| Message ID | 1433494358-29050-2-git-send-email-prladdha@cisco.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 06/05/2015 10:52 AM, Prashant Laddha wrote: > 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. > > To Do: Pass aspect ratio information to v4l2_detect_cvt() > RB v2 allows for non standard aspect ratios. In RB v2 vsync does not > indicate aspect ratio. In the absence of aspect ratio information, > v4l2_detect_cvt() cannot calculate image width from image height. Reading the CVT spec I see that RB v2 assumes that the pixel aspect ratio is always square (section 3.4.3, item 7 says that the aspect ratio is to be derived from the active video resolution, which is only possible if the pixel aspect ratio is square. So I would suggest adding a 'frame_width' argument to v4l2_detect_cvt: this will be used in the v2 case. If RB v2 is detected and frame_width is 0, then v4l2_detect_cvt will return false. Since RB v2 is something we'll only see with digital video interfaces where we always know the horizontal active video, this shouldn't be a problem. Some code comments below: > > Cc: Hans Verkuil <hans.verkuil@cisco.com> > Signed-off-by: Prashant Laddha <prladdha@cisco.com> > --- > drivers/media/v4l2-core/v4l2-dv-timings.c | 72 +++++++++++++++++++++++-------- > 1 file changed, 54 insertions(+), 18 deletions(-) > > diff --git a/drivers/media/v4l2-core/v4l2-dv-timings.c b/drivers/media/v4l2-core/v4l2-dv-timings.c > index 0d849fc..4efc6f6 100644 > --- a/drivers/media/v4l2-core/v4l2-dv-timings.c > +++ b/drivers/media/v4l2-core/v4l2-dv-timings.c > @@ -309,6 +309,7 @@ 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 */ > @@ -328,10 +329,14 @@ 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. > @@ -356,9 +361,10 @@ bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync, > 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) > @@ -368,17 +374,32 @@ 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 && 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; > @@ -415,22 +436,40 @@ bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync, > else > return false; > break; > + case 8: > + /* To Do: > + * For Reduced Blanking v2, vsync does not indicate aspect ratio and > + * hence can not be used to derive image width. In such a case, either > + * aspect ratio information or image width should be supplied to > + * v4l2_detect_cvt(). This would need API change. As of now assuming > + * 16:9 as default aspect ratio. > + * */ > + image_width = (image_height * 16) / 9; > + 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; > > - h_bp = CVT_RB_H_BPORCH; > + if (rb_v2) > + h_blank = CVT_RB_V2_H_BLANK; > + else > + h_blank = CVT_RB_H_BLANK; I prefer: h_blank = rb_v2 ? CVT_RB_V2_H_BLANK : CVT_RB_H_BLANK > + > + pix_clk = (image_width + h_blank) * hfreq; > + pix_clk = (pix_clk / CVT_PXL_CLK_GRAN_RB_V2) * CVT_PXL_CLK_GRAN_RB_V2; Shouldn't the granularity be dependent on rb_v2? > + > + 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; > @@ -438,11 +477,9 @@ bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync, > > 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; > - Why the spurious whitespace changes? > pix_clk = (image_width + h_blank) * hfreq; > pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN; > > @@ -483,7 +520,6 @@ bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync, > > if (reduced_blanking) > fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING; > - Ditto. > return true; > } > EXPORT_SYMBOL_GPL(v4l2_detect_cvt); > Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 06/08/2015 12:44 PM, Hans Verkuil wrote: > On 06/05/2015 10:52 AM, Prashant Laddha wrote: >> 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. >> >> To Do: Pass aspect ratio information to v4l2_detect_cvt() >> RB v2 allows for non standard aspect ratios. In RB v2 vsync does not >> indicate aspect ratio. In the absence of aspect ratio information, >> v4l2_detect_cvt() cannot calculate image width from image height. > > Reading the CVT spec I see that RB v2 assumes that the pixel aspect ratio > is always square (section 3.4.3, item 7 says that the aspect ratio is > to be derived from the active video resolution, which is only possible > if the pixel aspect ratio is square. > > So I would suggest adding a 'frame_width' argument to v4l2_detect_cvt: this > will be used in the v2 case. If RB v2 is detected and frame_width is 0, then > v4l2_detect_cvt will return false. Sorry, this should be active_width (or perhaps just image_width), not frame_width. The latter