1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * MIPI Display Bus Interface (DBI) LCD controller support 4 * 5 * Copyright 2016 Noralf Trønnes 6 */ 7 8 #include <linux/debugfs.h> 9 #include <linux/delay.h> 10 #include <linux/dma-buf.h> 11 #include <linux/gpio/consumer.h> 12 #include <linux/module.h> 13 #include <linux/regulator/consumer.h> 14 #include <linux/spi/spi.h> 15 16 #include <drm/drm_connector.h> 17 #include <drm/drm_damage_helper.h> 18 #include <drm/drm_drv.h> 19 #include <drm/drm_gem_cma_helper.h> 20 #include <drm/drm_format_helper.h> 21 #include <drm/drm_fourcc.h> 22 #include <drm/drm_gem_framebuffer_helper.h> 23 #include <drm/drm_mipi_dbi.h> 24 #include <drm/drm_modes.h> 25 #include <drm/drm_probe_helper.h> 26 #include <drm/drm_rect.h> 27 #include <video/mipi_display.h> 28 29 #define MIPI_DBI_MAX_SPI_READ_SPEED 2000000 /* 2MHz */ 30 31 #define DCS_POWER_MODE_DISPLAY BIT(2) 32 #define DCS_POWER_MODE_DISPLAY_NORMAL_MODE BIT(3) 33 #define DCS_POWER_MODE_SLEEP_MODE BIT(4) 34 #define DCS_POWER_MODE_PARTIAL_MODE BIT(5) 35 #define DCS_POWER_MODE_IDLE_MODE BIT(6) 36 #define DCS_POWER_MODE_RESERVED_MASK (BIT(0) | BIT(1) | BIT(7)) 37 38 /** 39 * DOC: overview 40 * 41 * This library provides helpers for MIPI Display Bus Interface (DBI) 42 * compatible display controllers. 43 * 44 * Many controllers for tiny lcd displays are MIPI compliant and can use this 45 * library. If a controller uses registers 0x2A and 0x2B to set the area to 46 * update and uses register 0x2C to write to frame memory, it is most likely 47 * MIPI compliant. 48 * 49 * Only MIPI Type 1 displays are supported since a full frame memory is needed. 50 * 51 * There are 3 MIPI DBI implementation types: 52 * 53 * A. Motorola 6800 type parallel bus 54 * 55 * B. Intel 8080 type parallel bus 56 * 57 * C. SPI type with 3 options: 58 * 59 * 1. 9-bit with the Data/Command signal as the ninth bit 60 * 2. Same as above except it's sent as 16 bits 61 * 3. 8-bit with the Data/Command signal as a separate D/CX pin 62 * 63 * Currently mipi_dbi only supports Type C options 1 and 3 with 64 * mipi_dbi_spi_init(). 65 */ 66 67 #define MIPI_DBI_DEBUG_COMMAND(cmd, data, len) \ 68 ({ \ 69 if (!len) \ 70 DRM_DEBUG_DRIVER("cmd=%02x\n", cmd); \ 71 else if (len <= 32) \ 72 DRM_DEBUG_DRIVER("cmd=%02x, par=%*ph\n", cmd, (int)len, data);\ 73 else \ 74 DRM_DEBUG_DRIVER("cmd=%02x, len=%zu\n", cmd, len); \ 75 }) 76 77 static const u8 mipi_dbi_dcs_read_commands[] = { 78 MIPI_DCS_GET_DISPLAY_ID, 79 MIPI_DCS_GET_RED_CHANNEL, 80 MIPI_DCS_GET_GREEN_CHANNEL, 81 MIPI_DCS_GET_BLUE_CHANNEL, 82 MIPI_DCS_GET_DISPLAY_STATUS, 83 MIPI_DCS_GET_POWER_MODE, 84 MIPI_DCS_GET_ADDRESS_MODE, 85 MIPI_DCS_GET_PIXEL_FORMAT, 86 MIPI_DCS_GET_DISPLAY_MODE, 87 MIPI_DCS_GET_SIGNAL_MODE, 88 MIPI_DCS_GET_DIAGNOSTIC_RESULT, 89 MIPI_DCS_READ_MEMORY_START, 90 MIPI_DCS_READ_MEMORY_CONTINUE, 91 MIPI_DCS_GET_SCANLINE, 92 MIPI_DCS_GET_DISPLAY_BRIGHTNESS, 93 MIPI_DCS_GET_CONTROL_DISPLAY, 94 MIPI_DCS_GET_POWER_SAVE, 95 MIPI_DCS_GET_CABC_MIN_BRIGHTNESS, 96 MIPI_DCS_READ_DDB_START, 97 MIPI_DCS_READ_DDB_CONTINUE, 98 0, /* sentinel */ 99 }; 100 101 static bool mipi_dbi_command_is_read(struct mipi_dbi *dbi, u8 cmd) 102 { 103 unsigned int i; 104 105 if (!dbi->read_commands) 106 return false; 107 108 for (i = 0; i < 0xff; i++) { 109 if (!dbi->read_commands[i]) 110 return false; 111 if (cmd == dbi->read_commands[i]) 112 return true; 113 } 114 115 return false; 116 } 117 118 /** 119 * mipi_dbi_command_read - MIPI DCS read command 120 * @dbi: MIPI DBI structure 121 * @cmd: Command 122 * @val: Value read 123 * 124 * Send MIPI DCS read command to the controller. 125 * 126 * Returns: 127 * Zero on success, negative error code on failure. 128 */ 129 int mipi_dbi_command_read(struct mipi_dbi *dbi, u8 cmd, u8 *val) 130 { 131 if (!dbi->read_commands) 132 return -EACCES; 133 134 if (!mipi_dbi_command_is_read(dbi, cmd)) 135 return -EINVAL; 136 137 return mipi_dbi_command_buf(dbi, cmd, val, 1); 138 } 139 EXPORT_SYMBOL(mipi_dbi_command_read); 140 141 /** 142 * mipi_dbi_command_buf - MIPI DCS command with parameter(s) in an array 143 * @dbi: MIPI DBI structure 144 * @cmd: Command 145 * @data: Parameter buffer 146 * @len: Buffer length 147 * 148 * Returns: 149 * Zero on success, negative error code on failure. 