patch-2.4.10 linux/drivers/usb/usbvideo.c

• Lines: 2475
• Date: Fri Sep 7 09:28:37 2001
• Orig file: v2.4.9/linux/drivers/usb/usbvideo.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.9/linux/drivers/usb/usbvideo.c linux/drivers/usb/usbvideo.c
@@ -0,0 +1,2474 @@
+/*
+ * 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, 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#define	__NO_VERSION__		/* Temporary: usbvideo is not a module yet */
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/smp_lock.h>
+#include <linux/vmalloc.h>
+#include <linux/wrapper.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+
+#include <asm/io.h>
+
+#include "usbvideo.h"
+
+#if defined(MAP_NR)
+#define	virt_to_page(v)	MAP_NR(v)	/* Kernels 2.2.x */
+#endif
+
+static int video_nr = -1;
+MODULE_PARM(video_nr, "i");
+
+/*
+ * Local prototypes.
+ */
+#if USES_PROC_FS
+static void usbvideo_procfs_level1_create(usbvideo_t *ut);
+static void usbvideo_procfs_level1_destroy(usbvideo_t *ut);
+static void usbvideo_procfs_level2_create(uvd_t *uvd);
+static void usbvideo_procfs_level2_destroy(uvd_t *uvd);
+static int usbvideo_default_procfs_read_proc(
+	char *page, char **start, off_t off, int count,
+	int *eof, void *data);
+static int usbvideo_default_procfs_write_proc(
+	struct file *file, const char *buffer, 
+	unsigned long count, void *data);
+#endif
+
+/*******************************/
+/* Memory management functions */
+/*******************************/
+
+#define MDEBUG(x)	do { } while(0)		/* Debug memory management */
+
+/* Given PGD from the address space's page table, return the kernel
+ * virtual mapping of the physical memory mapped at ADR.
+ */
+unsigned long usbvideo_uvirt_to_kva(pgd_t *pgd, unsigned long adr)
+{
+	unsigned long ret = 0UL;
+	pmd_t *pmd;
+	pte_t *ptep, pte;
+
+	if (!pgd_none(*pgd)) {
+		pmd = pmd_offset(pgd, adr);
+		if (!pmd_none(*pmd)) {
+			ptep = pte_offset(pmd, adr);
+			pte = *ptep;
+			if (pte_present(pte)) {
+				ret = (unsigned long) page_address(pte_page(pte));
+				ret |= (adr & (PAGE_SIZE-1));
+			}
+		}
+	}
+	MDEBUG(printk("uv2kva(%lx-->%lx)", adr, ret));
+	return ret;
+}
+
+unsigned long usbvideo_uvirt_to_bus(unsigned long adr)
+{
+	unsigned long kva, ret;
+
+	kva = usbvideo_uvirt_to_kva(pgd_offset(current->mm, adr), adr);
+	ret = virt_to_bus((void *)kva);
+	MDEBUG(printk("uv2b(%lx-->%lx)", adr, ret));
+	return ret;
+}
+
+unsigned long usbvideo_kvirt_to_bus(unsigned long adr)
+{
+	unsigned long va, kva, ret;
+
+	va = VMALLOC_VMADDR(adr);
+	kva = usbvideo_uvirt_to_kva(pgd_offset_k(va), va);
+	ret = virt_to_bus((void *)kva);
+	MDEBUG(printk("kv2b(%lx-->%lx)", adr, ret));
+	return ret;
+}
+
+/*
+ * Here we want the physical address of the memory.
+ * This is used when initializing the contents of the
+ * area and marking the pages as reserved.
+ */
+unsigned long usbvideo_kvirt_to_pa(unsigned long adr)
+{
+	unsigned long va, kva, ret;
+
+	va = VMALLOC_VMADDR(adr);
+	kva = usbvideo_uvirt_to_kva(pgd_offset_k(va), va);
+	ret = __pa(kva);
+	MDEBUG(printk("kv2pa(%lx-->%lx)", adr, ret));
+	return ret;
+}
+
+void *usbvideo_rvmalloc(unsigned long size)
+{
+	void *mem;
+	unsigned long adr, page;
+
+	/* Round it off to PAGE_SIZE */
+	size += (PAGE_SIZE - 1);
+	size &= ~(PAGE_SIZE - 1);
+
+	mem = vmalloc_32(size);
+	if (!mem)
+		return NULL;
+
+	memset(mem, 0, size); /* Clear the ram out, no junk to the user */
+	adr = (unsigned long) mem;
+	while (size > 0) {
+		page = usbvideo_kvirt_to_pa(adr);
+		mem_map_reserve(virt_to_page(__va(page)));
+		adr += PAGE_SIZE;
+		if (size > PAGE_SIZE)
+			size -= PAGE_SIZE;
+		else
+			size = 0;
+	}
+
+	return mem;
+}
+
+void usbvideo_rvfree(void *mem, unsigned long size)
+{
+	unsigned long adr, page;
+
+	if (!mem)
+		return;
+
+	size += (PAGE_SIZE - 1);
+	size &= ~(PAGE_SIZE - 1);
+
+	adr=(unsigned long) mem;
+	while (size > 0) {
+		page = usbvideo_kvirt_to_pa(adr);
+		mem_map_unreserve(virt_to_page(__va(page)));
+		adr += PAGE_SIZE;
+		if (size > PAGE_SIZE)
+			size -= PAGE_SIZE;
+		else
+			size = 0;
+	}
+	vfree(mem);
+}
+
+void RingQueue_Initialize(RingQueue_t *rq)
+{
+	assert(rq != NULL);
+	init_waitqueue_head(&rq->wqh);
+}
+
+void RingQueue_Allocate(RingQueue_t *rq, int rqLen)
+{
+	assert(rq != NULL);
+	assert(rqLen > 0);
+	rq->length = rqLen;
+	rq->queue = usbvideo_rvmalloc(rq->length);
+	assert(rq->queue != NULL);
+}
+
+int RingQueue_IsAllocated(const RingQueue_t *rq)
+{
+	if (rq == NULL)
+		return 0;
+	return (rq->queue != NULL) && (rq->length > 0);
+}
+
+void RingQueue_Free(RingQueue_t *rq)
+{
+	assert(rq != NULL);
+	if (RingQueue_IsAllocated(rq)) {
+		usbvideo_rvfree(rq->queue, rq->length);
+		rq->queue = NULL;
+		rq->length = 0;
+	}
+}
+
+int RingQueue_Dequeue(RingQueue_t *rq, unsigned char *dst, int len)
+{
+	int i;
+	assert(rq != NULL);
+	assert(dst != NULL);
+	for (i=0; i < len; i++) {
+		dst[i] = rq->queue[rq->ri];
+		RING_QUEUE_DEQUEUE_BYTES(rq,1);
+	}
+	return len;
+}
+
+int RingQueue_Enqueue(RingQueue_t *rq, const unsigned char *cdata, int n)
+{
+	int enqueued = 0;
+
+	assert(rq != NULL);
+	assert(cdata != NULL);
+	assert(rq->length > 0);
+	while (n > 0) {
+		int m, q_avail;
+
+		/* Calculate the largest chunk that fits the tail of the ring */
+		q_avail = rq->length - rq->wi;
+		if (q_avail <= 0) {
+			rq->wi = 0;
+			q_avail = rq->length;
+		}
+		m = n;
+		assert(q_avail > 0);
+		if (m > q_avail)
+			m = q_avail;
+
+		memmove(rq->queue + rq->wi, cdata, m);
+		RING_QUEUE_ADVANCE_INDEX(rq, wi, m);
+		cdata += m;
+		enqueued += m;
+		n -= m;
+	}
+	return enqueued;
+}
+
+int RingQueue_GetLength(const RingQueue_t *rq)
+{
+	int ri, wi;
+
+	assert(rq != NULL);
+
+	ri = rq->ri;
+	wi = rq->wi;
+	if (ri == wi)
+		return 0;
+	else if (ri < wi)
+		return wi - ri;
+	else
+		return wi + (rq->length - ri);
+}
+
+void RingQueue_InterruptibleSleepOn(RingQueue_t *rq)
+{
+	assert(rq != NULL);
+	interruptible_sleep_on(&rq->wqh);
+}
+
+void RingQueue_WakeUpInterruptible(RingQueue_t *rq)
+{
+	assert(rq != NULL);
+	if (waitqueue_active(&rq->wqh))
+		wake_up_interruptible(&rq->wqh);
+}
+
+/*
+ * usbvideo_VideosizeToString()
+ *
+ * This procedure converts given videosize value to readable string.
+ *
+ * History:
+ * 07-Aug-2000 Created.
+ * 19-Oct-2000 Reworked for usbvideo module.
+ */
+void usbvideo_VideosizeToString(char *buf, int bufLen, videosize_t vs)
+{
+	char tmp[40];
+	int n;
+
+	n = 1 + sprintf(tmp, "%ldx%ld", VIDEOSIZE_X(vs), VIDEOSIZE_Y(vs));
+	assert(n < sizeof(tmp));
+	if ((buf == NULL) || (bufLen < n))
+		err("usbvideo_VideosizeToString: buffer is too small.");
+	else
+		memmove(buf, tmp, n);
+}
+
+/*
+ * usbvideo_OverlayChar()
+ *
+ * History:
+ * 01-Feb-2000 Created.
+ */
+void usbvideo_OverlayChar(uvd_t *uvd, usbvideo_frame_t *frame,
+			  int x, int y, int ch)
+{
+	static const unsigned short digits[16] = {
+		0xF6DE, /* 0 */
+		0x2492, /* 1 */
+		0xE7CE, /* 2 */
+		0xE79E, /* 3 */
+		0xB792, /* 4 */
+		0xF39E, /* 5 */
+		0xF3DE, /* 6 */
+		0xF492, /* 7 */
+		0xF7DE, /* 8 */
+		0xF79E, /* 9 */
+		0x77DA, /* a */
+		0xD75C, /* b */
+		0xF24E, /* c */
+		0xD6DC, /* d */
+		0xF34E, /* e */
+		0xF348  /* f */
+	};
+	unsigned short digit;
+	int ix, iy;
+
+	if ((uvd == NULL) || (frame == NULL))
+		return;
+
+	if (ch >= '0' && ch <= '9')
+		ch -= '0';
+	else if (ch >= 'A' && ch <= 'F')
+		ch = 10 + (ch - 'A');
+	else if (ch >= 'a' && ch <= 'f')
+		ch = 10 + (ch - 'a');
+	else
+		return;
+	digit = digits[ch];
+
+	for (iy=0; iy < 5; iy++) {
+		for (ix=0; ix < 3; ix++) {
+			if (digit & 0x8000) {
+				if (uvd->paletteBits & (1L << VIDEO_PALETTE_RGB24)) {
+/* TODO */				RGB24_PUTPIXEL(frame, x+ix, y+iy, 0xFF, 0xFF, 0xFF);
+				}
+			}
+			digit = digit << 1;
+		}
+	}
+}
+
+/*
+ * usbvideo_OverlayString()
+ *
+ * History:
+ * 01-Feb-2000 Created.
+ */
+void usbvideo_OverlayString(uvd_t *uvd, usbvideo_frame_t *frame,
+			    int x, int y, const char *str)
+{
+	while (*str) {
+		usbvideo_OverlayChar(uvd, frame, x, y, *str);
+		str++;
+		x += 4; /* 3 pixels character + 1 space */
+	}
+}
+
+/*
+ * usbvideo_OverlayStats()
+ *
+ * Overlays important debugging information.
