xref: /openbmc/u-boot/drivers/video/tegra.c (revision 1155d555)
1 /*
2  * Copyright (c) 2011 The Chromium OS Authors.
3  * See file CREDITS for list of people who contributed to this
4  * project.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation; either version 2 of
9  * the License, or (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
19  * MA 02111-1307 USA
20  */
21 
22 #include <common.h>
23 #include <fdtdec.h>
24 #include <lcd.h>
25 
26 #include <asm/system.h>
27 #include <asm/gpio.h>
28 
29 #include <asm/arch/clock.h>
30 #include <asm/arch/funcmux.h>
31 #include <asm/arch/pinmux.h>
32 #include <asm/arch/pwm.h>
33 #include <asm/arch/display.h>
34 #include <asm/arch-tegra/timer.h>
35 
36 DECLARE_GLOBAL_DATA_PTR;
37 
38 /* These are the stages we go throuh in enabling the LCD */
39 enum stage_t {
40 	STAGE_START,
41 	STAGE_PANEL_VDD,
42 	STAGE_LVDS,
43 	STAGE_BACKLIGHT_VDD,
44 	STAGE_PWM,
45 	STAGE_BACKLIGHT_EN,
46 	STAGE_DONE,
47 };
48 
49 static enum stage_t stage;	/* Current stage we are at */
50 static unsigned long timer_next; /* Time we can move onto next stage */
51 
52 /* Our LCD config, set up in handle_stage() */
53 static struct fdt_panel_config config;
54 struct fdt_disp_config *disp_config;	/* Display controller config */
55 
56 enum {
57 	/* Maximum LCD size we support */
58 	LCD_MAX_WIDTH		= 1366,
59 	LCD_MAX_HEIGHT		= 768,
60 	LCD_MAX_LOG2_BPP	= 4,		/* 2^4 = 16 bpp */
61 };
62 
63 vidinfo_t panel_info = {
64 	/* Insert a value here so that we don't end up in the BSS */
65 	.vl_col = -1,
66 };
67 
68 #ifndef CONFIG_OF_CONTROL
69 #error "You must enable CONFIG_OF_CONTROL to get Tegra LCD support"
70 #endif
71 
72 static void update_panel_size(struct fdt_disp_config *config)
73 {
74 	panel_info.vl_col = config->width;
75 	panel_info.vl_row = config->height;
76 	panel_info.vl_bpix = config->log2_bpp;
77 }
78 
79 /*
80  *  Main init function called by lcd driver.
81  *  Inits and then prints test pattern if required.
82  */
83 
84 void lcd_ctrl_init(void *lcdbase)
85 {
86 	int type = DCACHE_OFF;
87 	int size;
88 
89 	assert(disp_config);
90 
91 	/* Make sure that we can acommodate the selected LCD */
92 	assert(disp_config->width <= LCD_MAX_WIDTH);
93 	assert(disp_config->height <= LCD_MAX_HEIGHT);
94 	assert(disp_config->log2_bpp <= LCD_MAX_LOG2_BPP);
95 	if (disp_config->width <= LCD_MAX_WIDTH
96 			&& disp_config->height <= LCD_MAX_HEIGHT
97 			&& disp_config->log2_bpp <= LCD_MAX_LOG2_BPP)
98 		update_panel_size(disp_config);
99 	size = lcd_get_size(&lcd_line_length);
100 
101 	/* Set up the LCD caching as requested */
102 	if (config.cache_type & FDT_LCD_CACHE_WRITE_THROUGH)
103 		type = DCACHE_WRITETHROUGH;
104 	else if (config.cache_type & FDT_LCD_CACHE_WRITE_BACK)
105 		type = DCACHE_WRITEBACK;
106 	mmu_set_region_dcache_behaviour(disp_config->frame_buffer, size, type);
107 
108 	/* Enable flushing after LCD writes if requested */
109 	lcd_set_flush_dcache(config.cache_type & FDT_LCD_CACHE_FLUSH);
110 
111 	debug("LCD frame buffer at %08X\n", disp_config->frame_buffer);
112 }
113 
114 ulong calc_fbsize(void)
115 {
116 	return (panel_info.vl_col * panel_info.vl_row *
117 		NBITS(panel_info.vl_bpix)) / 8;
118 }
119 
120 void lcd_setcolreg(ushort regno, ushort red, ushort green, ushort blue)
121 {
122 }
123 
124 void tegra_lcd_early_init(const void *blob)
125 {
126 	/*
127 	 * Go with the maximum size for now. We will fix this up after
128 	 * relocation. These values are only used for memory alocation.
