1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * DRM driver for Pervasive Displays RePaper branded e-ink panels 4 * 5 * Copyright 2013-2017 Pervasive Displays, Inc. 6 * Copyright 2017 Noralf Trønnes 7 * 8 * The driver supports: 9 * Material Film: Aurora Mb (V231) 10 * Driver IC: G2 (eTC) 11 * 12 * The controller code was taken from the userspace driver: 13 * https://github.com/repaper/gratis 14 */ 15 16 #include <linux/delay.h> 17 #include <linux/dma-buf.h> 18 #include <linux/gpio/consumer.h> 19 #include <linux/module.h> 20 #include <linux/property.h> 21 #include <linux/sched/clock.h> 22 #include <linux/spi/spi.h> 23 #include <linux/thermal.h> 24 25 #include <drm/drm_atomic_helper.h> 26 #include <drm/drm_connector.h> 27 #include <drm/drm_damage_helper.h> 28 #include <drm/drm_drv.h> 29 #include <drm/drm_fb_cma_helper.h> 30 #include <drm/drm_fb_helper.h> 31 #include <drm/drm_format_helper.h> 32 #include <drm/drm_gem_cma_helper.h> 33 #include <drm/drm_gem_framebuffer_helper.h> 34 #include <drm/drm_managed.h> 35 #include <drm/drm_modes.h> 36 #include <drm/drm_rect.h> 37 #include <drm/drm_probe_helper.h> 38 #include <drm/drm_simple_kms_helper.h> 39 40 #define REPAPER_RID_G2_COG_ID 0x12 41 42 enum repaper_model { 43 /* 0 is reserved to avoid clashing with NULL */ 44 E1144CS021 = 1, 45 E1190CS021, 46 E2200CS021, 47 E2271CS021, 48 }; 49 50 enum repaper_stage { /* Image pixel -> Display pixel */ 51 REPAPER_COMPENSATE, /* B -> W, W -> B (Current Image) */ 52 REPAPER_WHITE, /* B -> N, W -> W (Current Image) */ 53 REPAPER_INVERSE, /* B -> N, W -> B (New Image) */ 54 REPAPER_NORMAL /* B -> B, W -> W (New Image) */ 55 }; 56 57 enum repaper_epd_border_byte { 58 REPAPER_BORDER_BYTE_NONE, 59 REPAPER_BORDER_BYTE_ZERO, 60 REPAPER_BORDER_BYTE_SET, 61 }; 62 63 struct repaper_epd { 64 struct drm_device drm; 65 struct drm_simple_display_pipe pipe; 66 const struct drm_display_mode *mode; 67 struct drm_connector connector; 68 struct spi_device *spi; 69 70 struct gpio_desc *panel_on; 71 struct gpio_desc *border; 72 struct gpio_desc *discharge; 73 struct gpio_desc *reset; 74 struct gpio_desc *busy; 75 76 struct thermal_zone_device *thermal; 77 78 unsigned int height; 79 unsigned int width; 80 unsigned int bytes_per_scan; 81 const u8 *channel_select; 82 unsigned int stage_time; 83 unsigned int factored_stage_time; 84 bool middle_scan; 85 bool pre_border_byte; 86 enum repaper_epd_border_byte border_byte; 87 88 u8 *line_buffer; 89 void *current_frame; 90 91 bool enabled; 92 bool cleared; 93 bool partial; 94 }; 95 96 static inline struct repaper_epd *drm_to_epd(struct drm_device *drm) 97 { 98 return container_of(drm, struct repaper_epd, drm); 99 } 100 101 static int repaper_spi_transfer(struct spi_device *spi, u8 header, 102 const void *tx, void *rx, size_t len) 103 { 104 void *txbuf = NULL, *rxbuf = NULL; 105 struct spi_transfer tr[2] = {}; 106 u8 *headerbuf; 107 int ret; 108 109 headerbuf = kmalloc(1, GFP_KERNEL); 110 if (!headerbuf) 111 return -ENOMEM; 112 113 headerbuf[0] = header; 114 tr[0].tx_buf = headerbuf; 115 tr[0].len = 1; 116 117 /* Stack allocated tx? */ 118 if (tx && len <= 32) { 119 txbuf = kmemdup(tx, len, GFP_KERNEL); 120 if (!txbuf) { 121 ret = -ENOMEM; 122 goto out_free; 123 } 124 } 125 126 if (rx) { 127 rxbuf = kmalloc(len, GFP_KERNEL); 128 if (!rxbuf) { 129 ret = -ENOMEM; 130 goto out_free; 131 } 132 } 133 134 tr[1].tx_buf = txbuf ? txbuf : tx; 135 tr[1].rx_buf = rxbuf; 136 tr[1].len = len; 137 138 ndelay(80); 139 ret = spi_sync_transfer(spi, tr, 2); 140 if (rx && !ret) 141 memcpy(rx, rxbuf, len); 142 143 out_free: 144 kfree(headerbuf); 145 kfree(txbuf); 146 kfree(rxbuf); 147 148 return ret; 149 } 150 151 static int repaper_write_buf(struct spi_device *spi, u8 reg, 152 const u8 *buf, size_t len) 153 { 154 int ret; 155 156 ret = repaper_spi_transfer(spi, 0x70, ®, NULL, 1); 157 if (ret) 158 return ret; 159 160 return repaper_spi_transfer(spi, 0x72, buf, NULL, len); 161 } 162 163 static int repaper_write_val(struct spi_device *spi, u8 reg, u8 val) 164 { 165 return repaper_write_buf(spi, reg, &val, 