xref: /openbmc/u-boot/drivers/video/am335x-fb.c (revision db00e921)
1 /*
2  * Copyright (C) 2013-2018 Hannes Schmelzer <oe5hpm@oevsv.at>
3  * B&R Industrial Automation GmbH - http://www.br-automation.com
4  *
5  * minimal framebuffer driver for TI's AM335x SoC to be compatible with
6  * Wolfgang Denk's LCD-Framework (CONFIG_LCD, common/lcd.c)
7  *
8  * - supporting 16/24/32bit RGB/TFT raster Mode (not using palette)
9  * - sets up LCD controller as in 'am335x_lcdpanel' struct given
10  * - starts output DMA from gd->fb_base buffer
11  *
12  * SPDX-License-Identifier:	GPL-2.0+
13  */
14 #include <common.h>
15 #include <asm/io.h>
16 #include <asm/arch/hardware.h>
17 #include <asm/arch/omap.h>
18 #include <asm/arch/clock.h>
19 #include <asm/arch/sys_proto.h>
20 #include <lcd.h>
21 #include "am335x-fb.h"
22 
23 #if !defined(LCD_CNTL_BASE)
24 #error "hw-base address of LCD-Controller (LCD_CNTL_BASE) not defined!"
25 #endif
26 
27 #define LCDC_FMAX				200000000
28 
29 /* LCD Control Register */
30 #define LCD_CLK_DIVISOR(x)			((x) << 8)
31 #define LCD_RASTER_MODE				0x01
32 /* LCD Clock Enable Register */
33 #define LCD_CORECLKEN				(0x01 << 0)
34 #define LCD_LIDDCLKEN				(0x01 << 1)
35 #define LCD_DMACLKEN				(0x01 << 2)
36 /* LCD DMA Control Register */
37 #define LCD_DMA_BURST_SIZE(x)			((x) << 4)
38 #define LCD_DMA_BURST_1				0x0
39 #define LCD_DMA_BURST_2				0x1
40 #define LCD_DMA_BURST_4				0x2
41 #define LCD_DMA_BURST_8				0x3
42 #define LCD_DMA_BURST_16			0x4
43 /* LCD Timing_0 Register */
44 #define LCD_HBPLSB(x)				((((x)-1) & 0xFF) << 24)
45 #define LCD_HFPLSB(x)				((((x)-1) & 0xFF) << 16)
46 #define LCD_HSWLSB(x)				((((x)-1) & 0x3F) << 10)
47 #define LCD_HORLSB(x)				(((((x) >> 4)-1) & 0x3F) << 4)
48 #define LCD_HORMSB(x)				(((((x) >> 4)-1) & 0x40) >> 4)
49 /* LCD Timing_1 Register */
50 #define LCD_VBP(x)				((x) << 24)
51 #define LCD_VFP(x)				((x) << 16)
52 #define LCD_VSW(x)				(((x)-1) << 10)
53 #define LCD_VERLSB(x)				(((x)-1) & 0x3FF)
54 /* LCD Timing_2 Register */
55 #define LCD_HSWMSB(x)				((((x)-1) & 0x3C0) << 21)
56 #define LCD_VERMSB(x)				((((x)-1) & 0x400) << 16)
57 #define LCD_HBPMSB(x)				((((x)-1) & 0x300) >> 4)
58 #define LCD_HFPMSB(x)				((((x)-1) & 0x300) >> 8)
59 #define LCD_INVMASK(x)				((x) & 0x3F00000)
60 /* LCD Raster Ctrl Register */
61 #define LCD_TFT_24BPP_MODE			(1 << 25)
62 #define LCD_TFT_24BPP_UNPACK			(1 << 26)
63 #define LCD_PALMODE_RAWDATA			(0x02 << 20)
64 #define LCD_TFT_MODE				(0x01 << 7)
65 #define LCD_RASTER_ENABLE			(0x01 << 0)
66 
67 
68 /* Macro definitions */
69 #define FBSIZE(x)	((x->hactive * x->vactive * x->bpp) >> 3)
70 
71 struct am335x_lcdhw {
72 	unsigned int		pid;			/* 0x00 */
73 	unsigned int		ctrl;			/* 0x04 */
74 	unsigned int		gap0;			/* 0x08 */