+ *
+ * History:
+ * 01-Feb-2000 Created.
+ */
+void usbvideo_OverlayStats(uvd_t *uvd, usbvideo_frame_t *frame)
+{
+	const int y_diff = 8;
+	char tmp[16];
+	int x = 10, y=10;
+	long i, j, barLength;
+	const int qi_x1 = 60, qi_y1 = 10;
+	const int qi_x2 = VIDEOSIZE_X(frame->request) - 10, qi_h = 10;
+
+	/* Call the user callback, see if we may proceed after that */
+	if (VALID_CALLBACK(uvd, overlayHook)) {
+		if (GET_CALLBACK(uvd, overlayHook)(uvd, frame) < 0)
+			return;
+	}
+
+	/*
+	 * We draw a (mostly) hollow rectangle with qi_xxx coordinates.
+	 * Left edge symbolizes the queue index 0; right edge symbolizes
+	 * the full capacity of the queue.
+	 */
+	barLength = qi_x2 - qi_x1 - 2;
+	if ((barLength > 10) && (uvd->paletteBits & (1L << VIDEO_PALETTE_RGB24))) {
+/* TODO */	long u_lo, u_hi, q_used;
+		long m_ri, m_wi, m_lo, m_hi;
+
+		/*
+		 * Determine fill zones (used areas of the queue):
+		 * 0 xxxxxxx u_lo ...... uvd->dp.ri xxxxxxxx u_hi ..... uvd->dp.length
+		 *
+		 * if u_lo < 0 then there is no first filler.
+		 */
+
+		q_used = RingQueue_GetLength(&uvd->dp);
+		if ((uvd->dp.ri + q_used) >= uvd->dp.length) {
+			u_hi = uvd->dp.length;
+			u_lo = (q_used + uvd->dp.ri) % uvd->dp.length;
+		} else {
+			u_hi = (q_used + uvd->dp.ri);
+			u_lo = -1;
+		}
+
+		/* Convert byte indices into screen units */
+		m_ri = qi_x1 + ((barLength * uvd->dp.ri) / uvd->dp.length);
+		m_wi = qi_x1 + ((barLength * uvd->dp.wi) / uvd->dp.length);
+		m_lo = (u_lo > 0) ? (qi_x1 + ((barLength * u_lo) / uvd->dp.length)) : -1;
+		m_hi = qi_x1 + ((barLength * u_hi) / uvd->dp.length);
+
+		for (j=qi_y1; j < (qi_y1 + qi_h); j++) {
+			for (i=qi_x1; i < qi_x2; i++) {
+				/* Draw border lines */
+				if ((j == qi_y1) || (j == (qi_y1 + qi_h - 1)) ||
+				    (i == qi_x1) || (i == (qi_x2 - 1))) {
+					RGB24_PUTPIXEL(frame, i, j, 0xFF, 0xFF, 0xFF);
+					continue;
+				}
+				/* For all other points the Y coordinate does not matter */
+				if ((i >= m_ri) && (i <= (m_ri + 3))) {
+					RGB24_PUTPIXEL(frame, i, j, 0x00, 0xFF, 0x00);
+				} else if ((i >= m_wi) && (i <= (m_wi + 3))) {
+					RGB24_PUTPIXEL(frame, i, j, 0xFF, 0x00, 0x00);
+				} else if ((i < m_lo) || ((i > m_ri) && (i < m_hi)))
+					RGB24_PUTPIXEL(frame, i, j, 0x00, 0x00, 0xFF);
+			}
+		}
+	}
+
+	sprintf(tmp, "%8lx", uvd->stats.frame_num);
+	usbvideo_OverlayString(uvd, frame, x, y, tmp);
+	y += y_diff;
+
+	sprintf(tmp, "%8lx", uvd->stats.urb_count);
+	usbvideo_OverlayString(uvd, frame, x, y, tmp);
+	y += y_diff;
+
+	sprintf(tmp, "%8lx", uvd->stats.urb_length);
+	usbvideo_OverlayString(uvd, frame, x, y, tmp);
+	y += y_diff;
+
+	sprintf(tmp, "%8lx", uvd->stats.data_count);
+	usbvideo_OverlayString(uvd, frame, x, y, tmp);
+	y += y_diff;
+
+	sprintf(tmp, "%8lx", uvd->stats.header_count);
+	usbvideo_OverlayString(uvd, frame, x, y, tmp);
+	y += y_diff;
+
+	sprintf(tmp, "%8lx", uvd->stats.iso_skip_count);
+	usbvideo_OverlayString(uvd, frame, x, y, tmp);
+	y += y_diff;
+
+	sprintf(tmp, "%8lx", uvd->stats.iso_err_count);
+	usbvideo_OverlayString(uvd, frame, x, y, tmp);
+	y += y_diff;
+
+	sprintf(tmp, "%8x", uvd->vpic.colour);
+	usbvideo_OverlayString(uvd, frame, x, y, tmp);
+	y += y_diff;
+
+	sprintf(tmp, "%8x", uvd->vpic.hue);
+	usbvideo_OverlayString(uvd, frame, x, y, tmp);
+	y += y_diff;
+
+	sprintf(tmp, "%8x", uvd->vpic.brightness >> 8);
+	usbvideo_OverlayString(uvd, frame, x, y, tmp);
+	y += y_diff;
+
+	sprintf(tmp, "%8x", uvd->vpic.contrast >> 12);
+	usbvideo_OverlayString(uvd, frame, x, y, tmp);
+	y += y_diff;
+
+	sprintf(tmp, "%8d", uvd->vpic.whiteness >> 8);
+	usbvideo_OverlayString(uvd, frame, x, y, tmp);
+	y += y_diff;
+}
+
+/*
+ * usbvideo_ReportStatistics()
+ *
+ * This procedure prints packet and transfer statistics.
+ *
+ * History:
+ * 14-Jan-2000 Corrected default multiplier.
+ */
+void usbvideo_ReportStatistics(const uvd_t *uvd)
+{
+	if ((uvd != NULL) && (uvd->stats.urb_count > 0)) {
+		unsigned long allPackets, badPackets, goodPackets, percent;
+		allPackets = uvd->stats.urb_count * CAMERA_URB_FRAMES;
+		badPackets = uvd->stats.iso_skip_count + uvd->stats.iso_err_count;
+		goodPackets = allPackets - badPackets;
+		/* Calculate percentage wisely, remember integer limits */
+		assert(allPackets != 0);
+		if (goodPackets < (((unsigned long)-1)/100))
+			percent = (100 * goodPackets) / allPackets;
+		else
+			percent = goodPackets / (allPackets / 100);
+		info("Packet Statistics: Total=%lu. Empty=%lu. Usage=%lu%%",
+		     allPackets, badPackets, percent);
+		if (uvd->iso_packet_len > 0) {
+			unsigned long allBytes, xferBytes;
+			char multiplier = ' ';
+			allBytes = allPackets * uvd->iso_packet_len;
+			xferBytes = uvd->stats.data_count;
+			assert(allBytes != 0);
+			if (xferBytes < (((unsigned long)-1)/100))
+				percent = (100 * xferBytes) / allBytes;
+			else
+				percent = xferBytes / (allBytes / 100);
+			/* Scale xferBytes for easy reading */
+			if (xferBytes > 10*1024) {
+				xferBytes /= 1024;
+				multiplier = 'K';
+				if (xferBytes > 10*1024) {
+					xferBytes /= 1024;
+					multiplier = 'M';
+					if (xferBytes > 10*1024) {
+						xferBytes /= 1024;
+						multiplier = 'G';
+						if (xferBytes > 10*1024) {
+							xferBytes /= 1024;
+							multiplier = 'T';
+						}
+					}
+				}
+			}
+			info("Transfer Statistics: Transferred=%lu%cB Usage=%lu%%",
+			     xferBytes, multiplier, percent);
+		}
+	}
+}
+
+/*
+ * usbvideo_DrawLine()
+ *
+ * A standard implementation of Bresenham's line drawing algorithm.
+ * This procedure is provided primarily for debugging or demo
+ * purposes.
+ */
+void usbvideo_DrawLine(
+	usbvideo_frame_t *frame,
+	int x1, int y1,
+	int x2, int y2,
+	unsigned char cr, unsigned char cg, unsigned char cb)
+{
+	int i, dx, dy, np, d;
+	int dinc1, dinc2, x, xinc1, xinc2, y, yinc1, yinc2;
+
+	if ((dx = x2 - x1) < 0)
+		dx = -dx;
+	if ((dy = y2 - y1) < 0)
+		dy = -dy;
+	if (dx >= dy) {
+		np = dx + 1;
+		d = (2 * dy) - dx;
+		dinc1 = dy << 1;
+		dinc2 = (dy - dx) << 1;
+		xinc1 = 1;
+		xinc2 = 1;
+		yinc1 = 0;
+		yinc2 = 1;
+	} else {
+		np = dy + 1;
+		d = (2 * dx) - dy;
+		dinc1 = dx << 1;
+		dinc2 = (dx - dy) << 1;
+		xinc1 = 0;
+		xinc2 = 1;
+		yinc1 = 1;
+		yinc2 = 1;
+	}
+	/* Make sure x and y move in the right directions */
+	if (x1 > x2) {
+		xinc1 = -xinc1;
+		xinc2 = -xinc2;
+	}
+	if (y1 > y2) {
+		yinc1 = -yinc1;
+		yinc2 = -yinc2;
+	}
+	for (i=0, x=x1, y=y1; i < np; i++) {
+		if (frame->palette == VIDEO_PALETTE_RGB24) {
+/* TODO */		RGB24_PUTPIXEL(frame, x, y, cr, cg, cb);
+		}
+		if (d < 0) {
+			d += dinc1;
+			x += xinc1;
+			y += yinc1;
+		} else {
+			d += dinc2;
+			x += xinc2;
+			y += yinc2;
+		}
+	}
+}
+
+/*
+ * usbvideo_TestPattern()
+ *
+ * Procedure forms a test pattern (yellow grid on blue background).
+ *
+ * Parameters:
+ * fullframe: if TRUE then entire frame is filled, otherwise the procedure
+ *	      continues from the current scanline.
+ * pmode      0: fill the frame with solid blue color (like on VCR or TV)
+ *	      1: Draw a colored grid
+ *
+ * History:
+ * 01-Feb-2000 Created.
