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