--- /dev/null
+/*
+ * 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>
+
+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;
+
+ 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%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" : "",
+ (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 */
+
+/* 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.
+ *
+ * TODO: VESA defined a new version 2 of their reduced blanking
+ * formula. Support for that is currently missing in this CVT
+ * detection function.
+ */
+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->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;
+ 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);
+ image_width = (image_width + GTF_CELL_GRAN/2) & ~(GTF_CELL_GRAN - 1);
+
+ /* 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->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;
+ 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.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 */
+ tmp = aspect.denominator;
+ aspect.denominator = aspect.numerator;
+ aspect.numerator = tmp;
+ return aspect;
+}
+EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio);
Code Review / kvmfornfv.git / blobdiff