+ */
+void usbvideo_TestPattern(uvd_t *uvd, int fullframe, int pmode)
+{
+	static const char proc[] = "usbvideo_TestPattern";
+	usbvideo_frame_t *frame;
+	int num_cell = 0;
+	int scan_length = 0;
+	static int num_pass = 0;
+
+	if (uvd == NULL) {
+		err("%s: uvd == NULL", proc);
+		return;
+	}
+	if ((uvd->curframe < 0) || (uvd->curframe >= USBVIDEO_NUMFRAMES)) {
+		err("%s: uvd->curframe=%d.", proc, uvd->curframe);
+		return;
+	}
+
+	/* Grab the current frame */
+	frame = &uvd->frame[uvd->curframe];
+
+	/* Optionally start at the beginning */
+	if (fullframe) {
+		frame->curline = 0;
+		frame->seqRead_Length = 0;
+	}
+#if 0
+	{	/* For debugging purposes only */
+		char tmp[20];
+		usbvideo_VideosizeToString(tmp, sizeof(tmp), frame->request);
+		info("testpattern: frame=%s", tmp);
+	}
+#endif
+	/* Form every scan line */
+	for (; frame->curline < VIDEOSIZE_Y(frame->request); frame->curline++) {
+		int i;
+		unsigned char *f = frame->data +
+			(VIDEOSIZE_X(frame->request) * V4L_BYTES_PER_PIXEL * frame->curline);
+		for (i=0; i < VIDEOSIZE_X(frame->request); i++) {
+			unsigned char cb=0x80;
+			unsigned char cg = 0;
+			unsigned char cr = 0;
+
+			if (pmode == 1) {
+				if (frame->curline % 32 == 0)
+					cb = 0, cg = cr = 0xFF;
+				else if (i % 32 == 0) {
+					if (frame->curline % 32 == 1)
+						num_cell++;
+					cb = 0, cg = cr = 0xFF;
+				} else {
+					cb = ((num_cell*7) + num_pass) & 0xFF;
+					cg = ((num_cell*5) + num_pass*2) & 0xFF;
+					cr = ((num_cell*3) + num_pass*3) & 0xFF;
+				}
+			} else {
+				/* Just the blue screen */
+			}
+				
+			*f++ = cb;
+			*f++ = cg;
+			*f++ = cr;
+			scan_length += 3;
+		}
+	}
+
+	frame->frameState = FrameState_Done;
+	frame->seqRead_Length += scan_length;
+	++num_pass;
+
+	/* We do this unconditionally, regardless of FLAGS_OVERLAY_STATS */
+	usbvideo_OverlayStats(uvd, frame);
+}
+
+/*
+ * usbvideo_HexDump()
+ *
+ * A debugging tool. Prints hex dumps.
+ *
+ * History:
+ * 29-Jul-2000 Added printing of offsets.
+ */
+void usbvideo_HexDump(const unsigned char *data, int len)
+{
+	const int bytes_per_line = 32;
+	char tmp[128]; /* 32*3 + 5 */
+	int i, k;
+
+	for (i=k=0; len > 0; i++, len--) {
+		if (i > 0 && ((i % bytes_per_line) == 0)) {
+			printk("%s\n", tmp);
+			k=0;
+		}
+		if ((i % bytes_per_line) == 0)
+			k += sprintf(&tmp[k], "%04x: ", i);
+		k += sprintf(&tmp[k], "%02x ", data[i]);
+	}
+	if (k > 0)
+		printk("%s\n", tmp);
+}
+
+/* Debugging aid */
+void usbvideo_SayAndWait(const char *what)
+{
+	wait_queue_head_t wq;
+	init_waitqueue_head(&wq);
+	info("Say: %s", what);
+	interruptible_sleep_on_timeout (&wq, HZ*3); /* Timeout */
+}
+
+/* ******************************************************************** */
+
+static void usbvideo_ClientIncModCount(uvd_t *uvd)
+{
+	static const char proc[] = "usbvideo_ClientIncModCount";
+	if (uvd == NULL) {
+		err("%s: uvd == NULL", proc);
+		return;
+	}
+	if (uvd->handle == NULL) {
+		err("%s: uvd->handle == NULL", proc);
+		return;
+	}
+	if (uvd->handle->md_module == NULL) {
+		err("%s: uvd->handle->md_module == NULL", proc);
+		return;
+	}
+	__MOD_INC_USE_COUNT(uvd->handle->md_module);
+}
+
+static void usbvideo_ClientDecModCount(uvd_t *uvd)
+{
+	static const char proc[] = "usbvideo_ClientDecModCount";
+	if (uvd == NULL) {
+		err("%s: uvd == NULL", proc);
+		return;
+	}
+	if (uvd->handle == NULL) {
+		err("%s: uvd->handle == NULL", proc);
+		return;
+	}
+	if (uvd->handle->md_module == NULL) {
+		err("%s: uvd->handle->md_module == NULL", proc);
+		return;
+	}
+	__MOD_DEC_USE_COUNT(uvd->handle->md_module);
+}
+
+int usbvideo_register(
+	usbvideo_t **pCams,
+	const int num_cams,
+	const int num_extra,
+	const char *driverName,
+	const usbvideo_cb_t *cbTbl,
+	struct module *md )
+{
+	static const char proc[] = "usbvideo_register";
+	usbvideo_t *cams;
+	int i, base_size;
+
+	/* Check parameters for sanity */
+	if ((num_cams <= 0) || (pCams == NULL) || (cbTbl == NULL)) {
+		err("%s: Illegal call", proc);
+		return -EINVAL;
+	}
+
+	/* Check registration callback - must be set! */
+	if (cbTbl->probe == NULL) {
+		err("%s: probe() is required!", proc);
+		return -EINVAL;
+	}
+
+	base_size = num_cams * sizeof(uvd_t) + sizeof(usbvideo_t);
+	cams = (usbvideo_t *) kmalloc(base_size, GFP_KERNEL);
+	if (cams == NULL) {
+		err("Failed to allocate %d. bytes for usbvideo_t", base_size);
+		return -ENOMEM;
+	}
+	dbg("%s: Allocated $%p (%d. bytes) for %d. cameras",
+	    proc, cams, base_size, num_cams);
+	memset(cams, 0, base_size);
+
+	/* Copy callbacks, apply defaults for those that are not set */
+	memmove(&cams->cb, cbTbl, sizeof(cams->cb));
+	if (cams->cb.getFrame == NULL)
+		cams->cb.getFrame = usbvideo_GetFrame;
+	if (cams->cb.disconnect == NULL)
+		cams->cb.disconnect = usbvideo_Disconnect;
+#if USES_PROC_FS
+	/*
+	 * If both /proc fs callbacks are NULL then we assume that the driver
+	 * does not need procfs services at all. Leave them NULL.
+	 */
+	cams->uses_procfs = (cams->cb.procfs_read != NULL) || (cams->cb.procfs_write == NULL);
+	if (cams->uses_procfs) {
+		if (cams->cb.procfs_read == NULL)
+			cams->cb.procfs_read = usbvideo_default_procfs_read_proc;
+		if (cams->cb.procfs_write == NULL)
+			cams->cb.procfs_write = usbvideo_default_procfs_write_proc;
+	}
+#else /* !USES_PROC_FS */
+	/* Report a warning so that user knows why there is no /proc entries */
+	if ((cams->cb.procfs_read != NULL) || (cams->cb.procfs_write == NULL)) {
+		dbg("%s: /proc fs support requested but not configured!", proc);
+	}
+#endif
+	cams->num_cameras = num_cams;
+	cams->cam = (uvd_t *) &cams[1];
+	cams->md_module = md;
+	if (cams->md_module == NULL)
+		warn("%s: module == NULL!", proc);
+	init_MUTEX(&cams->lock);	/* to 1 == available */
+
+	for (i = 0; i < num_cams; i++) {
+		uvd_t *up = &cams->cam[i];
+
+		up->handle = cams;
+
+		/* Allocate user_data separately because of kmalloc's limits */
+		if (num_extra > 0) {
+			up->user_size = num_cams * num_extra;
+			up->user_data = (char *) kmalloc(up->user_size, GFP_KERNEL);
+			if (up->user_data == NULL) {
+				up->user_size = 0;
+				err("%s: Failed to allocate user_data (%d. bytes)",
+				    proc, up->user_size);
+				return -ENOMEM;
+			}
+			dbg("%s: Allocated cams[%d].user_data=$%p (%d. bytes)",
+			     proc, i, up->user_data, up->user_size);
+		}
+	}
+
+	/*
+	 * Register ourselves with USB stack.
+	 */
+	strcpy(cams->drvName, (driverName != NULL) ? driverName : "Unknown");
+	cams->usbdrv.name = cams->drvName;
+	cams->usbdrv.probe = cams->cb.probe;
+	cams->usbdrv.disconnect = cams->cb.disconnect;
+
+#if USES_PROC_FS
+	if (cams->uses_procfs) {
+		dbg("%s: Creating /proc filesystem entries.", proc);
+		usbvideo_procfs_level1_create(cams);
+	}
+#endif
+
+	/*
+	 * Update global handle to usbvideo. This is very important
+	 * because probe() can be called before usb_register() returns.
+	 * If the handle is not yet updated then the probe() will fail.
+	 */
+	*pCams = cams;
+	usb_register(&cams->usbdrv);
+
+	return 0;
+}
+
+/*
+ * usbvideo_Deregister()
+ *
+ * Procedure frees all usbvideo and user data structures. Be warned that
+ * if you had some dynamically allocated components in ->user field then
+ * you should free them before calling here.
+ */
+void usbvideo_Deregister(usbvideo_t **pCams)
+{
+	static const char proc[] = "usbvideo_deregister";
+	usbvideo_t *cams;
+	int i;
+
+	if (pCams == NULL) {
+		err("%s: pCams == NULL", proc);
+		return;
+	}
+	cams = *pCams;
+	if (cams == NULL) {
+		err("%s: cams == NULL", proc);
+		return;
+	}
+
+#if USES_PROC_FS
+	if (cams->uses_procfs) {
+		dbg("%s: Deregistering filesystem entries.", proc);
+		usbvideo_procfs_level1_destroy(cams);
+	}
+#endif
+
+	dbg("%s: Deregistering %s driver.", proc, cams->drvName);
+	usb_deregister(&cams->usbdrv);
+
+	dbg("%s: Deallocating cams=$%p (%d. cameras)", proc, cams, cams->num_cameras);
+	for (i=0; i < cams->num_cameras; i++) {
+		uvd_t *up = &cams->cam[i];
+		int warning = 0;
+
+		if (up->user_data != NULL) {
+			if (up->user_size <= 0)
+				++warning;
+		} else {
+			if (up->user_size > 0)
+				++warning;
+		}
+		if (warning) {
+			err("%s: Warning: user_data=$%p user_size=%d.",
+			    proc, up->user_data, up->user_size);
+		} else {
+			dbg("%s: Freeing %d. $%p->user_data=$%p",
+			    proc, i, up, up->user_data);
+			kfree(up->user_data);
+		}
+	}
+	/* Whole array was allocated in one chunk */
+	dbg("%s: Freed %d uvd_t structures",
+	    proc, cams->num_cameras);
+	kfree(cams);
+	*pCams = NULL;
+}
+
+/*
+ * usbvideo_Disconnect()
+ *
+ * This procedure stops all driver activity. Deallocation of
+ * the interface-private structure (pointed by 'ptr') is done now
+ * (if we don't have any open files) or later, when those files
+ * are closed. After that driver should be removable.
+ *
+ * This code handles surprise removal. The uvd->user is a counter which
+ * increments on open() and decrements on close(). If we see here that
+ * this counter is not 0 then we have a client who still has us opened.
+ * We set uvd->remove_pending flag as early as possible, and after that
+ * all access to the camera will gracefully fail. These failures should
+ * prompt client to (eventually) close the video device, and then - in
+ * usbvideo_v4l_close() - we decrement uvd->uvd_used and usage counter.
+ *
+ * History:
+ * 22-Jan-2000 Added polling of MOD_IN_USE to delay removal until all users gone.
+ * 27-Jan-2000 Reworked to allow pending disconnects; see xxx_close()
+ * 24-May-2000 Corrected to prevent race condition (MOD_xxx_USE_COUNT).
