drivers/media/video/pvrusb2/pvrusb2-std.c - kernel/msm-4.19 - Gitiles

 /*
  *
  *  $Id$
  *
  *  Copyright (C) 2005 Mike Isely <isely@pobox.com>
  *
  *  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
  *
  *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  *
  */

 #include "pvrusb2-std.h"
 #include "pvrusb2-debug.h"
 #include <asm/string.h>
 #include <linux/slab.h>

 struct std_name {
 	const char *name;
 	v4l2_std_id id;
 };


 #define CSTD_PAL \
 	(V4L2_STD_PAL_B| \
 	 V4L2_STD_PAL_B1| \
 	 V4L2_STD_PAL_G| \
 	 V4L2_STD_PAL_H| \
 	 V4L2_STD_PAL_I| \
 	 V4L2_STD_PAL_D| \
 	 V4L2_STD_PAL_D1| \
 	 V4L2_STD_PAL_K| \
 	 V4L2_STD_PAL_M| \
 	 V4L2_STD_PAL_N| \
 	 V4L2_STD_PAL_Nc| \
 	 V4L2_STD_PAL_60)

 #define CSTD_NTSC \
 	(V4L2_STD_NTSC_M| \
 	 V4L2_STD_NTSC_M_JP| \
 	 V4L2_STD_NTSC_M_KR| \
 	 V4L2_STD_NTSC_443)

 #define CSTD_SECAM \
 	(V4L2_STD_SECAM_B| \
 	 V4L2_STD_SECAM_D| \
 	 V4L2_STD_SECAM_G| \
 	 V4L2_STD_SECAM_H| \
 	 V4L2_STD_SECAM_K| \
 	 V4L2_STD_SECAM_K1| \
 	 V4L2_STD_SECAM_L| \
 	 V4L2_STD_SECAM_LC)

 #define TSTD_B   (V4L2_STD_PAL_B|V4L2_STD_SECAM_B)
 #define TSTD_B1  (V4L2_STD_PAL_B1)
 #define TSTD_D   (V4L2_STD_PAL_D|V4L2_STD_SECAM_D)
 #define TSTD_D1  (V4L2_STD_PAL_D1)
 #define TSTD_G   (V4L2_STD_PAL_G|V4L2_STD_SECAM_G)
 #define TSTD_H   (V4L2_STD_PAL_H|V4L2_STD_SECAM_H)
 #define TSTD_I   (V4L2_STD_PAL_I)
 #define TSTD_K   (V4L2_STD_PAL_K|V4L2_STD_SECAM_K)
 #define TSTD_K1  (V4L2_STD_SECAM_K1)
 #define TSTD_L   (V4L2_STD_SECAM_L)
 #define TSTD_M   (V4L2_STD_PAL_M|V4L2_STD_NTSC_M)
 #define TSTD_N   (V4L2_STD_PAL_N)
 #define TSTD_Nc  (V4L2_STD_PAL_Nc)
 #define TSTD_60  (V4L2_STD_PAL_60)

 #define CSTD_ALL (CSTD_PAL|CSTD_NTSC|CSTD_SECAM)

 /* Mapping of standard bits to color system */
 static const struct std_name std_groups[] = {
 	{"PAL",CSTD_PAL},
 	{"NTSC",CSTD_NTSC},
 	{"SECAM",CSTD_SECAM},
 };

 /* Mapping of standard bits to modulation system */
 static const struct std_name std_items[] = {
 	{"B",TSTD_B},
 	{"B1",TSTD_B1},
 	{"D",TSTD_D},
 	{"D1",TSTD_D1},
 	{"G",TSTD_G},
 	{"H",TSTD_H},
 	{"I",TSTD_I},
 	{"K",TSTD_K},
 	{"K1",TSTD_K1},
 	{"L",TSTD_L},
 	{"LC",V4L2_STD_SECAM_LC},
 	{"M",TSTD_M},
 	{"Mj",V4L2_STD_NTSC_M_JP},
 	{"443",V4L2_STD_NTSC_443},
 	{"Mk",V4L2_STD_NTSC_M_KR},
 	{"N",TSTD_N},
 	{"Nc",TSTD_Nc},
 	{"60",TSTD_60},
 };


