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linux/drivers/media/v4l2-core/v4l2-dv-timings.c
Prashant Laddha 227da85e77 [media] v4l2-dv-timings: print refresh rate with better precision 
In many cases, refresh rate is not exact integer. In such cases,
fraction was lost and it used to print, say, 59 in case of 59.94.
Now, capturing the fraction up to 2 decimal places.

Signed-off-by: Prashant Laddha <prladdha@cisco.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-07-06 08:25:53 -03:00

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/*
* 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>
#include <linux/math64.h>
MODULE_AUTHOR("Hans Verkuil");
MODULE_DESCRIPTION("V4L2 DV Timings Helper Functions");
MODULE_LICENSE("GPL");
const struct v4l2_dv_timings v4l2_dv_timings_presets[] = {
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,
V4L2_DV_BT_CEA_3840X2160P24,
V4L2_DV_BT_CEA_3840X2160P25,
V4L2_DV_BT_CEA_3840X2160P30,
V4L2_DV_BT_CEA_3840X2160P50,
V4L2_DV_BT_CEA_3840X2160P60,
V4L2_DV_BT_CEA_4096X2160P24,
V4L2_DV_BT_CEA_4096X2160P25,
V4L2_DV_BT_CEA_4096X2160P30,
V4L2_DV_BT_CEA_4096X2160P50,
V4L2_DV_BT_DMT_4096X2160P59_94_RB,
V4L2_DV_BT_CEA_4096X2160P60,
{ }
};
EXPORT_SYMBOL_GPL(v4l2_dv_timings_presets);
bool v4l2_valid_dv_timings(const struct v4l2_dv_timings *t,
const struct v4l2_dv_timings_cap *dvcap,
v4l2_check_dv_timings_fnc fnc,
void *fnc_handle)
{
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 &&
!(bt->standards & cap->standards)) ||
(bt->interlaced && !(caps & V4L2_DV_BT_CAP_INTERLACED)) ||
(!bt->interlaced && !(caps & V4L2_DV_BT_CAP_PROGRESSIVE)))
return false;
return fnc == NULL || fnc(t, fnc_handle);
}
EXPORT_SYMBOL_GPL(v4l2_valid_dv_timings);
int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t,
const struct v4l2_dv_timings_cap *cap,
v4l2_check_dv_timings_fnc fnc,
void *fnc_handle)
{
u32 i, idx;
memset(t->reserved, 0, sizeof(t->reserved));
for (i = idx = 0; v4l2_dv_timings_presets[i].bt.width; i++) {
if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap,
fnc, fnc_handle) &&
idx++ == t->index) {
t->timings = v4l2_dv_timings_presets[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,
v4l2_check_dv_timings_fnc fnc,
void *fnc_handle)
{
int i;
if (!v4l2_valid_dv_timings(t, cap, fnc, fnc_handle))
return false;
for (i = 0; i < v4l2_dv_timings_presets[i].bt.width; i++) {
if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap,
fnc, fnc_handle) &&
v4l2_match_dv_timings(t, v4l2_dv_timings_presets + i,
pclock_delta)) {
*t = v4l2_dv_timings_presets[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;
u32 fps;
if (t->type != V4L2_DV_BT_656_1120)
return;
htot = V4L2_DV_BT_FRAME_WIDTH(bt);
vtot = V4L2_DV_BT_FRAME_HEIGHT(bt);
if (bt->interlaced)
vtot /= 2;
fps = (htot * vtot) > 0 ? div_u64((100 * (u64)bt->pixelclock),
(htot * vtot)) : 0;
if (prefix == NULL)
prefix = "";
pr_info("%s: %s%ux%u%s%u.%u (%ux%u)\n", dev_prefix, prefix,
bt->width, bt->height, bt->interlaced ? "i" : "p",
fps / 100, fps % 100, 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);
if (bt->interlaced)
pr_info("%s: vertical bottom field: fp = %u, %ssync = %u, bp = %u\n",
dev_prefix, bt->il_vfrontporch,
(bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-",
bt->il_vsync, bt->il_vbackporch);
pr_info("%s: pixelclock: %llu\n", dev_prefix, bt->pixelclock);
pr_info("%s: flags (0x%x):%s%s%s%s%s%s\n", dev_prefix, bt->flags,
(bt->flags & V4L2_DV_FL_REDUCED_BLANKING) ?
" REDUCED_BLANKING" : "",
((bt->flags & V4L2_DV_FL_REDUCED_BLANKING) &&
bt->vsync == 8) ? " (V2)" : "",
(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" : "",
(bt->flags & V4L2_DV_FL_IS_CE_VIDEO) ?
" CE_VIDEO" : "");
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 */
#define CVT_PXL_CLK_GRAN_RB_V2 1000 /* granularity for reduced blanking v2*/
/* 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) */
#define CVT_HSYNC_PERCENT 8 /* nominal hsync as percentage of line */
/* 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_BLANK 160 /* pixels */
/* Reduce blanking Version 2 */
#define CVT_RB_V2_H_BLANK 80 /* pixels */
#define CVT_RB_MIN_V_FPORCH 3 /* lines */
#define CVT_RB_V2_MIN_V_FPORCH 1 /* lines */
#define CVT_RB_V_BPORCH 6 /* lines */
/** 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.
* @active_width - active width of image (does not include blanking). This
* information is needed only in case of version 2 of reduced blanking.
