1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Novatek NT39016 TFT LCD panel driver 4 * 5 * Copyright (C) 2017, Maarten ter Huurne <maarten@treewalker.org> 6 * Copyright (C) 2019, Paul Cercueil <paul@crapouillou.net> 7 */ 8 9 #include <linux/delay.h> 10 #include <linux/device.h> 11 #include <linux/gpio/consumer.h> 12 #include <linux/media-bus-format.h> 13 #include <linux/module.h> 14 #include <linux/of.h> 15 #include <linux/regmap.h> 16 #include <linux/regulator/consumer.h> 17 #include <linux/spi/spi.h> 18 19 #include <drm/drm_modes.h> 20 #include <drm/drm_panel.h> 21 22 enum nt39016_regs { 23 NT39016_REG_SYSTEM, 24 NT39016_REG_TIMING, 25 NT39016_REG_OP, 26 NT39016_REG_DATA_IN, 27 NT39016_REG_SRC_TIMING_DELAY, 28 NT39016_REG_GATE_TIMING_DELAY, 29 NT39016_REG_RESERVED, 30 NT39016_REG_INITIAL_FUNC, 31 NT39016_REG_CONTRAST, 32 NT39016_REG_BRIGHTNESS, 33 NT39016_REG_HUE_SATURATION, 34 NT39016_REG_RB_SUBCONTRAST, 35 NT39016_REG_R_SUBBRIGHTNESS, 36 NT39016_REG_B_SUBBRIGHTNESS, 37 NT39016_REG_VCOMDC, 38 NT39016_REG_VCOMAC, 39 NT39016_REG_VGAM2, 40 NT39016_REG_VGAM34, 41 NT39016_REG_VGAM56, 42 NT39016_REG_VCOMDC_TRIM = 0x1e, 43 NT39016_REG_DISPLAY_MODE = 0x20, 44 }; 45 46 #define NT39016_SYSTEM_RESET_N BIT(0) 47 #define NT39016_SYSTEM_STANDBY BIT(1) 48 49 struct nt39016_panel_info { 50 const struct drm_display_mode *display_modes; 51 unsigned int num_modes; 52 u16 width_mm, height_mm; 53 u32 bus_format, bus_flags; 54 }; 55 56 struct nt39016 { 57 struct drm_panel drm_panel; 58 struct regmap *map; 59 struct regulator *supply; 60 const struct nt39016_panel_info *panel_info; 61 62 struct gpio_desc *reset_gpio; 63 }; 64 65 static inline struct nt39016 *to_nt39016(struct drm_panel *panel) 66 { 67 return container_of(panel, struct nt39016, drm_panel); 68 } 69 70 #define RV(REG, VAL) { .reg = (REG), .def = (VAL), .delay_us = 2 } 71 static const struct reg_sequence nt39016_panel_regs[] = { 72 RV(NT39016_REG_SYSTEM, 0x00), 73 RV(NT39016_REG_TIMING, 0x00), 74 RV(NT39016_REG_OP, 0x03), 75 RV(NT39016_REG_DATA_IN, 0xCC), 76 RV(NT39016_REG_SRC_TIMING_DELAY, 0x46), 77 RV(NT39016_REG_GATE_TIMING_DELAY, 0x05), 78 RV(NT39016_REG_RESERVED, 0x00), 79 RV(NT39016_REG_INITIAL_FUNC, 0x00), 80 RV(NT39016_REG_CONTRAST, 0x08), 81 RV(NT39016_REG_BRIGHTNESS, 0x40), 82 RV(NT39016_REG_HUE_SATURATION, 0x88), 83 RV(NT39016_REG_RB_SUBCONTRAST, 0x88), 84 RV(NT39016_REG_R_SUBBRIGHTNESS, 0x20), 85 RV(NT39016_REG_B_SUBBRIGHTNESS, 0x20), 86 RV(NT39016_REG_VCOMDC, 0x67), 87 RV(NT39016_REG_VCOMAC, 0xA4), 88 RV(NT39016_REG_VGAM2, 0x04), 89 RV(NT39016_REG_VGAM34, 0x24), 90 RV(NT39016_REG_VGAM56, 0x24), 91 RV(NT39016_REG_DISPLAY_MODE, 0x00), 92 }; 93 94 #undef RV 95 96 static const struct regmap_range nt39016_regmap_no_ranges[] = { 97 regmap_reg_range(0x13, 0x1D), 98 regmap_reg_range(0x1F, 0x1F), 99 }; 100 101 static const struct regmap_access_table nt39016_regmap_access_table = { 102 .no_ranges = nt39016_regmap_no_ranges, 103 .n_no_ranges = ARRAY_SIZE(nt39016_regmap_no_ranges), 104 }; 105 106 static const struct regmap_config nt39016_regmap_config = { 107 .reg_bits = 6, 108 .pad_bits = 2, 109 .val_bits = 8, 110 111 .max_register = NT39016_REG_DISPLAY_MODE, 112 .wr_table = &nt39016_regmap_access_table, 113 .write_flag_mask = 0x02, 114 115 .cache_type = REGCACHE_FLAT, 116 }; 117 118 static int nt39016_prepare(struct drm_panel *drm_panel) 119 { 120 struct nt39016 *panel = to_nt39016(drm_panel); 121 int err; 122 123 err = regulator_enable(panel->supply); 124 if (err) { 125 dev_err(drm_panel->dev, "Failed to enable power supply: %d\n", err); 126 return err; 127 } 128 129 /* 130 * Reset the NT39016. 