+ * 19-Oct-2000 Moved to usbvideo module.
+ */
+void usbvideo_Disconnect(struct usb_device *dev, void *ptr)
+{
+	static const char proc[] = "usbvideo_Disconnect";
+	uvd_t *uvd = (uvd_t *) ptr;
+	int i;
+
+	if ((dev == NULL) || (uvd == NULL)) {
+		err("%s($%p,$%p): Illegal call.", proc, dev, ptr);
+		return;
+	}
+	usbvideo_ClientIncModCount(uvd);
+	if (uvd->debug > 0)
+		info("%s(%p,%p.)", proc, dev, ptr);
+
+	down(&uvd->lock);
+	uvd->remove_pending = 1; /* Now all ISO data will be ignored */
+
+	/* At this time we ask to cancel outstanding URBs */
+	usbvideo_StopDataPump(uvd);
+
+	for (i=0; i < USBVIDEO_NUMSBUF; i++)
+		usb_free_urb(uvd->sbuf[i].urb);
+
+	usb_dec_dev_use(uvd->dev);
+	uvd->dev = NULL;    	    /* USB device is no more */
+
+	if (uvd->user)
+		info("%s: In use, disconnect pending.", proc);
+	else
+		usbvideo_CameraRelease(uvd);
+	up(&uvd->lock);
+	info("USB camera disconnected.");
+
+	usbvideo_ClientDecModCount(uvd);
+}
+
+/*
+ * usbvideo_CameraRelease()
+ *
+ * This code does final release of uvd_t. This happens
+ * after the device is disconnected -and- all clients
+ * closed their files.
+ *
+ * History:
+ * 27-Jan-2000 Created.
+ */
+void usbvideo_CameraRelease(uvd_t *uvd)
+{
+	static const char proc[] = "usbvideo_CameraRelease";
+	if (uvd == NULL) {
+		err("%s: Illegal call", proc);
+		return;
+	}
+	video_unregister_device(&uvd->vdev);
+	if (uvd->debug > 0)
+		info("%s: Video unregistered.", proc);
+
+#if USES_PROC_FS
+	assert(uvd->handle != NULL);
+	if (uvd->handle->uses_procfs) {
+		dbg("%s: Removing /proc/%s/ filesystem entries.", proc, uvd->handle->drvName);
+		usbvideo_procfs_level2_destroy(uvd);
+	}
+#endif
+
+	RingQueue_Free(&uvd->dp);
+	if (VALID_CALLBACK(uvd, userFree))
+		GET_CALLBACK(uvd, userFree)(uvd);
+	uvd->uvd_used = 0;	/* This is atomic, no need to take mutex */
+}
+
+/*
+ * usbvideo_find_struct()
+ *
+ * This code searches the array of preallocated (static) structures
+ * and returns index of the first one that isn't in use. Returns -1
+ * if there are no free structures.
+ *
+ * History:
+ * 27-Jan-2000 Created.
+ */
+static int usbvideo_find_struct(usbvideo_t *cams)
+{
+	int u, rv = -1;
+
+	if (cams == NULL) {
+		err("No usbvideo_t handle?");
+		return -1;
+	}
+	down(&cams->lock);
+	for (u = 0; u < cams->num_cameras; u++) {
+		uvd_t *uvd = &cams->cam[u];
+		if (!uvd->uvd_used) /* This one is free */
+		{
+			uvd->uvd_used = 1;	/* In use now */
+			init_MUTEX(&uvd->lock);	/* to 1 == available */
+			uvd->dev = NULL;
+			rv = u;
+			break;
+		}
+	}
+	up(&cams->lock);
+	return rv;
+}
+
+uvd_t *usbvideo_AllocateDevice(usbvideo_t *cams)
+{
+	int i, devnum;
+	uvd_t *uvd = NULL;
+
+	if (cams == NULL) {
+		err("No usbvideo_t handle?");
+		return NULL;
+	}
+
+	devnum = usbvideo_find_struct(cams);
+	if (devnum == -1) {
+		err("IBM USB camera driver: Too many devices!");
+		return NULL;
+	}
+	uvd = &cams->cam[devnum];
+	dbg("Device entry #%d. at $%p", devnum, uvd);
+
+	/* Not relying upon caller we increase module counter ourselves */
+	usbvideo_ClientIncModCount(uvd);
+
+	down(&uvd->lock);
+	for (i=0; i < USBVIDEO_NUMSBUF; i++) {
+		uvd->sbuf[i].urb = usb_alloc_urb(FRAMES_PER_DESC);
+		if (uvd->sbuf[i].urb == NULL) {
+			err("usb_alloc_urb(%d.) failed.", FRAMES_PER_DESC);
+			uvd->uvd_used = 0;
+			uvd = NULL;
+			goto allocate_done;
+		}
+	}
+	uvd->user=0;
+	uvd->remove_pending = 0;
+	uvd->last_error = 0;
+	RingQueue_Initialize(&uvd->dp);
+
+	/* Initialize video device structure */
+	memset(&uvd->vdev, 0, sizeof(uvd->vdev));
+	i = sprintf(uvd->vdev.name, "%s USB Camera", cams->drvName);
+	if (i >= sizeof(uvd->vdev.name)) {
+		err("Wrote too much into uvd->vdev.name, expect trouble!");
+	}
+	uvd->vdev.type = VID_TYPE_CAPTURE;
+	uvd->vdev.hardware = VID_HARDWARE_CPIA;
+	uvd->vdev.open = usbvideo_v4l_open;
+	uvd->vdev.close = usbvideo_v4l_close;
+	uvd->vdev.read = usbvideo_v4l_read;
+	uvd->vdev.write = usbvideo_v4l_write;
+	uvd->vdev.ioctl = usbvideo_v4l_ioctl;
+	uvd->vdev.mmap = usbvideo_v4l_mmap;
+	uvd->vdev.initialize = usbvideo_v4l_initialize;
+	/*
+	 * The client is free to overwrite those because we
+	 * return control to the client's probe function right now.
+	 */
+allocate_done:
+	up (&uvd->lock);
+	usbvideo_ClientDecModCount(uvd);
+	return uvd;
+}
+
+int usbvideo_RegisterVideoDevice(uvd_t *uvd)
+{
+	static const char proc[] = "usbvideo_RegisterVideoDevice";
+	char tmp1[20], tmp2[20];	/* Buffers for printing */
+
+	if (uvd == NULL) {
+		err("%s: Illegal call.", proc);
+		return -EINVAL;
+	}
+	if (uvd->video_endp == 0) {
+		info("%s: No video endpoint specified; data pump disabled.", proc);
+	}
+	if (uvd->paletteBits == 0) {
+		err("%s: No palettes specified!", proc);
+		return -EINVAL;
+	}
+	if (uvd->defaultPalette == 0) {
+		info("%s: No default palette!", proc);
+	}
+
+	uvd->max_frame_size = VIDEOSIZE_X(uvd->canvas) *
+		VIDEOSIZE_Y(uvd->canvas) * V4L_BYTES_PER_PIXEL;
+	usbvideo_VideosizeToString(tmp1, sizeof(tmp1), uvd->videosize);
+	usbvideo_VideosizeToString(tmp2, sizeof(tmp2), uvd->canvas);
+
+	if (uvd->debug > 0) {
+		info("%s: iface=%d. endpoint=$%02x paletteBits=$%08lx",
+		     proc, uvd->iface, uvd->video_endp, uvd->paletteBits);
+	}
+	if (video_register_device(&uvd->vdev, VFL_TYPE_GRABBER, video_nr) == -1) {
+		err("%s: video_register_device failed", proc);
+		return -EPIPE;
+	}
+	if (uvd->debug > 1) {
+		info("%s: video_register_device() successful", proc);
+	}
+	if (uvd->dev == NULL) {
+		err("%s: uvd->dev == NULL", proc);
+		return -EINVAL;
+	}
+
+	info("%s on /dev/video%d: canvas=%s videosize=%s",
+	     (uvd->handle != NULL) ? uvd->handle->drvName : "???",
+	     uvd->vdev.minor, tmp2, tmp1);
+
+#if USES_PROC_FS
+	assert(uvd->handle != NULL);
+	if (uvd->handle->uses_procfs) {
+		if (uvd->debug > 0) {
+			info("%s: Creating /proc/%s/ filesystem entries.",
+			     proc, uvd->handle->drvName);
+		}
+		usbvideo_procfs_level2_create(uvd);
+	}
+#endif
+
+	usb_inc_dev_use(uvd->dev);
+	return 0;
+}
+
+/* ******************************************************************** */
+
+int usbvideo_v4l_initialize(struct video_device *dev)
+{
+	return 0;
+}
+
+long usbvideo_v4l_write(struct video_device *dev, const char *buf,
+			unsigned long count, int noblock)
+{
+	return -EINVAL;
+}
+
+int usbvideo_v4l_mmap(struct video_device *dev, const char *adr, unsigned long size)
+{
+	uvd_t *uvd = (uvd_t *) dev;
+	unsigned long start = (unsigned long) adr;
+	unsigned long page, pos;
+
+	if (!CAMERA_IS_OPERATIONAL(uvd))
+		return -EFAULT;
+
+	if (size > (((2 * uvd->max_frame_size) + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1)))
+		return -EINVAL;
+
+	pos = (unsigned long) uvd->fbuf;
+	while (size > 0) {
+		page = usbvideo_kvirt_to_pa(pos);
+		if (remap_page_range(start, page, PAGE_SIZE, PAGE_SHARED))
+			return -EAGAIN;
+
+		start += PAGE_SIZE;
+		pos += PAGE_SIZE;
+		if (size > PAGE_SIZE)
+			size -= PAGE_SIZE;
+		else
+			size = 0;
+	}
+
+	return 0;
+}
+
+/*
+ * usbvideo_v4l_open()
+ *
+ * This is part of Video 4 Linux API. The driver can be opened by one
+ * client only (checks internal counter 'uvdser'). The procedure
+ * then allocates buffers needed for video processing.
+ *
+ * History:
+ * 22-Jan-2000 Rewrote, moved scratch buffer allocation here. Now the
+ *             camera is also initialized here (once per connect), at
+ *             expense of V4L client (it waits on open() call).
+ * 27-Jan-2000 Used USBVIDEO_NUMSBUF as number of URB buffers.
+ * 24-May-2000 Corrected to prevent race condition (MOD_xxx_USE_COUNT).
+ */
+int usbvideo_v4l_open(struct video_device *dev, int flags)
+{
+	static const char proc[] = "usbvideo_v4l_open";
+	uvd_t *uvd = (uvd_t *) dev;
+	const int sb_size = FRAMES_PER_DESC * uvd->iso_packet_len;
+	int i, errCode = 0;
+
+	if (uvd->debug > 1)
+		info("%s($%p,$%08x", proc, dev, flags);
+
+	usbvideo_ClientIncModCount(uvd);
+	down(&uvd->lock);
+
+	if (uvd->user) {
+		err("%s: Someone tried to open an already opened device!", proc);
+		errCode = -EBUSY;
+	} else {
+		/* Clear statistics */
+		memset(&uvd->stats, 0, sizeof(uvd->stats));
+
+		/* Clean pointers so we know if we allocated something */
+		for (i=0; i < USBVIDEO_NUMSBUF; i++)
+			uvd->sbuf[i].data = NULL;
+
+		/* Allocate memory for the frame buffers */
+		uvd->fbuf_size = USBVIDEO_NUMFRAMES * uvd->max_frame_size;
+		uvd->fbuf = usbvideo_rvmalloc(uvd->fbuf_size);
+		RingQueue_Allocate(&uvd->dp, 128*1024); /* FIXME #define */
+		if ((uvd->fbuf == NULL) ||
+		    (!RingQueue_IsAllocated(&uvd->dp))) {
+			err("%s: Failed to allocate fbuf or dp", proc);
+			errCode = -ENOMEM;
+		} else {
+			/* Allocate all buffers */
+			for (i=0; i < USBVIDEO_NUMFRAMES; i++) {
+				uvd->frame[i].frameState = FrameState_Unused;
+				uvd->frame[i].data = uvd->fbuf + i*(uvd->max_frame_size);
+				/*
+				 * Set default sizes in case IOCTL (VIDIOCMCAPTURE)
+				 * is not used (using read() instead).