150 */ 151 int mipi_dbi_command_buf(struct mipi_dbi *dbi, u8 cmd, u8 *data, size_t len) 152 { 153 u8 *cmdbuf; 154 int ret; 155 156 /* SPI requires dma-safe buffers */ 157 cmdbuf = kmemdup(&cmd, 1, GFP_KERNEL); 158 if (!cmdbuf) 159 return -ENOMEM; 160 161 mutex_lock(&dbi->cmdlock); 162 ret = dbi->command(dbi, cmdbuf, data, len); 163 mutex_unlock(&dbi->cmdlock); 164 165 kfree(cmdbuf); 166 167 return ret; 168 } 169 EXPORT_SYMBOL(mipi_dbi_command_buf); 170 171 /* This should only be used by mipi_dbi_command() */ 172 int mipi_dbi_command_stackbuf(struct mipi_dbi *dbi, u8 cmd, const u8 *data, 173 size_t len) 174 { 175 u8 *buf; 176 int ret; 177 178 buf = kmemdup(data, len, GFP_KERNEL); 179 if (!buf) 180 return -ENOMEM; 181 182 ret = mipi_dbi_command_buf(dbi, cmd, buf, len); 183 184 kfree(buf); 185 186 return ret; 187 } 188 EXPORT_SYMBOL(mipi_dbi_command_stackbuf); 189 190 /** 191 * mipi_dbi_buf_copy - Copy a framebuffer, transforming it if necessary 192 * @dst: The destination buffer 193 * @fb: The source framebuffer 194 * @clip: Clipping rectangle of the area to be copied 195 * @swap: When true, swap MSB/LSB of 16-bit values 196 * 197 * Returns: 198 * Zero on success, negative error code on failure. 199 */ 200 int mipi_dbi_buf_copy(void *dst, struct drm_framebuffer *fb, 201 struct drm_rect *clip, bool swap) 202 { 203 struct drm_gem_object *gem = drm_gem_fb_get_obj(fb, 0); 204 struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(gem); 205 struct dma_buf_attachment *import_attach = gem->import_attach; 206 struct drm_format_name_buf format_name; 207 void *src = cma_obj->vaddr; 208 int ret = 0; 209 210 if (import_attach) { 211 ret = dma_buf_begin_cpu_access(import_attach->dmabuf, 212 DMA_FROM_DEVICE); 213 if (ret) 214 return ret; 215 } 216 217 switch (fb->format->format) { 218 case DRM_FORMAT_RGB565: 219 if (swap) 220 drm_fb_swab(dst, src, fb, clip, !import_attach); 221 else 222 drm_fb_memcpy(dst, src, fb, clip); 223 break; 224 case DRM_FORMAT_XRGB8888: 225 drm_fb_xrgb8888_to_rgb565(dst, src, fb, clip, swap); 226 break; 227 default: 228 drm_err_once(fb->dev, "Format is not supported: %s\n", 229 drm_get_format_name(fb->format->format, &format_name)); 230 return -EINVAL; 231 } 232 233 if (import_attach) 234 ret = dma_buf_end_cpu_access(import_attach->dmabuf, 235 DMA_FROM_DEVICE); 236 return ret; 237 } 238 EXPORT_SYMBOL(mipi_dbi_buf_copy); 239 240 static void mipi_dbi_set_window_address(struct mipi_dbi_dev *dbidev, 241 unsigned int xs, unsigned int xe, 242 unsigned int ys, unsigned int ye) 243 { 244 struct mipi_dbi *dbi = &dbidev->dbi; 245 246 xs += dbidev->left_offset; 247 xe += dbidev->left_offset; 248 ys += dbidev->top_offset; 249 ye += dbidev->top_offset; 250 251 mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS, (xs >> 8) & 0xff, 252 xs & 0xff, (xe >> 8) & 0xff, xe & 0xff); 253 mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS, (ys >> 8) & 0xff, 254 ys & 0xff, (ye >> 8) & 0xff, ye & 0xff); 255 } 256 257 static void mipi_dbi_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect) 258 { 259 struct drm_gem_object *gem = drm_gem_fb_get_obj(fb, 0); 260 struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(gem); 261 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev); 262 unsigned int height = rect->y2 - rect->y1; 263 unsigned int width = rect->x2 - rect->x1; 264 struct mipi_dbi *dbi = &dbidev->dbi; 265 bool swap = dbi->swap_bytes; 266 int idx, ret = 0; 267 bool full; 268 void *tr; 269 270 if (WARN_ON(!fb)) 271 return; 272 273 if (!drm_dev_enter(fb->dev, &idx)) 274 return; 275 276 full = width == fb->width && height == fb->height; 277 278 DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect)); 279 280 if (!dbi->dc || !full || swap || 281 fb->format->format == DRM_FORMAT_XRGB8888) { 282 tr = dbidev->tx_buf; 283 ret = mipi_dbi_buf_copy(dbidev->tx_buf, fb, rect, swap); 284 if (ret) 285 goto err_msg; 286 } else { 287 tr = cma_obj->vaddr; 288 } 289 290 mipi_dbi_set_window_address(dbidev, rect->x1, rect->x2 - 1, rect->y1, 291 rect->y2 - 1); 292 293 ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START, tr, 294 width * height * 2); 295 err_msg: 296 if (ret) 297 drm_err_once(fb->dev, "Failed to update display %d\n", ret); 298 299 drm_dev_exit(idx); 300 } 301 302 /** 303 * mipi_dbi_pipe_update - Display pipe update helper 304 * @pipe: Simple display pipe 305 * @old_state: Old plane state 306 * 307 * This function handles framebuffer flushing and vblank events. Drivers can use 308 * this as their &drm_simple_display_pipe_funcs->update callback. 