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-rw-r--r--drivers/media/v4l2-core/v4l2-common.c325
-rw-r--r--include/media/v4l2-common.h9
2 files changed, 334 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
index 028133ba4c6b..b6ee929f7ba5 100644
--- a/drivers/media/v4l2-core/v4l2-common.c
+++ b/drivers/media/v4l2-core/v4l2-common.c
@@ -630,6 +630,331 @@ bool v4l_match_dv_timings(const struct v4l2_dv_timings *t1,
}
EXPORT_SYMBOL_GPL(v4l_match_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 + 999999) / 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 + 999999) / 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 {
+ int h_blank;
+ unsigned ideal_duty_cycle = CVT_C_PRIME - (CVT_M_PRIME * 1000) / hfreq;
+
+ h_blank = (image_width * ideal_duty_cycle + (100 - ideal_duty_cycle) / 2) /
+ (100 - ideal_duty_cycle);
+ h_blank = h_blank - h_blank % (2 * CVT_CELL_GRAN);
+
+ if (h_blank * 100 / image_width < 20) {
+ h_blank = image_width / 5;
+ h_blank = (h_blank + 0x7) & ~0x7;
+ }
+
+ 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, h_bp, 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;
+ h_bp = h_blank / 2;
+
+ 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);
+
const struct v4l2_frmsize_discrete *v4l2_find_nearest_format(
const struct v4l2_discrete_probe *probe,
s32 width, s32 height)
diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
index 447f4b6b716c..1a0b2db4c5d3 100644
--- a/include/media/v4l2-common.h
+++ b/include/media/v4l2-common.h
@@ -216,4 +216,13 @@ bool v4l_match_dv_timings(const struct v4l2_dv_timings *t1,
const struct v4l2_dv_timings *t2,
unsigned pclock_delta);
+bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync,
+ u32 polarities, struct v4l2_dv_timings *fmt);
+
+bool v4l2_detect_gtf(unsigned frame_height, unsigned hfreq, unsigned vsync,
+ u32 polarities, struct v4l2_fract aspect,
+ struct v4l2_dv_timings *fmt);
+
+struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait);
+
#endif /* V4L2_COMMON_H_ */
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-30 09:22:20 +0300