 // Search an array of std_name structures and return a pointer to the
 // element with the matching name.
 static const struct std_name *find_std_name(const struct std_name *arrPtr,
 					    unsigned int arrSize,
 					    const char *bufPtr,
 					    unsigned int bufSize)
 {
 	unsigned int idx;
 	const struct std_name *p;
 	for (idx = 0; idx < arrSize; idx++) {
 		p = arrPtr + idx;
 		if (strlen(p->name) != bufSize) continue;
 		if (!memcmp(bufPtr,p->name,bufSize)) return p;
 	}
 	return NULL;
 }


 int pvr2_std_str_to_id(v4l2_std_id *idPtr,const char *bufPtr,
 		       unsigned int bufSize)
 {
 	v4l2_std_id id = 0;
 	v4l2_std_id cmsk = 0;
 	v4l2_std_id t;
 	int mMode = 0;
 	unsigned int cnt;
 	char ch;
 	const struct std_name *sp;

 	while (bufSize) {
 		if (!mMode) {
 			cnt = 0;
 			while ((cnt < bufSize) && (bufPtr[cnt] != '-')) cnt++;
 			if (cnt >= bufSize) return 0; // No more characters
 			sp = find_std_name(
 				std_groups,
 				sizeof(std_groups)/sizeof(std_groups[0]),
 				bufPtr,cnt);
 			if (!sp) return 0; // Illegal color system name
 			cnt++;
 			bufPtr += cnt;
 			bufSize -= cnt;
 			mMode = !0;
 			cmsk = sp->id;
 			continue;
 		}
 		cnt = 0;
 		while (cnt < bufSize) {
 			ch = bufPtr[cnt];
 			if (ch == ';') {
 				mMode = 0;
 				break;
 			}
 			if (ch == '/') break;
 			cnt++;
 		}
 		sp = find_std_name(std_items,
 				   sizeof(std_items)/sizeof(std_items[0]),
 				   bufPtr,cnt);
 		if (!sp) return 0; // Illegal modulation system ID
 		t = sp->id & cmsk;
 		if (!t) return 0; // Specific color + modulation system illegal
 		id |= t;
 		if (cnt < bufSize) cnt++;
 		bufPtr += cnt;
 		bufSize -= cnt;
 	}

 	if (idPtr) *idPtr = id;
 	return !0;
 }


 unsigned int pvr2_std_id_to_str(char *bufPtr, unsigned int bufSize,
 				v4l2_std_id id)
 {
 	unsigned int idx1,idx2;
 	const struct std_name *ip,*gp;
 	int gfl,cfl;
 	unsigned int c1,c2;
 	cfl = 0;
 	c1 = 0;
 	for (idx1 = 0;
 	     idx1 < sizeof(std_groups)/sizeof(std_groups[0]);
 	     idx1++) {
 		gp = std_groups + idx1;
 		gfl = 0;
 		for (idx2 = 0;
 		     idx2 < sizeof(std_items)/sizeof(std_items[0]);
 		     idx2++) {
 			ip = std_items + idx2;
 			if (!(gp->id & ip->id & id)) continue;
 			if (!gfl) {
 				if (cfl) {
 					c2 = scnprintf(bufPtr,bufSize,";");
 					c1 += c2;
 					bufSize -= c2;
 					bufPtr += c2;
 				}
 				cfl = !0;
 				c2 = scnprintf(bufPtr,bufSize,
 					       "%s-",gp->name);
 				gfl = !0;
 			} else {
 				c2 = scnprintf(bufPtr,bufSize,"/");
 			}
 			c1 += c2;
 			bufSize -= c2;
 			bufPtr += c2;
 			c2 = scnprintf(bufPtr,bufSize,
 				       ip->name);
 			c1 += c2;
 			bufSize -= c2;
 			bufPtr += c2;
 		}
 	}
 	return c1;
 }


