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