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

Source file repositories/reference/linux-study-clean/drivers/media/pci/cx18/cx18-av-vbi.c

File Facts

System
Linux kernel
Corpus path
drivers/media/pci/cx18/cx18-av-vbi.c
Extension
.c
Size
8211 bytes
Lines
292
Domain
Driver Families
Bucket
drivers/media
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct vbi_anc_data {
	/* u8 eav[4]; */
	/* u8 idle[]; Variable number of idle bytes */
	u8 preamble[3];
	u8 did;
	u8 sdid;
	u8 data_count;
	u8 idid[2];
	u8 payload[]; /* data_count of payload */
	/* u8 checksum; */
	/* u8 fill[]; Variable number of fill bytes */
};

static int decode_vps(u8 *dst, u8 *p)
{
	static const u8 biphase_tbl[] = {
		0xf0, 0x78, 0x70, 0xf0, 0xb4, 0x3c, 0x34, 0xb4,
		0xb0, 0x38, 0x30, 0xb0, 0xf0, 0x78, 0x70, 0xf0,
		0xd2, 0x5a, 0x52, 0xd2, 0x96, 0x1e, 0x16, 0x96,
		0x92, 0x1a, 0x12, 0x92, 0xd2, 0x5a, 0x52, 0xd2,
		0xd0, 0x58, 0x50, 0xd0, 0x94, 0x1c, 0x14, 0x94,
		0x90, 0x18, 0x10, 0x90, 0xd0, 0x58, 0x50, 0xd0,
		0xf0, 0x78, 0x70, 0xf0, 0xb4, 0x3c, 0x34, 0xb4,
		0xb0, 0x38, 0x30, 0xb0, 0xf0, 0x78, 0x70, 0xf0,
		0xe1, 0x69, 0x61, 0xe1, 0xa5, 0x2d, 0x25, 0xa5,
		0xa1, 0x29, 0x21, 0xa1, 0xe1, 0x69, 0x61, 0xe1,
		0xc3, 0x4b, 0x43, 0xc3, 0x87, 0x0f, 0x07, 0x87,
		0x83, 0x0b, 0x03, 0x83, 0xc3, 0x4b, 0x43, 0xc3,
		0xc1, 0x49, 0x41, 0xc1, 0x85, 0x0d, 0x05, 0x85,
		0x81, 0x09, 0x01, 0x81, 0xc1, 0x49, 0x41, 0xc1,
		0xe1, 0x69, 0x61, 0xe1, 0xa5, 0x2d, 0x25, 0xa5,
		0xa1, 0x29, 0x21, 0xa1, 0xe1, 0x69, 0x61, 0xe1,
		0xe0, 0x68, 0x60, 0xe0, 0xa4, 0x2c, 0x24, 0xa4,
		0xa0, 0x28, 0x20, 0xa0, 0xe0, 0x68, 0x60, 0xe0,
		0xc2, 0x4a, 0x42, 0xc2, 0x86, 0x0e, 0x06, 0x86,
		0x82, 0x0a, 0x02, 0x82, 0xc2, 0x4a, 0x42, 0xc2,
		0xc0, 0x48, 0x40, 0xc0, 0x84, 0x0c, 0x04, 0x84,
		0x80, 0x08, 0x00, 0x80, 0xc0, 0x48, 0x40, 0xc0,
		0xe0, 0x68, 0x60, 0xe0, 0xa4, 0x2c, 0x24, 0xa4,
		0xa0, 0x28, 0x20, 0xa0, 0xe0, 0x68, 0x60, 0xe0,
		0xf0, 0x78, 0x70, 0xf0, 0xb4, 0x3c, 0x34, 0xb4,
		0xb0, 0x38, 0x30, 0xb0, 0xf0, 0x78, 0x70, 0xf0,
		0xd2, 0x5a, 0x52, 0xd2, 0x96, 0x1e, 0x16, 0x96,
		0x92, 0x1a, 0x12, 0x92, 0xd2, 0x5a, 0x52, 0xd2,
		0xd0, 0x58, 0x50, 0xd0, 0x94, 0x1c, 0x14, 0x94,
		0x90, 0x18, 0x10, 0x90, 0xd0, 0x58, 0x50, 0xd0,
		0xf0, 0x78, 0x70, 0xf0, 0xb4, 0x3c, 0x34, 0xb4,
		0xb0, 0x38, 0x30, 0xb0, 0xf0, 0x78, 0x70, 0xf0,
	};

	u8 c, err = 0;
	int i;

	for (i = 0; i < 2 * 13; i += 2) {
		err |= biphase_tbl[p[i]] | biphase_tbl[p[i + 1]];
		c = (biphase_tbl[p[i + 1]] & 0xf) |
		    ((biphase_tbl[p[i]] & 0xf) << 4);
		dst[i / 2] = c;
	}

	return err & 0xf0;
}

int cx18_av_g_sliced_fmt(struct v4l2_subdev *sd, struct v4l2_sliced_vbi_format *svbi)
{
	struct cx18 *cx = v4l2_get_subdevdata(sd);
	struct cx18_av_state *state = &cx->av_state;
	static const u16 lcr2vbi[] = {
		0, V4L2_SLICED_TELETEXT_B, 0,	/* 1 */
		0, V4L2_SLICED_WSS_625, 0,	/* 4 */
		V4L2_SLICED_CAPTION_525,	/* 6 */
		0, 0, V4L2_SLICED_VPS, 0, 0,	/* 9 */
		0, 0, 0, 0
	};
	int is_pal = !(state->std & V4L2_STD_525_60);
	int i;

	memset(svbi->service_lines, 0, sizeof(svbi->service_lines));
	svbi->service_set = 0;

	/* we're done if raw VBI is active */
	if ((cx18_av_read(cx, 0x404) & 0x10) == 0)
		return 0;

	if (is_pal) {
		for (i = 7; i <= 23; i++) {
			u8 v = cx18_av_read(cx, 0x424 + i - 7);

			svbi->service_lines[0][i] = lcr2vbi[v >> 4];
			svbi->service_lines[1][i] = lcr2vbi[v & 0xf];

Annotation

Implementation Notes