drivers/media/platform/samsung/s5p-jpeg/jpeg-core.c

Source file repositories/reference/linux-study-clean/drivers/media/platform/samsung/s5p-jpeg/jpeg-core.c

File Facts

System
Linux kernel
Corpus path
drivers/media/platform/samsung/s5p-jpeg/jpeg-core.c
Extension
.c
Size
85325 bytes
Lines
3172
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

while (jpeg_buffer.curr < jpeg_buffer.size) {
			char id, class;

			c = get_byte(&jpeg_buffer);
			if (c == -1)
				return;
			id = c & 0xf;
			class = (c >> 4) & 0xf;
			n = 0;
			for (i = 0; i < 16; ++i) {
				c = get_byte(&jpeg_buffer);
				if (c == -1)
					return;
				word |= c << ((i % 4) * 8);
				if ((i + 1) % 4 == 0) {
					writel(word, jpeg->regs +
					exynos4_huff_tbl_len(class, id) +
					(i / 4) * 4);
					word = 0;
				}
				n += c;
			}
			word = 0;
			for (i = 0; i < n; ++i) {
				c = get_byte(&jpeg_buffer);
				if (c == -1)
					return;
				word |= c << ((i % 4) * 8);
				if ((i + 1) % 4 == 0) {
					writel(word, jpeg->regs +
					exynos4_huff_tbl_val(class, id) +
					(i / 4) * 4);
					word = 0;
				}
			}
			if (i % 4) {
				writel(word, jpeg->regs +
				exynos4_huff_tbl_val(class, id) + (i / 4) * 4);
			}
			word = 0;
		}
	}
}

static void exynos4_jpeg_parse_decode_q_tbl(struct s5p_jpeg_ctx *ctx)
{
	struct s5p_jpeg *jpeg = ctx->jpeg;
	struct vb2_v4l2_buffer *vb = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
	struct s5p_jpeg_buffer jpeg_buffer;
	int c, x, components;

	jpeg_buffer.size = ctx->out_q.sof_len;
	jpeg_buffer.data =
		(unsigned long)vb2_plane_vaddr(&vb->vb2_buf, 0) + ctx->out_q.sof;
	jpeg_buffer.curr = 0;

	skip(&jpeg_buffer, 5); /* P, Y, X */
	components = get_byte(&jpeg_buffer);
	if (components == -1)
		return;

	exynos4_jpeg_set_dec_components(jpeg->regs, components);

	while (components--) {
		c = get_byte(&jpeg_buffer);
		if (c == -1)
			return;
		skip(&jpeg_buffer, 1);
		x = get_byte(&jpeg_buffer);
		if (x == -1)
			return;
		exynos4_jpeg_select_dec_q_tbl(jpeg->regs, c, x);
	}
}

static void exynos4_jpeg_parse_q_tbl(struct s5p_jpeg_ctx *ctx)
{
	struct s5p_jpeg *jpeg = ctx->jpeg;
	struct vb2_v4l2_buffer *vb = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
	struct s5p_jpeg_buffer jpeg_buffer;
	unsigned int word;
	int c, i, j;

	for (j = 0; j < ctx->out_q.dqt.n; ++j) {
		jpeg_buffer.size = ctx->out_q.dqt.len[j];
		jpeg_buffer.data = (unsigned long)vb2_plane_vaddr(&vb->vb2_buf, 0) +
				   ctx->out_q.dqt.marker[j];
		jpeg_buffer.curr = 0;

		word = 0;

Annotation

Implementation Notes