V4L/DVB (9806): cx18: Enable raw VBI capture

A combined authorship patch from Hans Verkuil and Andy Walls.  Raw
VBI can now be captured but requires a video capture to be in progress as well.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 42 insertions, 7 deletions

diff --git a/drivers/media/video/cx18/cx18-driver.c b/drivers/media/video/cx18/cx18-driver.c
index e845cd653bb8..863ebf06a829 100644
--- a/drivers/media/video/cx18/cx18-driver.c
+++ b/drivers/media/video/cx18/cx18-driver.c
@@ -596,13 +596,47 @@ static int __devinit cx18_init_struct1(struct cx18 *cx)
         /* VBI */
         cx->vbi.in.type = V4L2_BUF_TYPE_VBI_CAPTURE;
         cx->vbi.sliced_in = &cx->vbi.in.fmt.sliced;
-        cx->vbi.raw_size = 1456;
-        cx->vbi.raw_decoder_line_size = 1456;
-        cx->vbi.raw_decoder_sav_odd_field = 0x20;
-        cx->vbi.raw_decoder_sav_even_field = 0x60;
-        cx->vbi.sliced_decoder_line_size = 272;
-        cx->vbi.sliced_decoder_sav_odd_field = 0xB0;
-        cx->vbi.sliced_decoder_sav_even_field = 0xF0;
+
+        /*
+         * The VBI line sizes depend on the pixel clock and the horiz rate
+         *
+         * (1/Fh)*(2*Fp) = Samples/line
+         *     = 4 bytes EAV + Anc data in hblank + 4 bytes SAV + active samples
+         *
+         *  Sliced VBI is sent as ancillary data during horizontal blanking
+         *  Raw VBI is sent as active video samples during vertcal blanking
+         *
+         *  We use a  BT.656 pxiel clock of 13.5 MHz and a BT.656 active line
+         *  length of 720 pixels @ 4:2:2 sampling.  Thus...
+         *
+         *  For NTSC:
+         *
+         *  (1/15,734 kHz) * 2 * 13.5 MHz = 1716 samples/line =
+         *  4 bytes SAV + 268 bytes anc data + 4 bytes SAV + 1440 active samples
+         *
+         *  For PAL:
+         *
+         *  (1/15,625 kHz) * 2 * 13.5 MHz = 1728 samples/line =
+         *  4 bytes SAV + 280 bytes anc data + 4 bytes SAV + 1440 active samples
+         *
+         */
+
+        /* CX18-AV-Core number of VBI samples output per horizontal line */
+        cx->vbi.raw_decoder_line_size = 1444;   /* 4 byte SAV + 2 * 720 */
+        cx->vbi.sliced_decoder_line_size = 272; /* 60 Hz: 268+4, 50 Hz: 280+4 */
+
+        /* CX18-AV-Core VBI samples/line possibly rounded up */
+        cx->vbi.raw_size = 1444;   /* Real max size is 1444 */
+        cx->vbi.sliced_size = 284; /* Real max size is  284 */
+
+        /*
+         * CX18-AV-Core SAV/EAV RP codes in VIP 1.x mode
+         * Task Field VerticalBlank HorizontalBlank 0 0 0 0
+         */
+        cx->vbi.raw_decoder_sav_odd_field = 0x20;     /*   V  */
+        cx->vbi.raw_decoder_sav_even_field = 0x60;    /*  FV  */
+        cx->vbi.sliced_decoder_sav_odd_field = 0xB0;  /* T VH - actually EAV */
+        cx->vbi.sliced_decoder_sav_even_field = 0xF0; /* TFVH - actually EAV */
         return 0;
 }
 
@@ -635,6 +669,7 @@ 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;
+        /* FIXME - 8 is NTSC value, investigate */
         cx->av_state.vbi_line_offset = 8;
 }