[deliverable/linux.git] / drivers / media / v4l2-core / v4l2-dv-timings.c

/*
 * v4l2-dv-timings - dv-timings helper functions
 *
 * Copyright 2013 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
 *
 * This program is free software; you may redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/videodev2.h>
#include <linux/v4l2-dv-timings.h>
#include <media/v4l2-dv-timings.h>

static const struct v4l2_dv_timings timings[] = {
	V4L2_DV_BT_CEA_640X480P59_94,
	V4L2_DV_BT_CEA_720X480I59_94,
	V4L2_DV_BT_CEA_720X480P59_94,
	V4L2_DV_BT_CEA_720X576I50,
	V4L2_DV_BT_CEA_720X576P50,
	V4L2_DV_BT_CEA_1280X720P24,
	V4L2_DV_BT_CEA_1280X720P25,
	V4L2_DV_BT_CEA_1280X720P30,
	V4L2_DV_BT_CEA_1280X720P50,
	V4L2_DV_BT_CEA_1280X720P60,
	V4L2_DV_BT_CEA_1920X1080P24,
	V4L2_DV_BT_CEA_1920X1080P25,
	V4L2_DV_BT_CEA_1920X1080P30,
	V4L2_DV_BT_CEA_1920X1080I50,
	V4L2_DV_BT_CEA_1920X1080P50,
	V4L2_DV_BT_CEA_1920X1080I60,
	V4L2_DV_BT_CEA_1920X1080P60,
	V4L2_DV_BT_DMT_640X350P85,
	V4L2_DV_BT_DMT_640X400P85,
	V4L2_DV_BT_DMT_720X400P85,
	V4L2_DV_BT_DMT_640X480P72,
	V4L2_DV_BT_DMT_640X480P75,
	V4L2_DV_BT_DMT_640X480P85,
	V4L2_DV_BT_DMT_800X600P56,
	V4L2_DV_BT_DMT_800X600P60,
	V4L2_DV_BT_DMT_800X600P72,
	V4L2_DV_BT_DMT_800X600P75,
	V4L2_DV_BT_DMT_800X600P85,
	V4L2_DV_BT_DMT_800X600P120_RB,
	V4L2_DV_BT_DMT_848X480P60,
	V4L2_DV_BT_DMT_1024X768I43,
	V4L2_DV_BT_DMT_1024X768P60,
	V4L2_DV_BT_DMT_1024X768P70,
	V4L2_DV_BT_DMT_1024X768P75,
	V4L2_DV_BT_DMT_1024X768P85,
	V4L2_DV_BT_DMT_1024X768P120_RB,
	V4L2_DV_BT_DMT_1152X864P75,
	V4L2_DV_BT_DMT_1280X768P60_RB,
	V4L2_DV_BT_DMT_1280X768P60,
	V4L2_DV_BT_DMT_1280X768P75,
	V4L2_DV_BT_DMT_1280X768P85,
	V4L2_DV_BT_DMT_1280X768P120_RB,
	V4L2_DV_BT_DMT_1280X800P60_RB,
	V4L2_DV_BT_DMT_1280X800P60,
	V4L2_DV_BT_DMT_1280X800P75,
	V4L2_DV_BT_DMT_1280X800P85,
	V4L2_DV_BT_DMT_1280X800P120_RB,
	V4L2_DV_BT_DMT_1280X960P60,
	V4L2_DV_BT_DMT_1280X960P85,
	V4L2_DV_BT_DMT_1280X960P120_RB,
	V4L2_DV_BT_DMT_1280X1024P60,
	V4L2_DV_BT_DMT_1280X1024P75,
	V4L2_DV_BT_DMT_1280X1024P85,
	V4L2_DV_BT_DMT_1280X1024P120_RB,
	V4L2_DV_BT_DMT_1360X768P60,
	V4L2_DV_BT_DMT_1360X768P120_RB,
	V4L2_DV_BT_DMT_1366X768P60,
	V4L2_DV_BT_DMT_1366X768P60_RB,
	V4L2_DV_BT_DMT_1400X1050P60_RB,
	V4L2_DV_BT_DMT_1400X1050P60,
	V4L2_DV_BT_DMT_1400X1050P75,
	V4L2_DV_BT_DMT_1400X1050P85,
	V4L2_DV_BT_DMT_1400X1050P120_RB,
	V4L2_DV_BT_DMT_1440X900P60_RB,
	V4L2_DV_BT_DMT_1440X900P60,
	V4L2_DV_BT_DMT_1440X900P75,
	V4L2_DV_BT_DMT_1440X900P85,
	V4L2_DV_BT_DMT_1440X900P120_RB,
	V4L2_DV_BT_DMT_1600X900P60_RB,
	V4L2_DV_BT_DMT_1600X1200P60,
	V4L2_DV_BT_DMT_1600X1200P65,
	V4L2_DV_BT_DMT_1600X1200P70,
	V4L2_DV_BT_DMT_1600X1200P75,
	V4L2_DV_BT_DMT_1600X1200P85,
	V4L2_DV_BT_DMT_1600X1200P120_RB,
	V4L2_DV_BT_DMT_1680X1050P60_RB,
	V4L2_DV_BT_DMT_1680X1050P60,
	V4L2_DV_BT_DMT_1680X1050P75,
	V4L2_DV_BT_DMT_1680X1050P85,
	V4L2_DV_BT_DMT_1680X1050P120_RB,
	V4L2_DV_BT_DMT_1792X1344P60,
	V4L2_DV_BT_DMT_1792X1344P75,
	V4L2_DV_BT_DMT_1792X1344P120_RB,
	V4L2_DV_BT_DMT_1856X1392P60,
	V4L2_DV_BT_DMT_1856X1392P75,
	V4L2_DV_BT_DMT_1856X1392P120_RB,
	V4L2_DV_BT_DMT_1920X1200P60_RB,
	V4L2_DV_BT_DMT_1920X1200P60,
	V4L2_DV_BT_DMT_1920X1200P75,
	V4L2_DV_BT_DMT_1920X1200P85,
	V4L2_DV_BT_DMT_1920X1200P120_RB,
	V4L2_DV_BT_DMT_1920X1440P60,
	V4L2_DV_BT_DMT_1920X1440P75,
	V4L2_DV_BT_DMT_1920X1440P120_RB,
	V4L2_DV_BT_DMT_2048X1152P60_RB,
	V4L2_DV_BT_DMT_2560X1600P60_RB,
	V4L2_DV_BT_DMT_2560X1600P60,
	V4L2_DV_BT_DMT_2560X1600P75,
	V4L2_DV_BT_DMT_2560X1600P85,
	V4L2_DV_BT_DMT_2560X1600P120_RB,
};