+				 */
+				uvd->frame[i].canvas = uvd->canvas;
+				uvd->frame[i].seqRead_Index = 0;
+			}
+			for (i=0; i < USBVIDEO_NUMSBUF; i++) {
+				uvd->sbuf[i].data = kmalloc(sb_size, GFP_KERNEL);
+				if (uvd->sbuf[i].data == NULL) {
+					errCode = -ENOMEM;
+					break;
+				}
+			}
+		}
+		if (errCode != 0) {
+			/* Have to free all that memory */
+			if (uvd->fbuf != NULL) {
+				usbvideo_rvfree(uvd->fbuf, uvd->fbuf_size);
+				uvd->fbuf = NULL;
+			}
+			RingQueue_Free(&uvd->dp);
+			for (i=0; i < USBVIDEO_NUMSBUF; i++) {
+				if (uvd->sbuf[i].data != NULL) {
+					kfree (uvd->sbuf[i].data);
+					uvd->sbuf[i].data = NULL;
+				}
+			}
+		}
+	}
+
+	/* If so far no errors then we shall start the camera */
+	if (errCode == 0) {
+		/* Start data pump if we have valid endpoint */
+		if (uvd->video_endp != 0)
+			errCode = usbvideo_StartDataPump(uvd);
+		if (errCode == 0) {
+			if (VALID_CALLBACK(uvd, setupOnOpen)) {
+				if (uvd->debug > 1)
+					info("%s: setupOnOpen callback", proc);
+				errCode = GET_CALLBACK(uvd, setupOnOpen)(uvd);
+				if (errCode < 0) {
+					err("%s: setupOnOpen callback failed (%d.).",
+					    proc, errCode);
+				} else if (uvd->debug > 1) {
+					info("%s: setupOnOpen callback successful", proc);
+				}
+			}
+			if (errCode == 0) {
+				uvd->settingsAdjusted = 0;
+				if (uvd->debug > 1)
+					info("%s: Open succeeded.", proc);
+				uvd->user++;
+			}
+		}
+	}
+	up(&uvd->lock);
+	if (errCode != 0)
+		usbvideo_ClientDecModCount(uvd);
+	if (uvd->debug > 0)
+		info("%s: Returning %d.", proc, errCode);
+	return errCode;
+}
+
+/*
+ * usbvideo_v4l_close()
+ *
+ * This is part of Video 4 Linux API. The procedure
+ * stops streaming and deallocates all buffers that were earlier
+ * allocated in usbvideo_v4l_open().
+ *
+ * History:
+ * 22-Jan-2000 Moved scratch buffer deallocation here.
+ * 27-Jan-2000 Used USBVIDEO_NUMSBUF as number of URB buffers.
+ * 24-May-2000 Moved MOD_DEC_USE_COUNT outside of code that can sleep.
+ */
+void usbvideo_v4l_close(struct video_device *dev)
+{
+	static const char proc[] = "usbvideo_v4l_close";
+	uvd_t *uvd = (uvd_t *)dev;
+	int i;
+
+	if (uvd->debug > 1)
+		info("%s($%p)", proc, dev);
+
+	down(&uvd->lock);	
+	usbvideo_StopDataPump(uvd);
+	usbvideo_rvfree(uvd->fbuf, uvd->fbuf_size);
+	uvd->fbuf = NULL;
+	RingQueue_Free(&uvd->dp);
+
+	for (i=0; i < USBVIDEO_NUMSBUF; i++) {
+		kfree(uvd->sbuf[i].data);
+		uvd->sbuf[i].data = NULL;
+	}
+
+#if USBVIDEO_REPORT_STATS
+	usbvideo_ReportStatistics(uvd);
+#endif    
+
+	uvd->user--;
+	if (uvd->remove_pending) {
+		if (uvd->debug > 0)
+			info("usbvideo_v4l_close: Final disconnect.");
+		usbvideo_CameraRelease(uvd);
+	}
+	up(&uvd->lock);
+	usbvideo_ClientDecModCount(uvd);
+
+	if (uvd->debug > 1)
+		info("%s: Completed.", proc);
+}
+
+/*
+ * usbvideo_v4l_ioctl()
+ *
+ * This is part of Video 4 Linux API. The procedure handles ioctl() calls.
+ *
+ * History:
+ * 22-Jan-2000 Corrected VIDIOCSPICT to reject unsupported settings.
+ */
+int usbvideo_v4l_ioctl(struct video_device *dev, unsigned int cmd, void *arg)
+{
+	uvd_t *uvd = (uvd_t *)dev;
+
+	if (!CAMERA_IS_OPERATIONAL(uvd))
+		return -EFAULT;
+
+	switch (cmd) {
+		case VIDIOCGCAP:
+		{
+			if (copy_to_user(arg, &uvd->vcap, sizeof(uvd->vcap)))
+				return -EFAULT;
+			return 0;
+		}
+		case VIDIOCGCHAN:
+		{
+			if (copy_to_user(arg, &uvd->vchan, sizeof(uvd->vchan)))
+				return -EFAULT;
+			return 0;
+		}
+		case VIDIOCSCHAN:
+		{	/* Not used but we return success */
+			int v;
+			if (copy_from_user(&v, arg, sizeof(v)))
+				return -EFAULT;
+			return 0;
+		}
+		case VIDIOCGPICT:
+		{
+			if (copy_to_user(arg, &uvd->vpic, sizeof(uvd->vpic)))
+				return -EFAULT;
+			return 0;
+		}
+		case VIDIOCSPICT:
+		{
+			struct video_picture tmp;
+			/*
+			 * Use temporary 'video_picture' structure to preserve our
+			 * own settings (such as color depth, palette) that we
+			 * aren't allowing everyone (V4L client) to change.
+			 */
+			if (copy_from_user(&tmp, arg, sizeof(tmp)))
+				return -EFAULT;
+			uvd->vpic.brightness = tmp.brightness;
+			uvd->vpic.hue = tmp.hue;
+			uvd->vpic.colour = tmp.colour;
+			uvd->vpic.contrast = tmp.contrast;
+			uvd->settingsAdjusted = 0;	/* Will force new settings */
+			return 0;
+		}
+		case VIDIOCSWIN:
+		{
+			struct video_window vw;
+
+			if (copy_from_user(&vw, arg, sizeof(vw)))
+				return -EFAULT;
+			if (vw.flags)
+				return -EINVAL;
+			if (vw.clipcount)
+				return -EINVAL;
+			if (vw.width != VIDEOSIZE_X(uvd->canvas))
+				return -EINVAL;
+			if (vw.height != VIDEOSIZE_Y(uvd->canvas))
+				return -EINVAL;
+
+			return 0;
+		}
+		case VIDIOCGWIN:
+		{
+			struct video_window vw;
+
+			vw.x = 0;
+			vw.y = 0;
+			vw.width = VIDEOSIZE_X(uvd->canvas);
+			vw.height = VIDEOSIZE_Y(uvd->canvas);
+			vw.chromakey = 0;
+			if (VALID_CALLBACK(uvd, getFPS))
+				vw.flags = GET_CALLBACK(uvd, getFPS)(uvd);
+			else 
+				vw.flags = 10; /* FIXME: do better! */
+
+			if (copy_to_user(arg, &vw, sizeof(vw)))
+				return -EFAULT;
+
+			return 0;
+		}
+		case VIDIOCGMBUF:
+		{
+			struct video_mbuf vm;
+
+			memset(&vm, 0, sizeof(vm));
+			vm.size = uvd->max_frame_size * 2;
+			vm.frames = 2;
+			vm.offsets[0] = 0;
+			vm.offsets[1] = uvd->max_frame_size;
+
+			if (copy_to_user((void *)arg, (void *)&vm, sizeof(vm)))
+				return -EFAULT;
+
+			return 0;
+		}
+		case VIDIOCMCAPTURE:
+		{
+			struct video_mmap vm;
+
+			if (copy_from_user((void *)&vm, (void *)arg, sizeof(vm))) {
+				err("VIDIOCMCAPTURE: copy_from_user() failed.");
+				return -EFAULT;
+			}
+			if (uvd->debug >= 1) {
+				info("VIDIOCMCAPTURE: frame=%d. size=%dx%d, format=%d.",
+				    vm.frame, vm.width, vm.height, vm.format);
+			}
+			/*
+			 * Check if the requested size is supported. If the requestor
+			 * requests too big a frame then we may be tricked into accessing
+			 * outside of own preallocated frame buffer (in uvd->frame).
+			 * This will cause oops or a security hole. Theoretically, we
+			 * could only clamp the size down to acceptable bounds, but then
+			 * we'd need to figure out how to insert our smaller buffer into
+			 * larger caller's buffer... this is not an easy question. So we
+			 * here just flatly reject too large requests, assuming that the
+			 * caller will resubmit with smaller size. Callers should know
+			 * what size we support (returned by VIDIOCGCAP). However vidcat,
+			 * for one, does not care and allows to ask for any size.
+			 */
+			if ((vm.width > VIDEOSIZE_X(uvd->canvas)) ||
+			    (vm.height > VIDEOSIZE_Y(uvd->canvas))) {
+				if (uvd->debug > 0) {
+					info("VIDIOCMCAPTURE: Size=%dx%d too large; "
+					     "allowed only up to %ldx%ld", vm.width, vm.height,
+					     VIDEOSIZE_X(uvd->canvas), VIDEOSIZE_Y(uvd->canvas));
+				}
+				return -EINVAL;
+			}
+			/* Check if the palette is supported */
+			if (((1L << vm.format) & uvd->paletteBits) == 0) {
+				if (uvd->debug > 0) {
+					info("VIDIOCMCAPTURE: format=%d. not supported"
+					     " (paletteBits=$%08lx)",
+					     vm.format, uvd->paletteBits);
+				}
+				return -EINVAL;
+			}
+			if ((vm.frame != 0) && (vm.frame != 1)) {
+				err("VIDIOCMCAPTURE: vm.frame=%d. !E [0,1]", vm.frame);
+				return -EINVAL;
+			}
+			if (uvd->frame[vm.frame].frameState == FrameState_Grabbing) {
+				/* Not an error - can happen */
+			}
+			uvd->frame[vm.frame].request = VIDEOSIZE(vm.width, vm.height);
+			uvd->frame[vm.frame].palette = vm.format;
+
+			/* Mark it as ready */
+			uvd->frame[vm.frame].frameState = FrameState_Ready;
+
+			return usbvideo_NewFrame(uvd, vm.frame);
+		}
+		case VIDIOCSYNC:
+		{
+			int frameNum, ret;
+
+			if (copy_from_user((void *)&frameNum, arg, sizeof(frameNum))) {
+				err("VIDIOCSYNC: copy_from_user() failed.");
+				return -EFAULT;
+			}
+			if(frameNum < 0 || frameNum >= USBVIDEO_NUMFRAMES)
+				return -EINVAL;
+				
+			if (uvd->debug >= 1)
+				info("VIDIOCSYNC: syncing to frame %d.", frameNum);
+			if (uvd->flags & FLAGS_NO_DECODING)
+				ret = usbvideo_GetFrame(uvd, frameNum);
+			else if (VALID_CALLBACK(uvd, getFrame)) {
+				ret = GET_CALLBACK(uvd, getFrame)(uvd, frameNum);
+				if ((ret < 0) && (uvd->debug >= 1)) {
+					err("VIDIOCSYNC: getFrame() returned %d.", ret);
+				}
+			} else {
+				err("VIDIOCSYNC: getFrame is not set");
+				ret = -EFAULT;
+			}
+
+			/*
+			 * The frame is in FrameState_Done_Hold state. Release it
+			 * right now because its data is already mapped into
+			 * the user space and it's up to the application to
+			 * make use of it until it asks for another frame.
