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_atomic_helper.h> 33 #include <drm/drm_gem_cma_helper.h> 34 #include <drm/drm_gem_framebuffer_helper.h> 35 #include <drm/drm_managed.h> 36 #include <drm/drm_modes.h> 37 #include <drm/drm_rect.h> 38 #include <drm/drm_probe_helper.h> 39 #include <drm/drm_simple_kms_helper.h> 40 41 #define REPAPER_RID_G2_COG_ID 0x12 42 43 enum repaper_model { 44 /* 0 is reserved to avoid clashing with NULL */ 45 E1144CS021 = 1, 46 E1190CS021, 47 E2200CS021, 48 E2271CS021, 49 }; 50 51 enum repaper_stage { /* Image pixel -> Display pixel */ 52 REPAPER_COMPENSATE, /* B -> W, W -> B (Current Image) */ 53 REPAPER_WHITE, /* B -> N, W -> W (Current Image) */ 54 REPAPER_INVERSE, /* B -> N, W -> B (New Image) */ 55 REPAPER_NORMAL /* B -> B, W -> W (New Image) */ 56 }; 57 58 enum repaper_epd_border_byte { 59 REPAPER_BORDER_BYTE_NONE, 60 REPAPER_BORDER_BYTE_ZERO, 61 REPAPER_BORDER_BYTE_SET, 62 }; 63 64 struct repaper_epd { 65 struct drm_device drm; 66 struct drm_simple_display_pipe pipe; 67 const struct drm_display_mode *mode; 68 struct drm_connector connector; 69 struct spi_device *spi; 70 71 struct gpio_desc *panel_on; 72 struct gpio_desc *border; 73 struct gpio_desc *discharge; 74 struct gpio_desc *reset; 75 struct gpio_desc *busy; 76 77 struct thermal_zone_device *thermal; 78 79 unsigned int height; 80 unsigned int width; 81 unsigned int bytes_per_scan; 82 const u8 *channel_select; 83 unsigned int stage_time; 84 unsigned int factored_stage_time; 85 bool middle_scan; 86 bool pre_border_byte; 87 enum repaper_epd_border_byte border_byte; 88 89 u8 *line_buffer; 90 void *current_frame; 91 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 (!drm_dev_enter(fb->dev, &idx)) 542 return -ENODEV; 543 544 /* repaper can't do partial updates */ 545 clip.x1 = 0; 546 clip.x2 = fb->width; 547 clip.y1 = 0; 548 clip.y2 = fb->height; 549 550 repaper_get_temperature(epd); 551 552 DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id, 553 epd->factored_stage_time); 554 555 buf = kmalloc_array(fb->width, fb->height, GFP_KERNEL); 556 if (!buf) { 557 ret = -ENOMEM; 558 goto out_exit; 559 } 560 561 if (import_attach) { 562 ret = dma_buf_begin_cpu_access(import_attach->dmabuf, 563 DMA_FROM_DEVICE); 564 if (ret) 565 goto out_free; 566 } 567 568 drm_fb_xrgb8888_to_gray8(buf, cma_obj->vaddr, fb, &clip); 569 570 if (import_attach) { 571 ret = dma_buf_end_cpu_access(import_attach->dmabuf, 572 DMA_FROM_DEVICE); 573 if (ret) 574 goto out_free; 575 } 576 577 repaper_gray8_to_mono_reversed(buf, fb->width, fb->height); 578 579 if (epd->partial) { 580 repaper_frame_data_repeat(epd, buf, epd->current_frame, 581 REPAPER_NORMAL); 582 } else if (epd->cleared) { 583 repaper_frame_data_repeat(epd, epd->current_frame, NULL, 584 REPAPER_COMPENSATE); 585 repaper_frame_data_repeat(epd, epd->current_frame, NULL, 586 REPAPER_WHITE); 587 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE); 588 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL); 589 590 epd->partial = true; 591 } else { 592 /* Clear display (anything -> white) */ 593 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_COMPENSATE); 594 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_WHITE); 595 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_INVERSE); 596 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_NORMAL); 597 598 /* Assuming a clear (white) screen output an image */ 599 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_COMPENSATE); 600 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_WHITE); 601 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE); 602 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL); 603 604 epd->cleared = true; 605 epd->partial = true; 606 } 607 608 memcpy(epd->current_frame, buf, fb->width * fb->height / 8); 609 610 /* 611 * An extra frame write is needed if pixels are set in the bottom line, 612 * or else grey lines rises up from the pixels 613 */ 614 if (epd->pre_border_byte) { 615 unsigned int x; 616 617 for (x = 0; x < (fb->width / 8); x++) 618 if (buf[x + (fb->width * (fb->height - 1) / 8)]) { 619 repaper_frame_data_repeat(epd, buf, 620 epd->current_frame, 621 REPAPER_NORMAL); 622 break; 623 } 624 } 625 626 out_free: 627 kfree(buf); 628 out_exit: 629 drm_dev_exit(idx); 630 631 return ret; 632 } 633 634 static void power_off(struct repaper_epd *epd) 635 { 636 /* Turn off power and all signals */ 637 gpiod_set_value_cansleep(epd->reset, 0); 638 gpiod_set_value_cansleep(epd->panel_on, 0); 639 if (epd->border) 640 gpiod_set_value_cansleep(epd->border, 0); 641 642 /* Ensure SPI MOSI and CLOCK are Low before CS Low */ 643 repaper_spi_mosi_low(epd->spi); 644 645 /* Discharge pulse */ 646 gpiod_set_value_cansleep(epd->discharge, 1); 647 msleep(150); 648 gpiod_set_value_cansleep(epd->discharge, 0); 649 } 650 651 static void repaper_pipe_enable(struct drm_simple_display_pipe *pipe, 652 struct drm_crtc_state *crtc_state, 653 struct drm_plane_state *plane_state) 654 { 655 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev); 656 struct spi_device *spi = epd->spi; 657 struct device *dev = &spi->dev; 658 bool dc_ok = false; 659 int i, ret, idx; 660 661 if (!drm_dev_enter(pipe->crtc.dev, &idx)) 662 return; 663 664 DRM_DEBUG_DRIVER("\n"); 665 666 /* Power up sequence */ 667 gpiod_set_value_cansleep(epd->reset, 0); 668 gpiod_set_value_cansleep(epd->panel_on, 0); 669 gpiod_set_value_cansleep(epd->discharge, 0); 670 if (epd->border) 671 gpiod_set_value_cansleep(epd->border, 0); 672 repaper_spi_mosi_low(spi); 673 usleep_range(5000, 10000); 674 675 gpiod_set_value_cansleep(epd->panel_on, 1); 676 /* 677 * This delay comes from the repaper.org userspace driver, it's not 678 * mentioned in the datasheet. 679 */ 680 usleep_range(10000, 15000); 681 gpiod_set_value_cansleep(epd->reset, 1); 682 if (epd->border) 683 gpiod_set_value_cansleep(epd->border, 1); 684 usleep_range(5000, 10000); 685 gpiod_set_value_cansleep(epd->reset, 0); 686 usleep_range(5000, 10000); 687 gpiod_set_value_cansleep(epd->reset, 1); 688 usleep_range(5000, 10000); 689 690 /* Wait for COG to become ready */ 691 for (i = 100; i > 0; i--) { 692 if (!gpiod_get_value_cansleep(epd->busy)) 693 break; 694 695 usleep_range(10, 100); 696 } 697 698 if (!i) { 699 DRM_DEV_ERROR(dev, "timeout waiting for panel to become ready.\n"); 700 power_off(epd); 701 goto out_exit; 702 } 703 704 repaper_read_id(spi); 705 ret = repaper_read_id(spi); 706 if (ret != REPAPER_RID_G2_COG_ID) { 707 if (ret < 0) 708 dev_err(dev, "failed to read chip (%d)\n", ret); 709 else 710 dev_err(dev, "wrong COG ID 0x%02x\n", ret); 711 power_off(epd); 712 goto out_exit; 713 } 714 715 /* Disable OE */ 716 repaper_write_val(spi, 0x02, 0x40); 717 718 ret = repaper_read_val(spi, 0x0f); 719 if (ret < 0 || !