[media] v4l2-dv-timings: add support for reduced blanking v2
authorPrashant Laddha <prladdha@cisco.com>
Wed, 10 Jun 2015 16:51:42 +0000 (13:51 -0300)
committerMauro Carvalho Chehab <mchehab@osg.samsung.com>
Mon, 6 Jul 2015 11:25:49 +0000 (08:25 -0300)
Added support for reduced blanking version 2 (RB v2) in cvt timings.
Standard specifies a fixed vsync pulse of 8 lines to indicate RB v2
timings. Vertical back porch is fixed at 6 lines and vertical front
porch is remainder of vertical blanking time.

For RB v2, horizontal blanking is fixed at 80 pixels. Horizontal sync
is fixed at 32. All horizontal timing counts (active pixels, front,
back porches) can be specified upto a precision of 1.

RB v2 allows for non standard aspect ratios. In RB v2 vsync does not
indicate aspect ratio. In absence of aspect ratio v4l2_detect_cvt()
cannot calculate image width from image height. Hence extending the
v4l2_detect_cvt() to pass image width in case of RB v2.

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>
drivers/media/i2c/adv7604.c
drivers/media/i2c/adv7842.c
drivers/media/platform/vivid/vivid-vid-cap.c
drivers/media/v4l2-core/v4l2-dv-timings.c
include/media/v4l2-dv-timings.h

index 808360fd6539a3b153c5e328b964032630485e2c..60630d62e663898b38550c0abc8cd093cdc6d4ee 100644 (file)
@@ -1328,7 +1328,7 @@ static int stdi2dv_timings(struct v4l2_subdev *sd,
                }
        }
 
-       if (v4l2_detect_cvt(stdi->lcf + 1, hfreq, stdi->lcvs,
+       if (v4l2_detect_cvt(stdi->lcf + 1, hfreq, stdi->lcvs, 0,
                        (stdi->hs_pol == '+' ? V4L2_DV_HSYNC_POS_POL : 0) |
                        (stdi->vs_pol == '+' ? V4L2_DV_VSYNC_POS_POL : 0),
                        false, timings))
index 4cf79b2422d4a431daff462aed35809980f06bd0..aa0d1a04543b32579d0b07dd1e4eebcf8113e5b7 100644 (file)
@@ -1442,7 +1442,7 @@ static int stdi2dv_timings(struct v4l2_subdev *sd,
                }
        }
 
-       if (v4l2_detect_cvt(stdi->lcf + 1, hfreq, stdi->lcvs,
+       if (v4l2_detect_cvt(stdi->lcf + 1, hfreq, stdi->lcvs, 0,
                        (stdi->hs_pol == '+' ? V4L2_DV_HSYNC_POS_POL : 0) |
                        (stdi->vs_pol == '+' ? V4L2_DV_VSYNC_POS_POL : 0),
                        false, timings))
index c4268d1b2f82b50dcfbffd913606904b473fb062..ed0b8788a66f8d63eb64d1eeed646a8189461b0e 100644 (file)
@@ -1627,7 +1627,7 @@ static bool valid_cvt_gtf_timings(struct v4l2_dv_timings *timings)
        h_freq = (u32)bt->pixelclock / total_h_pixel;
 
        if (bt->standards == 0 || (bt->standards & V4L2_DV_BT_STD_CVT)) {
-               if (v4l2_detect_cvt(total_v_lines, h_freq, bt->vsync,
+               if (v4l2_detect_cvt(total_v_lines, h_freq, bt->vsync, bt->width,
                                    bt->polarities, bt->interlaced, timings))
                        return true;
        }
index eefad4f17497592a5231dbaef4b76080141589d2..ddaad3d7f1dd92ac461d1be57908181e1ab621ba 100644 (file)
@@ -316,6 +316,7 @@ EXPORT_SYMBOL_GPL(v4l2_print_dv_timings);
  */
 
 #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 */
@@ -335,15 +336,22 @@ EXPORT_SYMBOL_GPL(v4l2_print_dv_timings);
 /* 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_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 */
+/* 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
@@ -352,20 +360,22 @@ EXPORT_SYMBOL_GPL(v4l2_print_dv_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, bool interlaced, struct v4l2_dv_timings *fmt)
+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 > 7)
+       if (vsync < 4 || vsync > 8)
                return false;
 
        if (polarities == V4L2_DV_VSYNC_POS_POL)
@@ -375,17 +385,35 @@ bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync,
        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) {
-               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;
+               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;
@@ -422,22 +450,32 @@ bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync,
                else
                        return false;
                break;
+       case 8:
+               image_width = active_width;
+               break;
        default:
                return false;
        }
 
-       image_width = image_width & ~7;
+       if (!rb_v2)
+               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;
+               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;
 
-               h_bp = CVT_RB_H_BPORCH;
+               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 = CVT_RB_H_BLANK - h_bp - hsync;
+               h_fp  = h_blank - h_bp - hsync;
 
-               frame_width = image_width + CVT_RB_H_BLANK;
+               frame_width = image_width + h_blank;
        } else {
                unsigned ideal_duty_cycle_per_myriad =
                        100 * CVT_C_PRIME - (CVT_M_PRIME * 100000) / hfreq;
index eecd3102a618cbdc441ec4925774209f5f0ed6da..e18a653549cdb988539273dd225d673b50ae0c8c 100644 (file)
@@ -115,6 +115,9 @@ void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix,
  * @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
@@ -125,7 +128,8 @@ void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix,
  * in with the found CVT timings.
  */
 bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync,
-               u32 polarities, bool interlaced, struct v4l2_dv_timings *fmt);
+               unsigned active_width, u32 polarities, bool interlaced,
+               struct v4l2_dv_timings *fmt);
 
 /** v4l2_detect_gtf - detect if the given timings follow the GTF standard
  * @frame_height - the total height of the frame (including blanking) in lines.
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