uvc_driver.c

linux camera下的uvc driver驱动源码

/*
 *      uvcvideo.c  --  USB Video Class driver
 *
 *      Copyright (C) 2005-2006
 *          Laurent Pinchart ([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.
 *
 */

/*
 * WARNING: This driver is definitely *NOT* complete. It will (hopefully)
 * support UVC devices with a camera sensors, a processing unit and several
 * optional extension units. Single-input selector units are ignored.
 * Everything else is unsupported.
 *
 * The driver doesn't support the deprecated v4l1 interface. It implements the
 * mmap capture method only, and doesn't do any image format conversion in
 * software. If your user-space application doesn't support YUYV or MJPEG, fix
 * it :-). Please note that the MJPEG data have been stripped from their
 * Huffman tables (DHT marker), you will need to add it back if your JPEG
 * codec can't handle MJPEG data.
 *
 * Although the driver compiles on 2.6.12, you should use a 2.6.15 or newer
 * kernel because of USB issues.
 */

#include <linux/kernel.h>
#include <linux/version.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/videodev.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>
#include <asm/atomic.h>

#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,15)
#include <media/v4l2-common.h>
#endif

#include "uvcvideo.h"
#include "version.h"

#define DRIVER_AUTHOR		"Laurent Pinchart <[e-mail]>"
#define DRIVER_DESC		"USB Video Class driver"
#ifndef DRIVER_VERSION
#define DRIVER_VERSION		"v0.1.0"
#endif

static unsigned int uvc_quirks_param = 0;
unsigned int uvc_trace_param = 0;

/* ------------------------------------------------------------------------
 * Control, formats, ...
 */

static struct uvc_format_desc uvc_fmts[] = {
	{
		.name		= "YUV 4:2:2 (YUYV)",
		.guid		= UVC_GUID_FORMAT_YUY2,
		.fcc		= V4L2_PIX_FMT_YUYV,
	},
	{
		.name		= "YUV 4:2:0 (NV12)",
		.guid		= UVC_GUID_FORMAT_NV12,
		.fcc		= V4L2_PIX_FMT_NV12,
	},
	{
		.name		= "MJPEG",
		.guid		= UVC_GUID_FORMAT_MJPEG,
		.fcc		= V4L2_PIX_FMT_MJPEG,
	},
	{
		.name		= "YVU 4:2:0 (YV12)",
		.guid		= UVC_GUID_FORMAT_YV12,
		.fcc		= V4L2_PIX_FMT_YVU420,
	},
	{
		.name		= "YUV 4:2:0 (I420)",
		.guid		= UVC_GUID_FORMAT_I420,
		.fcc		= V4L2_PIX_FMT_YUV420,
	},
	{
		.name		= "YUV 4:2:2 (UYVY)",
		.guid		= UVC_GUID_FORMAT_UYVY,
		.fcc		= V4L2_PIX_FMT_UYVY,
	},
	{
		.name		= "Greyscale",
		.guid		= UVC_GUID_FORMAT_Y800,
		.fcc		= V4L2_PIX_FMT_GREY,
	},
	{
		.name		= "RGB Bayer",
		.guid		= UVC_GUID_FORMAT_BY8,
		.fcc		= V4L2_PIX_FMT_SBGGR8,
	},
};