(ret & 0x80)) { 720 if (ret < 0) 721 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret); 722 else 723 DRM_DEV_ERROR(dev, "panel is reported broken\n"); 724 power_off(epd); 725 goto out_exit; 726 } 727 728 /* Power saving mode */ 729 repaper_write_val(spi, 0x0b, 0x02); 730 /* Channel select */ 731 repaper_write_buf(spi, 0x01, epd->channel_select, 8); 732 /* High power mode osc */ 733 repaper_write_val(spi, 0x07, 0xd1); 734 /* Power setting */ 735 repaper_write_val(spi, 0x08, 0x02); 736 /* Vcom level */ 737 repaper_write_val(spi, 0x09, 0xc2); 738 /* Power setting */ 739 repaper_write_val(spi, 0x04, 0x03); 740 /* Driver latch on */ 741 repaper_write_val(spi, 0x03, 0x01); 742 /* Driver latch off */ 743 repaper_write_val(spi, 0x03, 0x00); 744 usleep_range(5000, 10000); 745 746 /* Start chargepump */ 747 for (i = 0; i < 4; ++i) { 748 /* Charge pump positive voltage on - VGH/VDL on */ 749 repaper_write_val(spi, 0x05, 0x01); 750 msleep(240); 751 752 /* Charge pump negative voltage on - VGL/VDL on */ 753 repaper_write_val(spi, 0x05, 0x03); 754 msleep(40); 755 756 /* Charge pump Vcom on - Vcom driver on */ 757 repaper_write_val(spi, 0x05, 0x0f); 758 msleep(40); 759 760 /* check DC/DC */ 761 ret = repaper_read_val(spi, 0x0f); 762 if (ret < 0) { 763 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret); 764 power_off(epd); 765 goto out_exit; 766 } 767 768 if (ret & 0x40) { 769 dc_ok = true; 770 break; 771 } 772 } 773 774 if (!dc_ok) { 775 DRM_DEV_ERROR(dev, "dc/dc failed\n"); 776 power_off(epd); 777 goto out_exit; 778 } 779 780 /* 781 * Output enable to disable 782 * The userspace driver sets this to 0x04, but the datasheet says 0x06 783 */ 784 repaper_write_val(spi, 0x02, 0x04); 785 786 epd->partial = false; 787 out_exit: 788 drm_dev_exit(idx); 789 } 790 791 static void repaper_pipe_disable(struct drm_simple_display_pipe *pipe) 792 { 793 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev); 794 struct spi_device *spi = epd->spi; 795 unsigned int line; 796 797 /* 798 * This callback is not protected by drm_dev_enter/exit since we want to 799 * turn off the display on regular driver unload. It's highly unlikely 800 * that the underlying SPI controller is gone should this be called after 801 * unplug. 802 */ 803 804 DRM_DEBUG_DRIVER("\n"); 805 806 /* Nothing frame */ 807 for (line = 0; line < epd->height; line++) 808 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL, 809 REPAPER_COMPENSATE); 810 811 /* 2.7" */ 812 if (epd->border) { 813 /* Dummy line */ 814 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL, 815 REPAPER_COMPENSATE); 816 msleep(25); 817 gpiod_set_value_cansleep(epd->border, 0); 818 msleep(200); 819 gpiod_set_value_cansleep(epd->border, 1); 820 } else { 821 /* Border dummy line */ 822 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL, 823 REPAPER_NORMAL); 824 msleep(200); 825 } 826 827 /* not described in datasheet */ 828 repaper_write_val(spi, 0x0b, 0x00); 829 /* Latch reset turn on */ 830 repaper_write_val(spi, 0x03, 0x01); 831 /* Power off charge pump Vcom */ 832 repaper_write_val(spi, 0x05, 0x03); 833 /* Power off charge pump neg voltage */ 834 repaper_write_val(spi, 0x05, 0x01); 835 msleep(120); 836 /* Discharge internal */ 837 repaper_write_val(spi, 0x04, 0x80); 838 /* turn off all charge pumps */ 839 repaper_write_val(spi, 0x05, 0x00); 840 /* Turn off osc */ 841 repaper_write_val(spi, 0x07, 0x01); 842 msleep(50); 843 844 power_off(epd); 845 } 846 847 static