1 // SPDX-License-Identifier: GPL-2.0+
3 * Driver for AT91/AT32 LCD Controller
5 * Copyright (C) 2007 Atmel Corporation
15 #include <asm/global_data.h>
17 #include <asm/arch/gpio.h>
18 #include <asm/arch/clk.h>
19 #include <bmp_layout.h>
20 #include <atmel_lcdc.h>
21 #include <linux/delay.h>
23 DECLARE_GLOBAL_DATA_PTR;
26 /* Maximum LCD size we support */
29 LCD_MAX_LOG2_BPP = VIDEO_BPP16,
32 struct atmel_fb_priv {
33 struct display_timing timing;
36 /* configurable parameters */
37 #define ATMEL_LCDC_CVAL_DEFAULT 0xc8
38 #define ATMEL_LCDC_DMA_BURST_LEN 8
39 #ifndef ATMEL_LCDC_GUARD_TIME
40 #define ATMEL_LCDC_GUARD_TIME 1
43 #if defined(CONFIG_AT91SAM9263)
44 #define ATMEL_LCDC_FIFO_SIZE 2048
46 #define ATMEL_LCDC_FIFO_SIZE 512
49 #define lcdc_readl(mmio, reg) __raw_readl((mmio)+(reg))
50 #define lcdc_writel(mmio, reg, val) __raw_writel((val), (mmio)+(reg))
52 static void atmel_fb_init(ulong addr, struct display_timing *timing, int bpix,
53 bool tft, bool cont_pol_low, ulong lcdbase)
56 void *reg = (void *)addr;
58 /* Turn off the LCD controller and the DMA controller */
59 lcdc_writel(reg, ATMEL_LCDC_PWRCON,
60 ATMEL_LCDC_GUARD_TIME << ATMEL_LCDC_GUARDT_OFFSET);
62 /* Wait for the LCDC core to become idle */
63 while (lcdc_readl(reg, ATMEL_LCDC_PWRCON) & ATMEL_LCDC_BUSY)
66 lcdc_writel(reg, ATMEL_LCDC_DMACON, 0);
69 lcdc_writel(reg, ATMEL_LCDC_DMACON, ATMEL_LCDC_DMARST);
71 /* ...set frame size and burst length = 8 words (?) */
72 value = (timing->hactive.typ * timing->vactive.typ *
74 value |= ((ATMEL_LCDC_DMA_BURST_LEN - 1) << ATMEL_LCDC_BLENGTH_OFFSET);
75 lcdc_writel(reg, ATMEL_LCDC_DMAFRMCFG, value);
78 value = get_lcdc_clk_rate(0) / timing->pixelclock.typ;
79 if (get_lcdc_clk_rate(0) % timing->pixelclock.typ)
81 value = (value / 2) - 1;
84 lcdc_writel(reg, ATMEL_LCDC_LCDCON1, ATMEL_LCDC_BYPASS);
86 lcdc_writel(reg, ATMEL_LCDC_LCDCON1,
87 value << ATMEL_LCDC_CLKVAL_OFFSET);
89 /* Initialize control register 2 */
90 value = ATMEL_LCDC_MEMOR_LITTLE | ATMEL_LCDC_CLKMOD_ALWAYSACTIVE;
92 value |= ATMEL_LCDC_DISTYPE_TFT;
94 if (!(timing->flags & DISPLAY_FLAGS_HSYNC_HIGH))
95 value |= ATMEL_LCDC_INVLINE_INVERTED;
96 if (!(timing->flags & DISPLAY_FLAGS_VSYNC_HIGH))
97 value |= ATMEL_LCDC_INVFRAME_INVERTED;
99 lcdc_writel(reg, ATMEL_LCDC_LCDCON2, value);
101 /* Vertical timing */
102 value = (timing->vsync_len.typ - 1) << ATMEL_LCDC_VPW_OFFSET;
103 value |= timing->vback_porch.typ << ATMEL_LCDC_VBP_OFFSET;
104 value |= timing->vfront_porch.typ;
105 /* Magic! (Datasheet says "Bit 31 must be written to 1") */
107 lcdc_writel(reg, ATMEL_LCDC_TIM1, value);
109 /* Horizontal timing */
110 value = (timing->hfront_porch.typ - 1) << ATMEL_LCDC_HFP_OFFSET;
111 value |= (timing->hsync_len.typ - 1) << ATMEL_LCDC_HPW_OFFSET;
112 value |= (timing->hback_porch.typ - 1);
113 lcdc_writel(reg, ATMEL_LCDC_TIM2, value);