 // Template data for possible enumerated video standards.  Here we group
 // standards which share common frame rates and resolution.
 static struct v4l2_standard generic_standards[] = {
 	{
 		.id             = (TSTD_B|TSTD_B1|
 				   TSTD_D|TSTD_D1|
 				   TSTD_G|
 				   TSTD_H|
 				   TSTD_I|
 				   TSTD_K|TSTD_K1|
 				   TSTD_L|
 				   V4L2_STD_SECAM_LC |
 				   TSTD_N|TSTD_Nc),
 		.frameperiod    =
 		{
 			.numerator  = 1,
 			.denominator= 25
 		},
 		.framelines     = 625,
 		.reserved       = {0,0,0,0}
 	}, {
 		.id             = (TSTD_M|
 				   V4L2_STD_NTSC_M_JP|
 				   V4L2_STD_NTSC_M_KR),
 		.frameperiod    =
 		{
 			.numerator  = 1001,
 			.denominator= 30000
 		},
 		.framelines     = 525,
 		.reserved       = {0,0,0,0}
 	}, { // This is a total wild guess
 		.id             = (TSTD_60),
 		.frameperiod    =
 		{
 			.numerator  = 1001,
 			.denominator= 30000
 		},
 		.framelines     = 525,
 		.reserved       = {0,0,0,0}
 	}, { // This is total wild guess
 		.id             = V4L2_STD_NTSC_443,
 		.frameperiod    =
 		{
 			.numerator  = 1001,
 			.denominator= 30000
 		},
 		.framelines     = 525,
 		.reserved       = {0,0,0,0}
 	}
 };

 #define generic_standards_cnt (sizeof(generic_standards)/sizeof(generic_standards[0]))

 static struct v4l2_standard *match_std(v4l2_std_id id)
 {
 	unsigned int idx;
 	for (idx = 0; idx < generic_standards_cnt; idx++) {
 		if (generic_standards[idx].id & id) {
 			return generic_standards + idx;
 		}
 	}
 	return NULL;
 }

 static int pvr2_std_fill(struct v4l2_standard *std,v4l2_std_id id)
 {
 	struct v4l2_standard *template;
 	int idx;
 	unsigned int bcnt;
 	template = match_std(id);
 	if (!template) return 0;
 	idx = std->index;
 	memcpy(std,template,sizeof(*template));
 	std->index = idx;
 	std->id = id;
 	bcnt = pvr2_std_id_to_str(std->name,sizeof(std->name)-1,id);
 	std->name[bcnt] = 0;
 	pvr2_trace(PVR2_TRACE_INIT,"Set up standard idx=%u name=%s",
 		   std->index,std->name);
 	return !0;
 }

 /* These are special cases of combined standards that we should enumerate
    separately if the component pieces are present. */
 static v4l2_std_id std_mixes[] = {
 	V4L2_STD_PAL_B | V4L2_STD_PAL_G,
 	V4L2_STD_PAL_D | V4L2_STD_PAL_K,
 	V4L2_STD_SECAM_B | V4L2_STD_SECAM_G,
 	V4L2_STD_SECAM_D | V4L2_STD_SECAM_K,
 };

 struct v4l2_standard *pvr2_std_create_enum(unsigned int *countptr,
 					   v4l2_std_id id)
 {
 	unsigned int std_cnt = 0;
 	unsigned int idx,bcnt,idx2;
 	v4l2_std_id idmsk,cmsk,fmsk;
 	struct v4l2_standard *stddefs;

 	if (pvrusb2_debug & PVR2_TRACE_INIT) {
 		char buf[50];
 		bcnt = pvr2_std_id_to_str(buf,sizeof(buf),id);
 		pvr2_trace(
 			PVR2_TRACE_INIT,"Mapping standards mask=0x%x (%.*s)",
 			(int)id,bcnt,buf);
 	}