75 	unsigned int		lidd_ctrl;		/* 0x0C */
76 	unsigned int		lidd_cs0_conf;		/* 0x10 */
77 	unsigned int		lidd_cs0_addr;		/* 0x14 */
78 	unsigned int		lidd_cs0_data;		/* 0x18 */
79 	unsigned int		lidd_cs1_conf;		/* 0x1C */
80 	unsigned int		lidd_cs1_addr;		/* 0x20 */
81 	unsigned int		lidd_cs1_data;		/* 0x24 */
82 	unsigned int		raster_ctrl;		/* 0x28 */
83 	unsigned int		raster_timing0;		/* 0x2C */
84 	unsigned int		raster_timing1;		/* 0x30 */
85 	unsigned int		raster_timing2;		/* 0x34 */
86 	unsigned int		raster_subpanel;	/* 0x38 */
87 	unsigned int		raster_subpanel2;	/* 0x3C */
88 	unsigned int		lcddma_ctrl;		/* 0x40 */
89 	unsigned int		lcddma_fb0_base;	/* 0x44 */
90 	unsigned int		lcddma_fb0_ceiling;	/* 0x48 */
91 	unsigned int		lcddma_fb1_base;	/* 0x4C */
92 	unsigned int		lcddma_fb1_ceiling;	/* 0x50 */
93 	unsigned int		sysconfig;		/* 0x54 */
94 	unsigned int		irqstatus_raw;		/* 0x58 */
95 	unsigned int		irqstatus;		/* 0x5C */
96 	unsigned int		irqenable_set;		/* 0x60 */
97 	unsigned int		irqenable_clear;	/* 0x64 */
98 	unsigned int		gap1;			/* 0x68 */
99 	unsigned int		clkc_enable;		/* 0x6C */
100 	unsigned int		clkc_reset;		/* 0x70 */
101 };
102 
103 static struct am335x_lcdhw *lcdhw = (void *)LCD_CNTL_BASE;
104 
105 DECLARE_GLOBAL_DATA_PTR;
106 
107 int lcd_get_size(int *line_length)
108 {
109 	*line_length = (panel_info.vl_col * NBITS(panel_info.vl_bpix)) / 8;
110 	return *line_length * panel_info.vl_row + 0x20;
111 }
112 
113 int am335xfb_init(struct am335x_lcdpanel *panel)
114 {
115 	u32 raster_ctrl = 0;
116 
117 	struct cm_dpll *const cmdpll = (struct cm_dpll *)CM_DPLL;
118 	struct dpll_params dpll_disp = { 1, 0, 1, -1, -1, -1, -1 };
119 	unsigned int m, n, d, best_d = 2;
120 	int err = 0, err_r = 0;
121 
122 	if (gd->fb_base == 0) {
123 		printf("ERROR: no valid fb_base stored in GLOBAL_DATA_PTR!\n");
124 		return -1;
125 	}
126 	if (panel == NULL) {
127 		printf("ERROR: missing ptr to am335x_lcdpanel!\n");
128 		return -1;
129 	}
130 
131 	/* We can already set the bits for the raster_ctrl in this check */
132 	switch (panel->bpp) {
133 	case 16:
134 		break;
135 	case 32:
136 		raster_ctrl |= LCD_TFT_24BPP_UNPACK;
137 		/* fallthrough */
138 	case 24:
139 		raster_ctrl |= LCD_TFT_24BPP_MODE;
140 		break;
141 	default:
142 		pr_err("am335x-fb: invalid bpp value: %d\n", panel->bpp);
143 		return -1;
144 	}
145 
146 	/* check given clock-frequency */
147 	if (panel->pxl_clk > (LCDC_FMAX / 2)) {
148 		pr_err("am335x-fb: requested pxl-clk: %d not supported!\n",
149 		       panel->pxl_clk);
150 		return -1;
151 	}
152 
153 	debug("setting up LCD-Controller for %dx%dx%d (hfp=%d,hbp=%d,hsw=%d / ",
154 	      panel->hactive, panel->vactive, panel->bpp,
155 	      panel->hfp, panel->hbp, panel->hsw);
