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/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");