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 void *lcd_base; /* Start of framebuffer memory */ 64 65 vidinfo_t panel_info = { 66 /* Insert a value here so that we don't end up in the BSS */ 67 .vl_col = -1, 68 }; 69 70 #ifndef CONFIG_OF_CONTROL 71 #error "You must enable CONFIG_OF_CONTROL to get Tegra LCD support" 72 #endif 73 74 static void update_panel_size(struct fdt_disp_config *config) 75 { 76 panel_info.vl_col = config->width; 77 panel_info.vl_row = config->height; 78 panel_info.vl_bpix = config->log2_bpp; 79 } 80 81 /* 82 * Main init function called by lcd driver. 83 * Inits and then prints test pattern if required. 84 */ 85 86 void lcd_ctrl_init(void *lcdbase) 87 { 88 int type = DCACHE_OFF; 89 int size; 90 91 assert(disp_config); 92 93 lcd_base = (void *)disp_config->frame_buffer; 94 95 /* Make sure that we can acommodate the selected LCD */ 96 assert(disp_config->width <= LCD_MAX_WIDTH); 97 assert(disp_config->height <= LCD_MAX_HEIGHT); 98 assert(disp_config->log2_bpp <= LCD_MAX_LOG2_BPP); 99 if (disp_config->width <= LCD_MAX_WIDTH 100 && disp_config->height <= LCD_MAX_HEIGHT 101 && disp_config->log2_bpp <= LCD_MAX_LOG2_BPP) 102 update_panel_size(disp_config); 103 size = lcd_get_size(&lcd_line_length); 104 105 /* Set up the LCD caching as requested */ 106 if (config.cache_type & FDT_LCD_CACHE_WRITE_THROUGH) 107 type = DCACHE_WRITETHROUGH; 108 else if (config.cache_type & FDT_LCD_CACHE_WRITE_BACK) 109 type = DCACHE_WRITEBACK; 110 mmu_set_region_dcache_behaviour(disp_config->frame_buffer, size, type); 111 112 /* Enable flushing after LCD writes if requested */ 113 lcd_set_flush_dcache(config.cache_type & FDT_LCD_CACHE_FLUSH); 114 115 debug("LCD frame buffer at %p\n", lcd_base); 116 } 117 118 ulong calc_fbsize(void) 119 { 120 return (panel_info.vl_col * panel_info.vl_row * 121 NBITS(panel_info.vl_bpix)) / 8; 122 } 123 124 void lcd_setcolreg(ushort regno, ushort red, ushort green, ushort blue) 125 { 126 } 127 128 void tegra_lcd_early_init(const void *blob) 129 { 130 /* 131 * Go with the maximum size for now. We will fix this up after 132 * relocation. These values are only used for memory alocation. 133 */ 134 panel_info.vl_col = LCD_MAX_WIDTH; 135 panel_info.vl_row = LCD_MAX_HEIGHT; 136 panel_info.vl_bpix = LCD_MAX_LOG2_BPP; 137 } 138 139 /** 140 * Decode the panel information from the fdt. 141 * 142 * @param blob fdt blob 143 * @param config structure to store fdt config into 144 * @return 0 if ok, -ve on error 145 */ 146 static int fdt_decode_lcd(const void *blob, struct fdt_panel_config *config) 147 { 148 int display_node; 149 150 disp_config = tegra_display_get_config(); 151 if (!disp_config) { 152 debug("%s: Display controller is not configured\n", __func__); 153 return -1; 154 } 155 display_node = disp_config->panel_node; 156 if (display_node < 0) { 157 debug("%s: No panel configuration available\n", __func__); 158 return -1; 159 } 160 161 config->pwm_channel = pwm_request(blob, display_node, "nvidia,pwm"); 162 if (config->pwm_channel < 0) { 163 debug("%s: Unable to request PWM channel\n", __func__); 164 return -1; 165 } 166 167 config->cache_type = fdtdec_get_int(blob, display_node, 168 "nvidia,cache-type", 169 FDT_LCD_CACHE_WRITE_BACK_FLUSH); 170 171 /* These GPIOs are all optional */ 172 fdtdec_decode_gpio(blob, display_node, "nvidia,backlight-enable-gpios", 173 &config->backlight_en); 174 fdtdec_decode_gpio(blob, display_node, "nvidia,lvds-shutdown-gpios", 175 &config->lvds_shutdown); 176 fdtdec_decode_gpio(blob, display_node, "nvidia,backlight-vdd-gpios", 177 &config->backlight_vdd); 178 fdtdec_decode_gpio(blob, display_node, "nvidia,panel-vdd-gpios", 179 &config->panel_vdd); 180 181 return fdtdec_get_int_array(blob, display_node, "nvidia,panel-timings", 182 config->panel_timings, FDT_LCD_TIMINGS); 183 } 184 185 /** 186 * Handle the next stage of device init 187 */ 188 static int handle_stage(const void *blob) 189 { 190 