* In other cases, this parameter does not have any effect on timings.
* @polarities - the horizontal and vertical polarities (same as struct
* v4l2_bt_timings polarities).
* @interlaced - if this flag is true, it indicates interlaced format
* @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,
unsigned active_width,
u32 polarities,
bool interlaced,
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;
bool rb_v2 = false;
unsigned pix_clk;
if (vsync < 4 || vsync > 8)
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;
if (reduced_blanking && vsync == 8)
rb_v2 = true;
if (rb_v2 && active_width == 0)
return false;
if (!rb_v2 && vsync > 7)
return false;
if (hfreq == 0)
return false;
/* Vertical */
if (reduced_blanking) {
if (rb_v2) {
v_bp = CVT_RB_V_BPORCH;
v_fp = (CVT_RB_MIN_V_BLANK * hfreq) / 1000000 + 1;
v_fp -= vsync + v_bp;
if (v_fp < CVT_RB_V2_MIN_V_FPORCH)
v_fp = CVT_RB_V2_MIN_V_FPORCH;
} else {
v_fp = CVT_RB_V_FPORCH;
v_bp = (CVT_RB_MIN_V_BLANK * hfreq) / 1000000 + 1;
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) / 1000000 + 1 - vsync;
if (v_bp < CVT_MIN_V_BPORCH)
v_bp = CVT_MIN_V_BPORCH;
}
if (interlaced)
image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1;
else
image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
if (image_height < 0)
return false;
/* 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;
case 8:
image_width = active_width;
break;
default:
return false;
}
if (!rb_v2)
image_width = image_width & ~7;
/* Horizontal */
if (reduced_blanking) {
int h_blank;
int clk_gran;
h_blank = rb_v2 ? CVT_RB_V2_H_BLANK : CVT_RB_H_BLANK;
clk_gran = rb_v2 ? CVT_PXL_CLK_GRAN_RB_V2 : CVT_PXL_CLK_GRAN;
pix_clk = (image_width + h_blank) * hfreq;
pix_clk = (pix_clk / clk_gran) * clk_gran;
h_bp = h_blank / 2;
hsync = CVT_RB_H_SYNC;
h_fp = h_blank - h_bp - hsync;
frame_width = image_width + 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 * CVT_HSYNC_PERCENT / 100;
hsync = (hsync / CVT_CELL_GRAN) * CVT_CELL_GRAN;
h_fp = h_blank - hsync - h_bp;
}
fmt->type = V4L2_DV_BT_656_1120;
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;
if (!interlaced) {
fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
fmt->bt.interlaced = V4L2_DV_PROGRESSIVE;
} else {
fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp -
2 * vsync) / 2;
fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp -
2 * vsync - fmt->bt.vbackporch;
fmt->bt.il_vfrontporch = v_fp;
fmt->bt.il_vsync = vsync;
fmt->bt.flags |= V4L2_DV_FL_HALF_LINE;
fmt->bt.interlaced = V4L2_DV_INTERLACED;
}
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).
* @interlaced - if this flag is true, it indicates interlaced format
* @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,
bool interlaced,
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;
if (hfreq == 0)
return false;
/* Vertical */
v_fp = GTF_V_FP;
v_bp = (GTF_MIN_VSYNC_BP * hfreq + 500000) / 1000000 - vsync;
if (interlaced)
image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1;
else
image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
if (image_height < 0)
return false;
if (aspect.numerator == 0 || aspect.denominator == 0) {
aspect.numerator = 16;
aspect.denominator = 9;
}
image_width = ((image_height * aspect.numerator) / aspect.denominator);
image_width = (image_width + GTF_CELL_GRAN/2) & ~(GTF_CELL_GRAN - 1);
/* Horizontal */
if (default_gtf) {
u64 num;
u32 den;
num = ((image_width * GTF_D_C_PRIME * (u64)hfreq) -
((u64)image_width * GTF_D_M_PRIME * 1000));
den = (hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000) *
(2 * GTF_CELL_GRAN);
h_blank = div_u64((num + (den >> 1)), den);
h_blank *= (2 * GTF_CELL_GRAN);
} else {
u64 num;
u32 den;
num = ((image_width * GTF_S_C_PRIME * (u64)hfreq) -
((u64)image_width * GTF_S_M_PRIME * 1000));
den = (hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000) *
(2 * GTF_CELL_GRAN);
h_blank = div_u64((num + (den >> 1)), den);
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 + GTF_CELL_GRAN / 2) / GTF_CELL_GRAN) * GTF_CELL_GRAN;
h_fp = h_blank / 2 - hsync;
fmt->type = V4L2_DV_BT_656_1120;
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;
if (!interlaced) {
fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
fmt->bt.interlaced = V4L2_DV_PROGRESSIVE;
} else {
fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp -
2 * vsync) / 2;
fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp -
2 * vsync - fmt->bt.vbackporch;
fmt->bt.il_vfrontporch = v_fp;
fmt->bt.il_vsync = vsync;
fmt->bt.flags |= V4L2_DV_FL_HALF_LINE;
fmt->bt.interlaced = V4L2_DV_INTERLACED;
}
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 };
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.denominator = 3;
} else if (ratio == 68) {
aspect.numerator = 15;
aspect.denominator = 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 */
swap(aspect.denominator, aspect.numerator);
return aspect;
}
EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio);
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