void repaper_pipe_update(struct drm_simple_display_pipe *pipe, 848 struct drm_plane_state *old_state) 849 { 850 struct drm_plane_state *state = pipe->plane.state; 851 struct drm_rect rect; 852 853 if (!pipe->crtc.state->active) 854 return; 855 856 if (drm_atomic_helper_damage_merged(old_state, state, &rect)) 857 repaper_fb_dirty(state->fb); 858 } 859 860 static const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = { 861 .enable = repaper_pipe_enable, 862 .disable = repaper_pipe_disable, 863 .update = repaper_pipe_update, 864 .prepare_fb = drm_gem_simple_display_pipe_prepare_fb, 865 }; 866 867 static int repaper_connector_get_modes(struct drm_connector *connector) 868 { 869 struct repaper_epd *epd = drm_to_epd(connector->dev); 870 struct drm_display_mode *mode; 871 872 mode = drm_mode_duplicate(connector->dev, epd->mode); 873 if (!mode) { 874 DRM_ERROR("Failed to duplicate mode\n"); 875 return 0; 876 } 877 878 drm_mode_set_name(mode); 879 mode->type |= DRM_MODE_TYPE_PREFERRED; 880 drm_mode_probed_add(connector, mode); 881 882 connector->display_info.width_mm = mode->width_mm; 883 connector->display_info.height_mm = mode->height_mm; 884 885 return 1; 886 } 887 888 static const struct drm_connector_helper_funcs repaper_connector_hfuncs = { 889 .get_modes = repaper_connector_get_modes, 890 }; 891 892 static const struct drm_connector_funcs repaper_connector_funcs = { 893 .reset = drm_atomic_helper_connector_reset, 894 .fill_modes = drm_helper_probe_single_connector_modes, 895 .destroy = drm_connector_cleanup, 896 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, 897 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, 898 }; 899 900 static const struct drm_mode_config_funcs repaper_mode_config_funcs = { 901 .fb_create = drm_gem_fb_create_with_dirty, 902 .atomic_check = drm_atomic_helper_check, 903 .atomic_commit = drm_atomic_helper_commit, 904 }; 905 906 static const uint32_t repaper_formats[] = { 907 DRM_FORMAT_XRGB8888, 908 }; 909 910 static const struct drm_display_mode repaper_e1144cs021_mode = { 911 DRM_SIMPLE_MODE(128, 96, 29, 22), 912 }; 913 914 static const u8 repaper_e1144cs021_cs[] = { 0x00, 0x00, 0x00, 0x00, 915 0x00, 0x0f, 0xff, 0x00 }; 916 917 static const struct drm_display_mode repaper_e1190cs021_mode = { 918 DRM_SIMPLE_MODE(144, 128, 36, 32), 919 }; 920 921 static const u8 repaper_e1190cs021_cs[] = { 0x00, 0x00, 0x00, 0x03, 922 0xfc, 0x00, 0x00, 0xff }; 923 924 static const struct drm_display_mode repaper_e2200cs021_mode = { 925 DRM_SIMPLE_MODE(200, 96, 46, 22), 926 }; 927 928 static const u8 repaper_e2200cs021_cs[] = { 0x00, 0x00, 0x00, 0x00, 929 0x01, 0xff, 0xe0, 0x00 }; 930 931 static const struct drm_display_mode repaper_e2271cs021_mode = { 932 DRM_SIMPLE_MODE(264, 176, 57, 38), 933 }; 934 935 static const u8 repaper_e2271cs021_cs[] = { 0x00, 0x00, 0x00, 0x7f, 936 0xff, 0xfe, 0x00, 0x00 }; 937 938 DEFINE_DRM_GEM_CMA_FOPS(repaper_fops); 939 940 static const struct drm_driver repaper_driver = { 941 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 942 .fops = &repaper_fops, 943 DRM_GEM_CMA_DRIVER_OPS_VMAP, 944 .name = "repaper", 945 .desc = "Pervasive Displays RePaper e-ink panels", 946 .date = "20170405", 947 .major = 1, 948 .minor = 0, 949 }; 950 951 static const struct of_device_id repaper_of_match[] = { 952 { .compatible = "pervasive,e1144cs021", .data = (void *)E1144CS021 }, 953 { .compatible = "pervasive,e1190cs021", .data = (void *)E1190CS021 }, 954 { .compatible = "pervasive,e2200cs021", .data = (void *)E2200CS021 }, 955 { .compatible = "pervasive,e2271cs021", .data = (void *)E2271CS021 }, 956 {}, 957 }; 958 MODULE_DEVICE_TABLE(of, repaper_of_match); 959 960 static const struct spi_device_id repaper_id[] = { 961 { "e1144cs021", E1144CS021 }, 962 { "e1190cs021", E1190CS021 }, 963 { "e2200cs021", E2200CS021 }, 964 { "e2271cs021", E2271CS021 }, 965 { }, 966 }; 967 MODULE_DEVICE_TABLE(spi, repaper_id); 968 969 static int repaper_probe(struct spi_device *spi) 970 { 971 const struct drm_display_mode *mode; 972 const struct spi_device_id *spi_id; 973 struct device *dev = &spi->dev; 974 enum repaper_model model; 975 const char *thermal_zone; 976 struct repaper_epd *epd; 977 size_t line_buffer_size; 978 struct drm_device *drm; 979 const void *match; 980 int ret; 981 982 match = device_get_match_data(dev); 983 if (match) { 984 model = (enum repaper_model)match; 985 } else { 986 spi_id = spi_get_device_id(spi); 987 model = (enum repaper_model)spi_id->driver_data; 988 } 989 990 /* The SPI device is used to allocate dma memory */ 991 if (!dev->coherent_dma_mask) { 992 ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32)); 993 if (ret) { 994 dev_warn(dev, "Failed to set dma mask %d\n", ret); 995 return ret; 996 } 997 } 998 999 epd = devm_drm_dev_alloc(dev, &repaper_driver, 1000 struct repaper_epd, drm); 1001 if (IS_ERR(epd)) 1002 return PTR_ERR(epd); 1003 1004 drm = &epd->drm; 1005 1006 ret = drmm_mode_config_init(drm); 1007 if (ret) 1008 return ret; 1009 drm->mode_config.funcs = &repaper_mode_config_funcs; 1010 1011 epd->spi = spi; 1012 1013 epd->panel_on = devm_gpiod_get(dev, "panel-on", GPIOD_OUT_LOW); 1014 if (IS_ERR(epd->panel_on)) { 1015 ret = PTR_ERR(epd->panel_on); 1016 if (ret != -EPROBE_DEFER) 1017 DRM_DEV_ERROR(dev, "Failed to get gpio 'panel-on'\n"); 1018 return ret; 1019 } 1020 1021 epd->discharge = devm_gpiod_get(dev, "discharge", GPIOD_OUT_LOW); 1022 if (IS_ERR(epd->discharge)) { 1023 ret = PTR_ERR(epd->discharge); 1024 if (ret != -EPROBE_DEFER) 1025 DRM_DEV_ERROR(dev, "Failed to get gpio 'discharge'\n"); 1026 return ret; 1027 } 1028 1029 epd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW); 1030 if (IS_ERR(epd->reset)) { 1031 ret = PTR_ERR(epd->reset); 1032 if (ret != -EPROBE_DEFER) 1033 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n"); 1034 return ret; 1035 } 1036 1037 epd->busy = devm_gpiod_get(dev, "busy", GPIOD_IN); 1038 if (IS_ERR(epd->busy)) { 1039 ret = PTR_ERR(epd->busy); 1040 if (ret != -EPROBE_DEFER) 1041 DRM_DEV_ERROR(dev, "Failed to get gpio 'busy'\n"); 1042 return ret; 1043 } 1044 1045 if (!device_property_read_string(dev, "pervasive,thermal-zone", 1046 &thermal_zone)) { 1047 epd->thermal = thermal_zone_get_zone_by_name(thermal_zone); 1048 if (IS_ERR(epd->thermal)) { 1049 DRM_DEV_ERROR(dev, "Failed to get thermal zone: %s\n", thermal_zone); 1050 return PTR_ERR(epd->thermal); 1051 } 1052 } 1053 1054 switch (model) { 1055 case E1144CS021: 1056 mode = &repaper_e1144cs021_mode; 1057 epd->channel_select = repaper_e1144cs021_cs; 1058 epd->stage_time = 480; 1059 epd->bytes_per_scan = 96 / 4; 1060 epd->middle_scan = true; /* data-scan-data */ 1061 epd->pre_border_byte = false; 1062 epd->border_byte = REPAPER_BORDER_BYTE_ZERO; 1063 break; 1064 1065 case E1190CS021: 1066 mode = &repaper_e1190cs021_mode; 1067 epd->channel_select = repaper_e1190cs021_cs; 1068 epd->stage_time = 480; 1069 epd->bytes_per_scan = 128 / 4 / 2; 1070 epd->middle_scan = false; /* scan-data-scan */ 1071 epd->pre_border_byte = false; 1072 epd->border_byte = REPAPER_BORDER_BYTE_SET; 1073 break; 1074 1075 case E2200CS021: 1076 mode = &repaper_e2200cs021_mode; 1077 epd->channel_select = repaper_e2200cs021_cs; 1078 epd->stage_time = 480; 1079 epd->bytes_per_scan = 96 / 4; 1080 epd->middle_scan = true; /* data-scan-data */ 1081 epd->pre_border_byte = true; 1082 epd->border_byte = REPAPER_BORDER_BYTE_NONE; 1083 break; 1084 1085 case E2271CS021: 1086 epd->border = devm_gpiod_get(dev, "border", GPIOD_OUT_LOW); 1087 if (IS_ERR(epd->border)) { 1088 ret = PTR_ERR(epd->border); 1089 if (ret != -EPROBE_DEFER) 1090 DRM_DEV_ERROR(dev, "Failed to get gpio 'border'\n"); 1091 return ret; 1092 } 1093 1094 mode = &repaper_e2271cs021_mode; 1095 epd->channel_select = repaper_e2271cs021_cs; 1096 epd->stage_time = 630; 1097 epd->bytes_per_scan = 176 / 4; 1098 epd->middle_scan = true; /* data-scan-data */ 1099 epd->pre_border_byte = true; 1100 epd->border_byte = REPAPER_BORDER_BYTE_NONE; 1101 break; 1102 1103 default: 1104 return -ENODEV; 1105 } 1106 1107 epd->mode = mode; 1108 epd->width = mode->hdisplay; 1109 epd->height = mode->vdisplay; 1110 epd->factored_stage_time = epd->stage_time; 1111 1112 line_buffer_size = 2 * epd->width / 8 + epd->bytes_per_scan + 2; 1113 epd->line_buffer = devm_kzalloc(dev, line_buffer_size, GFP_KERNEL); 1114 if (!epd->line_buffer) 1115 return -ENOMEM; 1116 1117 epd->current_frame = devm_kzalloc(dev, epd->width * epd->height / 8, 1118 GFP_KERNEL); 1119 if (!epd->current_frame) 1120 return -ENOMEM; 1121 1122 drm->mode_config.min_width = mode->hdisplay; 1123 drm->mode_config.max_width = mode->hdisplay; 1124 drm->mode_config.min_height = mode->vdisplay; 1125 drm->mode_config.max_height = mode->vdisplay; 1126 1127 drm_connector_helper_add(&epd->connector, &repaper_connector_hfuncs); 1128 ret = drm_connector_init(drm, &epd->connector, &repaper_connector_funcs, 1129 DRM_MODE_CONNECTOR_SPI); 1130 if (ret) 1131 return ret; 1132 1133 ret = drm_simple_display_pipe_init(drm, &epd->pipe, &repaper_pipe_funcs, 1134 repaper_formats, ARRAY_SIZE(repaper_formats), 1135 NULL, &epd->connector); 1136 if (ret) 1137 return ret; 1138 1139 drm_mode_config_reset(drm); 1140 1141 ret = drm_dev_register(drm, 0); 1142 if (ret) 1143 return ret; 1144 1145 spi_set_drvdata(spi, drm); 1146 1147 DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000); 1148 1149 drm_fbdev_generic_setup(drm, 0); 1150 1151 return 0; 1152 } 1153 1154 static int repaper_remove(struct spi_device *spi) 1155 { 1156 struct drm_device *drm = spi_get_drvdata(spi); 1157 1158 drm_dev_unplug(drm); 1159 drm_atomic_helper_shutdown(drm); 1160 1161 return 0; 1162 } 1163 1164 static void repaper_shutdown(struct spi_device *spi) 1165 { 1166 drm_atomic_helper_shutdown(spi_get_drvdata(spi)); 1167 } 1168 1169 static struct spi_driver repaper_spi_driver = { 1170 .driver = { 1171 .name = "repaper", 1172 .of_match_table = repaper_of_match, 1173 }, 1174 .id_table = repaper_id, 1175 .probe = repaper_probe, 1176 .remove = repaper_remove, 1177 .shutdown = repaper_shutdown, 1178 }; 1179 module_spi_driver(repaper_spi_driver); 1180 1181 MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver"); 1182 MODULE_AUTHOR("Noralf Trønnes"); 1183 MODULE_LICENSE("GPL"); 1184