1); 166 } 167 168 static int repaper_read_val(struct spi_device *spi, u8 reg) 169 { 170 int ret; 171 u8 val; 172 173 ret = repaper_spi_transfer(spi, 0x70, ®, NULL, 1); 174 if (ret) 175 return ret; 176 177 ret = repaper_spi_transfer(spi, 0x73, NULL, &val, 1); 178 179 return ret ? ret : val; 180 } 181 182 static int repaper_read_id(struct spi_device *spi) 183 { 184 int ret; 185 u8 id; 186 187 ret = repaper_spi_transfer(spi, 0x71, NULL, &id, 1); 188 189 return ret ? ret : id; 190 } 191 192 static void repaper_spi_mosi_low(struct spi_device *spi) 193 { 194 const u8 buf[1] = { 0 }; 195 196 spi_write(spi, buf, 1); 197 } 198 199 /* pixels on display are numbered from 1 so even is actually bits 1,3,5,... */ 200 static void repaper_even_pixels(struct repaper_epd *epd, u8 **pp, 201 const u8 *data, u8 fixed_value, const u8 *mask, 202 enum repaper_stage stage) 203 { 204 unsigned int b; 205 206 for (b = 0; b < (epd->width / 8); b++) { 207 if (data) { 208 u8 pixels = data[b] & 0xaa; 209 u8 pixel_mask = 0xff; 210 u8 p1, p2, p3, p4; 211 212 if (mask) { 213 pixel_mask = (mask[b] ^ pixels) & 0xaa; 214 pixel_mask |= pixel_mask >> 1; 215 } 216 217 switch (stage) { 218 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */ 219 pixels = 0xaa | ((pixels ^ 0xaa) >> 1); 220 break; 221 case REPAPER_WHITE: /* B -> N, W -> W (Current) */ 222 pixels = 0x55 + ((pixels ^ 0xaa) >> 1); 223 break; 224 case REPAPER_INVERSE: /* B -> N, W -> B (New) */ 225 pixels = 0x55 | (pixels ^ 0xaa); 226 break; 227 case REPAPER_NORMAL: /* B -> B, W -> W (New) */ 228 pixels = 0xaa | (pixels >> 1); 229 break; 230 } 231 232 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x55); 233 p1 = (pixels >> 6) & 0x03; 234 p2 = (pixels >> 4) & 0x03; 235 p3 = (pixels >> 2) & 0x03; 236 p4 = (pixels >> 0) & 0x03; 237 pixels = (p1 << 0) | (p2 << 2) | (p3 << 4) | (p4 << 6); 238 *(*pp)++ = pixels; 239 } else { 240 *(*pp)++ = fixed_value; 241 } 242 } 243 } 244 245 /* pixels on display are numbered from 1 so odd is actually bits 0,2,4,... */ 246 static void repaper_odd_pixels(struct repaper_epd *epd, u8 **pp, 247 const u8 *data, u8 fixed_value, const u8 *mask, 248 enum repaper_stage stage) 249 { 250 unsigned int b; 251 252 for (b = epd->width / 8; b > 0; b--) { 253 if (data) { 254 u8 pixels = data[b - 1] & 0x55; 255 u8 pixel_mask = 0xff; 256 257 if (mask) { 258 pixel_mask = (mask[b - 1] ^ pixels) & 0x55; 259 pixel_mask |= pixel_mask << 1; 260 } 261 262 switch (stage) { 263 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */ 264 pixels = 0xaa | (pixels ^ 0x55); 265 break; 266 case REPAPER_WHITE: /* B -> N, W -> W (Current) */ 267 pixels = 0x55 + (pixels ^ 0x55); 268 break; 269 case REPAPER_INVERSE: /* B -> N, W -> B (New) */ 270 pixels = 0x55 | ((pixels ^ 0x55) << 1); 271 break; 272 case REPAPER_NORMAL: /* B -> B, W -> W (New) */ 273 pixels = 0xaa | pixels; 274 break; 275 } 276 277 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x55); 278 *(*pp)++ = pixels; 279 } else { 280 *(*pp)++ = fixed_value; 281 } 282 } 283 } 284 285 /* interleave bits: (byte)76543210 -> (16 bit).7.6.5.4.3.2.1 */ 286 static inline u16 repaper_interleave_bits(u16 value) 287 { 288 value = (value | (value << 4)) & 0x0f0f; 289 value = (value | (value << 2)) & 0x3333; 290 value = (value | (value << 1)) & 0x5555; 291 292 return value; 293 } 294 295 /* pixels on display are numbered from 1 */ 296 static void repaper_all_pixels(struct repaper_epd *epd, u8 **pp, 297 const u8 *data, u8 fixed_value, const u8 *mask, 298 enum repaper_stage stage) 299 { 300 unsigned int b; 301 302 for (b = epd->width / 8; b > 0; b--) { 303 if (data) { 304 u16 pixels = repaper_interleave_bits(data[b - 1]); 305 u16 pixel_mask = 0xffff; 306 307 if (mask) { 308 pixel_mask = repaper_interleave_bits(mask[b - 1]); 309 310 pixel_mask = (pixel_mask ^ pixels) & 0x5555; 311 pixel_mask |= pixel_mask << 1; 312 } 313 314 switch (stage) { 315 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */ 316 pixels = 0xaaaa | (pixels ^ 0x5555); 317 break; 318 case REPAPER_WHITE: /* B -> N, W -> W (Current) */ 