#if 0
static void uvc_print_streaming_control(struct uvc_streaming_control *ctrl)
{
	printk(KERN_DEBUG "bmHint:                      0x%04x\n", ctrl->bmHint);
	printk(KERN_DEBUG "bFormatIndex:                   %3u\n", ctrl->bFormatIndex);
	printk(KERN_DEBUG "bFrameIndex:                    %3u\n", ctrl->bFrameIndex);
	printk(KERN_DEBUG "dwFrameInterval:          %9u\n", ctrl->dwFrameInterval);
	printk(KERN_DEBUG "wKeyFrameRate:                %5u\n", ctrl->wKeyFrameRate);
	printk(KERN_DEBUG "wPFrameRate:                  %5u\n", ctrl->wPFrameRate);
	printk(KERN_DEBUG "wCompQuality:                 %5u\n", ctrl->wCompQuality);
	printk(KERN_DEBUG "wCompWindowSize:              %5u\n", ctrl->wCompWindowSize);
	printk(KERN_DEBUG "wDelay:                       %5u\n", ctrl->wDelay);
	printk(KERN_DEBUG "dwMaxVideoFrameSize:      %9u\n", ctrl->dwMaxVideoFrameSize);
	printk(KERN_DEBUG "dwMaxPayloadTransferSize: %9u\n", ctrl->dwMaxPayloadTransferSize);
	printk(KERN_DEBUG "dwClockFrequency:         %9u\n", ctrl->dwClockFrequency);
	printk(KERN_DEBUG "bmFramingInfo:                 0x%02x\n", ctrl->bmFramingInfo);
	printk(KERN_DEBUG "bPreferedVersion:               %3u\n", ctrl->bPreferedVersion);
	printk(KERN_DEBUG "bMinVersion:                    %3u\n", ctrl->bMinVersion);
	printk(KERN_DEBUG "bMaxVersion:                    %3u\n", ctrl->bMaxVersion);
}
#endif

/* ------------------------------------------------------------------------
 * Utility functions
 */

struct usb_host_endpoint *uvc_find_endpoint(struct usb_host_interface *alts,
		__u8 epaddr)
{
	struct usb_host_endpoint *ep;
	unsigned int i;

	for (i = 0; i < alts->desc.bNumEndpoints; ++i) {
		ep = &alts->endpoint[i];
		if (ep->desc.bEndpointAddress == epaddr)
			return ep;
	}

	return NULL;
}

static struct uvc_format_desc *uvc_format_by_guid(const __u8 guid[16])
{
	unsigned int len = ARRAY_SIZE(uvc_fmts);
	unsigned int i;

	for (i = 0; i < len; ++i) {
		if (memcmp(guid, uvc_fmts[i].guid, 16) == 0)
			return &uvc_fmts[i];
	}

	return NULL;
}

static __u32 uvc_colorspace(const __u8 primaries)
{
	static const __u8 colorprimaries[] = {
		0,
		V4L2_COLORSPACE_SRGB,
		V4L2_COLORSPACE_470_SYSTEM_M,
		V4L2_COLORSPACE_470_SYSTEM_BG,
		V4L2_COLORSPACE_SMPTE170M,
		V4L2_COLORSPACE_SMPTE240M,
	};

	if (primaries < ARRAY_SIZE(colorprimaries))
		return colorprimaries[primaries];

	return 0;
}

/* Simplify a fraction using a simple continued fraction decomposition. The
 * idea here is to convert fractions such as 333333/10000000 to 1/30 using
 * 32 bit arithmetic only. The algorithm is not perfect and relies upon two
 * arbitrary parameters to remove non-significative terms from the simple
 * continued fraction decomposition. Using 8 and 333 for n_terms and threshold
 * respectively seems to give nice results.
 */
void uvc_simplify_fraction(uint32_t *numerator, uint32_t *denominator,
		unsigned int n_terms, unsigned int threshold)
{
	uint32_t *an;
	uint32_t x, y, r;
	unsigned int i, n;

	an = kmalloc(n_terms * sizeof *an, GFP_KERNEL);
	if (an == NULL)
		return;

	/* Convert the fraction to a simple continued fraction. See
	 * http://mathforum.org/dr.math/faq/faq.fractions.html
	 * Stop if the current term is bigger than or equal to the given
	 * threshold.
	 */
	x = *numerator;
	y = *denominator;

	for (n = 0; n < n_terms && y != 0; ++n) {
		an[n] = x / y;
		if (an[n] >= threshold) {
			if (n < 2)
				n++;
			break;
		}

		r = x - an[n] * y;
		x = y;
		y = r;
	}

	/* Expand the simple continued fraction back to an integer fraction. */
	x = 0;
	y = 1;

	for (i = n; i > 0; --i) {
		r = y;
		y = an[i-1] * y + x;
		x = r;
	}

	*numerator = y;
	*denominator = x;
	kfree(an);
}

/* Convert a fraction to a frame interval in 100ns multiples. The idea here is
 * to compute numerator / denominator * 10000000 using 32 bit fixed point
 * arithmetic only.
 */
uint32_t uvc_fraction_to_interval(uint32_t numerator, uint32_t denominator)
{
	uint32_t multiplier;