+			 */
+			uvd->frame[frameNum].frameState = FrameState_Unused;
+			return ret;
+		}
+		case VIDIOCGFBUF:
+		{
+			struct video_buffer vb;
+
+			memset(&vb, 0, sizeof(vb));
+			vb.base = NULL;	/* frame buffer not supported, not used */
+
+			if (copy_to_user((void *)arg, (void *)&vb, sizeof(vb)))
+				return -EFAULT;
+
+ 			return 0;
+ 		}
+		case VIDIOCKEY:
+			return 0;
+
+		case VIDIOCCAPTURE:
+			return -EINVAL;
+
+		case VIDIOCSFBUF:
+
+		case VIDIOCGTUNER:
+		case VIDIOCSTUNER:
+
+		case VIDIOCGFREQ:
+		case VIDIOCSFREQ:
+
+		case VIDIOCGAUDIO:
+		case VIDIOCSAUDIO:
+			return -EINVAL;
+
+		default:
+			return -ENOIOCTLCMD;
+	}
+	return 0;
+}
+
+/*
+ * usbvideo_v4l_read()
+ *
+ * This is mostly boring stuff. We simply ask for a frame and when it
+ * arrives copy all the video data from it into user space. There is
+ * no obvious need to override this method.
+ *
+ * History:
+ * 20-Oct-2000 Created.
+ * 01-Nov-2000 Added mutex (uvd->lock).
+ */
+long usbvideo_v4l_read(struct video_device *dev, char *buf, unsigned long count, int noblock)
+{
+	static const char proc[] = "usbvideo_v4l_read";
+	uvd_t *uvd = (uvd_t *) dev;
+	int frmx = -1;
+	usbvideo_frame_t *frame;
+
+	if (!CAMERA_IS_OPERATIONAL(uvd) || (buf == NULL))
+		return -EFAULT;
+
+	if (uvd->debug >= 1)
+		info("%s: %ld. bytes, noblock=%d.", proc, count, noblock);
+
+	down(&uvd->lock);	
+
+	/* See if a frame is completed, then use it. */
+	if ((uvd->frame[0].frameState == FrameState_Done) ||
+	    (uvd->frame[0].frameState == FrameState_Done_Hold) ||
+	    (uvd->frame[0].frameState == FrameState_Error)) {
+		frmx = 0;
+	} else if ((uvd->frame[1].frameState >= FrameState_Done) ||
+		   (uvd->frame[1].frameState == FrameState_Done_Hold) ||
+		   (uvd->frame[1].frameState >= FrameState_Done)) {
+		frmx = 1;
+	}
+
+	/* FIXME: If we don't start a frame here then who ever does? */
+	if (noblock && (frmx == -1)) {
+		count = -EAGAIN;
+		goto read_done;
+	}
+
+	/*
+	 * If no FrameState_Done, look for a FrameState_Grabbing state.
+	 * See if a frame is in process (grabbing), then use it.
+	 * We will need to wait until it becomes cooked, of course.
+	 */
+	if (frmx == -1) {
+		if (uvd->frame[0].frameState == FrameState_Grabbing)
+			frmx = 0;
+		else if (uvd->frame[1].frameState == FrameState_Grabbing)
+			frmx = 1;
+	}
+
+	/*
+	 * If no frame is active, start one. We don't care which one
+	 * it will be, so #0 is as good as any.
+	 * In read access mode we don't have convenience of VIDIOCMCAPTURE
+	 * to specify the requested palette (video format) on per-frame
+	 * basis. This means that we have to return data in -some- format
+	 * and just hope that the client knows what to do with it.
+	 * The default format is configured in uvd->defaultPalette field
+	 * as one of VIDEO_PALETTE_xxx values. We stuff it into the new
+	 * frame and initiate the frame filling process.
+	 */
+	if (frmx == -1) {
+		if (uvd->defaultPalette == 0) {
+			err("%s: No default palette; don't know what to do!", proc);
+			count = -EFAULT;
+			goto read_done;
+		}
+		frmx = 0;
+		/*
+		 * We have no per-frame control over video size.
+		 * Therefore we only can use whatever size was
+		 * specified as default.
+		 */
+		uvd->frame[frmx].request = uvd->videosize;
+		uvd->frame[frmx].palette = uvd->defaultPalette;
+		uvd->frame[frmx].frameState = FrameState_Ready;
+		usbvideo_NewFrame(uvd, frmx);
+		/* Now frame 0 is supposed to start filling... */
+	}
+
+	/*
+	 * Get a pointer to the active frame. It is either previously
+	 * completed frame or frame in progress but not completed yet.
+	 */
+	frame = &uvd->frame[frmx];
+
+	/*
+	 * Sit back & wait until the frame gets filled and postprocessed.
+	 * If we fail to get the picture [in time] then return the error.
+	 * In this call we specify that we want the frame to be waited for,
+	 * postprocessed and switched into FrameState_Done_Hold state. This
+	 * state is used to hold the frame as "fully completed" between
+	 * subsequent partial reads of the same frame.
+	 */
+	if (frame->frameState != FrameState_Done_Hold) {
+		long rv = -EFAULT;
+		if (uvd->flags & FLAGS_NO_DECODING)
+			rv = usbvideo_GetFrame(uvd, frmx);
+		else if (VALID_CALLBACK(uvd, getFrame))
+			rv = GET_CALLBACK(uvd, getFrame)(uvd, frmx);
+		else
+			err("getFrame is not set");
+		if ((rv != 0) || (frame->frameState != FrameState_Done_Hold)) {
+			count = rv;
+			goto read_done;
+		}
+	}
+
+	/*
+	 * Copy bytes to user space. We allow for partial reads, which
+	 * means that the user application can request read less than
+	 * the full frame size. It is up to the application to issue
+	 * subsequent calls until entire frame is read.
+	 *
+	 * First things first, make sure we don't copy more than we
+	 * have - even if the application wants more. That would be
+	 * a big security embarassment!
+	 */
+	if ((count + frame->seqRead_Index) > frame->seqRead_Length)
+		count = frame->seqRead_Length - frame->seqRead_Index;
+
+	/*
+	 * Copy requested amount of data to user space. We start
+	 * copying from the position where we last left it, which
+	 * will be zero for a new frame (not read before).
+	 */
+	if (copy_to_user(buf, frame->data + frame->seqRead_Index, count)) {
+		count = -EFAULT;
+		goto read_done;
+	}
+
+	/* Update last read position */
+	frame->seqRead_Index += count;
+	if (uvd->debug >= 1) {
+		err("%s: {copy} count used=%ld, new seqRead_Index=%ld",
+			proc, count, frame->seqRead_Index);
+	}
+
+	/* Finally check if the frame is done with and "release" it */
+	if (frame->seqRead_Index >= frame->seqRead_Length) {
+		/* All data has been read */
+		frame->seqRead_Index = 0;
+
+		/* Mark it as available to be used again. */
+		uvd->frame[frmx].frameState = FrameState_Unused;
+		if (usbvideo_NewFrame(uvd, frmx ? 0 : 1)) {
+			err("%s: usbvideo_NewFrame failed.", proc);
+		}
+	}
+read_done:
+	up(&uvd->lock);	
+	return count;
+}
+
+/*
+ * Make all of the blocks of data contiguous
+ */
+static int usbvideo_CompressIsochronous(uvd_t *uvd, urb_t *urb)
+{
+	char *cdata;
+	int i, totlen = 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;
+
+		/* Detect and ignore errored packets */
+		if (st < 0) {
+			if (uvd->debug >= 1)
+				err("Data error: packet=%d. len=%d. status=%d.", i, n, st);
+			uvd->stats.iso_err_count++;
+			continue;
+		}
+
+		/* Detect and ignore empty packets */
+		if (n <= 0) {
+			uvd->stats.iso_skip_count++;
+			continue;
+		}
+		totlen += n;	/* Little local accounting */
+		RingQueue_Enqueue(&uvd->dp, cdata, n);
+	}
+	return totlen;
+}
+
+static void usbvideo_IsocIrq(struct urb *urb)
+{
+	int i, len;
+	uvd_t *uvd = urb->context;
+
+	/* We don't want to do anything if we are about to be removed! */
+	if (!CAMERA_IS_OPERATIONAL(uvd))
+		return;
+#if 0
+	if (urb->actual_length > 0) {
+		info("urb=$%p status=%d. errcount=%d. length=%d.",
+		     urb, urb->status, urb->error_count, urb->actual_length);
+	} else {
+		static int c = 0;
+		if (c++ % 100 == 0)
+			info("No Isoc data");
+	}
+#endif
+
+	if (!uvd->streaming) {
+		if (uvd->debug >= 1)
+			info("Not streaming, but interrupt!");
+		return;
+	}
+	
+	uvd->stats.urb_count++;
+	if (urb->actual_length <= 0)
+		goto urb_done_with;
+
+	/* Copy the data received into ring queue */
+	len = usbvideo_CompressIsochronous(uvd, urb);
+	uvd->stats.urb_length = len;
+	if (len <= 0)
+		goto urb_done_with;
+
+	/* Here we got some data */
+	uvd->stats.data_count += len;
+	RingQueue_WakeUpInterruptible(&uvd->dp);
+
+urb_done_with:
+	for (i = 0; i < FRAMES_PER_DESC; i++) {
+		urb->iso_frame_desc[i].status = 0;
+		urb->iso_frame_desc[i].actual_length = 0;
+	}
+	return;
+}
+
+/*
+ * usbvideo_StartDataPump()
+ *
+ * History:
+ * 27-Jan-2000 Used ibmcam->iface, ibmcam->ifaceAltActive instead
+ *             of hardcoded values. Simplified by using for loop,
+ *             allowed any number of URBs.
