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yaml
---
r: 330938
b: refs/heads/master
c: c61bd6a
h: refs/heads/master
v: v3
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Hans Verkuil authored and Mauro Carvalho Chehab committed Sep 13, 2012
1 parent 404b97e commit bade83b
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2 changes: 1 addition & 1 deletion [refs]
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@@ -1,2 +1,2 @@
---
refs/heads/master: c2a667fa2b40ccb7d21a99ffae53610699a3102c
refs/heads/master: c61bd6a0e2a92009f3879457eeec75b5ad102303
325 changes: 325 additions & 0 deletions trunk/drivers/media/v4l2-core/v4l2-common.c
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Expand Up @@ -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)
Expand Down
9 changes: 9 additions & 0 deletions trunk/include/media/v4l2-common.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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_ */

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