bool v4l2_dv_valid_timings(const struct v4l2_dv_timings *t,
			   const struct v4l2_dv_timings_cap *dvcap)
{
	const struct v4l2_bt_timings *bt = &t->bt;
	const struct v4l2_bt_timings_cap *cap = &dvcap->bt;
	u32 caps = cap->capabilities;

	if (t->type != V4L2_DV_BT_656_1120)
		return false;
	if (t->type != dvcap->type ||
	    bt->height < cap->min_height ||
	    bt->height > cap->max_height ||
	    bt->width < cap->min_width ||
	    bt->width > cap->max_width ||
	    bt->pixelclock < cap->min_pixelclock ||
	    bt->pixelclock > cap->max_pixelclock ||
	    (cap->standards && !(bt->standards & cap->standards)) ||
	    (bt->interlaced && !(caps & V4L2_DV_BT_CAP_INTERLACED)) ||
	    (!bt->interlaced && !(caps & V4L2_DV_BT_CAP_PROGRESSIVE)))
		return false;
	return true;
}
EXPORT_SYMBOL_GPL(v4l2_dv_valid_timings);

int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t,
			     const struct v4l2_dv_timings_cap *cap)
{
	u32 i, idx;

	memset(t->reserved, 0, sizeof(t->reserved));
	for (i = idx = 0; i < ARRAY_SIZE(timings); i++) {
		if (v4l2_dv_valid_timings(timings + i, cap) &&
		    idx++ == t->index) {
			t->timings = timings[i];
			return 0;
		}
	}
	return -EINVAL;
}
EXPORT_SYMBOL_GPL(v4l2_enum_dv_timings_cap);

bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t,
			      const struct v4l2_dv_timings_cap *cap,
			      unsigned pclock_delta)
{
	int i;

	if (!v4l2_dv_valid_timings(t, cap))
		return false;

	for (i = 0; i < ARRAY_SIZE(timings); i++) {
		if (v4l2_dv_valid_timings(timings + i, cap) &&
		    v4l2_match_dv_timings(t, timings + i, pclock_delta)) {
			*t = timings[i];
			return true;
		}
	}
	return false;
}
EXPORT_SYMBOL_GPL(v4l2_find_dv_timings_cap);

/**
 * v4l2_match_dv_timings - check if two timings match
 * @t1 - compare this v4l2_dv_timings struct...
 * @t2 - with this struct.
 * @pclock_delta - the allowed pixelclock deviation.
 *
 * Compare t1 with t2 with a given margin of error for the pixelclock.
 */
bool v4l2_match_dv_timings(const struct v4l2_dv_timings *t1,
			   const struct v4l2_dv_timings *t2,
			   unsigned pclock_delta)
{
	if (t1->type != t2->type || t1->type != V4L2_DV_BT_656_1120)
		return false;
	if (t1->bt.width == t2->bt.width &&
	    t1->bt.height == t2->bt.height &&
	    t1->bt.interlaced == t2->bt.interlaced &&
	    t1->bt.polarities == t2->bt.polarities &&
	    t1->bt.pixelclock >= t2->bt.pixelclock - pclock_delta &&
	    t1->bt.pixelclock <= t2->bt.pixelclock + pclock_delta &&
	    t1->bt.hfrontporch == t2->bt.hfrontporch &&
	    t1->bt.vfrontporch == t2->bt.vfrontporch &&
	    t1->bt.vsync == t2->bt.vsync &&
	    t1->bt.vbackporch == t2->bt.vbackporch &&
	    (!t1->bt.interlaced ||
		(t1->bt.il_vfrontporch == t2->bt.il_vfrontporch &&
		 t1->bt.il_vsync == t2->bt.il_vsync &&
		 t1->bt.il_vbackporch == t2->bt.il_vbackporch)))
		return true;
	return false;
}
EXPORT_SYMBOL_GPL(v4l2_match_dv_timings);

void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix,
			   const struct v4l2_dv_timings *t, bool detailed)
{
	const struct v4l2_bt_timings *bt = &t->bt;
	u32 htot, vtot;

	if (t->type != V4L2_DV_BT_656_1120)
		return;

	htot = V4L2_DV_BT_FRAME_WIDTH(bt);
	vtot = V4L2_DV_BT_FRAME_HEIGHT(bt);

	if (prefix == NULL)
		prefix = "";

	pr_info("%s: %s%ux%u%s%u (%ux%u)\n", dev_prefix, prefix,
		bt->width, bt->height, bt->interlaced ? "i" : "p",
		(htot * vtot) > 0 ? ((u32)bt->pixelclock / (htot * vtot)) : 0,
		htot, vtot);

	if (!detailed)
		return;

	pr_info("%s: horizontal: fp = %u, %ssync = %u, bp = %u\n",
			dev_prefix, bt->hfrontporch,
			(bt->polarities & V4L2_DV_HSYNC_POS_POL) ? "+" : "-",
			bt->hsync, bt->hbackporch);
	pr_info("%s: vertical: fp = %u, %ssync = %u, bp = %u\n",
			dev_prefix, bt->vfrontporch,
			(bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-",
			bt->vsync, bt->vbackporch);
	pr_info("%s: pixelclock: %llu\n", dev_prefix, bt->pixelclock);
	pr_info("%s: flags (0x%x):%s%s%s%s\n", dev_prefix, bt->flags,
			(bt->flags & V4L2_DV_FL_REDUCED_BLANKING) ?
			" REDUCED_BLANKING" : "",
			(bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS) ?
			" CAN_REDUCE_FPS" : "",
			(bt->flags & V4L2_DV_FL_REDUCED_FPS) ?
			" REDUCED_FPS" : "",
			(bt->flags & V4L2_DV_FL_HALF_LINE) ?
			" HALF_LINE" : "");
	pr_info("%s: standards (0x%x):%s%s%s%s\n", dev_prefix, bt->standards,
			(bt->standards & V4L2_DV_BT_STD_CEA861) ?  " CEA" : "",
			(bt->standards & V4L2_DV_BT_STD_DMT) ?  " DMT" : "",
			(bt->standards & V4L2_DV_BT_STD_CVT) ?  " CVT" : "",
			(bt->standards & V4L2_DV_BT_STD_GTF) ?  " GTF" : "");
}
EXPORT_SYMBOL_GPL(v4l2_print_dv_timings);

/*
 * CVT defines
 * Based on Coordinated Video Timings Standard
 * version 1.1 September 10, 2003
 */

#define CVT_PXL_CLK_GRAN	250000	/* pixel clock granularity */

/* Normal blanking */
#define CVT_MIN_V_BPORCH	7	/* lines */
#define CVT_MIN_V_PORCH_RND	3	/* lines */
#define CVT_MIN_VSYNC_BP	550	/* min time of vsync + back porch (us) */

