1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * DRM driver for MIPI DBI compatible display panels 4 * 5 * Copyright 2022 Noralf Trønnes 6 */ 7 8 #include <linux/backlight.h> 9 #include <linux/delay.h> 10 #include <linux/firmware.h> 11 #include <linux/gpio/consumer.h> 12 #include <linux/module.h> 13 #include <linux/of.h> 14 #include <linux/property.h> 15 #include <linux/regulator/consumer.h> 16 #include <linux/spi/spi.h> 17 18 #include <drm/clients/drm_client_setup.h> 19 #include <drm/drm_atomic_helper.h> 20 #include <drm/drm_drv.h> 21 #include <drm/drm_fbdev_dma.h> 22 #include <drm/drm_gem_atomic_helper.h> 23 #include <drm/drm_gem_dma_helper.h> 24 #include <drm/drm_managed.h> 25 #include <drm/drm_mipi_dbi.h> 26 #include <drm/drm_modes.h> 27 #include <drm/drm_modeset_helper.h> 28 #include <drm/drm_print.h> 29 30 #include <video/mipi_display.h> 31 32 struct panel_mipi_dbi_format { 33 const char *name; 34 u32 fourcc; 35 unsigned int bpp; 36 }; 37 38 static const struct panel_mipi_dbi_format panel_mipi_dbi_formats[] = { 39 { "r5g6b5", DRM_FORMAT_RGB565, 16 }, 40 { "b6x2g6x2r6x2", DRM_FORMAT_RGB888, 24 }, 41 }; 42 43 static int panel_mipi_dbi_get_format(struct device *dev, u32 *formats, unsigned int *bpp) 44 { 45 const char *format_name; 46 unsigned int i; 47 int ret; 48 49 formats[1] = DRM_FORMAT_XRGB8888; 50 51 ret = device_property_read_string(dev, "format", &format_name); 52 if (ret) { 53 /* Old Device Trees don't have this property */ 54 formats[0] = DRM_FORMAT_RGB565; 55 *bpp = 16; 56 return 0; 57 } 58 59 for (i = 0; i < ARRAY_SIZE(panel_mipi_dbi_formats); i++) { 60 const struct panel_mipi_dbi_format *format = &panel_mipi_dbi_formats[i]; 61 62 if (strcmp(format_name, format->name)) 63 continue; 64 65 formats[0] = format->fourcc; 66 *bpp = format->bpp; 67 return 0; 68 } 69 70 dev_err(dev, "Pixel format is not supported: '%s'\n", format_name); 71 72 return -EINVAL; 73 } 74 75 static const u8 panel_mipi_dbi_magic[15] = { 'M', 'I', 'P', 'I', ' ', 'D', 'B', 'I', 76 0, 0, 0, 0, 0, 0, 0 }; 77 78 /* 79 * The display controller configuration is stored in a firmware file. 80 * The Device Tree 'compatible' property value with a '.bin' suffix is passed 81 * to request_firmware() to fetch this file. 82 */ 83 struct panel_mipi_dbi_config { 84 /* Magic string: panel_mipi_dbi_magic */ 85 u8 magic[15]; 86 87 /* Config file format version */ 88 u8 file_format_version; 89 90 /* 91 * MIPI commands to execute when the display pipeline is enabled. 92 * This is used to configure the display controller. 93 * 94 * The commands are stored in a byte array with the format: 95 * command, num_parameters, [ parameter, ...], command, ... 96 * 97 * Some commands require a pause before the next command can be received. 98 * Inserting a delay in the command sequence is done by using the NOP command with one 99 * parameter: delay in miliseconds (the No Operation command is part of the MIPI Display 100 * Command Set where it has no parameters). 