309 */ 310 void mipi_dbi_pipe_update(struct drm_simple_display_pipe *pipe, 311 struct drm_plane_state *old_state) 312 { 313 struct drm_plane_state *state = pipe->plane.state; 314 struct drm_rect rect; 315 316 if (!pipe->crtc.state->active) 317 return; 318 319 if (drm_atomic_helper_damage_merged(old_state, state, &rect)) 320 mipi_dbi_fb_dirty(state->fb, &rect); 321 } 322 EXPORT_SYMBOL(mipi_dbi_pipe_update); 323 324 /** 325 * mipi_dbi_enable_flush - MIPI DBI enable helper 326 * @dbidev: MIPI DBI device structure 327 * @crtc_state: CRTC state 328 * @plane_state: Plane state 329 * 330 * Flushes the whole framebuffer and enables the backlight. Drivers can use this 331 * in their &drm_simple_display_pipe_funcs->enable callback. 332 * 333 * Note: Drivers which don't use mipi_dbi_pipe_update() because they have custom 334 * framebuffer flushing, can't use this function since they both use the same 335 * flushing code. 336 */ 337 void mipi_dbi_enable_flush(struct mipi_dbi_dev *dbidev, 338 struct drm_crtc_state *crtc_state, 339 struct drm_plane_state *plane_state) 340 { 341 struct drm_framebuffer *fb = plane_state->fb; 342 struct drm_rect rect = { 343 .x1 = 0, 344 .x2 = fb->width, 345 .y1 = 0, 346 .y2 = fb->height, 347 }; 348 int idx; 349 350 if (!drm_dev_enter(&dbidev->drm, &idx)) 351 return; 352 353 mipi_dbi_fb_dirty(fb, &rect); 354 backlight_enable(dbidev->backlight); 355 356 drm_dev_exit(idx); 357 } 358 EXPORT_SYMBOL(mipi_dbi_enable_flush); 359 360 static void mipi_dbi_blank(struct mipi_dbi_dev *dbidev) 361 { 362 struct drm_device *drm = &dbidev->drm; 363 u16 height = drm->mode_config.min_height; 364 u16 width = drm->mode_config.min_width; 365 struct mipi_dbi *dbi = &dbidev->dbi; 366 size_t len = width * height * 2; 367 int idx; 368 369 if (!drm_dev_enter(drm, &idx)) 370 return; 371 372 memset(dbidev->tx_buf, 0, len); 373 374 mipi_dbi_set_window_address(dbidev, 0, width - 1, 0, height - 1); 375 mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START, 376 (u8 *)dbidev->tx_buf, len); 377 378 drm_dev_exit(idx); 379 } 380 381 /** 382 * mipi_dbi_pipe_disable - MIPI DBI pipe disable helper 383 * @pipe: Display pipe 384 * 385 * This function disables backlight if present, if not the display memory is 386 * blanked. The regulator is disabled if in use. Drivers can use this as their 387 * &drm_simple_display_pipe_funcs->disable callback. 388 */ 389 void mipi_dbi_pipe_disable(struct drm_simple_display_pipe *pipe) 390 { 391 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev); 392 393 DRM_DEBUG_KMS("\n"); 394 395 if (dbidev->backlight) 396 backlight_disable(dbidev->backlight); 397 else 398 mipi_dbi_blank(dbidev); 399 400 if (dbidev->regulator) 401 regulator_disable(dbidev->regulator); 402 } 403 EXPORT_SYMBOL(mipi_dbi_pipe_disable); 404 405 static int mipi_dbi_connector_get_modes(struct drm_connector *connector) 406 { 407 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(connector->dev); 408 struct drm_display_mode *mode; 409 410 mode = drm_mode_duplicate(connector->dev, &dbidev->mode); 411 if (!mode) { 412 DRM_ERROR("Failed to duplicate mode\n"); 413 return 0; 414 } 415 416 if (mode->name[0] == '\0') 417 drm_mode_set_name(mode); 418 419 mode->type |= DRM_MODE_TYPE_PREFERRED; 420 drm_mode_probed_add(connector, mode); 421 422 if (mode->width_mm) { 423 connector->display_info.width_mm = mode->width_mm; 424 connector->display_info.height_mm = mode->height_mm; 425 } 426 427 return 1; 428 } 429 430 static const struct drm_connector_helper_funcs mipi_dbi_connector_hfuncs = { 431 .get_modes = mipi_dbi_connector_get_modes, 432 }; 433 434 static const struct drm_connector_funcs mipi_dbi_connector_funcs = { 435 .reset = drm_atomic_helper_connector_reset, 436 .fill_modes = drm_helper_probe_single_connector_modes, 437 .destroy = drm_connector_cleanup, 438 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, 439 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, 440 }; 441 442 static int mipi_dbi_rotate_mode(struct drm_display_mode *mode, 443 unsigned int rotation) 444 { 445 if (rotation == 0 || rotation == 180) { 446 return 0; 447 } else if (rotation == 90 || rotation == 270) { 448 swap(mode->hdisplay, mode->vdisplay); 449 swap(mode->hsync_start, mode->vsync_start); 450 swap(mode->hsync_end, mode->vsync_end); 451 swap(mode->htotal, mode->vtotal); 452 swap(mode->width_mm, mode->height_mm); 453 return 0; 454 } else { 455 return -EINVAL; 456 } 457 } 458 459 static const struct drm_mode_config_funcs mipi_dbi_mode_config_funcs = { 460 .fb_create = drm_gem_fb_create_with_dirty, 461 .atomic_check = drm_atomic_helper_check, 462 .atomic_commit = drm_atomic_helper_commit, 463 }; 464 465 static const uint32_t mipi_dbi_formats[] = { 466 DRM_FORMAT_RGB565, 467 DRM_FORMAT_XRGB8888, 468 }; 469 470 /** 471 * mipi_dbi_dev_init_with_formats - MIPI DBI device initialization with custom formats 472 * @dbidev: MIPI DBI device structure to initialize 473 * @funcs: Display pipe functions 474 * @formats: Array of supported formats (DRM_FORMAT\_\*). 