 	*countptr = 0;
 	std_cnt = 0;
 	fmsk = 0;
 	for (idmsk = 1, cmsk = id; cmsk; idmsk <<= 1) {
 		if (!(idmsk & cmsk)) continue;
 		cmsk &= ~idmsk;
 		if (match_std(idmsk)) {
 			std_cnt++;
 			continue;
 		}
 		fmsk |= idmsk;
 	}

 	for (idx2 = 0; idx2 < sizeof(std_mixes)/sizeof(std_mixes[0]); idx2++) {
 		if ((id & std_mixes[idx2]) == std_mixes[idx2]) std_cnt++;
 	}

 	if (fmsk) {
 		char buf[50];
 		bcnt = pvr2_std_id_to_str(buf,sizeof(buf),fmsk);
 		pvr2_trace(
 			PVR2_TRACE_ERROR_LEGS,
 			"WARNING:"
 			" Failed to classify the following standard(s): %.*s",
 			bcnt,buf);
 	}

 	pvr2_trace(PVR2_TRACE_INIT,"Setting up %u unique standard(s)",
 		   std_cnt);
 	if (!std_cnt) return NULL; // paranoia

 	stddefs = kmalloc(sizeof(struct v4l2_standard) * std_cnt,
 			  GFP_KERNEL);
 	memset(stddefs,0,sizeof(struct v4l2_standard) * std_cnt);
 	for (idx = 0; idx < std_cnt; idx++) stddefs[idx].index = idx;

 	idx = 0;

 	/* Enumerate potential special cases */
 	for (idx2 = 0; ((idx2 < sizeof(std_mixes)/sizeof(std_mixes[0])) &&
 			(idx < std_cnt)); idx2++) {
 		if (!(id & std_mixes[idx2])) continue;
 		if (pvr2_std_fill(stddefs+idx,std_mixes[idx2])) idx++;
 	}
 	/* Now enumerate individual pieces */
 	for (idmsk = 1, cmsk = id; cmsk && (idx < std_cnt); idmsk <<= 1) {
 		if (!(idmsk & cmsk)) continue;
 		cmsk &= ~idmsk;
 		if (!pvr2_std_fill(stddefs+idx,idmsk)) continue;
 		idx++;
 	}

 	*countptr = std_cnt;
 	return stddefs;
 }

 v4l2_std_id pvr2_std_get_usable(void)
 {
 	return CSTD_ALL;
 }


 /*
   Stuff for Emacs to see, in order to encourage consistent editing style:
   *** Local Variables: ***
   *** mode: c ***
   *** fill-column: 75 ***
   *** tab-width: 8 ***
   *** c-basic-offset: 8 ***
   *** End: ***
   */
	/*
	*
	* $Id$
	*
	* Copyright (C) 2005 Mike Isely <isely@pobox.com>
	*
	* 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
	*
	* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*
	*/

	#include "pvrusb2-std.h"
	#include "pvrusb2-debug.h"
	#include <asm/string.h>
	#include <linux/slab.h>

	struct std_name {
	const char *name;
	v4l2_std_id id;
	};


	#define CSTD_PAL \
	(V4L2_STD_PAL_B\| \
	V4L2_STD_PAL_B1\| \
	V4L2_STD_PAL_G\| \
	V4L2_STD_PAL_H\| \
	V4L2_STD_PAL_I\| \
	V4L2_STD_PAL_D\| \
	V4L2_STD_PAL_D1\| \
	V4L2_STD_PAL_K\| \
	V4L2_STD_PAL_M\| \
	V4L2_STD_PAL_N\| \
	V4L2_STD_PAL_Nc\| \
	V4L2_STD_PAL_60)

	#define CSTD_NTSC \
	(V4L2_STD_NTSC_M\| \
	V4L2_STD_NTSC_M_JP\| \
	V4L2_STD_NTSC_M_KR\| \
	V4L2_STD_NTSC_443)

	#define CSTD_SECAM \
	(V4L2_STD_SECAM_B\| \
	V4L2_STD_SECAM_D\| \
	V4L2_STD_SECAM_G\| \
	V4L2_STD_SECAM_H\| \
	V4L2_STD_SECAM_K\| \
	V4L2_STD_SECAM_K1\| \
	V4L2_STD_SECAM_L\| \
	V4L2_STD_SECAM_LC)

	#define TSTD_B (V4L2_STD_PAL_B\|V4L2_STD_SECAM_B)
	#define TSTD_B1 (V4L2_STD_PAL_B1)
	#define TSTD_D (V4L2_STD_PAL_D\|V4L2_STD_SECAM_D)
	#define TSTD_D1 (V4L2_STD_PAL_D1)
	#define TSTD_G (V4L2_STD_PAL_G\|V4L2_STD_SECAM_G)
	#define TSTD_H (V4L2_STD_PAL_H\|V4L2_STD_SECAM_H)
	#define TSTD_I (V4L2_STD_PAL_I)
	#define TSTD_K (V4L2_STD_PAL_K\|V4L2_STD_SECAM_K)
	#define TSTD_K1 (V4L2_STD_SECAM_K1)
	#define TSTD_L (V4L2_STD_SECAM_L)
	#define TSTD_M (V4L2_STD_PAL_M\|V4L2_STD_NTSC_M)
	#define TSTD_N (V4L2_STD_PAL_N)
	#define TSTD_Nc (V4L2_STD_PAL_Nc)
	#define TSTD_60 (V4L2_STD_PAL_60)

	#define CSTD_ALL (CSTD_PAL\|CSTD_NTSC\|CSTD_SECAM)

	/* Mapping of standard bits to color system */
	static const struct std_name std_groups[] = {
	{"PAL",CSTD_PAL},
	{"NTSC",CSTD_NTSC},
	{"SECAM",CSTD_SECAM},
	};

	/* Mapping of standard bits to modulation system */
	static const struct std_name std_items[] = {
	{"B",TSTD_B},
	{"B1",TSTD_B1},
	{"D",TSTD_D},
	{"D1",TSTD_D1},
	{"G",TSTD_G},
	{"H",TSTD_H},
	{"I",TSTD_I},
	{"K",TSTD_K},
	{"K1",TSTD_K1},
	{"L",TSTD_L},
	{"LC",V4L2_STD_SECAM_LC},
	{"M",TSTD_M},
	{"Mj",V4L2_STD_NTSC_M_JP},
	{"443",V4L2_STD_NTSC_443},
	{"Mk",V4L2_STD_NTSC_M_KR},
	{"N",TSTD_N},
	{"Nc",TSTD_Nc},
	{"60",TSTD_60},
	};


	// Search an array of std_name structures and return a pointer to the
	// element with the matching name.
	static const struct std_name find_std_name(const struct std_name arrPtr,
	unsigned int arrSize,
	const char *bufPtr,
	unsigned int bufSize)
	{
	unsigned int idx;
	const struct std_name *p;
	for (idx = 0; idx < arrSize; idx++) {
	p = arrPtr + idx;
	if (strlen(p->name) != bufSize) continue;
	if (!memcmp(bufPtr,p->name,bufSize)) return p;
	}
	return NULL;
	}


	int pvr2_std_str_to_id(v4l2_std_id idPtr,const char bufPtr,
	unsigned int bufSize)
	{
	v4l2_std_id id = 0;
	v4l2_std_id cmsk = 0;
	v4l2_std_id t;
	int mMode = 0;
	unsigned int cnt;
	char ch;
	const struct std_name *sp;

	while (bufSize) {
	if (!mMode) {
	cnt = 0;
	while ((cnt < bufSize) && (bufPtr[cnt] != '-')) cnt++;
	if (cnt >= bufSize) return 0; // No more characters
	sp = find_std_name(
	std_groups,
	sizeof(std_groups)/sizeof(std_groups[0]),
	bufPtr,cnt);
	if (!sp) return 0; // Illegal color system name
	cnt++;
	bufPtr += cnt;
	bufSize -= cnt;
	mMode = !0;
	cmsk = sp->id;
	continue;
	}
	cnt = 0;
	while (cnt < bufSize) {
	ch = bufPtr[cnt];
	if (ch == ';') {
	mMode = 0;
	break;
	}
	if (ch == '/') break;
	cnt++;
	}
	sp = find_std_name(std_items,
	sizeof(std_items)/sizeof(std_items[0]),
	bufPtr,cnt);
	if (!sp) return 0; // Illegal modulation system ID
	t = sp->id & cmsk;
	if (!t) return 0; // Specific color + modulation system illegal
	id \|= t;
	if (cnt < bufSize) cnt++;
	bufPtr += cnt;
	bufSize -= cnt;
	}