129 	 */
130 	panel_info.vl_col = LCD_MAX_WIDTH;
131 	panel_info.vl_row = LCD_MAX_HEIGHT;
132 	panel_info.vl_bpix = LCD_MAX_LOG2_BPP;
133 }
134 
135 /**
136  * Decode the panel information from the fdt.
137  *
138  * @param blob		fdt blob
139  * @param config	structure to store fdt config into
140  * @return 0 if ok, -ve on error
141  */
142 static int fdt_decode_lcd(const void *blob, struct fdt_panel_config *config)
143 {
144 	int display_node;
145 
146 	disp_config = tegra_display_get_config();
147 	if (!disp_config) {
148 		debug("%s: Display controller is not configured\n", __func__);
149 		return -1;
150 	}
151 	display_node = disp_config->panel_node;
152 	if (display_node < 0) {
153 		debug("%s: No panel configuration available\n", __func__);
154 		return -1;
155 	}
156 
157 	config->pwm_channel = pwm_request(blob, display_node, "nvidia,pwm");
158 	if (config->pwm_channel < 0) {
159 		debug("%s: Unable to request PWM channel\n", __func__);
160 		return -1;
161 	}
162 
163 	config->cache_type = fdtdec_get_int(blob, display_node,
164 					    "nvidia,cache-type",
165 					    FDT_LCD_CACHE_WRITE_BACK_FLUSH);
166 
167 	/* These GPIOs are all optional */
168 	fdtdec_decode_gpio(blob, display_node, "nvidia,backlight-enable-gpios",
169 			    &config->backlight_en);
170 	fdtdec_decode_gpio(blob, display_node, "nvidia,lvds-shutdown-gpios",
171 			   &config->lvds_shutdown);
172 	fdtdec_decode_gpio(blob, display_node, "nvidia,backlight-vdd-gpios",
173 			   &config->backlight_vdd);
174 	fdtdec_decode_gpio(blob, display_node, "nvidia,panel-vdd-gpios",
175 			   &config->panel_vdd);
176 
177 	return fdtdec_get_int_array(blob, display_node, "nvidia,panel-timings",
178 			config->panel_timings, FDT_LCD_TIMINGS);
179 }
180 
181 /**
182  * Handle the next stage of device init
183  */
184 static int handle_stage(const void *blob)
185 {
186 	debug("%s: stage %d\n", __func__, stage);
187 
188 	/* do the things for this stage */
189 	switch (stage) {
190 	case STAGE_START:
191 		/* Initialize the Tegra display controller */
192 		if (tegra_display_probe(gd->fdt_blob, (void *)gd->fb_base)) {
193 			printf("%s: Failed to probe display driver\n",
194 			__func__);
195 			return -1;
196 		}
197 
198 		/* get panel details */
199 		if (fdt_decode_lcd(blob, &config)) {
200 			printf("No valid LCD information in device tree\n");
201 			return -1;
202 		}
203 
204 		/*
205 		 * It is possible that the FDT has requested that the LCD be
206 		 * disabled. We currently don't support this. It would require
207 		 * changes to U-Boot LCD subsystem to have LCD support
208 		 * compiled in but not used. An easier option might be to
209 		 * still have a frame buffer, but leave the backlight off and
210 		 * remove all mention of lcd in the stdout environment
211 		 * variable.