would include blanking and we need the active width only. > > Since RB v2 is something we'll only see with digital video interfaces where > we always know the horizontal active video, this shouldn't be a problem. > > Some code comments below: BTW: make sure to remove the TODO comment at the start of v4l2_detect_cvt! Regards, Hans > >> >> Cc: Hans Verkuil <hans.verkuil@cisco.com> >> Signed-off-by: Prashant Laddha <prladdha@cisco.com> >> --- >> drivers/media/v4l2-core/v4l2-dv-timings.c | 72 +++++++++++++++++++++++-------- >> 1 file changed, 54 insertions(+), 18 deletions(-) >> >> diff --git a/drivers/media/v4l2-core/v4l2-dv-timings.c b/drivers/media/v4l2-core/v4l2-dv-timings.c >> index 0d849fc..4efc6f6 100644 >> --- a/drivers/media/v4l2-core/v4l2-dv-timings.c >> +++ b/drivers/media/v4l2-core/v4l2-dv-timings.c >> @@ -309,6 +309,7 @@ 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 */ >> @@ -328,10 +329,14 @@ 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. >> @@ -356,9 +361,10 @@ bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync, >> 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) >> @@ -368,17 +374,32 @@ 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 && 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; >> @@ -415,22 +436,40 @@ bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync, >> else >> return false; >> break; >> + case 8: >> + /* To Do: >> + * For Reduced Blanking v2, vsync does not indicate aspect ratio and >> + * hence can not be used to derive image width. In such a case, either >> + * aspect ratio information or image width should be supplied to >> + * v4l2_detect_cvt(). This would need API change. As of now assuming >> + * 16:9 as default aspect ratio. >> + * */ >> + image_width = (image_height * 16) / 9; >> + 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; >> >> - h_bp = CVT_RB_H_BPORCH; >> + if (rb_v2) >> + h_blank = CVT_RB_V2_H_BLANK; >> + else >> + h_blank = CVT_RB_H_BLANK; > > I prefer: h_blank = rb_v2 ? CVT_RB_V2_H_BLANK : CVT_RB_H_BLANK > >> + >> + pix_clk = (image_width + h_blank) * hfreq; >> + pix_clk = (pix_clk / CVT_PXL_CLK_GRAN_RB_V2) * CVT_PXL_CLK_GRAN_RB_V2; > > Shouldn't the granularity be dependent on rb_v2? > >> + >> + 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; >> @@ -438,11 +477,9 @@ bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync, >> >> 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; >> - > > Why the spurious whitespace changes? > >> pix_clk = (image_width + h_blank) * hfreq; >> pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN; >> >> @@ -483,7 +520,6 @@ bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync, >> >> if (reduced_blanking) >> fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING; >> - > > Ditto. > >> return true; >> } >> EXPORT_SYMBOL_GPL(v4l2_detect_cvt); >> > > Regards, > > Hans > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Thanks for the review Hans. I will address your comments and post revised patches for this. Regards, Prashant On 08/06/15 4:14 pm, "Hans Verkuil" <hverkuil@xs4all.nl> wrote: >On 06/05/2015 10:52 AM, Prashant Laddha wrote: >> 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. >> >> To Do: Pass aspect ratio information to v4l2_detect_cvt() >> RB v2 allows for non standard aspect ratios. In RB v2 vsync does not >> indicate aspect ratio. In the absence of aspect ratio information, >> v4l2_detect_cvt() cannot calculate image width from image height. > >Reading the CVT spec I see that RB v2 assumes that the pixel aspect ratio >is always square (section 3.4.3, item 7 says that the aspect ratio is >to be derived from the active video resolution, which is only possible >if the pixel aspect ratio is square. > >So I would suggest adding a 'frame_width' argument to v4l2_detect_cvt: >this >will be used in the v2 case. If RB v2 is detected and frame_width is 0, >then >v4l2_detect_cvt will return false. > >Since RB v2 is something we'll only see with digital video interfaces >where >we always know the horizontal active video, this shouldn't be a problem. > >Some code comments below: > >> >> Cc: Hans Verkuil <hans.verkuil@cisco.com> >> Signed-off-by: Prashant Laddha <prladdha@cisco.com> >> --- >> drivers/media/v4l2-core/v4l2-dv-timings.c | 72 >>+++++++++++++++++++++++-------- >> 1 file changed, 54 insertions(+), 18 deletions(-) >> >> diff --git a/drivers/media/v4l2-core/v4l2-dv-timings.c >>b/drivers/media/v4l2-core/v4l2-dv-timings.c >> index 0d849fc..4efc6f6 100644 >> --- a/drivers/media/v4l2-core/v4l2-dv-timings.c >> +++ b/drivers/media/v4l2-core/v4l2-dv-timings.c >> @@ -309,6 +309,7 @@ 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 */ >> @@ -328,10 +329,14 @@ 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. >> @@ -356,9 +361,10 @@ bool v4l2_detect_cvt(unsigned frame_height, >>unsigned hfreq, unsigned vsync, >> 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) >> @@ -368,17 +374,32 @@ 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 && 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; >> @@ -415,22 +436,40 @@ bool v4l2_detect_cvt(unsigned frame_height, >>unsigned hfreq, unsigned vsync, >> else >> return false; >> break; >> + case 8: >> + /* To Do: >> + * For Reduced Blanking v2, vsync does not indicate aspect ratio and >> + * hence can not be used to derive image width. In such a case, either >> + * aspect ratio information or image width should be supplied to >> + * v4l2_detect_cvt(). This would need API change. As of now assuming >> + * 16:9 as default aspect ratio. >> + * */ >> + image_width = (image_height * 16) / 9; >> + 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; >> >> - h_bp = CVT_RB_H_BPORCH; >> + if (rb_v2) >> + h_blank = CVT_RB_V2_H_BLANK; >> + else >> + h_blank = CVT_RB_H_BLANK; > >I prefer: h_blank = rb_v2 ? CVT_RB_V2_H_BLANK : CVT_RB_H_BLANK > >> + >> + pix_clk = (image_width + h_blank) * hfreq; >> + pix_clk = (pix_clk / CVT_PXL_CLK_GRAN_RB_V2) * >>CVT_PXL_CLK_GRAN_RB_V2; > >Shouldn't the granularity be dependent on rb_v2? > >> + >> + 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; >> @@ -438,11 +477,9 @@ bool v4l2_detect_cvt(unsigned frame_height, >>unsigned hfreq, unsigned vsync, >> >> 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; >> - > >Why the spurious whitespace changes? > >> pix_clk = (image_width + h_blank) * hfreq; >> pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN; >> >> @@ -483,7 +520,6 @@ bool v4l2_detect_cvt(unsigned frame_height, >>unsigned hfreq, unsigned vsync, >> >> if (reduced_blanking) >> fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING; >> - > >Ditto. > >> return true; >> } >> EXPORT_SYMBOL_GPL(v4l2_detect_cvt); >> > >Regards, > > Hans -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/media/v4l2-core/v4l2-dv-timings.c b/drivers/media/v4l2-core/v4l2-dv-timings.c index 0d849fc..4efc6f6 100644 --- a/drivers/media/v4l2-core/v4l2-dv-timings.c +++ b/drivers/media/v4l2-core/v4l2-dv-timings.c @@ -309,6 +309,7 @@ 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 */ @@ -328,10 +329,14 @@ 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. @@ -356,9 +361,10 @@ bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync, 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) @@ -368,17 +374,32 @@ 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 && 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; @@ -415,22 +436,40 @@ bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync, else return false; break; + case 8: + /* To Do: + * For Reduced Blanking v2, vsync does not indicate aspect ratio and + * hence can not be used to derive image width. In such a case, either + * aspect ratio information or image width should be supplied to + * v4l2_detect_cvt(). This would need API change. As of now assuming + * 16:9 as default aspect ratio. + * */ + image_width = (image_height * 16) / 9; + 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; - h_bp = CVT_RB_H_BPORCH; + if (rb_v2) + h_blank = CVT_RB_V2_H_BLANK; + else + h_blank = CVT_RB_H_BLANK; + + pix_clk = (image_width + h_blank) * hfreq; + pix_clk = (pix_clk / CVT_PXL_CLK_GRAN_RB_V2) * CVT_PXL_CLK_GRAN_RB_V2; + + 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; @@ -438,11 +477,9 @@ bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync, 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; @@ -483,7 +520,6 @@ bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync, if (reduced_blanking) fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING; - return true; } EXPORT_SYMBOL_GPL(v4l2_detect_cvt);
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. To Do: Pass aspect ratio information to v4l2_detect_cvt() RB v2 allows for non standard aspect ratios. In RB v2 vsync does not indicate aspect ratio. In the absence of aspect ratio information, v4l2_detect_cvt() cannot calculate image width from image height. Cc: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Prashant Laddha <prladdha@cisco.com> --- drivers/media/v4l2-core/v4l2-dv-timings.c | 72 +++++++++++++++++++++++-------- 1 file changed, 54 insertions(+), 18 deletions(-)