/*
 *	Video4Linux Colour QuickCam driver
 *	Copyright 1997-2000 Philip Blundell <philb@gnu.org>
 *
 *    Module parameters:
 *
 *	parport=auto      -- probe all parports (default)
 *	parport=0         -- parport0 becomes qcam1
 *	parport=2,0,1     -- parports 2,0,1 are tried in that order
 *
 *	probe=0		  -- do no probing, assume camera is present
 *	probe=1		  -- use IEEE-1284 autoprobe data only (default)
 *	probe=2		  -- probe aggressively for cameras
 *
 *	force_rgb=1       -- force data format to RGB (default is BGR)
 *
 * The parport parameter controls which parports will be scanned.
 * Scanning all parports causes some printers to print a garbage page.
 *       -- March 14, 1999  Billy Donahue <billy@escape.com> 
 *
 * Fixed data format to BGR, added force_rgb parameter. Added missing
 * parport_unregister_driver() on module removal.
 *       -- May 28, 2000  Claudio Matsuoka <claudio@conectiva.com>
 */

#include <linux/module.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/parport.h>
#include <linux/sched.h>
#include <linux/videodev.h>
#include <asm/semaphore.h>
#include <asm/uaccess.h>

struct qcam_device {
	struct video_device vdev;
	struct pardevice *pdev;
	struct parport *pport;
	int width, height;
	int ccd_width, ccd_height;
	int mode;
	int contrast, brightness, whitebal;
	int top, left;
	unsigned int bidirectional;
	struct semaphore lock;
};

/* cameras maximum */
#define MAX_CAMS 4

/* The three possible QuickCam modes */
#define QC_MILLIONS	0x18
#define QC_BILLIONS	0x10
#define QC_THOUSANDS	0x08	/* with VIDEC compression (not supported) */

/* The three possible decimations */
#define QC_DECIMATION_1		0
#define QC_DECIMATION_2		2
#define QC_DECIMATION_4		4

#define BANNER "Colour QuickCam for Video4Linux v0.05"

static int parport[MAX_CAMS] = { [1 ... MAX_CAMS-1] = -1 };
static int probe = 2;
static int force_rgb = 0;
static int video_nr = -1;

static inline void qcam_set_ack(struct qcam_device *qcam, unsigned int i)
{
	/* note: the QC specs refer to the PCAck pin by voltage, not
	   software level.  PC ports have builtin inverters. */
	parport_frob_control(qcam->pport, 8, i?8:0);
}

static inline unsigned int qcam_ready1(struct qcam_device *qcam)
{
	return (parport_read_status(qcam->pport) & 0x8)?1:0;
}

static inline unsigned int qcam_ready2(struct qcam_device *qcam)
{
	return (parport_read_data(qcam->pport) & 0x1)?1:0;
}

static unsigned int qcam_await_ready1(struct qcam_device *qcam, 
					     int value)
{
	unsigned long oldjiffies = jiffies;
	unsigned int i;

	for (oldjiffies = jiffies; (jiffies - oldjiffies) < (HZ/25); )
		if (qcam_ready1(qcam) == value)
			return 0;

	/* If the camera didn't respond within 1/25 second, poll slowly 
	   for a while. */
	for (i = 0; i < 50; i++)
	{
		if (qcam_ready1(qcam) == value)
			return 0;
		msleep_interruptible(100);
	}

	/* Probably somebody pulled the plug out.  Not much we can do. */
	printk(KERN_ERR "c-qcam: ready1 timeout (%d) %x %x\n", value,
	       parport_read_status(qcam->pport),
	       parport_read_control(qcam->pport));
	return 1;
}

static unsigned int qcam_await_ready2(struct qcam_device *qcam, int value)
{
	unsigned long oldjiffies = jiffies;
	unsigned int i;

	for (oldjiffies = jiffies; (jiffies - oldjiffies) < (HZ/25); )
		if (qcam_ready2(qcam) == value)
			return 0;

	/* If the camera didn't respond within 1/25 second, poll slowly 
	   for a while. */
	for (i = 0; i < 50; i++)
	{
		if (qcam_ready2(qcam) == value)
			return 0;
		msleep_interruptible(100);
	}

