V4L/DVB (10446): cx18: Finally get sliced VBI working - for 525 line 60 Hz systems at least

Sliced VBI, in the manner that ivtv implements it as a separate data stream,
now works for 525 line 60 Hz systems like NTSC-M.  It may work for 625 line
50 Hz systems, but I have more engineering work to do, to verify it is operating
properly.  Sliced data insertion into the MPEG PS should be working, but is
untested.
Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/cx18/cx18-av-core.c

@@ -172,11 +172,11 @@ static void cx18_av_initialize(struct cx18 *cx)
 	/*
 	 * Initial VBI setup
 	 * VIP-1.1, 10 bit mode, enable Raw, disable sliced,
-	 * don't clamp raw samples when codes are in use, 4 byte user D-words,
-	 * programmed IDID, RP code V bit transition on VBLANK, data during
+	 * don't clamp raw samples when codes are in use, 1 byte user D-words,
+	 * IDID0 has line #, RP code V bit transition on VBLANK, data during
 	 * blanking intervals
 	 */
-	cx18_av_write4(cx, CXADEC_OUT_CTRL1, 0x4010252e);
+	cx18_av_write4(cx, CXADEC_OUT_CTRL1, 0x4013252e);
 
 	/* Set the video input.
 	   The setting in MODE_CTRL gets lost when we do the above setup */
@@ -218,6 +218,7 @@ void cx18_av_std_setup(struct cx18 *cx)
 		cx18_av_write(cx, 0x49f, 0x14);
 
 	if (std & V4L2_STD_625_50) {
+		/* FIXME - revisit these for Sliced VBI */
 		hblank = 132;
 		hactive = 720;
 		burst = 93;
@@ -241,13 +242,34 @@ void cx18_av_std_setup(struct cx18 *cx)
 			sc = 672351;
 		}
 	} else {
+		/*
+		 * The following relationships of half line counts should hold:
+		 * 525 = vsync + vactive + vblank656
+		 * 12 = vblank656 - vblank
+		 *
+		 * vsync:     always 6 half-lines of vsync pulses
+		 * vactive:   half lines of active video
+		 * vblank656: half lines, after line 3, of blanked video
+		 * vblank:    half lines, after line 9, of blanked video
+		 *
+		 * vblank656 starts counting from the falling edge of the first
+		 * 	vsync pulse (start of line 4)
+		 * vblank starts counting from the after the 6 vsync pulses and
+		 * 	6 equalization pulses (start of line 10)
+		 *
+		 * For 525 line systems the driver will extract VBI information
+		 * from lines 10 through 21.  To avoid the EAV RP code from
+		 * toggling at the start of hblank at line 22, where sliced VBI
+		 * data from line 21 is stuffed, also treat line 22 as blanked.
+		 */
+		vblank656 = 38; /* lines  4 through  22 */
+		vblank = 26;	/* lines 10 through  22 */
+		vactive = 481;  /* lines 23 through 262.5 */
+
 		hactive = 720;
 		hblank = 122;
-		vactive = 487;
 		luma_lpf = 1;
 		uv_lpf = 1;
-		vblank = 26;
-		vblank656 = 26;
 
 		src_decimation = 0x21f;
 		if (std == V4L2_STD_PAL_60) {
@@ -330,14 +352,14 @@ void cx18_av_std_setup(struct cx18 *cx)
 	cx18_av_write(cx, 0x47d, 0xff & sc >> 8);
 	cx18_av_write(cx, 0x47e, 0xff & sc >> 16);
 
-	/* Sets VBI parameters */
 	if (std & V4L2_STD_625_50) {
-		cx18_av_write(cx, 0x47f, 0x01);
-		state->vbi_line_offset = 5;
+		state->slicer_line_delay = 1;
+		state->slicer_line_offset = (6 + state->slicer_line_delay - 2);
 	} else {
-		cx18_av_write(cx, 0x47f, 0x00);
-		state->vbi_line_offset = 8;
+		state->slicer_line_delay = 0;
+		state->slicer_line_offset = (10 + state->slicer_line_delay - 2);
 	}
+	cx18_av_write(cx, 0x47f, state->slicer_line_delay);
 }
 
 /* ----------------------------------------------------------------------- */

drivers/media/video/cx18/cx18-av-core.h

@@ -79,11 +79,28 @@ struct cx18_av_state {
 	enum cx18_av_audio_input aud_input;
 	u32 audclk_freq;
 	int audmode;
-	int vbi_line_offset;
 	int default_volume;
 	u32 id;
 	u32 rev;
 	int is_initialized;
+
+	/*
+	 * The VBI slicer starts operating and counting lines, begining at
+	 * slicer line count of 1, at D lines after the deassertion of VRESET
+	 * This staring field line, S, is 6 or 10 for 625 or 525 line systems.
+	 * Sliced ancillary data captured on VBI slicer line M is sent at the
+	 * beginning of the next VBI slicer line, VBI slicer line count N = M+1.
+	 * Thus when the VBI slicer reports a VBI slicer line number with
+	 * ancillary data, the IDID0 byte indicates VBI slicer line N.
+	 * The actual field line that the captured data comes from is
+	 * L = M+(S+D-1) = N-1+(S+D-1) = N + (S+D-2).
+	 *
+	 * D is the slicer_line_delay value programmed into register 0x47f.
+	 * (S+D-2) is the slicer_line_offset used to convert slicer reported
+	 * line counts to actual field lines.
+	 */
+	int slicer_line_delay;
+	int slicer_line_offset;
 };
 
 

drivers/media/video/cx18/cx18-av-vbi.c

@@ -182,7 +182,6 @@ int cx18_av_vbi(struct cx18 *cx, unsigned int cmd, void *arg)
 	case VIDIOC_S_FMT:
 	{
 		int is_pal = !(state->std & V4L2_STD_525_60);
-		int vbi_offset = is_pal ? 1 : 0;
 		int i, x;
 		u8 lcr[24];
 