+ */
+int usbvideo_StartDataPump(uvd_t *uvd)
+{
+	static const char proc[] = "usbvideo_StartDataPump";
+	struct usb_device *dev = uvd->dev;
+	int i, errFlag;
+
+	if (uvd->debug > 1)
+		info("%s($%p)", proc, uvd);
+
+	if (!CAMERA_IS_OPERATIONAL(uvd)) {
+		err("%s: Camera is not operational",proc);
+		return -EFAULT;
+	}
+	uvd->curframe = -1;
+
+	/* Alternate interface 1 is is the biggest frame size */
+	i = usb_set_interface(dev, uvd->iface, uvd->ifaceAltActive);
+	if (i < 0) {
+		err("%s: usb_set_interface error", proc);
+		uvd->last_error = i;
+		return -EBUSY;
+	}
+	if (VALID_CALLBACK(uvd, videoStart))
+		GET_CALLBACK(uvd, videoStart)(uvd);
+	else 
+		err("%s: videoStart not set", proc);
+
+	/* We double buffer the Iso lists */
+	for (i=0; i < USBVIDEO_NUMSBUF; i++) {
+		int j, k;
+		urb_t *urb = uvd->sbuf[i].urb;
+		urb->dev = dev;
+		urb->context = uvd;
+		urb->pipe = usb_rcvisocpipe(dev, uvd->video_endp);
+		urb->transfer_flags = USB_ISO_ASAP;
+		urb->transfer_buffer = uvd->sbuf[i].data;
+		urb->complete = usbvideo_IsocIrq;
+		urb->number_of_packets = FRAMES_PER_DESC;
+		urb->transfer_buffer_length = uvd->iso_packet_len * FRAMES_PER_DESC;
+		for (j=k=0; j < FRAMES_PER_DESC; j++, k += uvd->iso_packet_len) {
+			urb->iso_frame_desc[j].offset = k;
+			urb->iso_frame_desc[j].length = uvd->iso_packet_len;
+		}
+	}
+
+	/* Link URBs into a ring so that they invoke each other infinitely */
+	for (i=0; i < USBVIDEO_NUMSBUF; i++) {
+		if ((i+1) < USBVIDEO_NUMSBUF)
+			uvd->sbuf[i].urb->next = uvd->sbuf[i+1].urb;
+		else
+			uvd->sbuf[i].urb->next = uvd->sbuf[0].urb;
+	}
+
+	/* Submit all URBs */
+	for (i=0; i < USBVIDEO_NUMSBUF; i++) {
+		errFlag = usb_submit_urb(uvd->sbuf[i].urb);
+		if (errFlag)
+			err("%s: usb_submit_isoc(%d) ret %d", proc, i, errFlag);
+	}
+
+	uvd->streaming = 1;
+	if (uvd->debug > 1)
+		info("%s: streaming=1 video_endp=$%02x", proc, uvd->video_endp);
+	return 0;
+}
+
+/*
+ * usbvideo_StopDataPump()
+ *
+ * This procedure stops streaming and deallocates URBs. Then it
+ * activates zero-bandwidth alt. setting of the video interface.
+ *
+ * History:
+ * 22-Jan-2000 Corrected order of actions to work after surprise removal.
+ * 27-Jan-2000 Used uvd->iface, uvd->ifaceAltInactive instead of hardcoded values.
+ */
+void usbvideo_StopDataPump(uvd_t *uvd)
+{
+	static const char proc[] = "usbvideo_StopDataPump";
+	int i, j;
+
+	if (uvd->debug > 1)
+		info("%s($%p)", proc, uvd);
+
+	if ((uvd == NULL) || (!uvd->streaming) || (uvd->dev == NULL))
+		return;
+
+	/* Unschedule all of the iso td's */
+	for (i=0; i < USBVIDEO_NUMSBUF; i++) {
+		j = usb_unlink_urb(uvd->sbuf[i].urb);
+		if (j < 0)
+			err("%s: usb_unlink_urb() error %d.", proc, j);
+	}
+	if (uvd->debug > 1)
+		info("%s: streaming=0", proc);
+	uvd->streaming = 0;
+
+	if (!uvd->remove_pending) {
+		/* Invoke minidriver's magic to stop the camera */
+		if (VALID_CALLBACK(uvd, videoStop))
+			GET_CALLBACK(uvd, videoStop)(uvd);
+		else 
+			err("%s: videoStop not set" ,proc);
+
+		/* Set packet size to 0 */
+		j = usb_set_interface(uvd->dev, uvd->iface, uvd->ifaceAltInactive);
+		if (j < 0) {
+			err("%s: usb_set_interface() error %d.", proc, j);
+			uvd->last_error = j;
+		}
+	}
+}
+
+/*
+ * usbvideo_NewFrame()
+ *
+ * History:
+ * 29-Mar-00 Added copying of previous frame into the current one.
+ * 6-Aug-00  Added model 3 video sizes, removed redundant width, height.
+ */
+int usbvideo_NewFrame(uvd_t *uvd, int framenum)
+{
+	usbvideo_frame_t *frame;
+	int n;
+
+	if (uvd->debug > 1)
+		info("usbvideo_NewFrame($%p,%d.)", uvd, framenum);
+
+	/* If we're not grabbing a frame right now and the other frame is */
+	/*  ready to be grabbed into, then use it instead */
+	if (uvd->curframe != -1)
+		return 0;
+
+	/* If necessary we adjust picture settings between frames */
+	if (!uvd->settingsAdjusted) {
+		if (VALID_CALLBACK(uvd, adjustPicture))
+			GET_CALLBACK(uvd, adjustPicture)(uvd);
+		uvd->settingsAdjusted = 1;
+	}
+
+	n = (framenum - 1 + USBVIDEO_NUMFRAMES) % USBVIDEO_NUMFRAMES;
+	if (uvd->frame[n].frameState == FrameState_Ready)
+		framenum = n;
+
+	frame = &uvd->frame[framenum];
+
+	frame->frameState = FrameState_Grabbing;
+	frame->scanstate = ScanState_Scanning;
+	frame->seqRead_Length = 0;	/* Accumulated in xxx_parse_data() */
+	frame->deinterlace = Deinterlace_None;
+	frame->flags = 0; /* No flags yet, up to minidriver (or us) to set them */
+	uvd->curframe = framenum;
+
+	/*
+	 * Normally we would want to copy previous frame into the current one
+	 * before we even start filling it with data; this allows us to stop
+	 * filling at any moment; top portion of the frame will be new and
+	 * bottom portion will stay as it was in previous frame. If we don't
+	 * do that then missing chunks of video stream will result in flickering
+	 * portions of old data whatever it was before.
+	 *
+	 * If we choose not to copy previous frame (to, for example, save few
+	 * bus cycles - the frame can be pretty large!) then we have an option
+	 * to clear the frame before using. If we experience losses in this
+	 * mode then missing picture will be black (no flickering).
+	 *
+	 * Finally, if user chooses not to clean the current frame before
+	 * filling it with data then the old data will be visible if we fail
+	 * to refill entire frame with new data.
+	 */
+	if (!(uvd->flags & FLAGS_SEPARATE_FRAMES)) {
+		/* This copies previous frame into this one to mask losses */
+		memmove(frame->data, uvd->frame[1-framenum].data, uvd->max_frame_size);
+	} else {
+		if (uvd->flags & FLAGS_CLEAN_FRAMES) {
+			/* This provides a "clean" frame but slows things down */
+			memset(frame->data, 0, uvd->max_frame_size);
+		}
+	}
+	return 0;
+}
+
+/*
+ * usbvideo_CollectRawData()
+ *
+ * This procedure can be used instead of 'processData' callback if you
+ * only want to dump the raw data from the camera into the output
+ * device (frame buffer). You can look at it with V4L client, but the
+ * image will be unwatchable. The main purpose of this code and of the
+ * mode FLAGS_NO_DECODING is debugging and capturing of datastreams from
+ * new, unknown cameras. This procedure will be automatically invoked
+ * instead of the specified callback handler when uvd->flags has bit
+ * FLAGS_NO_DECODING set. Therefore, any regular build of any driver
+ * based on usbvideo can use this feature at any time.
+ */
+void usbvideo_CollectRawData(uvd_t *uvd, usbvideo_frame_t *frame)
+{
+	int n;
+
+	assert(uvd != NULL);
+	assert(frame != NULL);
+
+	/* Try to move data from queue into frame buffer */
+	n = RingQueue_GetLength(&uvd->dp);
+	if (n > 0) {
+		int m;
+		/* See how much space we have left */
+		m = uvd->max_frame_size - frame->seqRead_Length;
+		if (n > m)
+			n = m;
+		/* Now move that much data into frame buffer */
+		RingQueue_Dequeue(
+			&uvd->dp,
+			frame->data + frame->seqRead_Length,
+			m);
+		frame->seqRead_Length += m;
+	}
+	/* See if we filled the frame */
+	if (frame->seqRead_Length >= uvd->max_frame_size) {
+		frame->frameState = FrameState_Done;
+		uvd->curframe = -1;
+		uvd->stats.frame_num++;
+	}
+}
+
+int usbvideo_GetFrame(uvd_t *uvd, int frameNum)
+{
+	static const char proc[] = "usbvideo_GetFrame";
+	usbvideo_frame_t *frame = &uvd->frame[frameNum];
+
+	if (uvd->debug >= 2)
+		info("%s($%p,%d.)", proc, uvd, frameNum);
+
+	switch (frame->frameState) {
+        case FrameState_Unused:
+		if (uvd->debug >= 2)
+			info("%s: FrameState_Unused", proc);
+		return -EINVAL;
+        case FrameState_Ready:
+        case FrameState_Grabbing:
+        case FrameState_Error:
+        {
+		int ntries, signalPending;
+	redo:
+		if (!CAMERA_IS_OPERATIONAL(uvd)) {
+			if (uvd->debug >= 2)
+				info("%s: Camera is not operational (1)", proc);
+			return -EIO;
+		}
+		ntries = 0; 
+		do {
+			RingQueue_InterruptibleSleepOn(&uvd->dp);
+			signalPending = signal_pending(current);
+			if (!CAMERA_IS_OPERATIONAL(uvd)) {
+				if (uvd->debug >= 2)
+					info("%s: Camera is not operational (2)", proc);
+				return -EIO;
+			}
+			assert(uvd->fbuf != NULL);
+			if (signalPending) {
+				if (uvd->debug >= 2)
+					info("%s: Signal=$%08x", proc, signalPending);
+				if (uvd->flags & FLAGS_RETRY_VIDIOCSYNC) {
+					usbvideo_TestPattern(uvd, 1, 0);
+					uvd->curframe = -1;
+					uvd->stats.frame_num++;
+					if (uvd->debug >= 2)
+						info("%s: Forced test pattern screen", proc);
+					return 0;
+				} else {
+					/* Standard answer: Interrupted! */
+					if (uvd->debug >= 2)
+						info("%s: Interrupted!", proc);
+					return -EINTR;
+				}
+			} else {
+				/* No signals - we just got new data in dp queue */
+				if (uvd->flags & FLAGS_NO_DECODING)
+					usbvideo_CollectRawData(uvd, frame);
+				else if (VALID_CALLBACK(uvd, processData))
+					GET_CALLBACK(uvd, processData)(uvd, frame);
+				else 
+					err("%s: processData not set", proc);
+			}
+		} while (frame->frameState == FrameState_Grabbing);
+		if (uvd->debug >= 2) {
+			info("%s: Grabbing done; state=%d. (%lu. bytes)",
+			     proc, frame->frameState, frame->seqRead_Length);
+		}
+		if (frame->frameState == FrameState_Error) {
+			int ret = usbvideo_NewFrame(uvd, frameNum);
+			if (ret < 0) {
+				err("%s: usbvideo_NewFrame() failed (%d.)", proc, ret);
+				return ret;
+			}
+			goto redo;
+		}
+		/* Note that we fall through to meet our destiny below */
+        }
+        case FrameState_Done:
+		/*
+		 * Do all necessary postprocessing of data prepared in
+		 * "interrupt" code and the collecting code above. The
+		 * frame gets marked as FrameState_Done by queue parsing code.