/* Normal blanking for CVT uses GTF to calculate horizontal blanking */
#define CVT_CELL_GRAN		8	/* character cell granularity */
#define CVT_M			600	/* blanking formula gradient */
#define CVT_C			40	/* blanking formula offset */
#define CVT_K			128	/* blanking formula scaling factor */
#define CVT_J			20	/* blanking formula scaling factor */
#define CVT_C_PRIME (((CVT_C - CVT_J) * CVT_K / 256) + CVT_J)
#define CVT_M_PRIME (CVT_K * CVT_M / 256)

/* Reduced Blanking */
#define CVT_RB_MIN_V_BPORCH    7       /* lines  */
#define CVT_RB_V_FPORCH        3       /* lines  */
#define CVT_RB_MIN_V_BLANK   460     /* us     */
#define CVT_RB_H_SYNC         32       /* pixels */
#define CVT_RB_H_BPORCH       80       /* pixels */
#define CVT_RB_H_BLANK       160       /* pixels */

/** v4l2_detect_cvt - detect if the given timings follow the CVT standard
 * @frame_height - the total height of the frame (including blanking) in lines.
 * @hfreq - the horizontal frequency in Hz.
 * @vsync - the height of the vertical sync in lines.
 * @polarities - the horizontal and vertical polarities (same as struct
 *		v4l2_bt_timings polarities).
 * @fmt - the resulting timings.
 *
 * This function will attempt to detect if the given values correspond to a
 * valid CVT format. If so, then it will return true, and fmt will be filled
 * in with the found CVT timings.
 */
bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync,
		u32 polarities, struct v4l2_dv_timings *fmt)
{
	int  v_fp, v_bp, h_fp, h_bp, hsync;
	int  frame_width, image_height, image_width;
	bool reduced_blanking;
	unsigned pix_clk;

	if (vsync < 4 || vsync > 7)
		return false;

	if (polarities == V4L2_DV_VSYNC_POS_POL)
		reduced_blanking = false;
	else if (polarities == V4L2_DV_HSYNC_POS_POL)
		reduced_blanking = true;
	else
		return false;

	/* Vertical */
	if (reduced_blanking) {
		v_fp = CVT_RB_V_FPORCH;
		v_bp = (CVT_RB_MIN_V_BLANK * hfreq + 1999999) / 1000000;
		v_bp -= vsync + v_fp;

		if (v_bp < CVT_RB_MIN_V_BPORCH)
			v_bp = CVT_RB_MIN_V_BPORCH;
	} else {
		v_fp = CVT_MIN_V_PORCH_RND;
		v_bp = (CVT_MIN_VSYNC_BP * hfreq + 1999999) / 1000000 - vsync;

		if (v_bp < CVT_MIN_V_BPORCH)
			v_bp = CVT_MIN_V_BPORCH;
	}
	image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;

	/* Aspect ratio based on vsync */
	switch (vsync) {
	case 4:
		image_width = (image_height * 4) / 3;
		break;
	case 5:
		image_width = (image_height * 16) / 9;
		break;
	case 6:
		image_width = (image_height * 16) / 10;
		break;
	case 7:
		/* special case */
		if (image_height == 1024)
			image_width = (image_height * 5) / 4;
		else if (image_height == 768)
			image_width = (image_height * 15) / 9;
		else
			return false;
		break;
	default:
		return false;
	}

	image_width = image_width & ~7;

	/* Horizontal */
	if (reduced_blanking) {
		pix_clk = (image_width + CVT_RB_H_BLANK) * hfreq;
		pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN;

		h_bp = CVT_RB_H_BPORCH;
		hsync = CVT_RB_H_SYNC;
		h_fp = CVT_RB_H_BLANK - h_bp - hsync;

		frame_width = image_width + CVT_RB_H_BLANK;
	} else {
		unsigned ideal_duty_cycle_per_myriad =
			100 * CVT_C_PRIME - (CVT_M_PRIME * 100000) / hfreq;
		int h_blank;

		if (ideal_duty_cycle_per_myriad < 2000)
			ideal_duty_cycle_per_myriad = 2000;

		h_blank = image_width * ideal_duty_cycle_per_myriad /
					(10000 - ideal_duty_cycle_per_myriad);
		h_blank = (h_blank / (2 * CVT_CELL_GRAN)) * 2 * CVT_CELL_GRAN;

		pix_clk = (image_width + h_blank) * hfreq;
		pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN;

		h_bp = h_blank / 2;
		frame_width = image_width + h_blank;

		hsync = (frame_width * 8 + 50) / 100;
		hsync = hsync - hsync % CVT_CELL_GRAN;
		h_fp = h_blank - hsync - h_bp;
	}

	fmt->bt.polarities = polarities;
	fmt->bt.width = image_width;
	fmt->bt.height = image_height;
	fmt->bt.hfrontporch = h_fp;
	fmt->bt.vfrontporch = v_fp;
	fmt->bt.hsync = hsync;
	fmt->bt.vsync = vsync;
	fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
	fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
	fmt->bt.pixelclock = pix_clk;
	fmt->bt.standards = V4L2_DV_BT_STD_CVT;
	if (reduced_blanking)
		fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
	return true;
}
EXPORT_SYMBOL_GPL(v4l2_detect_cvt);

/*
 * GTF defines
 * Based on Generalized Timing Formula Standard
 * Version 1.1 September 2, 1999
 */

#define GTF_PXL_CLK_GRAN	250000	/* pixel clock granularity */

#define GTF_MIN_VSYNC_BP	550	/* min time of vsync + back porch (us) */
#define GTF_V_FP		1	/* vertical front porch (lines) */
#define GTF_CELL_GRAN		8	/* character cell granularity */

/* Default */
#define GTF_D_M			600	/* blanking formula gradient */
#define GTF_D_C			40	/* blanking formula offset */
#define GTF_D_K			128	/* blanking formula scaling factor */
#define GTF_D_J			20	/* blanking formula scaling factor */
#define GTF_D_C_PRIME ((((GTF_D_C - GTF_D_J) * GTF_D_K) / 256) + GTF_D_J)
#define GTF_D_M_PRIME ((GTF_D_K * GTF_D_M) / 256)

/* Secondary */
#define GTF_S_M			3600	/* blanking formula gradient */
#define GTF_S_C			40	/* blanking formula offset */
#define GTF_S_K			128	/* blanking formula scaling factor */
#define GTF_S_J			35	/* blanking formula scaling factor */
#define GTF_S_C_PRIME ((((GTF_S_C - GTF_S_J) * GTF_S_K) / 256) + GTF_S_J)
#define GTF_S_M_PRIME ((GTF_S_K * GTF_S_M) / 256)