	/* Saturate the result if the operation would overflow. */
	if (denominator == 0 ||
	    numerator/denominator >= ((uint32_t)-1)/10000000)
		return (uint32_t)-1;

	/* Divide both the denominator and the multiplier by two until
	 * numerator * multiplier doesn't overflow. If anyone knows a better
	 * algorithm please let me know.
	 */
	multiplier = 10000000;
	while (numerator > ((uint32_t)-1)/multiplier) {
		multiplier /= 2;
		denominator /= 2;
	}

	return denominator ? numerator * multiplier / denominator : 0;
}

/* ------------------------------------------------------------------------
 * Terminal and unit management
 */

static struct uvc_entity *uvc_entity_by_id(struct uvc_device *dev, int id)
{
	struct uvc_entity *entity;

	list_for_each_entry(entity, &dev->entities, list) {
		if (entity->id == id)
			return entity;
	}

	return NULL;
}

static struct uvc_entity *uvc_entity_by_reference(struct uvc_device *dev,
	int id, struct uvc_entity *entity)
{
	unsigned int i;

	if (entity == NULL)
		entity = list_entry(&dev->entities, struct uvc_entity, list);

	list_for_each_entry_continue(entity, &dev->entities, list) {
		switch (UVC_ENTITY_TYPE(entity)) {
		case TT_STREAMING:
			if (entity->output.bSourceID == id)
				return entity;
			break;

		case VC_PROCESSING_UNIT:
			if (entity->processing.bSourceID == id)
				return entity;
			break;

		case VC_SELECTOR_UNIT:
			for (i = 0; i < entity->selector.bNrInPins; ++i)
				if (entity->selector.baSourceID[i] == id)
					return entity;
			break;

		case VC_EXTENSION_UNIT:
			for (i = 0; i < entity->extension.bNrInPins; ++i)
				if (entity->extension.baSourceID[i] == id)
					return entity;
			break;
		}
	}

	return NULL;
}

/* ------------------------------------------------------------------------
 * Descriptors handling
 */

static int uvc_parse_format(struct uvc_device *dev,
	struct uvc_streaming *streaming, struct uvc_format *format,
	__u32 **intervals, unsigned char *buffer, int buflen)
{
	struct usb_interface *intf = streaming->intf;
	struct usb_host_interface *alts = intf->cur_altsetting;
	struct uvc_format_desc *fmtdesc;
	struct uvc_frame *frame;
	const unsigned char *start = buffer;
	unsigned int interval;
	unsigned int i, n;
	__u8 ftype;

	format->type = buffer[2];
	format->index = buffer[3];

	switch (buffer[2]) {
	case VS_FORMAT_UNCOMPRESSED:
	case VS_FORMAT_FRAME_BASED:
		if (buflen < 27) {
			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
			       "interface %d FORMAT error\n",
			       dev->udev->devnum,
			       alts->desc.bInterfaceNumber);
			return -EINVAL;
		}

		/* Find the format descriptor from its GUID. */
		fmtdesc = uvc_format_by_guid(&buffer[5]);

		if (fmtdesc != NULL) {
			strncpy(format->name, fmtdesc->name, sizeof format->name);
			format->fcc = fmtdesc->fcc;
		} else {
			uvc_printk(KERN_INFO, "Unknown video format "
				UVC_GUID_FORMAT "\n",
				UVC_GUID_ARGS(&buffer[5]));
			snprintf(format->name, sizeof format->name,
				UVC_GUID_FORMAT, UVC_GUID_ARGS(&buffer[5]));
			format->fcc = 0;
		}

		format->bpp = buffer[21];
		if (buffer[2] == VS_FORMAT_UNCOMPRESSED) {
			ftype = VS_FRAME_UNCOMPRESSED;
		} else {
			ftype = VS_FRAME_FRAME_BASED;
			if (buffer[27])
				format->flags = UVC_FMT_FLAG_COMPRESSED;
		}
		break;