475 * @format_count: Number of elements in @formats 476 * @mode: Display mode 477 * @rotation: Initial rotation in degrees Counter Clock Wise 478 * @tx_buf_size: Allocate a transmit buffer of this size. 479 * 480 * This function sets up a &drm_simple_display_pipe with a &drm_connector that 481 * has one fixed &drm_display_mode which is rotated according to @rotation. 482 * This mode is used to set the mode config min/max width/height properties. 483 * 484 * Use mipi_dbi_dev_init() if you don't need custom formats. 485 * 486 * Note: 487 * Some of the helper functions expects RGB565 to be the default format and the 488 * transmit buffer sized to fit that. 489 * 490 * Returns: 491 * Zero on success, negative error code on failure. 492 */ 493 int mipi_dbi_dev_init_with_formats(struct mipi_dbi_dev *dbidev, 494 const struct drm_simple_display_pipe_funcs *funcs, 495 const uint32_t *formats, unsigned int format_count, 496 const struct drm_display_mode *mode, 497 unsigned int rotation, size_t tx_buf_size) 498 { 499 static const uint64_t modifiers[] = { 500 DRM_FORMAT_MOD_LINEAR, 501 DRM_FORMAT_MOD_INVALID 502 }; 503 struct drm_device *drm = &dbidev->drm; 504 int ret; 505 506 if (!dbidev->dbi.command) 507 return -EINVAL; 508 509 ret = drmm_mode_config_init(drm); 510 if (ret) 511 return ret; 512 513 dbidev->tx_buf = devm_kmalloc(drm->dev, tx_buf_size, GFP_KERNEL); 514 if (!dbidev->tx_buf) 515 return -ENOMEM; 516 517 drm_mode_copy(&dbidev->mode, mode); 518 ret = mipi_dbi_rotate_mode(&dbidev->mode, rotation); 519 if (ret) { 520 DRM_ERROR("Illegal rotation value %u\n", rotation); 521 return -EINVAL; 522 } 523 524 drm_connector_helper_add(&dbidev->connector, &mipi_dbi_connector_hfuncs); 525 ret = drm_connector_init(drm, &dbidev->connector, &mipi_dbi_connector_funcs, 526 DRM_MODE_CONNECTOR_SPI); 527 if (ret) 528 return ret; 529 530 ret = drm_simple_display_pipe_init(drm, &dbidev->pipe, funcs, formats, format_count, 531 modifiers, &dbidev->connector); 532 if (ret) 533 return ret; 534 535 drm_plane_enable_fb_damage_clips(&dbidev->pipe.plane); 536 537 drm->mode_config.funcs = &mipi_dbi_mode_config_funcs; 538 drm->mode_config.min_width = dbidev->mode.hdisplay; 539 drm->mode_config.max_width = dbidev->mode.hdisplay; 540 drm->mode_config.min_height = dbidev->mode.vdisplay; 541 drm->mode_config.max_height = dbidev->mode.vdisplay; 542 dbidev->rotation = rotation; 543 544 DRM_DEBUG_KMS("rotation = %u\n", rotation); 545 546 return 0; 547 } 548 EXPORT_SYMBOL(mipi_dbi_dev_init_with_formats); 549 550 /** 551 * mipi_dbi_dev_init - MIPI DBI device initialization 552 * @dbidev: MIPI DBI device structure to initialize 553 * @funcs: Display pipe functions 554 * @mode: Display mode 555 * @rotation: Initial rotation in degrees Counter Clock Wise 556 * 557 * This function sets up a &drm_simple_display_pipe with a &drm_connector that 558 * has one fixed &drm_display_mode which is rotated according to @rotation. 559 * This mode is used to set the mode config min/max width/height properties. 560 * Additionally &mipi_dbi.tx_buf is allocated. 561 * 562 * Supported formats: Native RGB565 and emulated XRGB8888. 563 * 564 * Returns: 565 * Zero on success, negative error code on failure. 566 */ 567 int mipi_dbi_dev_init(struct mipi_dbi_dev *dbidev, 568 const struct drm_simple_display_pipe_funcs *funcs, 569 const struct drm_display_mode *mode, unsigned int rotation) 570 { 571 size_t bufsize = mode->vdisplay * mode->hdisplay * sizeof(u16); 572 573 dbidev->drm.mode_config.preferred_depth = 16; 574 575 return mipi_dbi_dev_init_with_formats(dbidev, funcs, mipi_dbi_formats, 576 ARRAY_SIZE(mipi_dbi_formats), mode, 577 rotation, bufsize); 578 } 579 EXPORT_SYMBOL(mipi_dbi_dev_init); 580 581 /** 582 * mipi_dbi_hw_reset - Hardware reset of controller 583 * @dbi: MIPI DBI structure 584 * 585 * Reset controller if the &mipi_dbi->reset gpio is set. 586 */ 587 void mipi_dbi_hw_reset(struct mipi_dbi *dbi) 588 { 589 if (!dbi->reset) 590 return; 591 592 gpiod_set_value_cansleep(dbi->reset, 0); 593 usleep_range(20, 1000); 594 gpiod_set_value_cansleep(dbi->reset, 1); 595 msleep(120); 596 } 597 EXPORT_SYMBOL(mipi_dbi_hw_reset); 598 599 /** 600 * mipi_dbi_display_is_on - Check if display is on 601 * @dbi: MIPI DBI structure 602 * 603 * This function checks the Power Mode register (if readable) to see if 604 * display output is turned on. This can be used to see if the bootloader 605 * has already turned on the display avoiding flicker when the pipeline is 606 * enabled. 