+		 * This status means that we collected enough data and
+		 * most likely processed it as we went through. However
+		 * the data may need postprocessing, such as deinterlacing
+		 * or picture adjustments implemented in software (horror!)
+		 *
+		 * As soon as the frame becomes "final" it gets promoted to
+		 * FrameState_Done_Hold status where it will remain until the
+		 * caller consumed all the video data from the frame. Then
+		 * the empty shell of ex-frame is thrown out for dogs to eat.
+		 * But we, worried about pets, will recycle the frame!
+		 */
+		uvd->stats.frame_num++;
+		if ((uvd->flags & FLAGS_NO_DECODING) == 0) {
+			if (VALID_CALLBACK(uvd, postProcess))
+				GET_CALLBACK(uvd, postProcess)(uvd, frame);
+			if (frame->flags & USBVIDEO_FRAME_FLAG_SOFTWARE_CONTRAST)
+				usbvideo_SoftwareContrastAdjustment(uvd, frame);
+		}
+		frame->frameState = FrameState_Done_Hold;
+		if (uvd->debug >= 2)
+			info("%s: Entered FrameState_Done_Hold state.", proc);
+		return 0;
+
+	case FrameState_Done_Hold:
+		/*
+		 * We stay in this state indefinitely until someone external,
+		 * like ioctl() or read() call finishes digesting the frame
+		 * data. Then it will mark the frame as FrameState_Unused and
+		 * it will be released back into the wild to roam freely.
+		 */
+		if (uvd->debug >= 2)
+			info("%s: FrameState_Done_Hold state.", proc);
+		return 0;
+	}
+
+	/* Catch-all for other cases. We shall not be here. */
+	err("%s: Invalid state %d.", proc, frame->frameState);
+	frame->frameState = FrameState_Unused;
+	return 0;
+}
+
+/*
+ * usbvideo_DeinterlaceFrame()
+ *
+ * This procedure deinterlaces the given frame. Some cameras produce
+ * only half of scanlines - sometimes only even lines, sometimes only
+ * odd lines. The deinterlacing method is stored in frame->deinterlace
+ * variable.
+ *
+ * Here we scan the frame vertically and replace missing scanlines with
+ * average between surrounding ones - before and after. If we have no
+ * line above then we just copy next line. Similarly, if we need to
+ * create a last line then preceding line is used.
+ */
+void usbvideo_DeinterlaceFrame(uvd_t *uvd, usbvideo_frame_t *frame)
+{
+	if ((uvd == NULL) || (frame == NULL))
+		return;
+
+	if ((frame->deinterlace == Deinterlace_FillEvenLines) ||
+	    (frame->deinterlace == Deinterlace_FillOddLines))
+	{
+		const int v4l_linesize = VIDEOSIZE_X(frame->request) * V4L_BYTES_PER_PIXEL;
+		int i = (frame->deinterlace == Deinterlace_FillEvenLines) ? 0 : 1;
+
+		for (; i < VIDEOSIZE_Y(frame->request); i += 2) {
+			const unsigned char *fs1, *fs2;
+			unsigned char *fd;
+			int ip, in, j;	/* Previous and next lines */
+
+			/*
+			 * Need to average lines before and after 'i'.
+			 * If we go out of bounds seeking those lines then
+			 * we point back to existing line.
+			 */
+			ip = i - 1;	/* First, get rough numbers */
+			in = i + 1;
+
+			/* Now validate */
+			if (ip < 0)
+				ip = in;
+			if (in >= VIDEOSIZE_Y(frame->request))
+				in = ip;
+
+			/* Sanity check */
+			if ((ip < 0) || (in < 0) ||
+			    (ip >= VIDEOSIZE_Y(frame->request)) ||
+			    (in >= VIDEOSIZE_Y(frame->request)))
+			{
+				err("Error: ip=%d. in=%d. req.height=%ld.",
+				    ip, in, VIDEOSIZE_Y(frame->request));
+				break;
+			}
+
+			/* Now we need to average lines 'ip' and 'in' to produce line 'i' */
+			fs1 = frame->data + (v4l_linesize * ip);
+			fs2 = frame->data + (v4l_linesize * in);
+			fd = frame->data + (v4l_linesize * i);
+
+			/* Average lines around destination */
+			for (j=0; j < v4l_linesize; j++) {
+				fd[j] = (unsigned char)((((unsigned) fs1[j]) +
+							 ((unsigned)fs2[j])) >> 1);
+			}
+		}
+	}
+
+	/* Optionally display statistics on the screen */
+	if (uvd->flags & FLAGS_OVERLAY_STATS)
+		usbvideo_OverlayStats(uvd, frame);
+}
+
+/*
+ * usbvideo_SoftwareContrastAdjustment()
+ *
+ * This code adjusts the contrast of the frame, assuming RGB24 format.
+ * As most software image processing, this job is CPU-intensive.
+ * Get a camera that supports hardware adjustment!
+ *
+ * History:
+ * 09-Feb-2001  Created.
+ */
+void usbvideo_SoftwareContrastAdjustment(uvd_t *uvd, usbvideo_frame_t *frame)
+{
+	static const char proc[] = "usbvideo_SoftwareContrastAdjustment";
+	int i, j, v4l_linesize;
+	signed long adj;
+	const int ccm = 128; /* Color correction median - see below */
+
+	if ((uvd == NULL) || (frame == NULL)) {
+		err("%s: Illegal call.", proc);
+		return;
+	}
+	adj = (uvd->vpic.contrast - 0x8000) >> 8; /* -128..+127 = -ccm..+(ccm-1)*/
+	RESTRICT_TO_RANGE(adj, -ccm, ccm+1);
+	if (adj == 0) {
+		/* In rare case of no adjustment */
+		return;
+	}
+	v4l_linesize = VIDEOSIZE_X(frame->request) * V4L_BYTES_PER_PIXEL;
+	for (i=0; i < VIDEOSIZE_Y(frame->request); i++) {
+		unsigned char *fd = frame->data + (v4l_linesize * i);
+		for (j=0; j < v4l_linesize; j++) {
+			signed long v = (signed long) fd[j];
+			/* Magnify up to 2 times, reduce down to zero */
+			v = 128 + ((ccm + adj) * (v - 128)) / ccm;
+			RESTRICT_TO_RANGE(v, 0, 0xFF); /* Must flatten tails */
+			fd[j] = (unsigned char) v;
+		}
+	}
+}
+
+/*
+ * /proc interface
+ *
+ * We will be creating directories and entries under /proc/video using
+ * external 'video_proc_entry' directory which is exported by videodev.o
+ * module. Within that directory we will create $driver/ directory to
+ * uniquely and uniformly refer to our specific $driver. Within that
+ * directory we will finally create an entry that is named after the
+ * video device node - video3, for example. The format of that file
+ * is determined by callbacks that the minidriver may provide. If no
+ * callbacks are provided (neither read nor write) then we don't create
+ * the entry.
+ *
+ * Here is a sample directory entry: /proc/video/ibmcam/video3
+ *
+ * The "file" video3 (in example above) is readable and writeable, in
+ * theory. If the minidriver provides callbacks to do reading and
+ * writing then both those procedures are supported. However if the
+ * driver leaves callbacks in default (NULL) state the default
+ * read and write handlers are used. The default read handler reports
+ * that the driver does not support /proc fs. The default write handler
+ * returns error code on any write attempt.
+ */
+
+#if USES_PROC_FS
+
+extern struct proc_dir_entry *video_proc_entry;
+
+static void usbvideo_procfs_level1_create(usbvideo_t *ut)
+{
+	static const char proc[] = "usbvideo_procfs_level1_create";
+
+	if (ut == NULL) {
+		err("%s: ut == NULL", proc);
+		return;
+	}
+	if (video_proc_entry == NULL) {
+		err("%s: /proc/video/ doesn't exist.", proc);
+		return;
+	}
+	ut->procfs_dEntry = create_proc_entry(ut->drvName, S_IFDIR, video_proc_entry);
+	if (ut->procfs_dEntry != NULL) {
+		if (ut->md_module != NULL)
+			ut->procfs_dEntry->owner = ut->md_module;
+	} else {
+		err("%s: Unable to initialize /proc/video/%s", proc, ut->drvName);
+	}
+}
+
+static void usbvideo_procfs_level1_destroy(usbvideo_t *ut)
+{
+	static const char proc[] = "usbvideo_procfs_level1_destroy";
+
+	if (ut == NULL) {
+		err("%s: ut == NULL", proc);
+		return;
+	}
+	if (ut->procfs_dEntry != NULL) {
+		remove_proc_entry(ut->drvName, video_proc_entry);
+		ut->procfs_dEntry = NULL;
+	}
+}
+
+static void usbvideo_procfs_level2_create(uvd_t *uvd)
+{
+	static const char proc[] = "usbvideo_procfs_level2_create";
+
+	if (uvd == NULL) {
+		err("%s: uvd == NULL", proc);
+		return;
+	}
+	assert(uvd->handle != NULL);
+	if (uvd->handle->procfs_dEntry == NULL) {
+		err("%s: uvd->handle->procfs_dEntry == NULL", proc);
+		return;
+	}
+
+	sprintf(uvd->videoName, "video%d", uvd->vdev.minor);
+	uvd->procfs_vEntry = create_proc_entry(
+		uvd->videoName,
+		S_IFREG | S_IRUGO | S_IWUSR,
+		uvd->handle->procfs_dEntry);
+	if (uvd->procfs_vEntry != NULL) {
+		uvd->procfs_vEntry->data = uvd;
+		uvd->procfs_vEntry->read_proc = uvd->handle->cb.procfs_read;
+		uvd->procfs_vEntry->write_proc = uvd->handle->cb.procfs_write;
+	} else {
+		err("%s: Failed to create entry \"%s\"", proc, uvd->videoName);
+	}
+}
+
+static void usbvideo_procfs_level2_destroy(uvd_t *uvd)
+{
+	static const char proc[] = "usbvideo_procfs_level2_destroy";
+
+	if (uvd == NULL) {
+		err("%s: uvd == NULL", proc);
+		return;
+	}
+	if (uvd->procfs_vEntry != NULL) {
+		remove_proc_entry(uvd->videoName, uvd->procfs_vEntry);
+		uvd->procfs_vEntry = NULL;
+	}
+}
+
+static int usbvideo_default_procfs_read_proc(
+	char *page, char **start, off_t off, int count,
+	int *eof, void *data)
+{
+	char *out = page;
+	int len;
+	
+	/* Stay under PAGE_SIZE or else */
+	out += sprintf(out, "This driver does not support /proc services.\n");
+	len = out - page;
+	len -= off;
+	if (len < count) {
+		*eof = 1;
+		if (len <= 0)
+			return 0;
+	} else
+		len = count;
+	*start = page + off;
+	return len;	
+}
+
+static int usbvideo_default_procfs_write_proc(
+	struct file *file, const char *buffer, 
+	unsigned long count, void *data)
+{
+	return -EINVAL;
+}
+
+#endif /* USES_PROC_FS */