	case VS_FORMAT_MJPEG:
		if (buflen < 11) {
			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
			       "interface %d FORMAT error\n",
			       dev->udev->devnum,
			       alts->desc.bInterfaceNumber);
			return -EINVAL;
		}

		strncpy(format->name, "MJPEG", sizeof format->name);
		format->fcc = V4L2_PIX_FMT_MJPEG;
		format->flags = UVC_FMT_FLAG_COMPRESSED;
		format->bpp = 0;
		ftype = VS_FRAME_MJPEG;
		break;

	case VS_FORMAT_DV:
		if (buflen < 9) {
			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
			       "interface %d FORMAT error\n",
			       dev->udev->devnum,
			       alts->desc.bInterfaceNumber);
			return -EINVAL;
		}

		switch (buffer[8] & 0x7f) {
		case 0:
			strncpy(format->name, "SD-DV", sizeof format->name);
			break;
		case 1:
			strncpy(format->name, "SDL-DV", sizeof format->name);
			break;
		case 2:
			strncpy(format->name, "HD-DV", sizeof format->name);
			break;
		default:
			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
			       "interface %d: unknown DV format %u\n",
			       dev->udev->devnum,
			       alts->desc.bInterfaceNumber, buffer[8]);
			return -EINVAL;
		}

		strncat(format->name, buffer[8] & (1 << 7) ? " 60Hz" : " 50Hz",
			sizeof format->name);

		format->fcc = V4L2_PIX_FMT_DV;
		format->flags = UVC_FMT_FLAG_COMPRESSED | UVC_FMT_FLAG_STREAM;
		format->bpp = 0;
		ftype = 0;

		/* Create a dummy frame descriptor. */
		frame = &format->frame[0];
		memset(&format->frame[0], 0, sizeof format->frame[0]);
		frame->bFrameIntervalType = 1;
		frame->dwDefaultFrameInterval = 1;
		frame->dwFrameInterval = *intervals;
		*(*intervals)++ = 1;
		format->nframes = 1;
		break;

	case VS_FORMAT_MPEG2TS:
	case VS_FORMAT_STREAM_BASED:
		/* Not supported yet. */
	default:
		uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
		       "interface %d unsupported format %u\n",
		       dev->udev->devnum, alts->desc.bInterfaceNumber,
		       buffer[2]);
		return -EINVAL;
	}

	uvc_trace(UVC_TRACE_DESCR, "Found format %s.\n", format->name);

	buflen -= buffer[0];
	buffer += buffer[0];

	/* Parse the frame descriptors. Only uncompressed, MJPEG and frame
	 * based formats have frame descriptors.
	 */
	while (buflen > 2 && buffer[2] == ftype) {
		frame = &format->frame[format->nframes];

		if (ftype != VS_FRAME_FRAME_BASED)
			n = buflen > 25 ? buffer[25] : 0;
		else
			n = buflen > 21 ? buffer[21] : 0;

		n = n ? n : 3;

		if (buflen < 26 + 4*n) {
			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
			       "interface %d FRAME error\n", dev->udev->devnum,
			       alts->desc.bInterfaceNumber);
			return -EINVAL;
		}

		frame->bFrameIndex = buffer[3];
		frame->bmCapabilities = buffer[4];
		frame->wWidth = le16_to_cpup((__le16*)&buffer[5]);
		frame->wHeight = le16_to_cpup((__le16*)&buffer[7]);
		frame->dwMinBitRate = le32_to_cpup((__le32*)&buffer[9]);
		frame->dwMaxBitRate = le32_to_cpup((__le32*)&buffer[13]);
		if (ftype != VS_FRAME_FRAME_BASED) {
			frame->dwMaxVideoFrameBufferSize =
				le32_to_cpup((__le32*)&buffer[17]);
			frame->dwDefaultFrameInterval =
				le32_to_cpup((__le32*)&buffer[21]);
			frame->bFrameIntervalType = buffer[25];
		} else {
			frame->dwMaxVideoFrameBufferSize = 0;
			frame->dwDefaultFrameInterval =
				le32_to_cpup((__le32*)&buffer[17]);
			frame->bFrameIntervalType = buffer[21];