101 * 102 * Example: 103 * command 0x11 104 * sleep 120ms 105 * command 0xb1 parameters 0x01, 0x2c, 0x2d 106 * command 0x29 107 * 108 * Byte sequence: 109 * 0x11 0x00 110 * 0x00 0x01 0x78 111 * 0xb1 0x03 0x01 0x2c 0x2d 112 * 0x29 0x00 113 */ 114 u8 commands[]; 115 }; 116 117 struct panel_mipi_dbi_commands { 118 const u8 *buf; 119 size_t len; 120 }; 121 122 static struct panel_mipi_dbi_commands * 123 panel_mipi_dbi_check_commands(struct device *dev, const struct firmware *fw) 124 { 125 const struct panel_mipi_dbi_config *config = (struct panel_mipi_dbi_config *)fw->data; 126 struct panel_mipi_dbi_commands *commands; 127 size_t size = fw->size, commands_len; 128 unsigned int i = 0; 129 130 if (size < sizeof(*config) + 2) { /* At least 1 command */ 131 dev_err(dev, "config: file size=%zu is too small\n", size); 132 return ERR_PTR(-EINVAL); 133 } 134 135 if (memcmp(config->magic, panel_mipi_dbi_magic, sizeof(config->magic))) { 136 dev_err(dev, "config: Bad magic: %15ph\n", config->magic); 137 return ERR_PTR(-EINVAL); 138 } 139 140 if (config->file_format_version != 1) { 141 dev_err(dev, "config: version=%u is not supported\n", config->file_format_version); 142 return ERR_PTR(-EINVAL); 143 } 144 145 drm_dev_dbg(dev, DRM_UT_DRIVER, "size=%zu version=%u\n", size, config->file_format_version); 146 147 commands_len = size - sizeof(*config); 148 149 while ((i + 1) < commands_len) { 150 u8 command = config->commands[i++]; 151 u8 num_parameters = config->commands[i++]; 152 const u8 *parameters = &config->commands[i]; 153 154 i += num_parameters; 155 if (i > commands_len) { 156 dev_err(dev, "config: command=0x%02x num_parameters=%u overflows\n", 157 command, num_parameters); 158 return ERR_PTR(-EINVAL); 159 } 160 161 if (command == 0x00 && num_parameters == 1) 162 drm_dev_dbg(dev, DRM_UT_DRIVER, "sleep %ums\n", parameters[0]); 163 else 164 drm_dev_dbg(dev, DRM_UT_DRIVER, "command %02x %*ph\n", 165 command, num_parameters, parameters); 166 } 167 168 if (i != commands_len) { 169 dev_err(dev, "config: malformed command array\n"); 170 return ERR_PTR(-EINVAL); 171 } 172 173 commands = devm_kzalloc(dev, sizeof(*commands), GFP_KERNEL); 174 if (!commands) 175 return ERR_PTR(-ENOMEM); 176 177 commands->len = commands_len; 178 commands->buf = devm_kmemdup(dev, config->commands, commands->len, GFP_KERNEL); 179 if (!commands->buf) 180 return ERR_PTR(-ENOMEM); 181 182 return commands; 183 } 184 185 static struct panel_mipi_dbi_commands *panel_mipi_dbi_commands_from_fw(struct device *dev) 186 { 187 struct panel_mipi_dbi_commands *commands; 188 const struct firmware *fw; 189 const char *compatible; 190 char fw_name[40]; 191 int ret; 192 193 ret = of_property_read_string_index(dev->of_node, "compatible", 0, &compatible); 194 if (ret) 195 return ERR_PTR(ret); 196 197 snprintf(fw_name, sizeof(fw_name), "%s.bin", compatible); 198 ret = request_firmware(&fw, fw_name, dev); 199 if (ret) { 200 dev_err(dev, "No config file found for compatible '%s' (error=%d)\n", 201 compatible, ret); 202 203 return ERR_PTR(ret); 204 } 205 206 commands = panel_mipi_dbi_check_commands(dev, fw); 207 release_firmware(fw); 208 209 return commands; 210 } 211 212 static void panel_mipi_dbi_commands_execute(struct mipi_dbi *dbi, 213 struct panel_mipi_dbi_commands *commands) 214 { 215 unsigned int i = 0; 216 217 if (!commands) 218 return; 219 220 while (i < commands->len) { 221 u8 command = commands->buf[i++]; 222 u8 num_parameters = commands->buf[i++]; 223 const u8 *parameters = &commands->buf[i]; 224 225 if (command == 0x00 && num_parameters == 1) 226 msleep(parameters[0]); 227 else if (num_parameters) 228 mipi_dbi_command_stackbuf(dbi, command, parameters, num_parameters); 229 else 230 mipi_dbi_command(dbi, command); 231 232 i += num_parameters; 233 } 234 } 235 236 static void panel_mipi_dbi_enable(struct drm_simple_display_pipe *pipe, 237 struct drm_crtc_state *crtc_state, 238 struct