drivers/video/fbdev/omap/lcd_dma.c

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

File Facts

System
Linux kernel
Corpus path
drivers/video/fbdev/omap/lcd_dma.c
Extension
.c
Size
10774 bytes
Lines
446
Domain
Driver Families
Bucket
drivers/video
Inferred role
Driver Families: exported/initcall integration point
Status
integration 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 (!lcd_dma.mirror) {
			top = PIXADDR(0, 0);
			bottom = PIXADDR(lcd_dma.xres - 1, lcd_dma.yres - 1);
			/* 1510 DMA requires the bottom address to be 2 more
			 * than the actual last memory access location. */
			if (cpu_is_omap15xx() &&
				lcd_dma.data_type == OMAP_DMA_DATA_TYPE_S32)
					bottom += 2;
			ei = PIXSTEP(0, 0, 1, 0);
			fi = PIXSTEP(lcd_dma.xres - 1, 0, 0, 1);
		} else {
			top = PIXADDR(lcd_dma.xres - 1, 0);
			bottom = PIXADDR(0, lcd_dma.yres - 1);
			ei = PIXSTEP(1, 0, 0, 0);
			fi = PIXSTEP(0, 0, lcd_dma.xres - 1, 1);
		}
		en = lcd_dma.xres;
		fn = lcd_dma.yres;
		break;
	case 90:
		if (!lcd_dma.mirror) {
			top = PIXADDR(0, lcd_dma.yres - 1);
			bottom = PIXADDR(lcd_dma.xres - 1, 0);
			ei = PIXSTEP(0, 1, 0, 0);
			fi = PIXSTEP(0, 0, 1, lcd_dma.yres - 1);
		} else {
			top = PIXADDR(lcd_dma.xres - 1, lcd_dma.yres - 1);
			bottom = PIXADDR(0, 0);
			ei = PIXSTEP(0, 1, 0, 0);
			fi = PIXSTEP(1, 0, 0, lcd_dma.yres - 1);
		}
		en = lcd_dma.yres;
		fn = lcd_dma.xres;
		break;
	case 180:
		if (!lcd_dma.mirror) {
			top = PIXADDR(lcd_dma.xres - 1, lcd_dma.yres - 1);
			bottom = PIXADDR(0, 0);
			ei = PIXSTEP(1, 0, 0, 0);
			fi = PIXSTEP(0, 1, lcd_dma.xres - 1, 0);
		} else {
			top = PIXADDR(0, lcd_dma.yres - 1);
			bottom = PIXADDR(lcd_dma.xres - 1, 0);
			ei = PIXSTEP(0, 0, 1, 0);
			fi = PIXSTEP(lcd_dma.xres - 1, 1, 0, 0);
		}
		en = lcd_dma.xres;
		fn = lcd_dma.yres;
		break;
	case 270:
		if (!lcd_dma.mirror) {
			top = PIXADDR(lcd_dma.xres - 1, 0);
			bottom = PIXADDR(0, lcd_dma.yres - 1);
			ei = PIXSTEP(0, 0, 0, 1);
			fi = PIXSTEP(1, lcd_dma.yres - 1, 0, 0);
		} else {
			top = PIXADDR(0, 0);
			bottom = PIXADDR(lcd_dma.xres - 1, lcd_dma.yres - 1);
			ei = PIXSTEP(0, 0, 0, 1);
			fi = PIXSTEP(0, lcd_dma.yres - 1, 1, 0);
		}
		en = lcd_dma.yres;
		fn = lcd_dma.xres;
		break;
	default:
		BUG();
		return;	/* Suppress warning about uninitialized vars */
	}

	if (cpu_is_omap15xx()) {
		omap_writew(top >> 16, OMAP1510_DMA_LCD_TOP_F1_U);
		omap_writew(top, OMAP1510_DMA_LCD_TOP_F1_L);
		omap_writew(bottom >> 16, OMAP1510_DMA_LCD_BOT_F1_U);
		omap_writew(bottom, OMAP1510_DMA_LCD_BOT_F1_L);

		return;
	}

	/* 1610 regs */
	omap_writew(top >> 16, OMAP1610_DMA_LCD_TOP_B1_U);
	omap_writew(top, OMAP1610_DMA_LCD_TOP_B1_L);
	omap_writew(bottom >> 16, OMAP1610_DMA_LCD_BOT_B1_U);
	omap_writew(bottom, OMAP1610_DMA_LCD_BOT_B1_L);

	omap_writew(en, OMAP1610_DMA_LCD_SRC_EN_B1);
	omap_writew(fn, OMAP1610_DMA_LCD_SRC_FN_B1);

	w = omap_readw(OMAP1610_DMA_LCD_CSDP);
	w &= ~0x03;
	w |= lcd_dma.data_type;

Annotation

Implementation Notes