319 pixels = 0x5555 + (pixels ^ 0x5555); 320 break; 321 case REPAPER_INVERSE: /* B -> N, W -> B (New) */ 322 pixels = 0x5555 | ((pixels ^ 0x5555) << 1); 323 break; 324 case REPAPER_NORMAL: /* B -> B, W -> W (New) */ 325 pixels = 0xaaaa | pixels; 326 break; 327 } 328 329 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x5555); 330 *(*pp)++ = pixels >> 8; 331 *(*pp)++ = pixels; 332 } else { 333 *(*pp)++ = fixed_value; 334 *(*pp)++ = fixed_value; 335 } 336 } 337 } 338 339 /* output one line of scan and data bytes to the display */ 340 static void repaper_one_line(struct repaper_epd *epd, unsigned int line, 341 const u8 *data, u8 fixed_value, const u8 *mask, 342 enum repaper_stage stage) 343 { 344 u8 *p = epd->line_buffer; 345 unsigned int b; 346 347 repaper_spi_mosi_low(epd->spi); 348 349 if (epd->pre_border_byte) 350 *p++ = 0x00; 351 352 if (epd->middle_scan) { 353 /* data bytes */ 354 repaper_odd_pixels(epd, &p, data, fixed_value, mask, stage); 355 356 /* scan line */ 357 for (b = epd->bytes_per_scan; b > 0; b--) { 358 if (line / 4 == b - 1) 359 *p++ = 0x03 << (2 * (line & 0x03)); 360 else 361 *p++ = 0x00; 362 } 363 364 /* data bytes */ 365 repaper_even_pixels(epd, &p, data, fixed_value, mask, stage); 366 } else { 367 /* 368 * even scan line, but as lines on display are numbered from 1, 369 * line: 1,3,5,... 370 */ 371 for (b = 0; b < epd->bytes_per_scan; b++) { 372 if (0 != (line & 0x01) && line / 8 == b) 373 *p++ = 0xc0 >> (line & 0x06); 374 else 375 *p++ = 0x00; 376 } 377 378 /* data bytes */ 379 repaper_all_pixels(epd, &p, data, fixed_value, mask, stage); 380 381 /* 382 * odd scan line, but as lines on display are numbered from 1, 383 * line: 0,2,4,6,... 384 */ 385 for (b = epd->bytes_per_scan; b > 0; b--) { 386 if (0 == (line & 0x01) && line / 8 == b - 1) 387 *p++ = 0x03 << (line & 0x06); 388 else 389 *p++ = 0x00; 390 } 391 } 392 393 switch (epd->border_byte) { 394 case REPAPER_BORDER_BYTE_NONE: 395 break; 396 397 case REPAPER_BORDER_BYTE_ZERO: 398 *p++ = 0x00; 399 break; 400 401 case REPAPER_BORDER_BYTE_SET: 402 switch (stage) { 403 case REPAPER_COMPENSATE: 404 case REPAPER_WHITE: 405 case REPAPER_INVERSE: 406 *p++ = 0x00; 407 break; 408 case REPAPER_NORMAL: 409 *p++ = 0xaa; 410 break; 411 } 412 break; 413 } 414 415 repaper_write_buf(epd->spi, 0x0a, epd->line_buffer, 416 p - epd->line_buffer); 417 418 /* Output data to panel */ 419 repaper_write_val(epd->spi, 0x02, 0x07); 420 421 repaper_spi_mosi_low(epd->spi); 422 } 423 424 static void repaper_frame_fixed(struct repaper_epd *epd, u8 fixed_value, 425 enum repaper_stage stage) 426 { 427 unsigned int line; 428 429 for (line = 0; line < epd->height; line++) 430 repaper_one_line(epd, line, NULL, fixed_value, NULL, stage); 431 } 432 433 static void repaper_frame_data(struct repaper_epd *epd, const u8 *image, 434 const u8 *mask, enum repaper_stage stage) 435 { 436 unsigned int line; 437 438 if (!mask) { 439 for (line = 0; line < epd->height; line++) { 440 repaper_one_line(epd, line, 441 &image[line * (epd->width / 8)], 442 0, NULL, stage); 443 } 444 } else { 445 for (line = 0; line < epd->height; line++) { 446 size_t n = line * epd->width / 8; 447 448 repaper_one_line(epd, line, &image[n], 0, &mask[n], 449 stage); 450 } 451 } 452 } 453 454 static void repaper_frame_fixed_repeat(struct repaper_epd *epd, u8 fixed_value, 455 enum repaper_stage stage) 456 { 457 u64 start = local_clock(); 458 u64 end = start + (epd->factored_stage_time * 1000 * 1000); 459 460 do { 461 repaper_frame_fixed(epd, fixed_value, stage); 462 } while (local_clock() < end); 463 } 464 465 static void repaper_frame_data_repeat(struct repaper_epd *epd, const u8 *image, 466 const u8 *mask, enum repaper_stage stage) 467 { 468 u64 start = local_clock(); 469 u64 end = start + (epd->factored_stage_time * 1000 * 1000); 470 471 do { 472 repaper_frame_data(epd, image, mask, stage); 473 } while (local_clock() < end); 474 } 475 476 static void repaper_get_temperature(struct repaper_epd *epd) 477 { 478 int ret, temperature = 0; 479 unsigned int factor10x; 480 481 if (!epd->thermal) 482 return; 483 484 ret = thermal_zone_get_temp(epd->thermal, &temperature); 485 if (ret) { 486 DRM_DEV_ERROR(&epd->spi->dev, "Failed to get temperature (%d)\n", ret); 487 return; 488 } 489 490 temperature /= 1000; 491 492 if (temperature <= -10) 493 factor10x = 170; 494 else if (temperature <= -5) 495 factor10x = 120; 496 else if (temperature <= 5) 497 factor10x = 80; 498 else if (temperature <= 10) 499 factor10x = 40; 500 else if (temperature <= 15) 501 factor10x = 30; 502 else if (temperature <= 20) 503 factor10x = 20; 504 else if (temperature <= 40) 505 factor10x = 10; 506 else 507 factor10x = 7; 508 509 epd->factored_stage_time = epd->stage_time * factor10x / 10; 510 } 511 512 static void repaper_gray8_to_mono_reversed(u8 *buf, u32 width, u32 height) 513 { 514 u8 *gray8 = buf, *mono = buf; 515 int y, xb, i; 516 517 for (y = 0; y < height; y++) 518 for (xb = 0; xb < width / 8; xb++) { 519 u8 byte = 0x00; 520 521 for (i = 0; i < 8; i++) { 522 int x = xb * 8 + i; 523 524 byte >>= 1; 525 if (gray8[y * width + x] >> 7) 526 byte |= BIT(7); 527 } 528 *mono++ = byte; 529 } 530 } 531 532 static int repaper_fb_dirty(struct drm_framebuffer *fb) 533 { 534 struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0); 535 struct dma_buf_attachment *import_attach = cma_obj->base.import_attach; 536 struct repaper_epd *epd = drm_to_epd(fb->dev); 537 struct drm_rect clip; 538 int idx, ret = 0; 539 u8 *buf = NULL; 540 541 if (!epd->enabled) 542 return 0; 543 544 if (!drm_dev_enter(fb->dev, &idx)) 545 return -ENODEV; 546 547 /* repaper can't do partial updates */ 548 clip.x1 = 0; 549 clip.x2 = fb->width; 550 clip.y1 = 0; 551 clip.y2 = fb->height; 552 553 repaper_get_temperature(epd); 554 555 DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id, 556 epd->factored_stage_time); 557 558 buf = kmalloc_array(fb->width, fb->height, GFP_KERNEL); 559 if (!buf) { 560 ret = -ENOMEM; 561 goto out_exit; 562 } 563 564 if (import_attach) { 565 ret = dma_buf_begin_cpu_access(import_attach->dmabuf, 566 DMA_FROM_DEVICE); 567 if (ret) 568 goto out_free; 569 } 570 571 drm_fb_xrgb8888_to_gray8(buf, cma_obj->vaddr, fb, &clip); 572 573 if (import_attach) { 574 ret = dma_buf_end_cpu_access(import_attach->dmabuf, 575 DMA_FROM_DEVICE); 576 if (ret) 577 goto out_free; 578 } 579 580 repaper_gray8_to_mono_reversed(buf, fb->width, fb->height); 581 582 if (epd->partial) { 583 repaper_frame_data_repeat(epd, buf, epd->current_frame, 584 REPAPER_NORMAL); 585 } else if (epd->cleared) { 586 repaper_frame_data_repeat(epd, epd->current_frame, NULL, 587 REPAPER_COMPENSATE); 588 repaper_frame_data_repeat(epd, epd->current_frame, NULL, 589 REPAPER_WHITE); 590 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE); 591 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL); 592 593 epd->partial = true; 594 } else { 595 /* Clear display (anything -> white) */ 596 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_COMPENSATE); 597 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_WHITE); 598 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_INVERSE); 599 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_NORMAL); 600 601 /* Assuming a clear (white) screen output an image */ 602 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_COMPENSATE); 603 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_WHITE); 604 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE); 605 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL); 606 607 epd->cleared = true; 608 epd->partial = true; 609 } 610 611 memcpy(epd->current_frame, buf, fb->width * fb->height / 8); 612 613 /* 614 * An extra frame write is needed if pixels are set in the bottom line, 615 * or else grey lines rises up from the pixels 616 */ 617 if (epd->pre_border_byte) { 618 unsigned int x; 619 620 for (x = 0; x < (fb->width / 8); x++) 621 if (buf[x + (fb->width * (fb->height - 1) / 8)]) { 622 repaper_frame_data_repeat(epd, buf, 623 epd->current_frame, 624 REPAPER_NORMAL); 625 break; 626 } 627 } 628 629 out_free: 630 kfree(buf); 631 out_exit: 632 