drm_plane_state *plane_state) 239 { 240 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev); 241 struct mipi_dbi *dbi = &dbidev->dbi; 242 int ret, idx; 243 244 if (!drm_dev_enter(pipe->crtc.dev, &idx)) 245 return; 246 247 drm_dbg(pipe->crtc.dev, "\n"); 248 249 ret = mipi_dbi_poweron_conditional_reset(dbidev); 250 if (ret < 0) 251 goto out_exit; 252 if (!ret) 253 panel_mipi_dbi_commands_execute(dbi, dbidev->driver_private); 254 255 mipi_dbi_enable_flush(dbidev, crtc_state, plane_state); 256 out_exit: 257 drm_dev_exit(idx); 258 } 259 260 static const struct drm_simple_display_pipe_funcs panel_mipi_dbi_pipe_funcs = { 261 DRM_MIPI_DBI_SIMPLE_DISPLAY_PIPE_FUNCS(panel_mipi_dbi_enable), 262 }; 263 264 DEFINE_DRM_GEM_DMA_FOPS(panel_mipi_dbi_fops); 265 266 static const struct drm_driver panel_mipi_dbi_driver = { 267 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 268 .fops = &panel_mipi_dbi_fops, 269 DRM_GEM_DMA_DRIVER_OPS_VMAP, 270 DRM_FBDEV_DMA_DRIVER_OPS, 271 .debugfs_init = mipi_dbi_debugfs_init, 272 .name = "panel-mipi-dbi", 273 .desc = "MIPI DBI compatible display panel", 274 .major = 1, 275 .minor = 0, 276 }; 277 278 static int panel_mipi_dbi_get_mode(struct mipi_dbi_dev *dbidev, struct drm_display_mode *mode) 279 { 280 struct device *dev = dbidev->drm.dev; 281 u16 hback_porch, vback_porch; 282 int ret; 283 284 ret = of_get_drm_panel_display_mode(dev->of_node, mode, NULL); 285 if (ret) { 286 dev_err(dev, "%pOF: failed to get panel-timing (error=%d)\n", dev->of_node, ret); 287 return ret; 288 } 289 290 mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED; 291 292 hback_porch = mode->htotal - mode->hsync_end; 293 vback_porch = mode->vtotal - mode->vsync_end; 294 295 /* 296 * Make sure width and height are set and that only back porch and 297 * pixelclock are set in the other timing values. Also check that 298 * width and height don't exceed the 16-bit value specified by MIPI DCS. 299 */ 300 if (!mode->hdisplay || !mode->vdisplay || mode->flags || 301 mode->hsync_end > mode->hdisplay || (hback_porch + mode->hdisplay) > 0xffff || 302 mode->vsync_end > mode->vdisplay || (vback_porch + mode->vdisplay) > 0xffff) { 303 dev_err(dev, "%pOF: panel-timing out of bounds\n", dev->of_node); 304 return -EINVAL; 305 } 306 307 /* The driver doesn't use the pixel clock but it is mandatory so fake one if not set */ 308 if (!mode->clock) 309 mode->clock = mode->htotal * mode->vtotal * 60 / 1000; 310 311 dbidev->top_offset = vback_porch; 312 dbidev->left_offset = hback_porch; 313 314 return 0; 315 } 316 317 static int panel_mipi_dbi_spi_probe(struct spi_device *spi) 318 { 319 struct device *dev = &spi->dev; 320 struct drm_display_mode mode; 321 struct mipi_dbi_dev *dbidev; 322 struct drm_device *drm; 323 struct mipi_dbi *dbi; 324 struct gpio_desc *dc; 325 unsigned int bpp; 326 size_t buf_size; 327 u32 formats[2]; 328 int ret; 329 330 dbidev = devm_drm_dev_alloc(dev, &panel_mipi_dbi_driver, struct mipi_dbi_dev, drm); 331 if (IS_ERR(dbidev)) 332 return PTR_ERR(dbidev); 333 334 dbi = &dbidev->dbi; 335 drm = &dbidev->drm; 336 337 ret = panel_mipi_dbi_get_mode(dbidev, &mode); 338 if (ret) 339 return ret; 340 341 dbidev->regulator = devm_regulator_get(dev, "power"); 342 if (IS_ERR(dbidev->regulator)) 343 return dev_err_probe(dev, PTR_ERR(dbidev->regulator), 344 "Failed to get regulator 'power'\n"); 345 346 dbidev->io_regulator = devm_regulator_get(dev, "io"); 347 if (IS_ERR(dbidev->io_regulator)) 