116 value = (timing->hactive.typ - 1) << ATMEL_LCDC_HOZVAL_OFFSET;
117 value |= timing->vactive.typ - 1;
118 lcdc_writel(reg, ATMEL_LCDC_LCDFRMCFG, value);
120 /* FIFO Threshold: Use formula from data sheet */
121 value = ATMEL_LCDC_FIFO_SIZE - (2 * ATMEL_LCDC_DMA_BURST_LEN + 3);
122 lcdc_writel(reg, ATMEL_LCDC_FIFO, value);
124 /* Toggle LCD_MODE every frame */
125 lcdc_writel(reg, ATMEL_LCDC_MVAL, 0);
127 /* Disable all interrupts */
128 lcdc_writel(reg, ATMEL_LCDC_IDR, ~0UL);
131 value = ATMEL_LCDC_PS_DIV8 |
132 ATMEL_LCDC_ENA_PWMENABLE;
134 value |= ATMEL_LCDC_POL_POSITIVE;
135 lcdc_writel(reg, ATMEL_LCDC_CONTRAST_CTR, value);
136 lcdc_writel(reg, ATMEL_LCDC_CONTRAST_VAL, ATMEL_LCDC_CVAL_DEFAULT);
138 /* Set framebuffer DMA base address and pixel offset */
139 lcdc_writel(reg, ATMEL_LCDC_DMABADDR1, lcdbase);
141 lcdc_writel(reg, ATMEL_LCDC_DMACON, ATMEL_LCDC_DMAEN);
142 lcdc_writel(reg, ATMEL_LCDC_PWRCON,
143 (ATMEL_LCDC_GUARD_TIME << ATMEL_LCDC_GUARDT_OFFSET) | ATMEL_LCDC_PWR);
146 static int atmel_fb_lcd_probe(struct udevice *dev)
148 struct video_uc_plat *uc_plat = dev_get_uclass_plat(dev);
149 struct video_priv *uc_priv = dev_get_uclass_priv(dev);
150 struct atmel_fb_priv *priv = dev_get_priv(dev);
151 struct display_timing *timing = &priv->timing;
154 * For now some values are hard-coded. We could use the device tree
155 * bindings in simple-framebuffer.txt to specify the format/bpp and
156 * some Atmel-specific binding for tft and cont_pol_low.
158 atmel_fb_init(ATMEL_BASE_LCDC, timing, VIDEO_BPP16, true, false,
160 uc_priv->xsize = timing->hactive.typ;
161 uc_priv->ysize = timing->vactive.typ;
162 uc_priv->bpix = VIDEO_BPP16;
163 video_set_flush_dcache(dev, true);
164 debug("LCD frame buffer at %lx, size %x, %dx%d pixels\n", uc_plat->base,
165 uc_plat->size, uc_priv->xsize, uc_priv->ysize);
170 static int atmel_fb_of_to_plat(struct udevice *dev)
172 struct atmel_lcd_plat *plat = dev_get_plat(dev);
173 struct atmel_fb_priv *priv = dev_get_priv(dev);
174 struct display_timing *timing = &priv->timing;
175 const void *blob = gd->fdt_blob;
177 if (fdtdec_decode_display_timing(blob, dev_of_offset(dev),
178 plat->timing_index, timing)) {
179 debug("%s: Failed to decode display timing\n", __func__);
186 static int atmel_fb_lcd_bind(struct udevice *dev)
188 struct video_uc_plat *uc_plat = dev_get_uclass_plat(dev);
190 uc_plat->size = LCD_MAX_WIDTH * LCD_MAX_HEIGHT *
191 (1 << VIDEO_BPP16) / 8;
192 debug("%s: Frame buffer size %x\n", __func__, uc_plat->size);
197 static const struct udevice_id atmel_fb_lcd_ids[] = {
198 { .compatible = "atmel,at91sam9g45-lcdc" },
202 U_BOOT_DRIVER(atmel_fb) = {
205 .of_match = atmel_fb_lcd_ids,
206 .bind = atmel_fb_lcd_bind,
207 .of_to_plat = atmel_fb_of_to_plat,
208 .probe = atmel_fb_lcd_probe,
209 .plat_auto = sizeof(struct atmel_lcd_plat),
210 .priv_auto = sizeof(struct atmel_fb_priv),