drm_dev_exit(idx); 633 634 return ret; 635 } 636 637 static void power_off(struct repaper_epd *epd) 638 { 639 /* Turn off power and all signals */ 640 gpiod_set_value_cansleep(epd->reset, 0); 641 gpiod_set_value_cansleep(epd->panel_on, 0); 642 if (epd->border) 643 gpiod_set_value_cansleep(epd->border, 0); 644 645 /* Ensure SPI MOSI and CLOCK are Low before CS Low */ 646 repaper_spi_mosi_low(epd->spi); 647 648 /* Discharge pulse */ 649 gpiod_set_value_cansleep(epd->discharge, 1); 650 msleep(150); 651 gpiod_set_value_cansleep(epd->discharge, 0); 652 } 653 654 static void repaper_pipe_enable(struct drm_simple_display_pipe *pipe, 655 struct drm_crtc_state *crtc_state, 656 struct drm_plane_state *plane_state) 657 { 658 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev); 659 struct spi_device *spi = epd->spi; 660 struct device *dev = &spi->dev; 661 bool dc_ok = false; 662 int i, ret, idx; 663 664 if (!drm_dev_enter(pipe->crtc.dev, &idx)) 665 return; 666 667 DRM_DEBUG_DRIVER("\n"); 668 669 /* Power up sequence */ 670 gpiod_set_value_cansleep(epd->reset, 0); 671 gpiod_set_value_cansleep(epd->panel_on, 0); 672 gpiod_set_value_cansleep(epd->discharge, 0); 673 if (epd->border) 674 gpiod_set_value_cansleep(epd->border, 0); 675 repaper_spi_mosi_low(spi); 676 usleep_range(5000, 10000); 677 678 gpiod_set_value_cansleep(epd->panel_on, 1); 679 /* 680 * This delay comes from the repaper.org userspace driver, it's not 681 * mentioned in the datasheet. 682 */ 683 usleep_range(10000, 15000); 684 gpiod_set_value_cansleep(epd->reset, 1); 685 if (epd->border) 686 gpiod_set_value_cansleep(epd->border, 1); 687 usleep_range(5000, 10000); 688 gpiod_set_value_cansleep(epd->reset, 0); 689 usleep_range(5000, 10000); 690 gpiod_set_value_cansleep(epd->reset, 1); 691 usleep_range(5000, 10000); 692 693 /* Wait for COG to become ready */ 694 for (i = 100; i > 0; i--) { 695 if (!gpiod_get_value_cansleep(epd->busy)) 696 break; 697 698 usleep_range(10, 100); 699 } 700 701 if (!i) { 702 DRM_DEV_ERROR(dev, "timeout waiting for panel to become ready.\n"); 703 power_off(epd); 704 goto out_exit; 705 } 706 707 repaper_read_id(spi); 708 ret = repaper_read_id(spi); 709 if (ret != REPAPER_RID_G2_COG_ID) { 710 if (ret < 0) 711 dev_err(dev, "failed to read chip (%d)\n", ret); 712 else 713 dev_err(dev, "wrong COG ID 0x%02x\n", ret); 714 power_off(epd); 715 goto out_exit; 716 } 717 718 /* Disable OE */ 719 repaper_write_val(spi, 0x02, 0x40); 720 721 ret = repaper_read_val(spi, 0x0f); 722 if (ret < 0 || !(ret & 0x80)) { 723 if (ret < 0) 724 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret); 725 else 726 DRM_DEV_ERROR(dev, "panel is reported broken\n"); 727 power_off(epd); 728 goto out_exit; 729 } 730 731 /* Power saving mode */ 732 repaper_write_val(spi, 0x0b, 0x02); 733 /* Channel select */ 734 repaper_write_buf(spi, 0x01, epd->channel_select, 8); 735 /* High power mode osc */ 736 repaper_write_val(spi, 0x07, 0xd1); 737 /* Power setting */ 738 repaper_write_val(spi, 0x08, 0x02); 739 /* Vcom level */ 740 repaper_write_val(spi, 0x09, 0xc2); 741 /* Power setting */ 742 repaper_write_val(spi, 0x04, 0x03); 743 /* Driver latch on */ 744 repaper_write_val(spi, 0x03, 0x01); 745 /* Driver latch off */ 746 repaper_write_val(spi, 0x03, 0x00); 747 usleep_range(5000, 10000); 748 749 /* Start chargepump */ 750 for (i = 0; i < 4; ++i) { 751 /* Charge pump positive voltage on - VGH/VDL on */ 752 repaper_write_val(spi, 0x05, 0x01); 753 msleep(240); 754 755 /* Charge pump negative voltage on - VGL/VDL on */ 756 repaper_write_val(spi, 0x05, 0x03); 757 msleep(40); 758 759 /* Charge pump Vcom on - Vcom driver on */ 760 repaper_write_val(spi, 0x05, 0x0f); 761 msleep(40); 762 763 /* check DC/DC */ 764 ret = repaper_read_val(spi, 0x0f); 765 if (ret < 0) { 766 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret); 767 power_off(epd); 768 goto out_exit; 769 } 770 771 if (ret & 0x40) { 772 dc_ok = true; 773 break; 774 } 775 } 776 777 if (!dc_ok) { 778 DRM_DEV_ERROR(dev, "dc/dc failed\n"); 779 power_off(epd); 780 goto out_exit; 781 } 782 783 /* 784 * Output enable to disable 785 * The userspace driver sets this to 0x04, but the datasheet says 0x06 786 */ 787 repaper_write_val(spi, 0x02, 0x04); 788 789 epd->enabled = true; 790 epd->partial = false; 791 out_exit: 792 drm_dev_exit(idx); 793 } 794 795 static void repaper_pipe_disable(struct drm_simple_display_pipe *pipe) 796 { 797 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev); 798 struct spi_device *spi = epd->spi; 799 unsigned int line; 800 801 /* 802 * This callback is not protected by drm_dev_enter/exit since we want to 803 * turn off the display on regular driver unload. It's highly unlikely 804 * that the underlying SPI controller is gone should this be called after 805 * unplug. 806 */ 807 808 if (!epd->enabled) 809 return; 810 811 DRM_DEBUG_DRIVER("\n"); 812 813 epd->enabled = false; 814 815 /* Nothing frame */ 816 for (line = 0; line < epd->height; line++) 817 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL, 818 REPAPER_COMPENSATE); 819 820 /* 2.7" */ 821 if (epd->border) { 822 /* Dummy line */ 823 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL, 824 REPAPER_COMPENSATE); 825 msleep(25); 826 gpiod_set_value_cansleep(epd->border, 0); 827 msleep(200); 828 gpiod_set_value_cansleep(epd->border, 1); 829 } else { 830 /* Border dummy line */ 831 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL, 832 REPAPER_NORMAL); 833 msleep(200); 834 } 835 836 /* not described in datasheet */ 837 repaper_write_val(spi, 0x0b, 0x00); 838 /* Latch reset turn on */ 839 repaper_write_val(spi, 0x03, 0x01); 840 /* Power off charge pump Vcom */ 841 repaper_write_val(spi, 0x05, 0x03); 842 /* Power off charge pump neg voltage */ 843 repaper_write_val(spi, 0x05, 0x01); 844 msleep(120); 845 /* Discharge internal */ 846 repaper_write_val(spi, 0x04, 0x80); 847 /* turn off all charge pumps */ 848 repaper_write_val(spi, 0x05, 0x00); 849 /* Turn off osc */ 850 repaper_write_val(spi, 0x07, 0x01); 851 msleep(50); 852 853 power_off(epd); 854 } 855 856 static void repaper_pipe_update(struct drm_simple_display_pipe *pipe, 857 struct drm_plane_state *old_state) 858 { 859 struct drm_plane_state *state = pipe->plane.state; 860 struct drm_rect rect; 861 862 if (drm_atomic_helper_damage_merged(old_state, state, &rect)) 863 repaper_fb_dirty(state->fb); 864 } 865 866 static const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = { 867 .enable = repaper_pipe_enable, 868 .disable = repaper_pipe_disable, 869 .update = repaper_pipe_update, 870 .prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb, 871 }; 872 873 static int repaper_connector_get_modes(struct drm_connector *connector) 874 { 875 struct repaper_epd *epd = drm_to_epd(connector->dev); 876 struct drm_display_mode *mode; 877 878 mode = drm_mode_duplicate(connector->dev, epd->mode); 879 if (!mode) { 880 DRM_ERROR("Failed to duplicate mode\n"); 881 return 0; 882 } 883 884 drm_mode_set_name(mode); 885 mode->type |= DRM_MODE_TYPE_PREFERRED; 886 drm_mode_probed_add(connector, mode); 887 888 connector->display_info.width_mm = mode->width_mm; 889 connector->display_info.height_mm = mode->height_mm; 890 891 return 1; 892 } 893 894 static const struct drm_connector_helper_funcs repaper_connector_hfuncs = { 895 .get_modes = repaper_connector_get_modes, 896 }; 897 898 static const struct drm_connector_funcs repaper_connector_funcs = { 899 .reset = drm_atomic_helper_connector_reset, 900 .fill_modes = drm_helper_probe_single_connector_modes, 901 .destroy = drm_connector_cleanup, 902 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, 903 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, 904 }; 905 906 static const struct drm_mode_config_funcs repaper_mode_config_funcs = { 907 .fb_create = drm_gem_fb_create_with_dirty, 908 .atomic_check = drm_atomic_helper_check, 909 .atomic_commit = drm_atomic_helper_commit, 910 }; 911 912 static const uint32_t repaper_formats[] = { 913 DRM_FORMAT_XRGB8888, 914 }; 915 916 static const struct drm_display_mode repaper_e1144cs021_mode = { 917 DRM_SIMPLE_MODE(128, 96, 29, 22), 918 }; 919 920 static