diff options
| -rw-r--r-- | drivers/media/v4l2-core/v4l2-common.c | 325 | ||||
| -rw-r--r-- | include/media/v4l2-common.h | 9 |
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 028133ba4c6..b6ee929f7ba 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 447f4b6b716..1a0b2db4c5d 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_ */ |