/** v4l2_detect_gtf - detect if the given timings follow the GTF standard
 * @frame_height - the total height of the frame (including blanking) in lines.
 * @hfreq - the horizontal frequency in Hz.
 * @vsync - the height of the vertical sync in lines.
 * @polarities - the horizontal and vertical polarities (same as struct
 *		v4l2_bt_timings polarities).
 * @aspect - preferred aspect ratio. GTF has no method of determining the
 *		aspect ratio in order to derive the image width from the
 *		image height, so it has to be passed explicitly. Usually
 *		the native screen aspect ratio is used for this. If it
 *		is not filled in correctly, then 16:9 will be assumed.
 * @fmt - the resulting timings.
 *
 * This function will attempt to detect if the given values correspond to a
 * valid GTF format. If so, then it will return true, and fmt will be filled
 * in with the found GTF timings.
 */
bool v4l2_detect_gtf(unsigned frame_height,
		unsigned hfreq,
		unsigned vsync,
		u32 polarities,
		struct v4l2_fract aspect,
		struct v4l2_dv_timings *fmt)
{
	int pix_clk;
	int  v_fp, v_bp, h_fp, hsync;
	int frame_width, image_height, image_width;
	bool default_gtf;
	int h_blank;

	if (vsync != 3)
		return false;

	if (polarities == V4L2_DV_VSYNC_POS_POL)
		default_gtf = true;
	else if (polarities == V4L2_DV_HSYNC_POS_POL)
		default_gtf = false;
	else
		return false;

	/* Vertical */
	v_fp = GTF_V_FP;
	v_bp = (GTF_MIN_VSYNC_BP * hfreq + 999999) / 1000000 - vsync;
	image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;

	if (aspect.numerator == 0 || aspect.denominator == 0) {
		aspect.numerator = 16;
		aspect.denominator = 9;
	}
	image_width = ((image_height * aspect.numerator) / aspect.denominator);

	/* Horizontal */
	if (default_gtf)
		h_blank = ((image_width * GTF_D_C_PRIME * hfreq) -
					(image_width * GTF_D_M_PRIME * 1000) +
			(hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000) / 2) /
			(hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000);
	else
		h_blank = ((image_width * GTF_S_C_PRIME * hfreq) -
					(image_width * GTF_S_M_PRIME * 1000) +
			(hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000) / 2) /
			(hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000);

	h_blank = h_blank - h_blank % (2 * GTF_CELL_GRAN);
	frame_width = image_width + h_blank;

	pix_clk = (image_width + h_blank) * hfreq;
	pix_clk = pix_clk / GTF_PXL_CLK_GRAN * GTF_PXL_CLK_GRAN;

	hsync = (frame_width * 8 + 50) / 100;
	hsync = hsync - hsync % GTF_CELL_GRAN;

	h_fp = h_blank / 2 - hsync;

	fmt->bt.polarities = polarities;
	fmt->bt.width = image_width;
	fmt->bt.height = image_height;
	fmt->bt.hfrontporch = h_fp;
	fmt->bt.vfrontporch = v_fp;
	fmt->bt.hsync = hsync;
	fmt->bt.vsync = vsync;
	fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
	fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
	fmt->bt.pixelclock = pix_clk;
	fmt->bt.standards = V4L2_DV_BT_STD_GTF;
	if (!default_gtf)
		fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
	return true;
}
EXPORT_SYMBOL_GPL(v4l2_detect_gtf);

/** v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes
 *	0x15 and 0x16 from the EDID.
 * @hor_landscape - byte 0x15 from the EDID.
 * @vert_portrait - byte 0x16 from the EDID.
 *
 * Determines the aspect ratio from the EDID.
 * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2:
 * "Horizontal and Vertical Screen Size or Aspect Ratio"
 */
struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait)
{
	struct v4l2_fract aspect = { 16, 9 };
	u32 tmp;
	u8 ratio;