const u8 repaper_e1144cs021_cs[] = { 0x00, 0x00, 0x00, 0x00, 921 0x00, 0x0f, 0xff, 0x00 }; 922 923 static const struct drm_display_mode repaper_e1190cs021_mode = { 924 DRM_SIMPLE_MODE(144, 128, 36, 32), 925 }; 926 927 static const u8 repaper_e1190cs021_cs[] = { 0x00, 0x00, 0x00, 0x03, 928 0xfc, 0x00, 0x00, 0xff }; 929 930 static const struct drm_display_mode repaper_e2200cs021_mode = { 931 DRM_SIMPLE_MODE(200, 96, 46, 22), 932 }; 933 934 static const u8 repaper_e2200cs021_cs[] = { 0x00, 0x00, 0x00, 0x00, 935 0x01, 0xff, 0xe0, 0x00 }; 936 937 static const struct drm_display_mode repaper_e2271cs021_mode = { 938 DRM_SIMPLE_MODE(264, 176, 57, 38), 939 }; 940 941 static const u8 repaper_e2271cs021_cs[] = { 0x00, 0x00, 0x00, 0x7f, 942 0xff, 0xfe, 0x00, 0x00 }; 943 944 DEFINE_DRM_GEM_CMA_FOPS(repaper_fops); 945 946 static struct drm_driver repaper_driver = { 947 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 948 .fops = &repaper_fops, 949 DRM_GEM_CMA_VMAP_DRIVER_OPS, 950 .name = "repaper", 951 .desc = "Pervasive Displays RePaper e-ink panels", 952 .date = "20170405", 953 .major = 1, 954 .minor = 0, 955 }; 956 957 static const struct of_device_id repaper_of_match[] = { 958 { .compatible = "pervasive,e1144cs021", .data = (void *)E1144CS021 }, 959 { .compatible = "pervasive,e1190cs021", .data = (void *)E1190CS021 }, 960 { .compatible = "pervasive,e2200cs021", .data = (void *)E2200CS021 }, 961 { .compatible = "pervasive,e2271cs021", .data = (void *)E2271CS021 }, 962 {}, 963 }; 964 MODULE_DEVICE_TABLE(of, repaper_of_match); 965 966 static const struct spi_device_id repaper_id[] = { 967 { "e1144cs021", E1144CS021 }, 968 { "e1190cs021", E1190CS021 }, 969 { "e2200cs021", E2200CS021 }, 970 { "e2271cs021", E2271CS021 }, 971 { }, 972 }; 973 MODULE_DEVICE_TABLE(spi, repaper_id); 974 975 static int repaper_probe(struct spi_device *spi) 976 { 977 const struct drm_display_mode *mode; 978 const struct spi_device_id *spi_id; 979 struct device *dev = &spi->dev; 980 enum repaper_model model; 981 const char *thermal_zone; 982 struct repaper_epd *epd; 983 size_t line_buffer_size; 984 struct drm_device *drm; 985 const void *match; 986 int ret; 987 988 match = device_get_match_data(dev); 989 if (match) { 990 model = (enum repaper_model)match; 991 } else { 992 spi_id = spi_get_device_id(spi); 993 model = (enum repaper_model)spi_id->driver_data; 994 } 995 996 /* The SPI device is used to allocate dma memory */ 997 if (!dev->coherent_dma_mask) { 998 ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32)); 999 if (ret) { 1000 dev_warn(dev, "Failed to set dma mask %d\n", ret); 1001 return ret; 1002 } 1003 } 1004 1005 epd = devm_drm_dev_alloc(dev, &repaper_driver, 1006 struct repaper_epd, drm); 1007 if (IS_ERR(epd)) 1008 return PTR_ERR(epd); 1009 1010 drm = &epd->drm; 1011 1012 ret = drmm_mode_config_init(drm); 1013 if (ret) 1014 return ret; 1015 drm->mode_config.funcs = &repaper_mode_config_funcs; 1016 1017 epd->spi = spi; 1018 1019 epd->panel_on = devm_gpiod_get(dev, "panel-on", GPIOD_OUT_LOW); 1020 if (IS_ERR(epd->panel_on)) { 1021 ret = PTR_ERR(epd->panel_on); 1022 if (ret != -EPROBE_DEFER) 1023 DRM_DEV_ERROR(dev, "Failed to get gpio 'panel-on'\n"); 1024 return ret; 1025 } 1026 1027 epd->discharge = devm_gpiod_get(dev, "discharge", GPIOD_OUT_LOW); 1028 if (IS_ERR(epd->discharge)) { 1029 ret = PTR_ERR(epd->discharge); 1030 if (ret != -EPROBE_DEFER) 1031 DRM_DEV_ERROR(dev, "Failed to get gpio 'discharge'\n"); 1032 return ret; 1033 } 1034 1035 epd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW); 1036 if (IS_ERR(epd->reset)) { 1037 ret = PTR_ERR(epd->reset); 1038 if (ret != -EPROBE_DEFER) 1039 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n"); 1040 return ret; 1041 } 1042 1043 epd->busy = devm_gpiod_get(dev, "busy", GPIOD_IN); 1044 if (IS_ERR(epd->busy)) { 1045 ret = PTR_ERR(epd->busy); 1046 if (ret != -EPROBE_DEFER) 1047 DRM_DEV_ERROR(dev, "Failed to get gpio 'busy'\n"); 1048 return ret; 1049 } 1050 1051 if (!device_property_read_string(dev, "pervasive,thermal-zone", 1052 &thermal_zone)) { 1053 