drivers/gpu/drm/panel/panel-novatek-nt39016.c

   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");