	/* Nothing filled in, fallback to 16:9 */
	if (!hor_landscape && !vert_portrait)
		return aspect;
	/* Both filled in, so they are interpreted as the screen size in cm */
	if (hor_landscape && vert_portrait) {
		aspect.numerator = hor_landscape;
		aspect.denominator = vert_portrait;
		return aspect;
	}
	/* Only one is filled in, so interpret them as a ratio:
	   (val + 99) / 100 */
	ratio = hor_landscape | vert_portrait;
	/* Change some rounded values into the exact aspect ratio */
	if (ratio == 79) {
		aspect.numerator = 16;
		aspect.denominator = 9;
	} else if (ratio == 34) {
		aspect.numerator = 4;
		aspect.numerator = 3;
	} else if (ratio == 68) {
		aspect.numerator = 15;
		aspect.numerator = 9;
	} else {
		aspect.numerator = hor_landscape + 99;
		aspect.denominator = 100;
	}
	if (hor_landscape)
		return aspect;
	/* The aspect ratio is for portrait, so swap numerator and denominator */
	tmp = aspect.denominator;
	aspect.denominator = aspect.numerator;
	aspect.numerator = tmp;
	return aspect;
}
EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio);
Commit	Line	Data
b18787ed HV	1	/*
	2	* v4l2-dv-timings - dv-timings helper functions
	3	*
	4	* Copyright 2013 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
	5	*
	6	* This program is free software; you may redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; version 2 of the License.
	9	*
	10	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	11	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	12	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	13	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
	14	* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
	15	* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	16	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	17	* SOFTWARE.
	18	*
	19	*/
	20
	21	#include <linux/module.h>
	22	#include <linux/types.h>
	23	#include <linux/kernel.h>
	24	#include <linux/errno.h>
	25	#include <linux/videodev2.h>
	26	#include <linux/v4l2-dv-timings.h>
b18787ed HV	27	#include <media/v4l2-dv-timings.h>
	28
	29	static const struct v4l2_dv_timings timings[] = {
	30	V4L2_DV_BT_CEA_640X480P59_94,
	31	V4L2_DV_BT_CEA_720X480I59_94,
	32	V4L2_DV_BT_CEA_720X480P59_94,
	33	V4L2_DV_BT_CEA_720X576I50,
	34	V4L2_DV_BT_CEA_720X576P50,
	35	V4L2_DV_BT_CEA_1280X720P24,
	36	V4L2_DV_BT_CEA_1280X720P25,
	37	V4L2_DV_BT_CEA_1280X720P30,
	38	V4L2_DV_BT_CEA_1280X720P50,
	39	V4L2_DV_BT_CEA_1280X720P60,
	40	V4L2_DV_BT_CEA_1920X1080P24,
	41	V4L2_DV_BT_CEA_1920X1080P25,
	42	V4L2_DV_BT_CEA_1920X1080P30,
	43	V4L2_DV_BT_CEA_1920X1080I50,
	44	V4L2_DV_BT_CEA_1920X1080P50,
	45	V4L2_DV_BT_CEA_1920X1080I60,
	46	V4L2_DV_BT_CEA_1920X1080P60,
	47	V4L2_DV_BT_DMT_640X350P85,
	48	V4L2_DV_BT_DMT_640X400P85,
	49	V4L2_DV_BT_DMT_720X400P85,
	50	V4L2_DV_BT_DMT_640X480P72,
	51	V4L2_DV_BT_DMT_640X480P75,
	52	V4L2_DV_BT_DMT_640X480P85,
	53	V4L2_DV_BT_DMT_800X600P56,
	54	V4L2_DV_BT_DMT_800X600P60,
	55	V4L2_DV_BT_DMT_800X600P72,
	56	V4L2_DV_BT_DMT_800X600P75,
	57	V4L2_DV_BT_DMT_800X600P85,
	58	V4L2_DV_BT_DMT_800X600P120_RB,
	59	V4L2_DV_BT_DMT_848X480P60,
	60	V4L2_DV_BT_DMT_1024X768I43,
	61	V4L2_DV_BT_DMT_1024X768P60,
	62	V4L2_DV_BT_DMT_1024X768P70,
	63	V4L2_DV_BT_DMT_1024X768P75,
	64	V4L2_DV_BT_DMT_1024X768P85,
	65	V4L2_DV_BT_DMT_1024X768P120_RB,
	66	V4L2_DV_BT_DMT_1152X864P75,
	67	V4L2_DV_BT_DMT_1280X768P60_RB,
	68	V4L2_DV_BT_DMT_1280X768P60,
	69	V4L2_DV_BT_DMT_1280X768P75,
	70	V4L2_DV_BT_DMT_1280X768P85,
	71	V4L2_DV_BT_DMT_1280X768P120_RB,
	72	V4L2_DV_BT_DMT_1280X800P60_RB,
	73	V4L2_DV_BT_DMT_1280X800P60,
	74	V4L2_DV_BT_DMT_1280X800P75,
	75	V4L2_DV_BT_DMT_1280X800P85,
	76	V4L2_DV_BT_DMT_1280X800P120_RB,
	77	V4L2_DV_BT_DMT_1280X960P60,
	78	V4L2_DV_BT_DMT_1280X960P85,
	79	V4L2_DV_BT_DMT_1280X960P120_RB,
	80	V4L2_DV_BT_DMT_1280X1024P60,
	81	V4L2_DV_BT_DMT_1280X1024P75,
	82	V4L2_DV_BT_DMT_1280X1024P85,
	83	V4L2_DV_BT_DMT_1280X1024P120_RB,
	84	V4L2_DV_BT_DMT_1360X768P60,
	85	V4L2_DV_BT_DMT_1360X768P120_RB,
	86	V4L2_DV_BT_DMT_1366X768P60,
	87	V4L2_DV_BT_DMT_1366X768P60_RB,
	88	V4L2_DV_BT_DMT_1400X1050P60_RB,
	89	V4L2_DV_BT_DMT_1400X1050P60,
	90	V4L2_DV_BT_DMT_1400X1050P75,
91	V4L2_DV_BT_DMT_1400X1050P85,
92	V4L2_DV_BT_DMT_1400X1050P120_RB,
93	V4L2_DV_BT_DMT_1440X900P60_RB,
94	V4L2_DV_BT_DMT_1440X900P60,
95	V4L2_DV_BT_DMT_1440X900P75,
96	V4L2_DV_BT_DMT_1440X900P85,
97	V4L2_DV_BT_DMT_1440X900P120_RB,
98	V4L2_DV_BT_DMT_1600X900P60_RB,
99	V4L2_DV_BT_DMT_1600X1200P60,
100	V4L2_DV_BT_DMT_1600X1200P65,
101	V4L2_DV_BT_DMT_1600X1200P70,
102	V4L2_DV_BT_DMT_1600X1200P75,
103	V4L2_DV_BT_DMT_1600X1200P85,
104	V4L2_DV_BT_DMT_1600X1200P120_RB,
105	V4L2_DV_BT_DMT_1680X1050P60_RB,
106	V4L2_DV_BT_DMT_1680X1050P60,
107	V4L2_DV_BT_DMT_1680X1050P75,
108	V4L2_DV_BT_DMT_1680X1050P85,
109	V4L2_DV_BT_DMT_1680X1050P120_RB,
110	V4L2_DV_BT_DMT_1792X1344P60,
111	V4L2_DV_BT_DMT_1792X1344P75,
112	V4L2_DV_BT_DMT_1792X1344P120_RB,
113	V4L2_DV_BT_DMT_1856X1392P60,
114	V4L2_DV_BT_DMT_1856X1392P75,
115	V4L2_DV_BT_DMT_1856X1392P120_RB,
116	V4L2_DV_BT_DMT_1920X1200P60_RB,
117	V4L2_DV_BT_DMT_1920X1200P60,
118	V4L2_DV_BT_DMT_1920X1200P75,
119	V4L2_DV_BT_DMT_1920X1200P85,
120	V4L2_DV_BT_DMT_1920X1200P120_RB,
121	V4L2_DV_BT_DMT_1920X1440P60,
122	V4L2_DV_BT_DMT_1920X1440P75,
123	V4L2_DV_BT_DMT_1920X1440P120_RB,
124	V4L2_DV_BT_DMT_2048X1152P60_RB,
125	V4L2_DV_BT_DMT_2560X1600P60_RB,
126	V4L2_DV_BT_DMT_2560X1600P60,
127	V4L2_DV_BT_DMT_2560X1600P75,
128	V4L2_DV_BT_DMT_2560X1600P85,
129	V4L2_DV_BT_DMT_2560X1600P120_RB,
130	};
131