epd->thermal = thermal_zone_get_zone_by_name(thermal_zone); 1054 if (IS_ERR(epd->thermal)) { 1055 DRM_DEV_ERROR(dev, "Failed to get thermal zone: %s\n", thermal_zone); 1056 return PTR_ERR(epd->thermal); 1057 } 1058 } 1059 1060 switch (model) { 1061 case E1144CS021: 1062 mode = &repaper_e1144cs021_mode; 1063 epd->channel_select = repaper_e1144cs021_cs; 1064 epd->stage_time = 480; 1065 epd->bytes_per_scan = 96 / 4; 1066 epd->middle_scan = true; /* data-scan-data */ 1067 epd->pre_border_byte = false; 1068 epd->border_byte = REPAPER_BORDER_BYTE_ZERO; 1069 break; 1070 1071 case E1190CS021: 1072 mode = &repaper_e1190cs021_mode; 1073 epd->channel_select = repaper_e1190cs021_cs; 1074 epd->stage_time = 480; 1075 epd->bytes_per_scan = 128 / 4 / 2; 1076 epd->middle_scan = false; /* scan-data-scan */ 1077 epd->pre_border_byte = false; 1078 epd->border_byte = REPAPER_BORDER_BYTE_SET; 1079 break; 1080 1081 case E2200CS021: 1082 mode = &repaper_e2200cs021_mode; 1083 epd->channel_select = repaper_e2200cs021_cs; 1084 epd->stage_time = 480; 1085 epd->bytes_per_scan = 96 / 4; 1086 epd->middle_scan = true; /* data-scan-data */ 1087 epd->pre_border_byte = true; 1088 epd->border_byte = REPAPER_BORDER_BYTE_NONE; 1089 break; 1090 1091 case E2271CS021: 1092 epd->border = devm_gpiod_get(dev, "border", GPIOD_OUT_LOW); 1093 if (IS_ERR(epd->border)) { 1094 ret = PTR_ERR(epd->border); 1095 if (ret != -EPROBE_DEFER) 1096 DRM_DEV_ERROR(dev, "Failed to get gpio 'border'\n"); 1097 return ret; 1098 } 1099 1100 mode = &repaper_e2271cs021_mode; 1101 epd->channel_select = repaper_e2271cs021_cs; 1102 epd->stage_time = 630; 1103 epd->bytes_per_scan = 176 / 4; 1104 epd->middle_scan = true; /* data-scan-data */ 1105 epd->pre_border_byte = true; 1106 epd->border_byte = REPAPER_BORDER_BYTE_NONE; 1107 break; 1108 1109 default: 1110 return -ENODEV; 1111 } 1112 1113 epd->mode = mode; 1114 epd->width = mode->hdisplay; 1115 epd->height = mode->vdisplay; 1116 epd->factored_stage_time = epd->stage_time; 1117 1118 line_buffer_size = 2 * epd->width / 8 + epd->bytes_per_scan + 2; 1119 epd->line_buffer = devm_kzalloc(dev, line_buffer_size, GFP_KERNEL); 1120 if (!epd->line_buffer) 1121 return -ENOMEM; 1122 1123 epd->current_frame = devm_kzalloc(dev, epd->width * epd->height / 8, 1124 GFP_KERNEL); 1125 if (!epd->current_frame) 1126 return -ENOMEM; 1127 1128 drm->mode_config.min_width = mode->hdisplay; 1129 drm->mode_config.max_width = mode->hdisplay; 1130 drm->mode_config.min_height = mode->vdisplay; 1131 drm->mode_config.max_height = mode->vdisplay; 1132 1133 drm_connector_helper_add(&epd->connector, &repaper_connector_hfuncs); 1134 ret = drm_connector_init(drm, &epd->connector, &repaper_connector_funcs, 1135 DRM_MODE_CONNECTOR_SPI); 1136 if (ret) 1137 return ret; 1138 1139 ret = drm_simple_display_pipe_init(drm, &epd->pipe, &repaper_pipe_funcs, 1140 repaper_formats, ARRAY_SIZE(repaper_formats), 1141 NULL, &epd->connector); 1142 if (ret) 1143 return ret; 1144 1145 drm_mode_config_reset(drm); 1146 1147 ret = drm_dev_register(drm, 0); 1148 if (ret) 1149 return ret; 1150 1151 spi_set_drvdata(spi, drm); 1152 1153 DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000); 1154 1155 drm_fbdev_generic_setup(drm, 0); 1156 1157 return 0; 1158 } 1159 1160 static int repaper_remove(struct spi_device *spi) 1161 { 1162 struct drm_device *drm = spi_get_drvdata(spi); 1163 1164 drm_dev_unplug(drm); 1165 drm_atomic_helper_shutdown(drm); 1166 1167 return 0; 1168 } 1169 1170 static void repaper_shutdown(struct spi_device *spi) 1171 { 1172 drm_atomic_helper_shutdown(spi_get_drvdata(spi)); 1173 } 1174 1175 static struct spi_driver repaper_spi_driver = { 1176 .driver = { 1177 .name = "repaper", 1178 .of_match_table = repaper_of_match, 1179 }, 1180 .id_table = repaper_id, 1181 .probe = repaper_probe, 1182 .remove = repaper_remove, 1183 .shutdown = repaper_shutdown, 1184 }; 1185 module_spi_driver(repaper_spi_driver); 1186 1187 MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver"); 1188 MODULE_AUTHOR("Noralf Trønnes"); 1189 MODULE_LICENSE("GPL"); 1190