607 * 608 * Returns: 609 * true if the display can be verified to be on, false otherwise. 610 */ 611 bool mipi_dbi_display_is_on(struct mipi_dbi *dbi) 612 { 613 u8 val; 614 615 if (mipi_dbi_command_read(dbi, MIPI_DCS_GET_POWER_MODE, &val)) 616 return false; 617 618 val &= ~DCS_POWER_MODE_RESERVED_MASK; 619 620 /* The poweron/reset value is 08h DCS_POWER_MODE_DISPLAY_NORMAL_MODE */ 621 if (val != (DCS_POWER_MODE_DISPLAY | 622 DCS_POWER_MODE_DISPLAY_NORMAL_MODE | DCS_POWER_MODE_SLEEP_MODE)) 623 return false; 624 625 DRM_DEBUG_DRIVER("Display is ON\n"); 626 627 return true; 628 } 629 EXPORT_SYMBOL(mipi_dbi_display_is_on); 630 631 static int mipi_dbi_poweron_reset_conditional(struct mipi_dbi_dev *dbidev, bool cond) 632 { 633 struct device *dev = dbidev->drm.dev; 634 struct mipi_dbi *dbi = &dbidev->dbi; 635 int ret; 636 637 if (dbidev->regulator) { 638 ret = regulator_enable(dbidev->regulator); 639 if (ret) { 640 DRM_DEV_ERROR(dev, "Failed to enable regulator (%d)\n", ret); 641 return ret; 642 } 643 } 644 645 if (cond && mipi_dbi_display_is_on(dbi)) 646 return 1; 647 648 mipi_dbi_hw_reset(dbi); 649 ret = mipi_dbi_command(dbi, MIPI_DCS_SOFT_RESET); 650 if (ret) { 651 DRM_DEV_ERROR(dev, "Failed to send reset command (%d)\n", ret); 652 if (dbidev->regulator) 653 regulator_disable(dbidev->regulator); 654 return ret; 655 } 656 657 /* 658 * If we did a hw reset, we know the controller is in Sleep mode and 659 * per MIPI DSC spec should wait 5ms after soft reset. If we didn't, 660 * we assume worst case and wait 120ms. 661 */ 662 if (dbi->reset) 663 usleep_range(5000, 20000); 664 else 665 msleep(120); 666 667 return 0; 668 } 669 670 /** 671 * mipi_dbi_poweron_reset - MIPI DBI poweron and reset 672 * @dbidev: MIPI DBI device structure 673 * 674 * This function enables the regulator if used and does a hardware and software 675 * reset. 676 * 677 * Returns: 678 * Zero on success, or a negative error code. 679 */ 680 int mipi_dbi_poweron_reset(struct mipi_dbi_dev *dbidev) 681 { 682 return mipi_dbi_poweron_reset_conditional(dbidev, false); 683 } 684 EXPORT_SYMBOL(mipi_dbi_poweron_reset); 685 686 /** 687 * mipi_dbi_poweron_conditional_reset - MIPI DBI poweron and conditional reset 688 * @dbidev: MIPI DBI device structure 689 * 690 * This function enables the regulator if used and if the display is off, it 691 * does a hardware and software reset. If mipi_dbi_display_is_on() determines 692 * that the display is on, no reset is performed. 693 * 694 * Returns: 695 * Zero if the controller was reset, 1 if the display was already on, or a 696 * negative error code. 697 */ 698 int mipi_dbi_poweron_conditional_reset(struct mipi_dbi_dev *dbidev) 699 { 700 return mipi_dbi_poweron_reset_conditional(dbidev, true); 701 } 702 EXPORT_SYMBOL(mipi_dbi_poweron_conditional_reset); 703 704 #if IS_ENABLED(CONFIG_SPI) 705 706 /** 707 * mipi_dbi_spi_cmd_max_speed - get the maximum SPI bus speed 708 * @spi: SPI device 709 * @len: The transfer buffer length. 710 * 711 * Many controllers have a max speed of 10MHz, but can be pushed way beyond 712 * that. Increase reliability by running pixel data at max speed and the rest 713 * at 10MHz, preventing transfer glitches from messing up the init settings. 714 */ 715 u32 mipi_dbi_spi_cmd_max_speed(struct spi_device *spi, size_t len) 716 { 717 if (len > 64) 718 return 0; /* use default */ 719 720 return min_t(u32, 10000000, spi->max_speed_hz); 721 } 722 EXPORT_SYMBOL(mipi_dbi_spi_cmd_max_speed); 723 724 static bool mipi_dbi_machine_little_endian(void) 725 { 726 #if defined(__LITTLE_ENDIAN) 727 return true; 728 #else 729 return false; 730 #endif 731 } 732 733 /* 734 * MIPI DBI Type C Option 1 735 * 736 * If the SPI controller doesn't have 9 bits per word support, 737 * use blocks of 9 bytes to send 8x 9-bit words using a 8-bit SPI transfer. 738 * Pad partial blocks with MIPI_DCS_NOP (zero). 739 * This is how the D/C bit (x) is added: 740 * x7654321 741 * 0x765432 742 * 10x76543 743 * 210x7654 744 * 3210x765 745 * 43210x76 746 * 543210x7 747 * 6543210x 748 * 76543210 749 */ 750 751 static int mipi_dbi_spi1e_transfer(struct mipi_dbi *dbi, int dc, 752 const void *buf, size_t len, 753 unsigned int bpw) 754 { 755 bool swap_bytes = (bpw == 16 && mipi_dbi_machine_little_endian()); 756 size_t chunk, max_chunk = dbi->tx_buf9_len; 757 struct spi_device *spi = dbi->spi; 758 struct spi_transfer tr = { 759 .tx_buf = dbi->tx_buf9, 760 .bits_per_word = 8, 761 }; 762 struct spi_message m; 763 const u8 *src = buf; 764 int i, ret; 765 u8 *dst; 766 767 if (drm_debug_enabled(DRM_UT_DRIVER)) 768 pr_debug("[drm:%s] dc=%d, max_chunk=%zu, transfers:\n", 769 __func__, dc, max_chunk); 770 771 tr.speed_hz = mipi_dbi_spi_cmd_max_speed(spi, len); 772 spi_message_init_with_transfers(&m, &tr, 1); 773 774 if (!dc) { 775 if (WARN_ON_ONCE(len != 1)) 776 return -EINVAL; 777 778 /* Command: pad no-op's (zeroes) at beginning of block */ 779 dst = dbi->tx_buf9; 780 memset(dst, 0, 9); 781 dst[8] = *src; 782 tr.len = 9; 783 784 return spi_sync(spi, &m); 785 } 786 787 /* max with room for adding one bit per byte */ 788 max_chunk = max_chunk / 9 * 8; 789 /* but no bigger than len */ 790 max_chunk = min(max_chunk, len); 791 /* 8 byte blocks */ 792 max_chunk = max_t(size_t, 8, max_chunk & ~0x7); 793 794 while (len) { 795 size_t added = 0; 796 797 chunk = min(len, max_chunk); 798 len -= chunk; 799 dst = dbi->tx_buf9; 800 801 if (chunk < 8) { 802 u8 val, carry = 0; 803 804 /* Data: pad no-op's (zeroes) at end of block */ 805 memset(dst, 0, 9); 806 807 if (swap_bytes) { 808 for (i = 1; i < (chunk + 1); i++) { 809 val = src[1]; 810 *dst++ = carry | BIT(8 - i) | (val >> i); 811 carry = val << (8 - i); 812 i++; 813 val = src[0]; 814 *dst++ = carry | BIT(8 - i) | (val >> i); 815 carry = val << (8 - i); 816 src += 2; 817 } 818 *dst++ = carry; 819 } else { 820 for (i = 1; i < (chunk + 1); i++) { 821 val = *src++; 822 *dst++ = carry | BIT(8 - i) | (val >> i); 823 carry = val << (8 - i); 824 } 825 *dst++ = carry; 826 } 827 828 chunk = 8; 829 added = 1; 830 } else { 831 for (i = 0; i < chunk; i += 8) { 832 if (swap_bytes) { 833 *dst++ = BIT(7) | (src[1] >> 1); 834 *dst++ = (src[1] << 7) | BIT(6) | (src[0] >> 2); 835 *dst++ = (src[0] << 6) | BIT(5) | (src[3] >> 3); 836 *dst++ = (src[3] << 5) | BIT(4) | (src[2] >> 4); 837 *dst++ = (src[2] << 4) | BIT(3) | (src[5] >> 5); 838 *dst++ = (src[5] << 3) | BIT(2) | (src[4] >> 6); 839 *dst++ = (src[4] << 2) | BIT(1) | (src[7] >> 7); 840 *dst++ = (src[7] << 1) | BIT(0); 841 *dst++ = src[6]; 842 } else { 843 *dst++ = BIT(7) | (src[0] >> 1); 844 *dst++ = (src[0] << 7) | BIT(6) | (src[1] >> 2); 845 *dst++ = (src[1] << 6) | BIT(5) | (src[2] >> 3); 846 *dst++ = (src[2] << 5) | BIT(4) | (src[3] >> 4); 847 *dst++ = (src[3] << 4) | BIT(3) | (src[4] >> 5); 848 *dst++ = (src[4] << 3) | BIT(2) | (src[5] >> 6); 849 *dst++ = (src[5] << 2) | BIT(1) | (src[6] >> 7); 850 *dst++ = (src[6] << 1) | BIT(0); 851 *dst++ = src[7]; 852 } 853 854 src += 8; 855 added++; 856 } 857 } 858 859 tr.len = chunk + added; 860 861 ret = spi_sync(spi, &m); 862 if (ret) 863 return ret; 864 } 865 866 return 0; 867 } 868 869 static int mipi_dbi_spi1_transfer(struct mipi_dbi *dbi, int dc, 870 const void *buf, size_t len, 871 unsigned int bpw) 872 { 873 struct spi_device *spi = dbi->spi; 874 struct spi_transfer tr = { 875 .bits_per_word = 9, 876 }; 877 const u16 *src16 = buf; 878 const u8 *src8 = buf; 879 struct spi_message m; 880 size_t max_chunk; 881 u16 *dst16; 882 int ret; 883 884 if (!spi_is_bpw_supported(spi, 9)) 885 return mipi_dbi_spi1e_transfer(dbi, dc, buf, len, bpw); 886 887 tr.speed_hz = mipi_dbi_spi_cmd_max_speed(spi, len); 888 max_chunk = dbi->tx_buf9_len; 889 dst16 = dbi->tx_buf9; 890 891 if (drm_debug_enabled(DRM_UT_DRIVER)) 892 pr_debug("[drm:%s] dc=%d, max_chunk=%zu, transfers:\n", 893 __func__, dc, max_chunk); 894 895 max_chunk = min(max_chunk / 2, len); 896 897 spi_message_init_with_transfers(&m, &tr, 1); 898 tr.tx_buf = dst16; 899 900 while (len) { 901 size_t chunk = min(len, max_chunk); 902 unsigned int i; 903 904 if (bpw == 16 && mipi_dbi_machine_little_endian()) { 905 for (i = 0; i < (chunk * 2); i += 2) { 906 dst16[i] = *src16 >> 8; 907 dst16[i + 1] = *src16++ & 0xFF; 908 if (dc) { 909 dst16[i] |= 0x0100; 910 dst16[i + 1] |= 0x0100; 911 } 912 } 913 } else { 914 for (i = 0; i < chunk; i++) { 915 dst16[i] = *src8++; 916 if (dc) 917 dst16[i] |= 0x0100; 918 } 919 } 920 921 tr.len = chunk * 2; 922 len -= chunk; 923 924 ret = spi_sync(spi, &m); 925 if (ret) 926 return ret; 927 } 928 929 return 0; 930 } 931 932 static int mipi_dbi_typec1_command(struct mipi_dbi *dbi, u8 *cmd, 933 u8 *parameters, size_t num) 934 { 935 unsigned int bpw = (*cmd == MIPI_DCS_WRITE_MEMORY_START) ? 