132	bool v4l2_dv_valid_timings(const struct v4l2_dv_timings *t,
133	const struct v4l2_dv_timings_cap *dvcap)
134	{
135	const struct v4l2_bt_timings *bt = &t->bt;
136	const struct v4l2_bt_timings_cap *cap = &dvcap->bt;
137	u32 caps = cap->capabilities;
138
139	if (t->type != V4L2_DV_BT_656_1120)
140	return false;
141	if (t->type != dvcap->type \|\|
142	bt->height < cap->min_height \|\|
143	bt->height > cap->max_height \|\|
144	bt->width < cap->min_width \|\|
145	bt->width > cap->max_width \|\|
146	bt->pixelclock < cap->min_pixelclock \|\|
147	bt->pixelclock > cap->max_pixelclock \|\|
148	(cap->standards && !(bt->standards & cap->standards)) \|\|
149	(bt->interlaced && !(caps & V4L2_DV_BT_CAP_INTERLACED)) \|\|
150	(!bt->interlaced && !(caps & V4L2_DV_BT_CAP_PROGRESSIVE)))
151	return false;
152	return true;
153	}
154	EXPORT_SYMBOL_GPL(v4l2_dv_valid_timings);
155
156	int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t,
157	const struct v4l2_dv_timings_cap *cap)
158	{
159	u32 i, idx;
160
161	memset(t->reserved, 0, sizeof(t->reserved));
162	for (i = idx = 0; i < ARRAY_SIZE(timings); i++) {
163	if (v4l2_dv_valid_timings(timings + i, cap) &&
164	idx++ == t->index) {
165	t->timings = timings[i];
166	return 0;
167	}
168	}
169	return -EINVAL;
170	}
171	EXPORT_SYMBOL_GPL(v4l2_enum_dv_timings_cap);
172
173	bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t,
174	const struct v4l2_dv_timings_cap *cap,
175	unsigned pclock_delta)
176	{
177	int i;
178
179	if (!v4l2_dv_valid_timings(t, cap))
180	return false;
181
182	for (i = 0; i < ARRAY_SIZE(timings); i++) {
183	if (v4l2_dv_valid_timings(timings + i, cap) &&
ef1ed8f5	184	v4l2_match_dv_timings(t, timings + i, pclock_delta)) {
b18787ed HV	185	*t = timings[i];
	186	return true;
	187	}
	188	}
	189	return false;
	190	}
	191	EXPORT_SYMBOL_GPL(v4l2_find_dv_timings_cap);
25764158 HV	192
25764158 HV	193	/**
ef1ed8f5	194	* v4l2_match_dv_timings - check if two timings match
25764158 HV	195	* @t1 - compare this v4l2_dv_timings struct...
	196	* @t2 - with this struct.
	197	* @pclock_delta - the allowed pixelclock deviation.
	198	*
	199	* Compare t1 with t2 with a given margin of error for the pixelclock.
	200	*/
ef1ed8f5 HV	201	bool v4l2_match_dv_timings(const struct v4l2_dv_timings *t1,
	202	const struct v4l2_dv_timings *t2,
	203	unsigned pclock_delta)
25764158 HV	204	{
	205	if (t1->type != t2->type \|\| t1->type != V4L2_DV_BT_656_1120)
	206	return false;
	207	if (t1->bt.width == t2->bt.width &&
	208	t1->bt.height == t2->bt.height &&
	209	t1->bt.interlaced == t2->bt.interlaced &&
	210	t1->bt.polarities == t2->bt.polarities &&
	211	t1->bt.pixelclock >= t2->bt.pixelclock - pclock_delta &&
	212	t1->bt.pixelclock <= t2->bt.pixelclock + pclock_delta &&
	213	t1->bt.hfrontporch == t2->bt.hfrontporch &&
	214	t1->bt.vfrontporch == t2->bt.vfrontporch &&
	215	t1->bt.vsync == t2->bt.vsync &&
	216	t1->bt.vbackporch == t2->bt.vbackporch &&
	217	(!t1->bt.interlaced \|\|
	218	(t1->bt.il_vfrontporch == t2->bt.il_vfrontporch &&
	219	t1->bt.il_vsync == t2->bt.il_vsync &&
	220	t1->bt.il_vbackporch == t2->bt.il_vbackporch)))
	221	return true;
	222	return false;
	223	}
ef1ed8f5	224	EXPORT_SYMBOL_GPL(v4l2_match_dv_timings);
25764158	225
0216dc2f HV	226	void v4l2_print_dv_timings(const char dev_prefix, const char prefix,
	227	const struct v4l2_dv_timings *t, bool detailed)
	228	{
	229	const struct v4l2_bt_timings *bt = &t->bt;
	230	u32 htot, vtot;
	231
	232	if (t->type != V4L2_DV_BT_656_1120)
	233	return;
	234
	235	htot = V4L2_DV_BT_FRAME_WIDTH(bt);
	236	vtot = V4L2_DV_BT_FRAME_HEIGHT(bt);
	237
	238	if (prefix == NULL)
	239	prefix = "";
	240
	241	pr_info("%s: %s%ux%u%s%u (%ux%u)\n", dev_prefix, prefix,
	242	bt->width, bt->height, bt->interlaced ? "i" : "p",
	243	(htot * vtot) > 0 ? ((u32)bt->pixelclock / (htot * vtot)) : 0,
	244	htot, vtot);
	245
	246	if (!detailed)
	247	return;
	248
	249	pr_info("%s: horizontal: fp = %u, %ssync = %u, bp = %u\n",
	250	dev_prefix, bt->hfrontporch,
	251	(bt->polarities & V4L2_DV_HSYNC_POS_POL) ? "+" : "-",
	252	bt->hsync, bt->hbackporch);
	253	pr_info("%s: vertical: fp = %u, %ssync = %u, bp = %u\n",
	254	dev_prefix, bt->vfrontporch,
	255	(bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-",
	256	bt->vsync, bt->vbackporch);
	257	pr_info("%s: pixelclock: %llu\n", dev_prefix, bt->pixelclock);
	258	pr_info("%s: flags (0x%x):%s%s%s%s\n", dev_prefix, bt->flags,
	259	(bt->flags & V4L2_DV_FL_REDUCED_BLANKING) ?
	260	" REDUCED_BLANKING" : "",
	261	(bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS) ?
	262	" CAN_REDUCE_FPS" : "",
	263	(bt->flags & V4L2_DV_FL_REDUCED_FPS) ?
	264	" REDUCED_FPS" : "",
	265	(bt->flags & V4L2_DV_FL_HALF_LINE) ?
	266	" HALF_LINE" : "");
	267	pr_info("%s: standards (0x%x):%s%s%s%s\n", dev_prefix, bt->standards,
	268	(bt->standards & V4L2_DV_BT_STD_CEA861) ? " CEA" : "",
	269	(bt->standards & V4L2_DV_BT_STD_DMT) ? " DMT" : "",
	270	(bt->standards & V4L2_DV_BT_STD_CVT) ? " CVT" : "",
	271	(bt->standards & V4L2_DV_BT_STD_GTF) ? " GTF" : "");
	272	}
	273	EXPORT_SYMBOL_GPL(v4l2_print_dv_timings);
	274
25764158 HV	275	/*
	276	* CVT defines
	277	* Based on Coordinated Video Timings Standard
	278	* version 1.1 September 10, 2003
	279	*/
	280
	281	#define CVT_PXL_CLK_GRAN 250000 /* pixel clock granularity */
	282
	283	/* Normal blanking */
	284	#define CVT_MIN_V_BPORCH 7 /* lines */
	285	#define CVT_MIN_V_PORCH_RND 3 /* lines */
	286	#define CVT_MIN_VSYNC_BP 550 /* min time of vsync + back porch (us) */
	287