	/* Probably somebody pulled the plug out.  Not much we can do. */
	printk(KERN_ERR "c-qcam: ready2 timeout (%d) %x %x %x\n", value,
	       parport_read_status(qcam->pport),
	       parport_read_control(qcam->pport),
	       parport_read_data(qcam->pport));
	return 1;
}

static int qcam_read_data(struct qcam_device *qcam)
{
	unsigned int idata;
	qcam_set_ack(qcam, 0);
	if (qcam_await_ready1(qcam, 1)) return -1;
	idata = parport_read_status(qcam->pport) & 0xf0;
	qcam_set_ack(qcam, 1);
	if (qcam_await_ready1(qcam, 0)) return -1;
	idata |= (parport_read_status(qcam->pport) >> 4);
	return idata;
}

static int qcam_write_data(struct qcam_device *qcam, unsigned int data)
{
	unsigned int idata;
	parport_write_data(qcam->pport, data);
	idata = qcam_read_data(qcam);
	if (data != idata) 
	{
		printk(KERN_WARNING "cqcam: sent %x but received %x\n", data, 
		       idata);
		return 1;
	} 
	return 0;
}

static inline int qcam_set(struct qcam_device *qcam, unsigned int cmd, unsigned int data)
{
	if (qcam_write_data(qcam, cmd))
		return -1;
	if (qcam_write_data(qcam, data))
		return -1;
	return 0;
}

static inline int qcam_get(struct qcam_device *qcam, unsigned int cmd)
{
	if (qcam_write_data(qcam, cmd))
		return -1;
	return qcam_read_data(qcam);
}

static int qc_detect(struct qcam_device *qcam)
{
	unsigned int stat, ostat, i, count = 0;

	/* The probe routine below is not very reliable.  The IEEE-1284
	   probe takes precedence. */
	/* XXX Currently parport provides no way to distinguish between
	   "the IEEE probe was not done" and "the probe was done, but
	   no device was found".  Fix this one day. */
	if (qcam->pport->probe_info[0].class == PARPORT_CLASS_MEDIA
	    && qcam->pport->probe_info[0].model
	    && !strcmp(qcam->pdev->port->probe_info[0].model, 
		       "Color QuickCam 2.0")) {
		printk(KERN_DEBUG "QuickCam: Found by IEEE1284 probe.\n");
		return 1;
	}
	
	if (probe < 2)
		return 0;

	parport_write_control(qcam->pport, 0xc);

	/* look for a heartbeat */
	ostat = stat = parport_read_status(qcam->pport);
	for (i=0; i<250; i++) 
	{
		mdelay(1);
		stat = parport_read_status(qcam->pport);
		if (ostat != stat) 
		{
			if (++count >= 3) return 1;
			ostat = stat;
		}
	}

	/* Reset the camera and try again */
	parport_write_control(qcam->pport, 0xc);
	parport_write_control(qcam->pport, 0x8);
	mdelay(1);
	parport_write_control(qcam->pport, 0xc);
	mdelay(1);
	count = 0;

	ostat = stat = parport_read_status(qcam->pport);
	for (i=0; i<250; i++) 
	{
		mdelay(1);
		stat = parport_read_status(qcam->pport);
		if (ostat != stat) 
		{
			if (++count >= 3) return 1;
			ostat = stat;
		}
	}

	/* no (or flatline) camera, give up */
	return 0;
}

static void qc_reset(struct qcam_device *qcam)
{
	parport_write_control(qcam->pport, 0xc);
	parport_write_control(qcam->pport, 0x8);
	mdelay(1);
	parport_write_control(qcam->pport, 0xc);
	mdelay(1);          
}

/* Reset the QuickCam and program for brightness, contrast,
 * white-balance, and resolution. */

static void qc_setup(struct qcam_device *q)
{
	qc_reset(q);

	/* Set the brightness.  */
       	qcam_set(q, 11, q->brightness);

	/* Set the height and width.  These refer to the actual
	   CCD area *before* applying the selected decimation.  */
	qcam_set(q, 17, q->ccd_height);
	qcam_set(q, 19, q->ccd_width / 2);

	/* Set top and left.  */
	qcam_set(q, 0xd, q->top);
	qcam_set(q, 0xf, q->left);

	/* Set contrast and white balance.  */
	qcam_set(q, 0x19, q->contrast);
	qcam_set(q, 0x1f, q->whitebal);
	
	/* Set the speed.  */
	qcam_set(q, 45, 2);
}

/* Read some bytes from the camera and put them in the buffer. 
   nbytes should be a multiple of 3, because bidirectional mode gives
   us three bytes at a time.  */

static unsigned int qcam_read_bytes(struct qcam_device *q, unsigned char *buf, unsigned int nbytes)
{
	unsigned int bytes = 0;

	qcam_set_ack(q, 0);
	if (q->bidirectional)
	{
		/* It's a bidirectional port */
		while (bytes < nbytes)
		{
			unsigned int lo1, hi1, lo2, hi2;
			unsigned char r, g, b;

			if (qcam_await_ready2(q, 1)) return bytes;
			lo1 = parport_read_data(q->pport) >> 1;
			hi1 = ((parport_read_status(q->pport) >> 3) & 0x1f) ^ 0x10;
			qcam_set_ack(q, 1);
			if (qcam_await_ready2(q, 0)) return bytes;
			lo2 = parport_read_data(q->pport) >> 1;
			hi2 = ((parport_read_status(q->pport) >> 3) & 0x1f) ^ 0x10;
			qcam_set_ack(q, 0);
			r = (lo1 | ((hi1 & 1)<<7));
			g = ((hi1 & 0x1e)<<3) | ((hi2 & 0x1e)>>1);
			b = (lo2 | ((hi2 & 1)<<7));
			if (force_rgb) {
				buf[bytes++] = r;
				buf[bytes++] = g;
				buf[bytes++] = b;
			} else {
				buf[bytes++] = b;
				buf[bytes++] = g;
				buf[bytes++] = r;
			}
		}
	}
	else
	{
		/* It's a unidirectional port */
		int i = 0, n = bytes;
		unsigned char rgb[3];

		while (bytes < nbytes)
		{
			unsigned int hi, lo;

			if (qcam_await_ready1(q, 1)) return bytes;
			hi = (parport_read_status(q->pport) & 0xf0);
			qcam_set_ack(q, 1);
			if (qcam_await_ready1(q, 0)) return bytes;
			lo = (parport_read_status(q->pport) & 0xf0);
			qcam_set_ack(q, 0);
			/* flip some bits */
			rgb[(i = bytes++ % 3)] = (hi | (lo >> 4)) ^ 0x88;
			if (i >= 2) {
get_fragment:
				if (force_rgb) {
					buf[n++] = rgb[0];
					buf[n++] = rgb[1];
					buf[n++] = rgb[2];
				} else {
					buf[n++] = rgb[2];
					buf[n++] = rgb[1];
					buf[n++] = rgb[0];
				}
			}
		}
		if (i) {
			i = 0;
			goto get_fragment;
		}
	}
	return bytes;
}

#define BUFSZ	150

static long qc_capture(struct qcam_device *q, char __user *buf, unsigned long len)
{
	unsigned lines, pixelsperline, bitsperxfer;
	unsigned int is_bi_dir = q->bidirectional;
	size_t wantlen, outptr = 0;
	char tmpbuf[BUFSZ];

	if (!access_ok(VERIFY_WRITE, buf, len))
		return -EFAULT;

	/* Wait for camera to become ready */
	for (;;)
	{
		int i = qcam_get(q, 41);
		if (i == -1) {
			qc_setup(q);
			return -EIO;
		}
		if ((i & 0x80) == 0)
			break;
		else
			schedule();
	}

	if (qcam_set(q, 7, (q->mode | (is_bi_dir?1:0)) + 1))
		return -EIO;
	
	lines = q->height;
	pixelsperline = q->width;
	bitsperxfer = (is_bi_dir) ? 24 : 8;

	if (is_bi_dir)
	{
		/* Turn the port around */
		parport_data_reverse(q->pport);
		mdelay(3);
		qcam_set_ack(q, 0);
		if (qcam_await_ready1(q, 1)) {
			qc_setup(q);
			return -EIO;
		}
		qcam_set_ack(q, 1);
		if (qcam_await_ready1(q, 0)) {
			qc_setup(q);
			return -EIO;
		}
	}

	wantlen = lines * pixelsperline * 24 / 8;

	while (wantlen)
	{
		size_t t, s;
		s = (wantlen > BUFSZ)?BUFSZ:wantlen;
		t = qcam_read_bytes(q, tmpbuf, s);
		if (outptr < len)
		{
			size_t sz = len - outptr;
			if (sz > t) sz = t;
			if (__copy_to_user(buf+outptr, tmpbuf, sz))
				break;
			outptr += sz;
		}
		wantlen -= t;
		if (t < s)
			break;
		cond_resched();
	}

	len = outptr;

	if (wantlen)
	{
		printk("qcam: short read.\n");
		if (is_bi_dir)
			parport_data_forward(q->pport);
		qc_setup(q);
		return len;
	}

	if (is_bi_dir)
	{
		int l;
		do {
			l = qcam_read_bytes(q, tmpbuf, 3);
			cond_resched();
		} while (l && (tmpbuf[0] == 0x7e || tmpbuf[1] == 0x7e || tmpbuf[2] == 0x7e));
		if (force_rgb) {
			if (tmpbuf[0] != 0xe || tmpbuf[1] != 0x0 || tmpbuf[2] != 0xf)
				printk("qcam: bad EOF\n");
		} else {
			if (tmpbuf[0] != 0xf || tmpbuf[1] != 0x0 || tmpbuf[2] != 0xe)
				printk("qcam: bad EOF\n");
		}
		qcam_set_ack(q, 0);
		if (qcam_await_ready1(q, 1))
		{
			printk("qcam: no ack after EOF\n");
			parport_data_forward(q->pport);
			qc_setup(q);
			return len;
		}
		parport_data_forward(q->pport);
		mdelay(3);
		qcam_set_ack(q, 1);
		if (qcam_await_ready1(q, 0))
		{
			printk("qcam: no ack to port turnaround\n");
			qc_setup(q);
			return len;
		}
	}
	else
	{
		int l;
		do {
			l = qcam_read_bytes(q, tmpbuf, 1);
			cond_resched();
		} while (l && tmpbuf[0] == 0x7e);
		l = qcam_read_bytes(q, tmpbuf+1, 2);
		if (force_rgb) {
			if (tmpbuf[0] != 0xe || tmpbuf[1] != 0x0 || tmpbuf[2] != 0xf)
				printk("qcam: bad EOF\n");
		} else {
			if (tmpbuf[0] != 0xf || tmpbuf[1] != 0x0 || tmpbuf[2] != 0xe)
				printk("qcam: bad EOF\n");
		}
	}

	qcam_write_data(q, 0);
	return len;
}

/*
 *	Video4linux interfacing
 */

static int qcam_do_ioctl(struct inode *inode, struct file *file,
			 unsigned int cmd, void *arg)
{
	struct video_device *dev = video_devdata(file);
	struct qcam_device *qcam=(struct qcam_device *)dev;
	
	switch(cmd)
	{
		case VIDIOCGCAP:
		{
			struct video_capability *b = arg;
			strcpy(b->name, "Quickcam");
			b->type = VID_TYPE_CAPTURE|VID_TYPE_SCALES;
			b->channels = 1;
			b->audios = 0;
			b->maxwidth = 320;
			b->maxheight = 240;
			b->minwidth = 80;
			b->minheight = 60;
			return 0;
		}
		case VIDIOCGCHAN:
		{
			struct video_channel *v = arg;
			if(v->channel!=0)
				return -EINVAL;
			v->flags=0;
			v->tuners=0;
			/* Good question.. its composite or SVHS so.. */
			v->type = VIDEO_TYPE_CAMERA;
			strcpy(v->name, "Camera");
			return 0;
		}
		case VIDIOCSCHAN:
		{
			struct video_channel *v = arg;
			if(v->channel!=0)
				return -EINVAL;
			return 0;
		}
		case VIDIOCGTUNER:
		{
			struct video_tuner *v = arg;
			if(v->tuner)
				return -EINVAL;
			memset(v,0,sizeof(*v));
			strcpy(v->name, "Format");
			v->mode = VIDEO_MODE_AUTO;
			return 0;
		}
		case VIDIOCSTUNER:
		{
			struct video_tuner *v = arg;
			if(v->tuner)
				return -EINVAL;
			if(v->mode!=VIDEO_MODE_AUTO)
				return -EINVAL;
			return 0;
		}
		case VIDIOCGPICT:
		{
			struct video_picture *p = arg;
			p->colour=0x8000;
			p->hue=0x8000;
			p->brightness=qcam->brightness<<8;
			p->contrast=qcam->contrast<<8;
			p->whiteness=qcam->whitebal<<8;
			p->depth=24;
			p->palette=VIDEO_PALETTE_RGB24;
			return 0;
		}
		case VIDIOCSPICT:
		{
			struct video_picture *p = arg;