	if (idPtr) *idPtr = id;
	return !0;
	}


	unsigned int pvr2_std_id_to_str(char *bufPtr, unsigned int bufSize,
	v4l2_std_id id)
	{
	unsigned int idx1,idx2;
	const struct std_name ip,gp;
	int gfl,cfl;
	unsigned int c1,c2;
	cfl = 0;
	c1 = 0;
	for (idx1 = 0;
	idx1 < sizeof(std_groups)/sizeof(std_groups[0]);
	idx1++) {
	gp = std_groups + idx1;
	gfl = 0;
	for (idx2 = 0;
	idx2 < sizeof(std_items)/sizeof(std_items[0]);
	idx2++) {
	ip = std_items + idx2;
	if (!(gp->id & ip->id & id)) continue;
	if (!gfl) {
	if (cfl) {
	c2 = scnprintf(bufPtr,bufSize,";");
	c1 += c2;
	bufSize -= c2;
	bufPtr += c2;
	}
	cfl = !0;
	c2 = scnprintf(bufPtr,bufSize,
	"%s-",gp->name);
	gfl = !0;
	} else {
	c2 = scnprintf(bufPtr,bufSize,"/");
	}
	c1 += c2;
	bufSize -= c2;
	bufPtr += c2;
	c2 = scnprintf(bufPtr,bufSize,
	ip->name);
	c1 += c2;
	bufSize -= c2;
	bufPtr += c2;
	}
	}
	return c1;
	}


	// Template data for possible enumerated video standards. Here we group
	// standards which share common frame rates and resolution.
	static struct v4l2_standard generic_standards[] = {
	{
	.id = (TSTD_B\|TSTD_B1\|
	TSTD_D\|TSTD_D1\|
	TSTD_G\|
	TSTD_H\|
	TSTD_I\|
	TSTD_K\|TSTD_K1\|
	TSTD_L\|
	V4L2_STD_SECAM_LC \|
	TSTD_N\|TSTD_Nc),
	.frameperiod =
	{
	.numerator = 1,
	.denominator= 25
	},
	.framelines = 625,
	.reserved = {0,0,0,0}
	}, {
	.id = (TSTD_M\|
	V4L2_STD_NTSC_M_JP\|
	V4L2_STD_NTSC_M_KR),
	.frameperiod =
	{
	.numerator = 1001,
	.denominator= 30000
	},
	.framelines = 525,
	.reserved = {0,0,0,0}
	}, { // This is a total wild guess
	.id = (TSTD_60),
	.frameperiod =
	{
	.numerator = 1001,
	.denominator= 30000
	},
	.framelines = 525,
	.reserved = {0,0,0,0}
	}, { // This is total wild guess
	.id = V4L2_STD_NTSC_443,
	.frameperiod =
	{
	.numerator = 1001,
	.denominator= 30000
	},
	.framelines = 525,
	.reserved = {0,0,0,0}
	}
	};

	#define generic_standards_cnt (sizeof(generic_standards)/sizeof(generic_standards[0]))

	static struct v4l2_standard *match_std(v4l2_std_id id)
	{
	unsigned int idx;
	for (idx = 0; idx < generic_standards_cnt; idx++) {
	if (generic_standards[idx].id & id) {
	return generic_standards + idx;
	}
	}
	return NULL;
	}

	static int pvr2_std_fill(struct v4l2_standard *std,v4l2_std_id id)
	{
	struct v4l2_standard *template;
	int idx;
	unsigned int bcnt;
	template = match_std(id);
	if (!template) return 0;
	idx = std->index;
	memcpy(std,template,sizeof(*template));
	std->index = idx;
	std->id = id;
	bcnt = pvr2_std_id_to_str(std->name,sizeof(std->name)-1,id);
	std->name[bcnt] = 0;
	pvr2_trace(PVR2_TRACE_INIT,"Set up standard idx=%u name=%s",
	std->index,std->name);
	return !0;
	}