	288	/* Normal blanking for CVT uses GTF to calculate horizontal blanking */
	289	#define CVT_CELL_GRAN 8 /* character cell granularity */
	290	#define CVT_M 600 /* blanking formula gradient */
	291	#define CVT_C 40 /* blanking formula offset */
	292	#define CVT_K 128 /* blanking formula scaling factor */
	293	#define CVT_J 20 /* blanking formula scaling factor */
	294	#define CVT_C_PRIME (((CVT_C - CVT_J) * CVT_K / 256) + CVT_J)
	295	#define CVT_M_PRIME (CVT_K * CVT_M / 256)
	296
	297	/* Reduced Blanking */
	298	#define CVT_RB_MIN_V_BPORCH 7 /* lines */
	299	#define CVT_RB_V_FPORCH 3 /* lines */
	300	#define CVT_RB_MIN_V_BLANK 460 /* us */
	301	#define CVT_RB_H_SYNC 32 /* pixels */
	302	#define CVT_RB_H_BPORCH 80 /* pixels */
	303	#define CVT_RB_H_BLANK 160 /* pixels */
	304
	305	/** v4l2_detect_cvt - detect if the given timings follow the CVT standard
	306	* @frame_height - the total height of the frame (including blanking) in lines.
	307	* @hfreq - the horizontal frequency in Hz.
	308	* @vsync - the height of the vertical sync in lines.
	309	* @polarities - the horizontal and vertical polarities (same as struct
	310	* v4l2_bt_timings polarities).
	311	* @fmt - the resulting timings.
	312	*
	313	* This function will attempt to detect if the given values correspond to a
	314	* valid CVT format. If so, then it will return true, and fmt will be filled
	315	* in with the found CVT timings.
	316	*/
	317	bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync,
	318	u32 polarities, struct v4l2_dv_timings *fmt)
	319	{
	320	int v_fp, v_bp, h_fp, h_bp, hsync;
	321	int frame_width, image_height, image_width;
	322	bool reduced_blanking;
	323	unsigned pix_clk;
	324
	325	if (vsync < 4 \|\| vsync > 7)
	326	return false;
	327
	328	if (polarities == V4L2_DV_VSYNC_POS_POL)
	329	reduced_blanking = false;
	330	else if (polarities == V4L2_DV_HSYNC_POS_POL)
	331	reduced_blanking = true;
	332	else
	333	return false;
	334
	335	/* Vertical */
	336	if (reduced_blanking) {
	337	v_fp = CVT_RB_V_FPORCH;
c3e75c7d	338	v_bp = (CVT_RB_MIN_V_BLANK * hfreq + 1999999) / 1000000;
25764158 HV	339	v_bp -= vsync + v_fp;
	340
	341	if (v_bp < CVT_RB_MIN_V_BPORCH)
	342	v_bp = CVT_RB_MIN_V_BPORCH;
	343	} else {
	344	v_fp = CVT_MIN_V_PORCH_RND;
c3e75c7d	345	v_bp = (CVT_MIN_VSYNC_BP * hfreq + 1999999) / 1000000 - vsync;
25764158 HV	346
	347	if (v_bp < CVT_MIN_V_BPORCH)
	348	v_bp = CVT_MIN_V_BPORCH;
	349	}
	350	image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
	351
	352	/* Aspect ratio based on vsync */
	353	switch (vsync) {
	354	case 4:
	355	image_width = (image_height * 4) / 3;
	356	break;
	357	case 5:
	358	image_width = (image_height * 16) / 9;
	359	break;
	360	case 6:
	361	image_width = (image_height * 16) / 10;
	362	break;
	363	case 7:
	364	/* special case */
	365	if (image_height == 1024)
	366	image_width = (image_height * 5) / 4;
	367	else if (image_height == 768)
	368	image_width = (image_height * 15) / 9;
	369	else
	370	return false;
	371	break;
	372	default:
	373	return false;
	374	}
	375
	376	image_width = image_width & ~7;
	377
	378	/* Horizontal */
	379	if (reduced_blanking) {
	380	pix_clk = (image_width + CVT_RB_H_BLANK) * hfreq;
	381	pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN;
	382
	383	h_bp = CVT_RB_H_BPORCH;
	384	hsync = CVT_RB_H_SYNC;
	385	h_fp = CVT_RB_H_BLANK - h_bp - hsync;
	386
	387	frame_width = image_width + CVT_RB_H_BLANK;
	388	} else {
c3e75c7d MB	389	unsigned ideal_duty_cycle_per_myriad =
c3e75c7d MB	390	100 * CVT_C_PRIME - (CVT_M_PRIME * 100000) / hfreq;
25764158	391	int h_blank;
25764158	392
c3e75c7d MB	393	if (ideal_duty_cycle_per_myriad < 2000)
c3e75c7d MB	394	ideal_duty_cycle_per_myriad = 2000;
25764158	395
c3e75c7d MB	396	h_blank = image_width * ideal_duty_cycle_per_myriad /
	397	(10000 - ideal_duty_cycle_per_myriad);
	398	h_blank = (h_blank / (2 * CVT_CELL_GRAN)) * 2 * CVT_CELL_GRAN;
25764158 HV	399
	400	pix_clk = (image_width + h_blank) * hfreq;
	401	pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN;
	402
	403	h_bp = h_blank / 2;
	404	frame_width = image_width + h_blank;
	405
	406	hsync = (frame_width * 8 + 50) / 100;
	407	hsync = hsync - hsync % CVT_CELL_GRAN;
	408	h_fp = h_blank - hsync - h_bp;
	409	}
	410
	411	fmt->bt.polarities = polarities;
	412	fmt->bt.width = image_width;
	413	fmt->bt.height = image_height;
	414	fmt->bt.hfrontporch = h_fp;
	415	fmt->bt.vfrontporch = v_fp;
	416	fmt->bt.hsync = hsync;
	417	fmt->bt.vsync = vsync;
	418	fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
	419	fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
	420	fmt->bt.pixelclock = pix_clk;
	421	fmt->bt.standards = V4L2_DV_BT_STD_CVT;
	422	if (reduced_blanking)
	423	fmt->bt.flags \|= V4L2_DV_FL_REDUCED_BLANKING;
	424	return true;
	425	}
	426	EXPORT_SYMBOL_GPL(v4l2_detect_cvt);
	427
	428	/*
	429	* GTF defines
	430	* Based on Generalized Timing Formula Standard
	431	* Version 1.1 September 2, 1999
	432	*/
	433
	434	#define GTF_PXL_CLK_GRAN 250000 /* pixel clock granularity */
	435
	436	#define GTF_MIN_VSYNC_BP 550 /* min time of vsync + back porch (us) */
	437	#define GTF_V_FP 1 /* vertical front porch (lines) */
	438	#define GTF_CELL_GRAN 8 /* character cell granularity */
	439
	440	/* Default */
	441	#define GTF_D_M 600 /* blanking formula gradient */
	442	#define GTF_D_C 40 /* blanking formula offset */
	443	#define GTF_D_K 128 /* blanking formula scaling factor */
	444	#define GTF_D_J 20 /* blanking formula scaling factor */
	445	#define GTF_D_C_PRIME ((((GTF_D_C - GTF_D_J) * GTF_D_K) / 256) + GTF_D_J)