156 	debug("vfp=%d,vbp=%d,vsw=%d / clk=%d)\n",
157 	      panel->vfp, panel->vfp, panel->vsw, panel->pxl_clk);
158 	debug("using frambuffer at 0x%08x with size %d.\n",
159 	      (unsigned int)gd->fb_base, FBSIZE(panel));
160 
161 	/* setup display pll for requested clock frequency */
162 	err = panel->pxl_clk;
163 	err_r = err;
164 
165 	for (d = 2; d < 255; d++) {
166 		for (m = 2; m < 2047; m++) {
167 			if ((V_OSCK * m) < (panel->pxl_clk * d))
168 				continue;
169 			n = (V_OSCK * m) / (panel->pxl_clk * d);
170 			if (n > 127)
171 				break;
172 			if (((V_OSCK * m) / n) > LCDC_FMAX)
173 				break;
174 
175 			err = abs((V_OSCK * m) / n / d - panel->pxl_clk);
176 			if (err < err_r) {
177 				err_r = err;
178 				dpll_disp.m = m;
179 				dpll_disp.n = n;
180 				best_d = d;
181 			}
182 		}
183 	}
184 	debug("%s: PLL: best error %d Hz (M %d, N %d, DISP %d)\n",
185 	      __func__, err_r, dpll_disp.m, dpll_disp.n, best_d);
186 	do_setup_dpll(&dpll_disp_regs, &dpll_disp);
187 
188 	/* clock source for LCDC from dispPLL M2 */
189 	writel(0x0, &cmdpll->clklcdcpixelclk);
190 
191 	/* palette default entry */
192 	memset((void *)gd->fb_base, 0, 0x20);
193 	*(unsigned int *)gd->fb_base = 0x4000;
194 	/* point fb behind palette */
195 	gd->fb_base += 0x20;
196 
197 	/* turn ON display through powercontrol function if accessible */
198 	if (panel->panel_power_ctrl != NULL)
199 		panel->panel_power_ctrl(1);
200 
201 	debug("am335x-fb: wait for stable power ...\n");
202 	mdelay(panel->pup_delay);
203 	lcdhw->clkc_enable = LCD_CORECLKEN | LCD_LIDDCLKEN | LCD_DMACLKEN;
204 	lcdhw->raster_ctrl = 0;
205 	lcdhw->ctrl = LCD_CLK_DIVISOR(best_d) | LCD_RASTER_MODE;
206 	lcdhw->lcddma_fb0_base = gd->fb_base;
207 	lcdhw->lcddma_fb0_ceiling = gd->fb_base + FBSIZE(panel);
208 	lcdhw->lcddma_fb1_base = gd->fb_base;
209 	lcdhw->lcddma_fb1_ceiling = gd->fb_base + FBSIZE(panel);
210 	lcdhw->lcddma_ctrl = LCD_DMA_BURST_SIZE(LCD_DMA_BURST_16);
211 
212 	lcdhw->raster_timing0 = LCD_HORLSB(panel->hactive) |
213 				LCD_HORMSB(panel->hactive) |
214 				LCD_HFPLSB(panel->hfp) |
215 				LCD_HBPLSB(panel->hbp) |
216 				LCD_HSWLSB(panel->hsw);
217 	lcdhw->raster_timing1 = LCD_VBP(panel->vbp) |
218 				LCD_VFP(panel->vfp) |
219 				LCD_VSW(panel->vsw) |
220 				LCD_VERLSB(panel->vactive);
221 	lcdhw->raster_timing2 = LCD_HSWMSB(panel->hsw) |
222 				LCD_VERMSB(panel->vactive) |
223 				LCD_INVMASK(panel->pol) |
224 				LCD_HBPMSB(panel->hbp) |
225 				LCD_HFPMSB(panel->hfp) |
226 				0x0000FF00;	/* clk cycles for ac-bias */
227 	lcdhw->raster_ctrl =	raster_ctrl |
228 				LCD_PALMODE_RAWDATA |
229 				LCD_TFT_MODE |
230 				LCD_RASTER_ENABLE;
231 
232 	debug("am335x-fb: waiting picture to be stable.\n.");
233 	mdelay(panel->pon_delay);
234 
235 	return 0;
236 }
237