1 files changed, 325 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)