	446	#define GTF_D_M_PRIME ((GTF_D_K * GTF_D_M) / 256)
	447
	448	/* Secondary */
	449	#define GTF_S_M 3600 /* blanking formula gradient */
	450	#define GTF_S_C 40 /* blanking formula offset */
	451	#define GTF_S_K 128 /* blanking formula scaling factor */
	452	#define GTF_S_J 35 /* blanking formula scaling factor */
	453	#define GTF_S_C_PRIME ((((GTF_S_C - GTF_S_J) * GTF_S_K) / 256) + GTF_S_J)
	454	#define GTF_S_M_PRIME ((GTF_S_K * GTF_S_M) / 256)
	455
	456	/** v4l2_detect_gtf - detect if the given timings follow the GTF standard
	457	* @frame_height - the total height of the frame (including blanking) in lines.
	458	* @hfreq - the horizontal frequency in Hz.
	459	* @vsync - the height of the vertical sync in lines.
	460	* @polarities - the horizontal and vertical polarities (same as struct
	461	* v4l2_bt_timings polarities).
	462	* @aspect - preferred aspect ratio. GTF has no method of determining the
463	* aspect ratio in order to derive the image width from the
464	* image height, so it has to be passed explicitly. Usually
465	* the native screen aspect ratio is used for this. If it
466	* is not filled in correctly, then 16:9 will be assumed.
467	* @fmt - the resulting timings.
468	*
469	* This function will attempt to detect if the given values correspond to a
470	* valid GTF format. If so, then it will return true, and fmt will be filled
471	* in with the found GTF timings.
472	*/
473	bool v4l2_detect_gtf(unsigned frame_height,
474	unsigned hfreq,
475	unsigned vsync,
476	u32 polarities,
477	struct v4l2_fract aspect,
478	struct v4l2_dv_timings *fmt)
479	{
480	int pix_clk;
481	int v_fp, v_bp, h_fp, hsync;
482	int frame_width, image_height, image_width;
483	bool default_gtf;
484	int h_blank;
485
486	if (vsync != 3)
487	return false;
488
489	if (polarities == V4L2_DV_VSYNC_POS_POL)
490	default_gtf = true;
491	else if (polarities == V4L2_DV_HSYNC_POS_POL)
492	default_gtf = false;
493	else
494	return false;
495
496	/* Vertical */
497	v_fp = GTF_V_FP;
498	v_bp = (GTF_MIN_VSYNC_BP * hfreq + 999999) / 1000000 - vsync;
499	image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
500
501	if (aspect.numerator == 0 \|\| aspect.denominator == 0) {
502	aspect.numerator = 16;
503	aspect.denominator = 9;
504	}
505	image_width = ((image_height * aspect.numerator) / aspect.denominator);
506
507	/* Horizontal */
508	if (default_gtf)
509	h_blank = ((image_width * GTF_D_C_PRIME * hfreq) -
510	(image_width * GTF_D_M_PRIME * 1000) +
511	(hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000) / 2) /
512	(hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000);
513	else
514	h_blank = ((image_width * GTF_S_C_PRIME * hfreq) -
515	(image_width * GTF_S_M_PRIME * 1000) +
516	(hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000) / 2) /
517	(hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000);
518
519	h_blank = h_blank - h_blank % (2 * GTF_CELL_GRAN);
520	frame_width = image_width + h_blank;
521
522	pix_clk = (image_width + h_blank) * hfreq;
523	pix_clk = pix_clk / GTF_PXL_CLK_GRAN * GTF_PXL_CLK_GRAN;
524
525	hsync = (frame_width * 8 + 50) / 100;
526	hsync = hsync - hsync % GTF_CELL_GRAN;
527
528	h_fp = h_blank / 2 - hsync;
529
530	fmt->bt.polarities = polarities;
531	fmt->bt.width = image_width;
532	fmt->bt.height = image_height;
533	fmt->bt.hfrontporch = h_fp;
534	fmt->bt.vfrontporch = v_fp;
535	fmt->bt.hsync = hsync;
536	fmt->bt.vsync = vsync;
537	fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
538	fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
539	fmt->bt.pixelclock = pix_clk;
540	fmt->bt.standards = V4L2_DV_BT_STD_GTF;
541	if (!default_gtf)
542	fmt->bt.flags \|= V4L2_DV_FL_REDUCED_BLANKING;
543	return true;
544	}
545	EXPORT_SYMBOL_GPL(v4l2_detect_gtf);
546
547	/** v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes
548	* 0x15 and 0x16 from the EDID.
549	* @hor_landscape - byte 0x15 from the EDID.
550	* @vert_portrait - byte 0x16 from the EDID.
551	*
552	* Determines the aspect ratio from the EDID.
553	* See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2:
554	* "Horizontal and Vertical Screen Size or Aspect Ratio"
555	*/
556	struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait)
557	{
558	struct v4l2_fract aspect = { 16, 9 };
559	u32 tmp;
560	u8 ratio;
561
562	/* Nothing filled in, fallback to 16:9 */
563	if (!hor_landscape && !vert_portrait)
564	return aspect;
565	/* Both filled in, so they are interpreted as the screen size in cm */
566	if (hor_landscape && vert_portrait) {
567	aspect.numerator = hor_landscape;
568	aspect.denominator = vert_portrait;
569	return aspect;
570	}
571	/* Only one is filled in, so interpret them as a ratio:
572	(val + 99) / 100 */
573	ratio = hor_landscape \| vert_portrait;
574	/* Change some rounded values into the exact aspect ratio */
575	if (ratio == 79) {
576	aspect.numerator = 16;
577	aspect.denominator = 9;
578	} else if (ratio == 34) {
579	aspect.numerator = 4;
580	aspect.numerator = 3;
581	} else if (ratio == 68) {
582	aspect.numerator = 15;
583	aspect.numerator = 9;
584	} else {
585	aspect.numerator = hor_landscape + 99;
586	aspect.denominator = 100;
587	}
588	if (hor_landscape)
589	return aspect;
590	/* The aspect ratio is for portrait, so swap numerator and denominator */
591	tmp = aspect.denominator;
592	aspect.denominator = aspect.numerator;
593	aspect.numerator = tmp;
594	return aspect;
595	}
596	EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio);