = usb_submit_urb(ucpia->sbuf[0].urb, GFP_KERNEL);
#endif
	if (err) {
		printk(KERN_ERR "cpia_init_isoc: usb_submit_urb 0 ret %d\n",
			err);
		goto error_urb1;
	}
#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
	err = usb_submit_urb(ucpia->sbuf[1].urb);
#else
	err = usb_submit_urb(ucpia->sbuf[1].urb, GFP_KERNEL);
#endif
	if (err) {
		printk(KERN_ERR "cpia_init_isoc: usb_submit_urb 1 ret %d\n",
			err);
		goto error_urb1;
	}

	ucpia->streaming = 1;
	ucpia->open = 1;

	return 0;

error_urb1:		/* free urb 1 */
	usb_free_urb(ucpia->sbuf[1].urb);
	ucpia->sbuf[1].urb = NULL;
error_urb0:		/* free urb 0 */
	usb_free_urb(ucpia->sbuf[0].urb);
	ucpia->sbuf[0].urb = NULL;
error_1:
	kfree (ucpia->sbuf[1].data);
	ucpia->sbuf[1].data = NULL;
error_0:
	kfree (ucpia->sbuf[0].data);
	ucpia->sbuf[0].data = NULL;
	
	return retval;
}

//
// convenience functions
//

/****************************************************************************
 *
 *  WritePacket
 *
 ***************************************************************************/
static int WritePacket(struct usb_device *udev, const u8 *packet, u8 *buf, size_t size)
{
	if (!packet)
		return -EINVAL;

	return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
			 packet[1] + (packet[0] << 8),
			 USB_TYPE_VENDOR | USB_RECIP_DEVICE,
			 packet[2] + (packet[3] << 8), 
			 packet[4] + (packet[5] << 8), buf, size, HZ);
}

/****************************************************************************
 *
 *  ReadPacket
 *
 ***************************************************************************/
static int ReadPacket(struct usb_device *udev, u8 *packet, u8 *buf, size_t size)
{
	if (!packet || size <= 0)
		return -EINVAL;