131 * The documentation says the reset pulse should be at least 40 us to 132 * pass the glitch filter, but when testing I see some resets fail and 133 * some succeed when using a 70 us delay, so we use 100 us instead. 134 */ 135 gpiod_set_value_cansleep(panel->reset_gpio, 1); 136 usleep_range(100, 1000); 137 gpiod_set_value_cansleep(panel->reset_gpio, 0); 138 udelay(2); 139 140 /* Init all registers. */ 141 err = regmap_multi_reg_write(panel->map, nt39016_panel_regs, 142 ARRAY_SIZE(nt39016_panel_regs)); 143 if (err) { 144 dev_err(drm_panel->dev, "Failed to init registers: %d\n", err); 145 goto err_disable_regulator; 146 } 147 148 return 0; 149 150 err_disable_regulator: 151 regulator_disable(panel->supply); 152 return err; 153 } 154 155 static int nt39016_unprepare(struct drm_panel *drm_panel) 156 { 157 struct nt39016 *panel = to_nt39016(drm_panel); 158 159 gpiod_set_value_cansleep(panel->reset_gpio, 1); 160 161 regulator_disable(panel->supply); 162 163 return 0; 164 } 165 166 static int nt39016_enable(struct drm_panel *drm_panel) 167 { 168 struct nt39016 *panel = to_nt39016(drm_panel); 169 int ret; 170 171 ret = regmap_write(panel->map, NT39016_REG_SYSTEM, 172 NT39016_SYSTEM_RESET_N | NT39016_SYSTEM_STANDBY); 173 if (ret) { 174 dev_err(drm_panel->dev, "Unable to enable panel: %d\n", ret); 175 return ret; 176 } 177 178 if (drm_panel->backlight) { 179 /* Wait for the picture to be ready before enabling backlight */ 180 msleep(150); 181 } 182 183 return 0; 184 } 185 186 static int nt39016_disable(struct drm_panel *drm_panel) 187 { 188 struct nt39016 *panel = to_nt39016(drm_panel); 189 int err; 190 191 err = regmap_write(panel->map, NT39016_REG_SYSTEM, 192 NT39016_SYSTEM_RESET_N); 193 if (err) { 194 dev_err(drm_panel->dev, "Unable to disable panel: %d\n", err); 195 return err; 196 } 197 198 return 0; 199 } 200 201 static int nt39016_get_modes(struct drm_panel *drm_panel, 202 struct drm_connector *connector) 203 { 204 struct nt39016 *panel = to_nt39016(drm_panel); 205 const struct nt39016_panel_info *panel_info = panel->panel_info; 206 struct drm_display_mode *mode; 207 unsigned int i; 208 209 for (i = 0; i < panel_info->num_modes; i++) { 210 mode = drm_mode_duplicate(connector->dev, 211 &panel_info->display_modes[i]); 212 if (!mode) 213 return -ENOMEM; 214 215 drm_mode_set_name(mode); 216 217 mode->type = DRM_MODE_TYPE_DRIVER; 218 if (panel_info->num_modes == 1) 219 mode->type |= DRM_MODE_TYPE_PREFERRED; 220 221 drm_mode_probed_add(connector, mode); 222 } 223 224 connector->display_info.bpc = 8; 225 connector->display_info.width_mm = panel_info->width_mm; 226 connector->display_info.height_mm = panel_info->height_mm; 227 228 drm_display_info_set_bus_formats(&connector->display_info, 229 &panel_info->bus_format, 1); 230 connector->display_info.bus_flags = panel_info->bus_flags; 231 232 return panel_info->num_modes; 233 } 234 235 static const struct drm_panel_funcs nt39016_funcs = { 236 .prepare = nt39016_prepare, 237 .unprepare = nt39016_unprepare, 238 .enable = nt39016_enable, 239 .disable = nt39016_disable, 240 .get_modes = nt39016_get_modes, 241 }; 