16 : 8; 936 int ret; 937 938 if (mipi_dbi_command_is_read(dbi, *cmd)) 939 return -EOPNOTSUPP; 940 941 MIPI_DBI_DEBUG_COMMAND(*cmd, parameters, num); 942 943 ret = mipi_dbi_spi1_transfer(dbi, 0, cmd, 1, 8); 944 if (ret || !num) 945 return ret; 946 947 return mipi_dbi_spi1_transfer(dbi, 1, parameters, num, bpw); 948 } 949 950 /* MIPI DBI Type C Option 3 */ 951 952 static int mipi_dbi_typec3_command_read(struct mipi_dbi *dbi, u8 *cmd, 953 u8 *data, size_t len) 954 { 955 struct spi_device *spi = dbi->spi; 956 u32 speed_hz = min_t(u32, MIPI_DBI_MAX_SPI_READ_SPEED, 957 spi->max_speed_hz / 2); 958 struct spi_transfer tr[2] = { 959 { 960 .speed_hz = speed_hz, 961 .tx_buf = cmd, 962 .len = 1, 963 }, { 964 .speed_hz = speed_hz, 965 .len = len, 966 }, 967 }; 968 struct spi_message m; 969 u8 *buf; 970 int ret; 971 972 if (!len) 973 return -EINVAL; 974 975 /* 976 * Support non-standard 24-bit and 32-bit Nokia read commands which 977 * start with a dummy clock, so we need to read an extra byte. 978 */ 979 if (*cmd == MIPI_DCS_GET_DISPLAY_ID || 980 *cmd == MIPI_DCS_GET_DISPLAY_STATUS) { 981 if (!(len == 3 || len == 4)) 982 return -EINVAL; 983 984 tr[1].len = len + 1; 985 } 986 987 buf = kmalloc(tr[1].len, GFP_KERNEL); 988 if (!buf) 989 return -ENOMEM; 990 991 tr[1].rx_buf = buf; 992 gpiod_set_value_cansleep(dbi->dc, 0); 993 994 spi_message_init_with_transfers(&m, tr, ARRAY_SIZE(tr)); 995 ret = spi_sync(spi, &m); 996 if (ret) 997 goto err_free; 998 999 if (tr[1].len == len) { 1000 memcpy(data, buf, len); 1001 } else { 1002 unsigned int i; 1003 1004 for (i = 0; i < len; i++) 1005 data[i] = (buf[i] << 1) | (buf[i + 1] >> 7); 1006 } 1007 1008 MIPI_DBI_DEBUG_COMMAND(*cmd, data, len); 1009 1010 err_free: 1011 kfree(buf); 1012 1013 return ret; 1014 } 1015 1016 static int mipi_dbi_typec3_command(struct mipi_dbi *dbi, u8 *cmd, 1017 u8 *par, size_t num) 1018 { 1019 struct spi_device *spi = dbi->spi; 1020 unsigned int bpw = 8; 1021 u32 speed_hz; 1022 int ret; 1023 1024 if (mipi_dbi_command_is_read(dbi, *cmd)) 1025 return mipi_dbi_typec3_command_read(dbi, cmd, par, num); 1026 1027 MIPI_DBI_DEBUG_COMMAND(*cmd, par, num); 1028 1029 gpiod_set_value_cansleep(dbi->dc, 0); 1030 speed_hz = mipi_dbi_spi_cmd_max_speed(spi, 1); 1031 ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, cmd, 1); 1032 if (ret || !num) 1033 return ret; 1034 1035 if (*cmd == MIPI_DCS_WRITE_MEMORY_START && !dbi->swap_bytes) 1036 bpw = 16; 1037 1038 gpiod_set_value_cansleep(dbi->dc, 1); 1039 speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num); 1040 1041 return mipi_dbi_spi_transfer(spi, speed_hz, bpw, par, num); 1042 } 1043 1044 /** 1045 * mipi_dbi_spi_init - Initialize MIPI DBI SPI interface 1046 * @spi: SPI device 1047 * @dbi: MIPI DBI structure to initialize 1048 * @dc: D/C gpio (optional) 1049 * 1050 * This function sets &mipi_dbi->command, enables &mipi_dbi->read_commands for the 1051 * usual read commands. It should be followed by a call to mipi_dbi_dev_init() or 1052 * a driver-specific init. 1053 * 1054 * If @dc is set, a Type C Option 3 interface is assumed, if not 1055 * Type C Option 1. 1056 * 1057 * If the SPI master driver doesn't support the necessary bits per word, 1058 * the following transformation is used: 1059 * 1060 * - 9-bit: reorder buffer as 9x 8-bit words, padded with no-op command. 1061 * - 16-bit: if big endian send as 8-bit, if little endian swap bytes 1062 * 1063 * Returns: 1064 * Zero on success, negative error code on failure. 1065 */ 1066 int mipi_dbi_spi_init(struct spi_device *spi, struct mipi_dbi *dbi, 1067 struct gpio_desc *dc) 1068 { 1069 struct device *dev = &spi->dev; 1070 int ret; 1071 1072 /* 1073 * Even though it's not the SPI device that does DMA (the master does), 1074 * the dma mask is necessary for the dma_alloc_wc() in 1075 * drm_gem_cma_create(). The dma_addr returned will be a physical 1076 * address which might be different from the bus address, but this is 1077 * not a problem since the address will not be used. 1078 * The virtual address is used in the transfer and the SPI core 1079 * re-maps it on the SPI master device using the DMA streaming API 1080 * (spi_map_buf()). 1081 */ 1082 if (!dev->coherent_dma_mask) { 1083 ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32)); 1084 if (ret) { 1085 dev_warn(dev, "Failed to set dma mask %d\n", ret); 1086 return ret; 1087 } 1088 } 1089 1090 dbi->spi = spi; 1091 dbi->read_commands = mipi_dbi_dcs_read_commands; 1092 1093 if (dc) { 1094 dbi->command = mipi_dbi_typec3_command; 1095 dbi->dc = dc; 1096 if (mipi_dbi_machine_little_endian() && !spi_is_bpw_supported(spi, 16)) 1097 dbi->swap_bytes = true; 1098 } else { 1099 dbi->command = mipi_dbi_typec1_command; 1100 dbi->tx_buf9_len = SZ_16K; 1101 dbi->tx_buf9 = devm_kmalloc(dev, dbi->tx_buf9_len, GFP_KERNEL); 1102 if (!dbi->tx_buf9) 1103 return -ENOMEM; 1104 } 1105 1106 mutex_init(&dbi->cmdlock); 1107 1108 DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000); 1109 1110 return 0; 1111 } 1112 EXPORT_SYMBOL(mipi_dbi_spi_init); 1113 1114 /** 1115 * mipi_dbi_spi_transfer - SPI transfer helper 1116 * @spi: SPI device 1117 * @speed_hz: Override speed (optional) 1118 * @bpw: Bits per word 1119 * @buf: Buffer to transfer 1120 * @len: Buffer length 1121 * 1122 * This SPI transfer helper breaks up the transfer of @buf into chunks which 1123 * the SPI controller driver can handle. 