@@ -199,7 +198,7 @@ int cx18_av_vbi(struct cx18 *cx, unsigned int cmd, void *arg)
 			cx18_av_std_setup(cx);
 
 			/* VBI Offset */
-			cx18_av_write(cx, 0x47f, vbi_offset);
+			cx18_av_write(cx, 0x47f, state->slicer_line_delay);
 			cx18_av_write(cx, 0x404, 0x2e);
 			break;
 		}
@@ -213,7 +212,7 @@ int cx18_av_vbi(struct cx18 *cx, unsigned int cmd, void *arg)
 		/* Sliced VBI */
 		cx18_av_write(cx, 0x404, 0x32);	/* Ancillary data */
 		cx18_av_write(cx, 0x406, 0x13);
-		cx18_av_write(cx, 0x47f, vbi_offset);
+		cx18_av_write(cx, 0x47f, state->slicer_line_delay);
 
 		/* Force impossible lines to 0 */
 		if (is_pal) {
@@ -261,7 +260,8 @@ int cx18_av_vbi(struct cx18 *cx, unsigned int cmd, void *arg)
 		}
 
 		cx18_av_write(cx, 0x43c, 0x16);
-		cx18_av_write(cx, 0x474, is_pal ? 0x2a : 0x22);
+		/* FIXME - should match vblank set in cx18_av_std_setup() */
+		cx18_av_write(cx, 0x474, is_pal ? 0x2a : 26);
 		break;
 	}
 
@@ -286,7 +286,7 @@ int cx18_av_vbi(struct cx18 *cx, unsigned int cmd, void *arg)
 		did = anc->did;
 		sdid = anc->sdid & 0xf;
 		l = anc->idid[0] & 0x3f;
-		l += state->vbi_line_offset;
+		l += state->slicer_line_offset;
 		p = anc->payload;
 
 		/* Decode the SDID set by the slicer */

drivers/media/video/cx18/cx18-driver.c

@@ -633,7 +633,9 @@ static void __devinit cx18_init_struct2(struct cx18 *cx)
 	cx->av_state.aud_input = CX18_AV_AUDIO8;
 	cx->av_state.audclk_freq = 48000;
 	cx->av_state.audmode = V4L2_TUNER_MODE_LANG1;
-	cx->av_state.vbi_line_offset = 8;
+	cx->av_state.slicer_line_delay = 0;
+	cx->av_state.slicer_line_offset =
+		(10 + cx->av_state.slicer_line_delay - 2);
 }
 
 static int cx18_setup_pci(struct cx18 *cx, struct pci_dev *pci_dev,

drivers/media/video/cx18/cx18-streams.c

@@ -360,9 +360,16 @@ static void cx18_vbi_setup(struct cx18_stream *s)
 	if (raw) {
 		lines = cx->vbi.count * 2;
 	} else {
-		lines = cx->is_60hz ? 24 : 38;
-		if (cx->is_60hz)
-			lines += 2;
+		/*
+		 * For 525/60 systems, according to the VIP 2 & BT.656 std:
+		 * The EAV RP code's Field bit toggles on line 4, a few lines
+		 * after the Vertcal Blank bit has already toggled.
+		 * Tell the encoder to capture 21-4+1=18 lines per field,
+		 * since we want lines 10 through 21.
+		 *
+		 * FIXME - revisit for 625/50 systems
+		 */
+		lines = cx->is_60hz ? (21 - 4 + 1) * 2 : 38;
 	}
 
 	data[0] = s->handle;
@@ -402,9 +409,13 @@ static void cx18_vbi_setup(struct cx18_stream *s)
 		 *
 		 * Since the V bit is only allowed to toggle in the EAV RP code,
 		 * just before the first active region line, these two
-		 * are problematic and we have to ignore them:
+		 * are problematic:
 		 * 0x90 (Task                         HorizontalBlank)
 		 * 0xd0 (Task EvenField               HorizontalBlank)
+		 *
+		 * We have set the digitzer to consider the first active line
+		 * as part of VerticalBlank as well so we don't have to look for
+		 * these problem codes nor lose the last line of sliced data.
 		 */
 		data[4] = 0xB0F0B0F0;
 		/*

drivers/media/video/cx18/cx18-vbi.c

@@ -221,13 +221,22 @@ void cx18_process_vbi_data(struct cx18 *cx, struct cx18_buffer *buf,
 
 	pts = (be32_to_cpu(q[0] == 0x3fffffff)) ? be32_to_cpu(q[2]) : 0;
 
+	/*
+	 * For calls to compress_sliced_buf(), ensure there are an integral
+	 * number of lines by shifting the real data up over the 12 bytes header
+	 * that got stuffed in.
+	 * FIXME - there's a smarter way to do this with pointers, but for some
+	 * reason I can't get it to work correctly right now.
+	 */
+	memcpy(p, &buf->buf[12], size-12);
+
 	/* first field */
-	/* compress_sliced_buf() will skip the 12 bytes of header */
 	lines = compress_sliced_buf(cx, 0, p, size / 2, sliced_vbi_eav_rp[0]);
-	/* second field */
-	/* experimentation shows that the second half does not always
-	   begin at the exact address. So start a bit earlier
-	   (hence 32). */
+	/*
+	 * second field
+	 * In case the second half does not always begin at the exact address,
+	 * start a bit earlier (hence 32).
+	 */
 	lines = compress_sliced_buf(cx, lines, p + size / 2 - 32,
 			size / 2 + 32, sliced_vbi_eav_rp[1]);
 	/* always return at least one empty line */