// SPDX-License-Identifier: GPL-2.0-only
/*
 *
 *  Copyright (C) 2005 Mike Isely <isely@pobox.com>
 */

#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_ATSC \
	(V4L2_STD_ATSC_8_VSB| \
	 V4L2_STD_ATSC_16_VSB)

#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_ATSC|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},
	{"ATSC",CSTD_ATSC},
};

/* 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},
	{"8VSB",V4L2_STD_ATSC_8_VSB},
	{"16VSB",V4L2_STD_ATSC_16_VSB},
};


// 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, ARRAY_SIZE(std_groups),
					   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, ARRAY_SIZE(std_items),
				   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 < ARRAY_SIZE(std_groups); idx1++) {
		gp = std_groups + idx1;
		gfl = 0;
		for (idx2 = 0; idx2 < ARRAY_SIZE(std_items); 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}
	}
};

static struct v4l2_standard *match_std(v4l2_std_id id)
{
	unsigned int idx;
	for (idx = 0; idx < ARRAY_SIZE(generic_standards); 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_STD,"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_STD) {
		char buf[100];
		bcnt = pvr2_std_id_to_str(buf,sizeof(buf),id);
		pvr2_trace(
			PVR2_TRACE_STD,"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 < ARRAY_SIZE(std_mixes); idx2++) {
		if ((id & std_mixes[idx2]) == std_mixes[idx2]) std_cnt++;
	}

	/* Don't complain about ATSC standard values */
	fmsk &= ~CSTD_ATSC;

	if (fmsk) {
		char buf[100];
		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_STD,"Setting up %u unique standard(s)",
		   std_cnt);
	if (!std_cnt) return NULL; // paranoia

	stddefs = kcalloc(std_cnt, sizeof(struct v4l2_standard),
			  GFP_KERNEL);
	if (!stddefs)
		return NULL;

	for (idx = 0; idx < std_cnt; idx++)
		stddefs[idx].index = idx;

	idx = 0;

	/* Enumerate potential special cases */
	for (idx2 = 0; (idx2 < ARRAY_SIZE(std_mixes)) && (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;
}