212 		 */
213 
214 		funcmux_select(PERIPH_ID_DISP1, FUNCMUX_DEFAULT);
215 
216 		fdtdec_setup_gpio(&config.panel_vdd);
217 		fdtdec_setup_gpio(&config.lvds_shutdown);
218 		fdtdec_setup_gpio(&config.backlight_vdd);
219 		fdtdec_setup_gpio(&config.backlight_en);
220 
221 		/*
222 		 * TODO: If fdt includes output flag we can omit this code
223 		 * since fdtdec_setup_gpio will do it for us.
224 		 */
225 		if (fdt_gpio_isvalid(&config.panel_vdd))
226 			gpio_direction_output(config.panel_vdd.gpio, 0);
227 		if (fdt_gpio_isvalid(&config.lvds_shutdown))
228 			gpio_direction_output(config.lvds_shutdown.gpio, 0);
229 		if (fdt_gpio_isvalid(&config.backlight_vdd))
230 			gpio_direction_output(config.backlight_vdd.gpio, 0);
231 		if (fdt_gpio_isvalid(&config.backlight_en))
232 			gpio_direction_output(config.backlight_en.gpio, 0);
233 		break;
234 	case STAGE_PANEL_VDD:
235 		if (fdt_gpio_isvalid(&config.panel_vdd))
236 			gpio_direction_output(config.panel_vdd.gpio, 1);
237 		break;
238 	case STAGE_LVDS:
239 		if (fdt_gpio_isvalid(&config.lvds_shutdown))
240 			gpio_set_value(config.lvds_shutdown.gpio, 1);
241 		break;
242 	case STAGE_BACKLIGHT_VDD:
243 		if (fdt_gpio_isvalid(&config.backlight_vdd))
244 			gpio_set_value(config.backlight_vdd.gpio, 1);
245 		break;
246 	case STAGE_PWM:
247 		/* Enable PWM at 15/16 high, 32768 Hz with divider 1 */
248 		pinmux_set_func(PINGRP_GPU, PMUX_FUNC_PWM);
249 		pinmux_tristate_disable(PINGRP_GPU);
250 
251 		pwm_enable(config.pwm_channel, 32768, 0xdf, 1);
252 		break;
253 	case STAGE_BACKLIGHT_EN:
254 		if (fdt_gpio_isvalid(&config.backlight_en))
255 			gpio_set_value(config.backlight_en.gpio, 1);
256 		break;
257 	case STAGE_DONE:
258 		break;
259 	}
260 
261 	/* set up timer for next stage */
262 	timer_next = timer_get_us();
263 	if (stage < FDT_LCD_TIMINGS)
264 		timer_next += config.panel_timings[stage] * 1000;
265 
266 	/* move to next stage */
267 	stage++;
268 	return 0;
269 }
270 
271 int tegra_lcd_check_next_stage(const void *blob, int wait)
272 {
273 	if (stage == STAGE_DONE)
274 		return 0;
275 
276 	do {
277 		/* wait if we need to */
278 		debug("%s: stage %d\n", __func__, stage);
279 		if (stage != STAGE_START) {
280 			int delay = timer_next - timer_get_us();
281 
282 			if (delay > 0) {
283 				if (wait)
284 					udelay(delay);
285 				else
286 					return 0;
287 			}
288 		}
289 
290 		if (handle_stage(blob))
291 			return -1;
292 	} while (wait && stage != STAGE_DONE);
293 	if (stage == STAGE_DONE)
294 		debug("%s: LCD init complete\n", __func__);
295 
296 	return 0;
297 }
298 
299 void lcd_enable(void)
300 {
301 	/*
302 	 * Backlight and power init will be done separately in
303 	 * tegra_lcd_check_next_stage(), which should be called in
304 	 * board_late_init().
305 	 *
306 	 * U-Boot code supports only colour depth, selected at compile time.
307 	 * The device tree setting should match this. Otherwise the display
308 	 * will not look right, and U-Boot may crash.
309 	 */
310 	if (disp_config->log2_bpp != LCD_BPP) {
311 		printf("%s: Error: LCD depth configured in FDT (%d = %dbpp)"
312 			" must match setting of LCD_BPP (%d)\n", __func__,
313 		       disp_config->log2_bpp, disp_config->bpp, LCD_BPP);
314 	}
315 }
316