348 return dev_err_probe(dev, PTR_ERR(dbidev->io_regulator), 349 "Failed to get regulator 'io'\n"); 350 351 dbidev->backlight = devm_of_find_backlight(dev); 352 if (IS_ERR(dbidev->backlight)) 353 return dev_err_probe(dev, PTR_ERR(dbidev->backlight), "Failed to get backlight\n"); 354 355 dbi->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); 356 if (IS_ERR(dbi->reset)) 357 return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n"); 358 359 /* Multiple panels can share the "dc" GPIO, but only if they are on the same SPI bus! */ 360 dc = devm_gpiod_get_optional(dev, "dc", GPIOD_OUT_LOW | GPIOD_FLAGS_BIT_NONEXCLUSIVE); 361 if (IS_ERR(dc)) 362 return dev_err_probe(dev, PTR_ERR(dc), "Failed to get GPIO 'dc'\n"); 363 364 ret = mipi_dbi_spi_init(spi, dbi, dc); 365 if (ret) 366 return ret; 367 368 if (device_property_present(dev, "write-only")) 369 dbi->read_commands = NULL; 370 371 dbidev->driver_private = panel_mipi_dbi_commands_from_fw(dev); 372 if (IS_ERR(dbidev->driver_private)) 373 return PTR_ERR(dbidev->driver_private); 374 375 ret = panel_mipi_dbi_get_format(dev, formats, &bpp); 376 if (ret) 377 return ret; 378 379 buf_size = DIV_ROUND_UP(mode.hdisplay * mode.vdisplay * bpp, 8); 380 ret = mipi_dbi_dev_init_with_formats(dbidev, &panel_mipi_dbi_pipe_funcs, 381 formats, ARRAY_SIZE(formats), 382 &mode, 0, buf_size); 383 if (ret) 384 return ret; 385 386 drm_mode_config_reset(drm); 387 388 ret = drm_dev_register(drm, 0); 389 if (ret) 390 return ret; 391 392 spi_set_drvdata(spi, drm); 393 394 if (bpp == 16) 395 drm_client_setup_with_fourcc(drm, DRM_FORMAT_RGB565); 396 else 397 drm_client_setup_with_fourcc(drm, DRM_FORMAT_RGB888); 398 399 return 0; 400 } 401 402 static void panel_mipi_dbi_spi_remove(struct spi_device *spi) 403 { 404 struct drm_device *drm = spi_get_drvdata(spi); 405 406 drm_dev_unplug(drm); 407 drm_atomic_helper_shutdown(drm); 408 } 409 410 static void panel_mipi_dbi_spi_shutdown(struct spi_device *spi) 411 { 412 drm_atomic_helper_shutdown(spi_get_drvdata(spi)); 413 } 414 415 static int __maybe_unused panel_mipi_dbi_pm_suspend(struct device *dev) 416 { 417 return drm_mode_config_helper_suspend(dev_get_drvdata(dev)); 418 } 419 420 static int __maybe_unused panel_mipi_dbi_pm_resume(struct device *dev) 421 { 422 drm_mode_config_helper_resume(dev_get_drvdata(dev)); 423 424 return 0; 425 } 426 427 static const struct dev_pm_ops panel_mipi_dbi_pm_ops = { 428 SET_SYSTEM_SLEEP_PM_OPS(panel_mipi_dbi_pm_suspend, panel_mipi_dbi_pm_resume) 429 }; 430 431 static const struct of_device_id panel_mipi_dbi_spi_of_match[] = { 432 { .compatible = "panel-mipi-dbi-spi" }, 433 {}, 434 }; 435 MODULE_DEVICE_TABLE(of, panel_mipi_dbi_spi_of_match); 436 437 static const struct spi_device_id panel_mipi_dbi_spi_id[] = { 438 { "panel-mipi-dbi-spi", 0 }, 439 { }, 440 }; 441 MODULE_DEVICE_TABLE(spi, panel_mipi_dbi_spi_id); 442 443 static struct spi_driver panel_mipi_dbi_spi_driver = { 444 .driver = { 445 .name = "panel-mipi-dbi-spi", 446 .of_match_table = panel_mipi_dbi_spi_of_match, 447 .pm = &panel_mipi_dbi_pm_ops, 448 }, 449 .id_table = panel_mipi_dbi_spi_id, 450 .probe = panel_mipi_dbi_spi_probe, 451 .remove = panel_mipi_dbi_spi_remove, 452 .shutdown = panel_mipi_dbi_spi_shutdown, 453 }; 454 module_spi_driver(panel_mipi_dbi_spi_driver); 455 456 MODULE_DESCRIPTION("MIPI DBI compatible display panel driver"); 457 MODULE_AUTHOR("Noralf Trønnes"); 458 MODULE_LICENSE("GPL"); 459