			/*
			 *	Sanity check args
			 */
			if (p->depth != 24 || p->palette != VIDEO_PALETTE_RGB24)
				return -EINVAL;
			
			/*
			 *	Now load the camera.
			 */
			qcam->brightness = p->brightness>>8;
			qcam->contrast = p->contrast>>8;
			qcam->whitebal = p->whiteness>>8;

			down(&qcam->lock);			
			parport_claim_or_block(qcam->pdev);
			qc_setup(qcam); 
			parport_release(qcam->pdev);
			up(&qcam->lock);
			return 0;
		}
		case VIDIOCSWIN:
		{
			struct video_window *vw = arg;

			if(vw->flags)
				return -EINVAL;
			if(vw->clipcount)
				return -EINVAL;
			if(vw->height<60||vw->height>240)
				return -EINVAL;
			if(vw->width<80||vw->width>320)
				return -EINVAL;
				
			qcam->width = 80;
			qcam->height = 60;
			qcam->mode = QC_DECIMATION_4;
			
			if(vw->width>=160 && vw->height>=120)
			{
				qcam->width = 160;
				qcam->height = 120;
				qcam->mode = QC_DECIMATION_2;
			}
			if(vw->width>=320 && vw->height>=240)
			{
				qcam->width = 320;
				qcam->height = 240;
				qcam->mode = QC_DECIMATION_1;
			}
			qcam->mode |= QC_MILLIONS;
#if 0
			if(vw->width>=640 && vw->height>=480)
			{
				qcam->width = 640;
				qcam->height = 480;
				qcam->mode = QC_BILLIONS | QC_DECIMATION_1;
			}
#endif
			/* Ok we figured out what to use from our 
			   wide choice */
			down(&qcam->lock);
			parport_claim_or_block(qcam->pdev);
			qc_setup(qcam);
			parport_release(qcam->pdev);
			up(&qcam->lock);
			return 0;
		}
		case VIDIOCGWIN:
		{
			struct video_window *vw = arg;
			memset(vw, 0, sizeof(*vw));
			vw->width=qcam->width;
			vw->height=qcam->height;
			return 0;
		}
		case VIDIOCKEY:
			return 0;
		case VIDIOCCAPTURE:
		case VIDIOCGFBUF:
		case VIDIOCSFBUF:
		case VIDIOCGFREQ:
		case VIDIOCSFREQ:
		case VIDIOCGAUDIO:
		case VIDIOCSAUDIO:
			return -EINVAL;
		default:
			return -ENOIOCTLCMD;
	}
	return 0;
}

static int qcam_ioctl(struct inode *inode, struct file *file,
		     unsigned int cmd, unsigned long arg)
{
	return video_usercopy(inode, file, cmd, arg, qcam_do_ioctl);
}

static ssize_t qcam_read(struct file *file, char __user *buf,
			 size_t count, loff_t *ppos)
{
	struct video_device *v = video_devdata(file);
	struct qcam_device *qcam=(struct qcam_device *)v;
	int len;

	down(&qcam->lock);
	parport_claim_or_block(qcam->pdev);
	/* Probably should have a semaphore against multiple users */
	len = qc_capture(qcam, buf,count); 
	parport_release(qcam->pdev);
	up(&qcam->lock);
	return len;
}

/* video device template */
static struct file_operations qcam_fops = {
	.owner		= THIS_MODULE,
	.open           = video_exclusive_open,
	.release        = video_exclusive_release,
	.ioctl          = qcam_ioctl,
	.read		= qcam_read,
	.llseek         = no_llseek,
};

static struct video_device qcam_template=
{
	.owner		= THIS_MODULE,
	.name		= "Colour QuickCam",
	.type		= VID_TYPE_CAPTURE,
	.hardware	= VID_HARDWARE_QCAM_C,
	.fops           = &qcam_fops,
};