	/* These are special cases of combined standards that we should enumerate
	separately if the component pieces are present. */
	static v4l2_std_id std_mixes[] = {
	V4L2_STD_PAL_B \| V4L2_STD_PAL_G,
	V4L2_STD_PAL_D \| V4L2_STD_PAL_K,
	V4L2_STD_SECAM_B \| V4L2_STD_SECAM_G,
	V4L2_STD_SECAM_D \| V4L2_STD_SECAM_K,
	};

	struct v4l2_standard pvr2_std_create_enum(unsigned int countptr,
	v4l2_std_id id)
	{
	unsigned int std_cnt = 0;
	unsigned int idx,bcnt,idx2;
	v4l2_std_id idmsk,cmsk,fmsk;
	struct v4l2_standard *stddefs;

	if (pvrusb2_debug & PVR2_TRACE_INIT) {
	char buf[50];
	bcnt = pvr2_std_id_to_str(buf,sizeof(buf),id);
	pvr2_trace(
	PVR2_TRACE_INIT,"Mapping standards mask=0x%x (%.*s)",
	(int)id,bcnt,buf);
	}

	*countptr = 0;
	std_cnt = 0;
	fmsk = 0;
	for (idmsk = 1, cmsk = id; cmsk; idmsk <<= 1) {
	if (!(idmsk & cmsk)) continue;
	cmsk &= ~idmsk;
	if (match_std(idmsk)) {
	std_cnt++;
	continue;
	}
	fmsk \|= idmsk;
	}

	for (idx2 = 0; idx2 < sizeof(std_mixes)/sizeof(std_mixes[0]); idx2++) {
	if ((id & std_mixes[idx2]) == std_mixes[idx2]) std_cnt++;
	}

	if (fmsk) {
	char buf[50];
	bcnt = pvr2_std_id_to_str(buf,sizeof(buf),fmsk);
	pvr2_trace(
	PVR2_TRACE_ERROR_LEGS,
	"WARNING:"
	" Failed to classify the following standard(s): %.*s",
	bcnt,buf);
	}

	pvr2_trace(PVR2_TRACE_INIT,"Setting up %u unique standard(s)",
	std_cnt);
	if (!std_cnt) return NULL; // paranoia

	stddefs = kmalloc(sizeof(struct v4l2_standard) * std_cnt,
	GFP_KERNEL);
	memset(stddefs,0,sizeof(struct v4l2_standard) * std_cnt);
	for (idx = 0; idx < std_cnt; idx++) stddefs[idx].index = idx;

	idx = 0;

	/* Enumerate potential special cases */
	for (idx2 = 0; ((idx2 < sizeof(std_mixes)/sizeof(std_mixes[0])) &&
	(idx < std_cnt)); idx2++) {
	if (!(id & std_mixes[idx2])) continue;
	if (pvr2_std_fill(stddefs+idx,std_mixes[idx2])) idx++;
	}
	/* Now enumerate individual pieces */
	for (idmsk = 1, cmsk = id; cmsk && (idx < std_cnt); idmsk <<= 1) {
	if (!(idmsk & cmsk)) continue;
	cmsk &= ~idmsk;
	if (!pvr2_std_fill(stddefs+idx,idmsk)) continue;
	idx++;
	}

	*countptr = std_cnt;
	return stddefs;
	}

	v4l2_std_id pvr2_std_get_usable(void)
	{
	return CSTD_ALL;
	}


	/*
	Stuff for Emacs to see, in order to encourage consistent editing style:
	* Local Variables: *
	* mode: c *
	* fill-column: 75 *
	* tab-width: 8 *
	* c-basic-offset: 8 *
	* End: *
	*/