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/of_device.h> 16 #include <linux/regmap.h> 17 #include <linux/regulator/consumer.h> 18 #include <linux/spi/spi.h> 19 20 #include <drm/drm_modes.h> 21 #include <drm/drm_panel.h> 22 23 enum nt39016_regs { 24 NT39016_REG_SYSTEM, 25 NT39016_REG_TIMING, 26 NT39016_REG_OP, 27 NT39016_REG_DATA_IN, 28 NT39016_REG_SRC_TIMING_DELAY, 29 NT39016_REG_GATE_TIMING_DELAY, 30 NT39016_REG_RESERVED, 31 NT39016_REG_INITIAL_FUNC, 32 NT39016_REG_CONTRAST, 33 NT39016_REG_BRIGHTNESS, 34 NT39016_REG_HUE_SATURATION, 35 NT39016_REG_RB_SUBCONTRAST, 36 NT39016_REG_R_SUBBRIGHTNESS, 37 NT39016_REG_B_SUBBRIGHTNESS, 38 NT39016_REG_VCOMDC, 39 NT39016_REG_VCOMAC, 40 NT39016_REG_VGAM2, 41 NT39016_REG_VGAM34, 42 NT39016_REG_VGAM56, 43 NT39016_REG_VCOMDC_TRIM = 0x1e, 44 NT39016_REG_DISPLAY_MODE = 0x20, 45 }; 46 47 #define NT39016_SYSTEM_RESET_N BIT(0) 48 #define NT39016_SYSTEM_STANDBY BIT(1) 49 50 struct nt39016_panel_info { 51 const struct drm_display_mode *display_modes; 52 unsigned int num_modes; 53 u16 width_mm, height_mm; 54 u32 bus_format, bus_flags; 55 }; 56 57 struct nt39016 { 58 struct drm_panel drm_panel; 59 struct regmap *map; 60 struct regulator *supply; 61 const struct nt39016_panel_info *panel_info; 62 63 struct gpio_desc *reset_gpio; 64 }; 65 66 static inline struct nt39016 *to_nt39016(struct drm_panel *panel) 67 { 68 return container_of(panel, struct nt39016, drm_panel); 69 } 70 71 #define RV(REG, VAL) { .reg = (REG), .def = (VAL), .delay_us = 2 } 72 static const struct reg_sequence nt39016_panel_regs[] = { 73 RV(NT39016_REG_SYSTEM, 0x00), 74 RV(NT39016_REG_TIMING, 0x00), 75 RV(NT39016_REG_OP, 0x03), 76 RV(NT39016_REG_DATA_IN, 0xCC), 77 RV(NT39016_REG_SRC_TIMING_DELAY, 0x46), 78 RV(NT39016_REG_GATE_TIMING_DELAY, 0x05), 79 RV(NT39016_REG_RESERVED, 0x00), 80 RV(NT39016_REG_INITIAL_FUNC, 0x00), 81 RV(NT39016_REG_CONTRAST, 0x08), 82 RV(NT39016_REG_BRIGHTNESS, 0x40), 83 RV(NT39016_REG_HUE_SATURATION, 0x88), 84 RV(NT39016_REG_RB_SUBCONTRAST, 0x88), 85 RV(NT39016_REG_R_SUBBRIGHTNESS, 0x20), 86 RV(NT39016_REG_B_SUBBRIGHTNESS, 0x20), 87 RV(NT39016_REG_VCOMDC, 0x67), 88 RV(NT39016_REG_VCOMAC, 0xA4), 89 RV(NT39016_REG_VGAM2, 0x04), 90 RV(NT39016_REG_VGAM34, 0x24), 91 RV(NT39016_REG_VGAM56, 0x24), 92 RV(NT39016_REG_DISPLAY_MODE, 0x00), 93 }; 94 95 #undef RV 96 97 static const struct regmap_range nt39016_regmap_no_ranges[] = { 98 regmap_reg_range(0x13, 0x1D), 99 regmap_reg_range(0x1F, 0x1F), 100 }; 101 102 static const struct regmap_access_table nt39016_regmap_access_table = { 103 .no_ranges = nt39016_regmap_no_ranges, 104 .n_no_ranges = ARRAY_SIZE(nt39016_regmap_no_ranges), 105 }; 106 107 static const struct regmap_config nt39016_regmap_config = { 108 .reg_bits = 6, 109 .pad_bits = 2, 110 .val_bits = 8, 111 112 .max_register = NT39016_REG_DISPLAY_MODE, 113 .wr_table = &nt39016_regmap_access_table, 114 .write_flag_mask = 0x02, 115 116 .cache_type = REGCACHE_FLAT, 117 }; 118 119 static int nt39016_prepare(struct drm_panel *drm_panel) 120 { 121 struct nt39016 *panel = to_nt39016(drm_panel); 122 int err; 123 124 err = regulator_enable(panel->supply); 125 if (err) { 126 dev_err(drm_panel->dev, "Failed to enable power supply: %d\n", err); 127 return err; 128 } 129 130 /* 131 * Reset the NT39016. 