debug("%s: stage %d\n", __func__, stage); 191 192 /* do the things for this stage */ 193 switch (stage) { 194 case STAGE_START: 195 /* Initialize the Tegra display controller */ 196 if (tegra_display_probe(gd->fdt_blob, (void *)gd->fb_base)) { 197 printf("%s: Failed to probe display driver\n", 198 __func__); 199 return -1; 200 } 201 202 /* get panel details */ 203 if (fdt_decode_lcd(blob, &config)) { 204 printf("No valid LCD information in device tree\n"); 205 return -1; 206 } 207 208 /* 209 * It is possible that the FDT has requested that the LCD be 210 * disabled. We currently don't support this. It would require 211 * changes to U-Boot LCD subsystem to have LCD support 212 * compiled in but not used. An easier option might be to 213 * still have a frame buffer, but leave the backlight off and 214 * remove all mention of lcd in the stdout environment 215 * variable. 216 */ 217 218 funcmux_select(PERIPH_ID_DISP1, FUNCMUX_DEFAULT); 219 220 fdtdec_setup_gpio(&config.panel_vdd); 221 fdtdec_setup_gpio(&config.lvds_shutdown); 222 fdtdec_setup_gpio(&config.backlight_vdd); 223 fdtdec_setup_gpio(&config.backlight_en); 224 225 /* 226 * TODO: If fdt includes output flag we can omit this code 227 * since fdtdec_setup_gpio will do it for us. 228 */ 229 if (fdt_gpio_isvalid(&config.panel_vdd)) 230 gpio_direction_output(config.panel_vdd.gpio, 0); 231 if (fdt_gpio_isvalid(&config.lvds_shutdown)) 232 gpio_direction_output(config.lvds_shutdown.gpio, 0); 233 if (fdt_gpio_isvalid(&config.backlight_vdd)) 234 gpio_direction_output(config.backlight_vdd.gpio, 0); 235 if (fdt_gpio_isvalid(&config.backlight_en)) 236 gpio_direction_output(config.backlight_en.gpio, 0); 237 break; 238 case STAGE_PANEL_VDD: 239 if (fdt_gpio_isvalid(&config.panel_vdd)) 240 gpio_direction_output(config.panel_vdd.gpio, 1); 241 break; 242 case STAGE_LVDS: 243 if (fdt_gpio_isvalid(&config.lvds_shutdown)) 244 gpio_set_value(config.lvds_shutdown.gpio, 1); 245 break; 246 case STAGE_BACKLIGHT_VDD: 247 if (fdt_gpio_isvalid(&config.backlight_vdd)) 248 gpio_set_value(config.backlight_vdd.gpio, 1); 249 break; 250 case STAGE_PWM: 251 /* Enable PWM at 15/16 high, 32768 Hz with divider 1 */ 252 pinmux_set_func(PINGRP_GPU, PMUX_FUNC_PWM); 253 pinmux_tristate_disable(PINGRP_GPU); 254 255 pwm_enable(config.pwm_channel, 32768, 0xdf, 1); 256 break; 257 case STAGE_BACKLIGHT_EN: 258 if (fdt_gpio_isvalid(&config.backlight_en)) 259 gpio_set_value(config.backlight_en.gpio, 1); 260 break; 261 case STAGE_DONE: 262 break; 263 } 264 265 /* set up timer for next stage */ 266 timer_next = timer_get_us(); 267 if (stage < FDT_LCD_TIMINGS) 268 timer_next += config.panel_timings[stage] * 1000; 269 270 /* move to next stage */ 271 stage++; 272 return 0; 273 } 274 275 int tegra_lcd_check_next_stage(const void *blob, int wait) 276 { 277 if (stage == STAGE_DONE) 278 return 0; 279 280 do { 281 /* wait if we need to */ 282 debug("%s: stage %d\n", __func__, stage); 283 if (stage != STAGE_START) { 284 int delay = timer_next - timer_get_us(); 285 286 if (delay > 0) { 287 if (wait) 288 udelay(delay); 289 else 290 return 0; 291 } 292 } 293 294 if (handle_stage(blob)) 295 return -1; 296 } while (wait && stage != STAGE_DONE); 297 if (stage == STAGE_DONE) 298 debug("%s: LCD init complete\n", __func__); 299 300 return 0; 301 } 302 303 void lcd_enable(void) 304 { 305 /* 306 * Backlight and power init will be done separately in 307 * tegra_lcd_check_next_stage(), which should be called in 308 * board_late_init(). 309 * 310 * U-Boot code supports only colour depth, selected at compile time. 311 * The device tree setting should match this. Otherwise the display 312 * will not look right, and U-Boot may crash. 313 */ 314 if (disp_config->log2_bpp != LCD_BPP) { 315 printf("%s: Error: LCD depth configured in FDT (%d = %dbpp)" 316 " must match setting of LCD_BPP (%d)\n", __func__, 317 disp_config->log2_bpp, disp_config->bpp, LCD_BPP); 318 } 319 } 320