1124 * 1125 * Returns: 1126 * Zero on success, negative error code on failure. 1127 */ 1128 int mipi_dbi_spi_transfer(struct spi_device *spi, u32 speed_hz, 1129 u8 bpw, const void *buf, size_t len) 1130 { 1131 size_t max_chunk = spi_max_transfer_size(spi); 1132 struct spi_transfer tr = { 1133 .bits_per_word = bpw, 1134 .speed_hz = speed_hz, 1135 }; 1136 struct spi_message m; 1137 size_t chunk; 1138 int ret; 1139 1140 spi_message_init_with_transfers(&m, &tr, 1); 1141 1142 while (len) { 1143 chunk = min(len, max_chunk); 1144 1145 tr.tx_buf = buf; 1146 tr.len = chunk; 1147 buf += chunk; 1148 len -= chunk; 1149 1150 ret = spi_sync(spi, &m); 1151 if (ret) 1152 return ret; 1153 } 1154 1155 return 0; 1156 } 1157 EXPORT_SYMBOL(mipi_dbi_spi_transfer); 1158 1159 #endif /* CONFIG_SPI */ 1160 1161 #ifdef CONFIG_DEBUG_FS 1162 1163 static ssize_t mipi_dbi_debugfs_command_write(struct file *file, 1164 const char __user *ubuf, 1165 size_t count, loff_t *ppos) 1166 { 1167 struct seq_file *m = file->private_data; 1168 struct mipi_dbi_dev *dbidev = m->private; 1169 u8 val, cmd = 0, parameters[64]; 1170 char *buf, *pos, *token; 1171 int i, ret, idx; 1172 1173 if (!drm_dev_enter(&dbidev->drm, &idx)) 1174 return -ENODEV; 1175 1176 buf = memdup_user_nul(ubuf, count); 1177 if (IS_ERR(buf)) { 1178 ret = PTR_ERR(buf); 1179 goto err_exit; 1180 } 1181 1182 /* strip trailing whitespace */ 1183 for (i = count - 1; i > 0; i--) 1184 if (isspace(buf[i])) 1185 buf[i] = '\0'; 1186 else 1187 break; 1188 i = 0; 1189 pos = buf; 1190 while (pos) { 1191 token = strsep(&pos, " "); 1192 if (!token) { 1193 ret = -EINVAL; 1194 goto err_free; 1195 } 1196 1197 ret = kstrtou8(token, 16, &val); 1198 if (ret < 0) 1199 goto err_free; 1200 1201 if (token == buf) 1202 cmd = val; 1203 else 1204 parameters[i++] = val; 1205 1206 if (i == 64) { 1207 ret = -E2BIG; 1208 goto err_free; 1209 } 1210 } 1211 1212 ret = mipi_dbi_command_buf(&dbidev->dbi, cmd, parameters, i); 1213 1214 err_free: 1215 kfree(buf); 1216 err_exit: 1217 drm_dev_exit(idx); 1218 1219 return ret < 0 ? ret : count; 1220 } 1221 1222 static int mipi_dbi_debugfs_command_show(struct seq_file *m, void *unused) 1223 { 1224 struct mipi_dbi_dev *dbidev = m->private; 1225 struct mipi_dbi *dbi = &dbidev->dbi; 1226 u8 cmd, val[4]; 1227 int ret, idx; 1228 size_t len; 1229 1230 if (!drm_dev_enter(&dbidev->drm, &idx)) 1231 return -ENODEV; 1232 1233 for (cmd = 0; cmd < 255; cmd++) { 1234 if (!mipi_dbi_command_is_read(dbi, cmd)) 1235 continue; 1236 1237 switch (cmd) { 1238 case MIPI_DCS_READ_MEMORY_START: 1239 case MIPI_DCS_READ_MEMORY_CONTINUE: 1240 len = 2; 1241 break; 1242 case MIPI_DCS_GET_DISPLAY_ID: 1243 len = 3; 1244 break; 1245 case MIPI_DCS_GET_DISPLAY_STATUS: 1246 len = 4; 1247 break; 1248 default: 1249 len = 1; 1250 break; 1251 } 1252 1253 seq_printf(m, "%02x: ", cmd); 1254 ret = mipi_dbi_command_buf(dbi, cmd, val, len); 1255 if (ret) { 1256 seq_puts(m, "XX\n"); 1257 continue; 1258 } 1259 seq_printf(m, "%*phN\n", (int)len, val); 1260 } 1261 1262 drm_dev_exit(idx); 1263 1264 return 0; 1265 } 1266 1267 static int mipi_dbi_debugfs_command_open(struct inode *inode, 1268 struct file *file) 1269 { 1270 return single_open(file, mipi_dbi_debugfs_command_show, 1271 inode->i_private); 1272 } 1273 1274 static const struct file_operations mipi_dbi_debugfs_command_fops = { 1275 .owner = THIS_MODULE, 1276 .open = mipi_dbi_debugfs_command_open, 1277 .read = seq_read, 1278 .llseek = seq_lseek, 1279 .release = single_release, 1280 .write = mipi_dbi_debugfs_command_write, 1281 }; 1282 1283 /** 1284 * mipi_dbi_debugfs_init - Create debugfs entries 1285 * @minor: DRM minor 1286 * 1287 * This function creates a 'command' debugfs file for sending commands to the 1288 * controller or getting the read command values. 1289 * Drivers can use this as their &drm_driver->debugfs_init callback. 1290 * 1291 */ 1292 void mipi_dbi_debugfs_init(struct drm_minor *minor) 1293 { 1294 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(minor->dev); 1295 umode_t mode = S_IFREG | S_IWUSR; 1296 1297 if (dbidev->dbi.read_commands) 1298 mode |= S_IRUGO; 1299 debugfs_create_file("command", mode, minor->debugfs_root, dbidev, 1300 &mipi_dbi_debugfs_command_fops); 1301 } 1302 EXPORT_SYMBOL(mipi_dbi_debugfs_init); 1303 1304 #endif 1305 1306 MODULE_LICENSE("GPL"); 1307