/* Initialize the QuickCam driver control structure. */

static struct qcam_device *qcam_init(struct parport *port)
{
	struct qcam_device *q;
	
	q = kmalloc(sizeof(struct qcam_device), GFP_KERNEL);
	if(q==NULL)
		return NULL;

	q->pport = port;
	q->pdev = parport_register_device(port, "c-qcam", NULL, NULL,
					  NULL, 0, NULL);

	q->bidirectional = (q->pport->modes & PARPORT_MODE_TRISTATE)?1:0;

	if (q->pdev == NULL) 
	{
		printk(KERN_ERR "c-qcam: couldn't register for %s.\n",
		       port->name);
		kfree(q);
		return NULL;
	}
	
	memcpy(&q->vdev, &qcam_template, sizeof(qcam_template));

	init_MUTEX(&q->lock);
	q->width = q->ccd_width = 320;
	q->height = q->ccd_height = 240;
	q->mode = QC_MILLIONS | QC_DECIMATION_1;
	q->contrast = 192;
	q->brightness = 240;
	q->whitebal = 128;
	q->top = 1;
	q->left = 14;
	return q;
}

static struct qcam_device *qcams[MAX_CAMS];
static unsigned int num_cams = 0;

static int init_cqcam(struct parport *port)
{
	struct qcam_device *qcam;

	if (parport[0] != -1)
	{
		/* The user gave specific instructions */
		int i, found = 0;
		for (i = 0; i < MAX_CAMS && parport[i] != -1; i++)
		{
			if (parport[0] == port->number)
				found = 1;
		}
		if (!found)
			return -ENODEV;
	}

	if (num_cams == MAX_CAMS)
		return -ENOSPC;

	qcam = qcam_init(port);
	if (qcam==NULL)
		return -ENODEV;
		
	parport_claim_or_block(qcam->pdev);

	qc_reset(qcam);
	
	if (probe && qc_detect(qcam)==0)
	{
		parport_release(qcam->pdev);
		parport_unregister_device(qcam->pdev);
		kfree(qcam);
		return -ENODEV;
	}

	qc_setup(qcam);

	parport_release(qcam->pdev);
	
	if (video_register_device(&qcam->vdev, VFL_TYPE_GRABBER, video_nr)==-1)
	{
		printk(KERN_ERR "Unable to register Colour QuickCam on %s\n",
		       qcam->pport->name);
		parport_unregister_device(qcam->pdev);
		kfree(qcam);
		return -ENODEV;
	}

	printk(KERN_INFO "video%d: Colour QuickCam found on %s\n", 
	       qcam->vdev.minor, qcam->pport->name);
	
	qcams[num_cams++] = qcam;

	return 0;
}

static void close_cqcam(struct qcam_device *qcam)
{
	video_unregister_device(&qcam->vdev);
	parport_unregister_device(qcam->pdev);
	kfree(qcam);
}

static void cq_attach(struct parport *port)
{
	init_cqcam(port);
}

static void cq_detach(struct parport *port)
{
	/* Write this some day. */
}

static struct parport_driver cqcam_driver = {
	.name = "cqcam",
	.attach = cq_attach,
	.detach = cq_detach,
};

static int __init cqcam_init (void)
{
	printk(BANNER "\n");

	return parport_register_driver(&cqcam_driver);
}

static void __exit cqcam_cleanup (void)
{
	unsigned int i;

	for (i = 0; i < num_cams; i++)
		close_cqcam(qcams[i]);

	parport_unregister_driver(&cqcam_driver);
}

MODULE_AUTHOR("Philip Blundell <philb@gnu.org>");
MODULE_DESCRIPTION(BANNER);
MODULE_LICENSE("GPL");

/* FIXME: parport=auto would never have worked, surely? --RR */
MODULE_PARM_DESC(parport ,"parport=<auto|n[,n]...> for port detection method\n\
probe=<0|1|2> for camera detection method\n\
force_rgb=<0|1> for RGB data format (default BGR)");
module_param_array(parport, int, NULL, 0);
module_param(probe, int, 0);
module_param(force_rgb, bool, 0);
module_param(video_nr, int, 0);

module_init(cqcam_init);
module_exit(cqcam_cleanup);