drivers/video/fbdev/atafb_iplan2p4.c

Source file repositories/reference/linux-study-clean/drivers/video/fbdev/atafb_iplan2p4.c

File Facts

System
Linux kernel
Corpus path
drivers/video/fbdev/atafb_iplan2p4.c
Extension
.c
Size
6974 bytes
Lines
286
Domain
Driver Families
Bucket
drivers/video
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

if (upwards) {
			src = (u8 *)info->screen_base + sy * next_line + (sx & ~15) / (8 / BPL);
			dst = (u8 *)info->screen_base + dy * next_line + (dx & ~15) / (8 / BPL);
			if (sx & 15) {
				memmove32_col(dst, src, 0xff00ff, height, next_line - BPL * 2);
				src += BPL * 2;
				dst += BPL * 2;
				width -= 8;
			}
			w = width >> 4;
			if (w) {
				s = (u32 *)src;
				d = (u32 *)dst;
				w *= BPL / 2;
				l = next_line - w * 4;
				for (j = height; j > 0; j--) {
					for (i = w; i > 0; i--)
						*d++ = *s++;
					s = (u32 *)((u8 *)s + l);
					d = (u32 *)((u8 *)d + l);
				}
			}
			if (width & 15)
				memmove32_col(dst + width / (8 / BPL), src + width / (8 / BPL),
					      0xff00ff00, height, next_line - BPL * 2);
		} else {
			src = (u8 *)info->screen_base + (sy - 1) * next_line + ((sx + width + 8) & ~15) / (8 / BPL);
			dst = (u8 *)info->screen_base + (dy - 1) * next_line + ((dx + width + 8) & ~15) / (8 / BPL);

			if ((sx + width) & 15) {
				src -= BPL * 2;
				dst -= BPL * 2;
				memmove32_col(dst, src, 0xff00ff00, colsize, -next_line - BPL * 2);
				width -= 8;
			}
			w = width >> 4;
			if (w) {
				s = (u32 *)src;
				d = (u32 *)dst;
				w *= BPL / 2;
				l = next_line - w * 4;
				for (j = height; j > 0; j--) {
					for (i = w; i > 0; i--)
						*--d = *--s;
					s = (u32 *)((u8 *)s - l);
					d = (u32 *)((u8 *)d - l);
				}
			}
			if (sx & 15)
				memmove32_col(dst - (width - 16) / (8 / BPL),
					      src - (width - 16) / (8 / BPL),
					      0xff00ff, colsize, -next_line - BPL * 2);
		}
	} else {
		/* odd->even or even->odd */
		if (upwards) {
			u32 *src32, *dst32;
			u32 pval[4], v, v1, mask;
			int i, j, w, f;

			src = (u8 *)info->screen_base + sy * next_line + (sx & ~15) / (8 / BPL);
			dst = (u8 *)info->screen_base + dy * next_line + (dx & ~15) / (8 / BPL);

			mask = 0xff00ff00;
			f = 0;
			w = width;
			if (sx & 15) {
				f = 1;
				w += 8;
			}
			if ((sx + width) & 15)
				f |= 2;
			w >>= 4;
			for (i = height; i; i--) {
				src32 = (u32 *)src;
				dst32 = (u32 *)dst;

				if (f & 1) {
					pval[0] = (*src32++ << 8) & mask;
					pval[1] = (*src32++ << 8) & mask;
				} else {
					pval[0] = dst32[0] & mask;
					pval[1] = dst32[1] & mask;
				}

				for (j = w; j > 0; j--) {
					v = *src32++;
					v1 = v & mask;
					*dst32++ = pval[0] | (v1 >> 8);
					pval[0] = (v ^ v1) << 8;

Annotation

Implementation Notes