132 * The documentation says the reset pulse should be at least 40 us to 133 * pass the glitch filter, but when testing I see some resets fail and 134 * some succeed when using a 70 us delay, so we use 100 us instead. 135 */ 136 gpiod_set_value_cansleep(panel->reset_gpio, 1); 137 usleep_range(100, 1000); 138 gpiod_set_value_cansleep(panel->reset_gpio, 0); 139 udelay(2); 140 141 /* Init all registers. */ 142 err = regmap_multi_reg_write(panel->map, nt39016_panel_regs, 143 ARRAY_SIZE(nt39016_panel_regs)); 144 if (err) { 145 dev_err(drm_panel->dev, "Failed to init registers: %d\n", err); 146 goto err_disable_regulator; 147 } 148 149 return 0; 150 151 err_disable_regulator: 152 regulator_disable(panel->supply); 153 return err; 154 } 155 156 static int nt39016_unprepare(struct drm_panel *drm_panel) 157 { 158 struct nt39016 *panel = to_nt39016(drm_panel); 159 160 gpiod_set_value_cansleep(panel->reset_gpio, 1); 161 162 regulator_disable(panel->supply); 163 164 return 0; 165 } 166 167 static int nt39016_enable(struct drm_panel *drm_panel) 168 { 169 struct nt39016 *panel = to_nt39016(drm_panel); 170 int ret; 171 172 ret = regmap_write(panel->map, NT39016_REG_SYSTEM, 173 NT39016_SYSTEM_RESET_N | NT39016_SYSTEM_STANDBY); 174 if (ret) { 175 dev_err(drm_panel->dev, "Unable to enable panel: %d\n", ret); 176 return ret; 177 } 178 179 if (drm_panel->backlight) { 180 /* Wait for the picture to be ready before enabling backlight */ 181 msleep(150); 182 } 183 184 return 0; 185 } 186 187 static int nt39016_disable(struct drm_panel *drm_panel) 188 { 189 struct nt39016 *panel = to_nt39016(drm_panel); 190 int err; 191 192 err = regmap_write(panel->map, NT39016_REG_SYSTEM, 193 NT39016_SYSTEM_RESET_N); 194 if (err) { 195 dev_err(drm_panel->dev, "Unable to disable panel: %d\n", err); 196 return err; 197 } 198 199 return 0; 200 } 201 202 static int nt39016_get_modes(struct drm_panel *drm_panel, 203 struct drm_connector *connector) 204 { 205 struct nt39016 *panel = to_nt39016(drm_panel); 206 const struct nt39016_panel_info *panel_info = panel->panel_info; 207 struct drm_display_mode *mode; 208 unsigned int i; 209 210 for (i = 0; i < panel_info->num_modes; i++) { 211 mode = drm_mode_duplicate(connector->dev, 212 &panel_info->display_modes[i]); 213 if (!mode) 214 return -ENOMEM; 215 216 drm_mode_set_name(mode); 217 218 mode->type = DRM_MODE_TYPE_DRIVER; 219 if (panel_info->num_modes == 1) 220 mode->type |= DRM_MODE_TYPE_PREFERRED; 221 222 drm_mode_probed_add(connector, mode); 223 } 224 225 connector->display_info.bpc = 8; 226 connector->display_info.width_mm = panel_info->width_mm; 227 connector->display_info.height_mm = panel_info->height_mm; 228 229 drm_display_info_set_bus_formats(&connector->display_info, 230 &panel_info->bus_format, 1); 231 connector->display_info.bus_flags = panel_info->bus_flags; 232 233 return panel_info->num_modes; 234 } 235 236 static const struct drm_panel_funcs nt39016_funcs = { 237 .prepare = nt39016_prepare, 238 .unprepare = nt39016_unprepare, 239 .enable = nt39016_enable, 240 .disable = nt39016_disable, 241 .get_modes = nt39016_get_modes, 242 }; 243 244 static int nt39016_probe(struct spi_device *spi) 245 { 246 struct device *dev = &spi->dev; 247 struct nt39016 *panel; 248 int err; 249 250 panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL); 251 if (!panel) 252 return -ENOMEM; 253 254 spi_set_drvdata(spi, panel); 255 256 panel->panel_info = of_device_get_match_data(dev); 257 if (!panel->panel_info) 258 return -EINVAL; 259 260 panel->supply = devm_regulator_get(dev, "power"); 261 if (IS_ERR(panel->supply)) { 262 dev_err(dev, "Failed to get power supply\n"); 263 return PTR_ERR(panel->supply); 264 } 265 266 panel->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); 267 if (IS_ERR(panel->reset_gpio)) { 268 dev_err(dev, "Failed to get reset GPIO\n"); 269 return PTR_ERR(panel->reset_gpio); 270 } 271 272 spi->bits_per_word = 8; 273 spi->mode = SPI_MODE_3 | SPI_3WIRE; 274 err = spi_setup(spi); 275 if (err) { 276 dev_err(dev, "Failed to setup SPI\n"); 277 return err; 278 } 279 280 panel->map = devm_regmap_init_spi(spi, &nt39016_regmap_config); 281 if (IS_ERR(panel->map)) { 282 dev_err(dev, "Failed to init regmap\n"); 283 return PTR_ERR(panel->map); 284 } 285 286 drm_panel_init(&panel->drm_panel, dev, &nt39016_funcs, 287 DRM_MODE_CONNECTOR_DPI); 288 289 err = drm_panel_of_backlight(&panel->drm_panel); 290 if (err) { 291 if (err != -EPROBE_DEFER) 292 dev_err(dev, "Failed to get backlight handle\n"); 293 return err; 294 } 295 296 drm_panel_add(&panel->drm_panel); 297 298 return 0; 299 } 300 301 static int nt39016_remove(struct spi_device *spi) 302 { 303 struct nt39016 *panel = spi_get_drvdata(spi); 304 305 drm_panel_remove(&panel->drm_panel); 306 307 nt39016_disable(&panel->drm_panel); 308 nt39016_unprepare(&panel->drm_panel); 309 310 return 0; 311 } 312 313 static const struct drm_display_mode kd035g6_display_modes[] = { 314 { /* 60 Hz */ 315 .clock = 6000, 316 .hdisplay = 320, 317 .hsync_start = 320 + 10, 318 .hsync_end = 320 + 10 + 50, 319 .htotal = 320 + 10 + 50 + 20, 320 .vdisplay = 240, 321 .vsync_start = 240 + 5, 322 .vsync_end = 240 + 5 + 1, 323 .vtotal = 240 + 5 + 1 + 4, 324 .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC, 325 }, 326 { /* 50 Hz */ 327 .clock = 5400, 328 .hdisplay = 320, 329 .hsync_start = 320 + 42, 330 .hsync_end = 320 + 42 + 50, 331 .htotal = 320 + 42 + 50 + 20, 332 .vdisplay = 240, 333 .vsync_start = 240 + 5, 334 .vsync_end = 240 + 5 + 1, 335 .vtotal = 240 + 5 + 1 + 4, 336 .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC, 337 }, 338 }; 339 340 static const struct nt39016_panel_info kd035g6_info = { 341 .display_modes = kd035g6_display_modes, 342 .num_modes = ARRAY_SIZE(kd035g6_display_modes), 343 .width_mm = 71, 344 .height_mm = 53, 345 .bus_format = MEDIA_BUS_FMT_RGB888_1X24, 346 .bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE, 347 }; 348 349 static const struct of_device_id nt39016_of_match[] = { 350 { .compatible = "kingdisplay,kd035g6-54nt", .data = &kd035g6_info }, 351 { /* sentinel */ } 352 }; 353 MODULE_DEVICE_TABLE(of, nt39016_of_match); 354 355 static struct spi_driver nt39016_driver = { 356 .driver = { 357 .name = "nt39016", 358 .of_match_table = nt39016_of_match, 359 }, 360 .probe = nt39016_probe, 361 .remove = nt39016_remove, 362 }; 363 364 module_spi_driver(nt39016_driver); 365 366 MODULE_AUTHOR("Maarten ter Huurne <maarten@treewalker.org>"); 367 MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>"); 368 MODULE_LICENSE("GPL v2"); 369