drivers/media/platform/chips-media/coda/coda-h264.c

File Facts

System

Linux kernel

Corpus path

drivers/media/platform/chips-media/coda/coda-h264.c

Extension

.c

Size

9339 bytes

Lines

430

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.

• 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.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/kernel.h
• linux/string.h
• linux/videodev2.h
• coda.h

Detected Declarations

• struct rbsp
• function coda_sps_parse_profile
• function coda_h264_filler_nal
• function coda_h264_padding
• function coda_h264_profile
• function coda_h264_level
• function rbsp_read_bit
• function rbsp_write_bit
• function rbsp_read_bits
• function rbsp_write_bits
• function rbsp_read_uev
• function rbsp_write_uev
• function rbsp_read_sev
• function coda_h264_sps_fixup

Annotated Snippet

struct rbsp {
	char *buf;
	int size;
	int pos;
};

static inline int rbsp_read_bit(struct rbsp *rbsp)
{
	int shift = 7 - (rbsp->pos % 8);
	int ofs = rbsp->pos++ / 8;

	if (ofs >= rbsp->size)
		return -EINVAL;

	return (rbsp->buf[ofs] >> shift) & 1;
}

static inline int rbsp_write_bit(struct rbsp *rbsp, int bit)
{
	int shift = 7 - (rbsp->pos % 8);
	int ofs = rbsp->pos++ / 8;

	if (ofs >= rbsp->size)
		return -EINVAL;

	rbsp->buf[ofs] &= ~(1 << shift);
	rbsp->buf[ofs] |= bit << shift;

	return 0;
}

static inline int rbsp_read_bits(struct rbsp *rbsp, int num, int *val)
{
	int i, ret;
	int tmp = 0;

	if (num > 32)
		return -EINVAL;

	for (i = 0; i < num; i++) {
		ret = rbsp_read_bit(rbsp);
		if (ret < 0)
			return ret;
		tmp |= ret << (num - i - 1);
	}

	if (val)
		*val = tmp;

	return 0;
}

static int rbsp_write_bits(struct rbsp *rbsp, int num, int value)
{
	int ret;

	while (num--) {
		ret = rbsp_write_bit(rbsp, (value >> num) & 1);
		if (ret)
			return ret;
	}

	return 0;
}

static int rbsp_read_uev(struct rbsp *rbsp, unsigned int *val)
{
	int leading_zero_bits = 0;
	unsigned int tmp = 0;
	int ret;

	while ((ret = rbsp_read_bit(rbsp)) == 0)
		leading_zero_bits++;
	if (ret < 0)
		return ret;

	if (leading_zero_bits > 0) {
		ret = rbsp_read_bits(rbsp, leading_zero_bits, &tmp);
		if (ret)
			return ret;
	}

	if (val)
		*val = (1 << leading_zero_bits) - 1 + tmp;

	return 0;
}

static int rbsp_write_uev(struct rbsp *rbsp, unsigned int value)
{

Annotation

• Immediate include surface: `linux/kernel.h`, `linux/string.h`, `linux/videodev2.h`, `coda.h`.
• Detected declarations: `struct rbsp`, `function coda_sps_parse_profile`, `function coda_h264_filler_nal`, `function coda_h264_padding`, `function coda_h264_profile`, `function coda_h264_level`, `function rbsp_read_bit`, `function rbsp_write_bit`, `function rbsp_read_bits`, `function rbsp_write_bits`.
• Atlas domain: Driver Families / drivers/media.
• Implementation status: source implementation candidate.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.