242 243 static int nt39016_probe(struct spi_device *spi) 244 { 245 struct device *dev = &spi->dev; 246 struct nt39016 *panel; 247 int err; 248 249 panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL); 250 if (!panel) 251 return -ENOMEM; 252 253 spi_set_drvdata(spi, panel); 254 255 panel->panel_info = of_device_get_match_data(dev); 256 if (!panel->panel_info) 257 return -EINVAL; 258 259 panel->supply = devm_regulator_get(dev, "power"); 260 if (IS_ERR(panel->supply)) 261 return dev_err_probe(dev, PTR_ERR(panel->supply), 262 "Failed to get power supply\n"); 263 264 panel->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); 265 if (IS_ERR(panel->reset_gpio)) 266 return dev_err_probe(dev, PTR_ERR(panel->reset_gpio), "Failed to get reset GPIO\n"); 267 268 spi->bits_per_word = 8; 269 spi->mode = SPI_MODE_3 | SPI_3WIRE; 270 err = spi_setup(spi); 271 if (err) { 272 dev_err(dev, "Failed to setup SPI\n"); 273 return err; 274 } 275 276 panel->map = devm_regmap_init_spi(spi, &nt39016_regmap_config); 277 if (IS_ERR(panel->map)) { 278 dev_err(dev, "Failed to init regmap\n"); 279 return PTR_ERR(panel->map); 280 } 281 282 drm_panel_init(&panel->drm_panel, dev, &nt39016_funcs, 283 DRM_MODE_CONNECTOR_DPI); 284 285 err = drm_panel_of_backlight(&panel->drm_panel); 286 if (err) 287 return dev_err_probe(dev, err, "Failed to get backlight handle\n"); 288 289 drm_panel_add(&panel->drm_panel); 290 291 return 0; 292 } 293 294 static void nt39016_remove(struct spi_device *spi) 295 { 296 struct nt39016 *panel = spi_get_drvdata(spi); 297 298 drm_panel_remove(&panel->drm_panel); 299 300 nt39016_disable(&panel->drm_panel); 301 nt39016_unprepare(&panel->drm_panel); 302 } 303 304 static const struct drm_display_mode kd035g6_display_modes[] = { 305 { /* 60 Hz */ 306 .clock = 6000, 307 .hdisplay = 320, 308 .hsync_start = 320 + 10, 309 .hsync_end = 320 + 10 + 50, 310 .htotal = 320 + 10 + 50 + 20, 311 .vdisplay = 240, 312 .vsync_start = 240 + 5, 313 .vsync_end = 240 + 5 + 1, 314 .vtotal = 240 + 5 + 1 + 4, 315 .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC, 316 }, 317 { /* 50 Hz */ 318 .clock = 5400, 319 .hdisplay = 320, 320 .hsync_start = 320 + 42, 321 .hsync_end = 320 + 42 + 50, 322 .htotal = 320 + 42 + 50 + 20, 323 .vdisplay = 240, 324 .vsync_start = 240 + 5, 325 .vsync_end = 240 + 5 + 1, 326 .vtotal = 240 + 5 + 1 + 4, 327 .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC, 328 }, 329 }; 330 331 static const struct nt39016_panel_info kd035g6_info = { 332 .display_modes = kd035g6_display_modes, 333 .num_modes = ARRAY_SIZE(kd035g6_display_modes), 334 .width_mm = 71, 335 .height_mm = 53, 336 .bus_format = MEDIA_BUS_FMT_RGB888_1X24, 337 .bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE, 338 }; 339 340 static const struct of_device_id nt39016_of_match[] = { 341 { .compatible = "kingdisplay,kd035g6-54nt", .data = &kd035g6_info }, 342 { /* sentinel */ } 343 }; 344 MODULE_DEVICE_TABLE(of, nt39016_of_match); 345 346 static struct spi_driver nt39016_driver = { 347 .driver = { 348 .name = "nt39016", 349 .of_match_table = nt39016_of_match, 350 }, 351 .probe = nt39016_probe, 352 .remove = nt39016_remove, 353 }; 354 355 module_spi_driver(nt39016_driver); 356 357 MODULE_AUTHOR("Maarten ter Huurne <maarten@treewalker.org>"); 358 MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>"); 359 MODULE_LICENSE("GPL v2"); 360