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 int repaper_fb_dirty(struct drm_framebuffer *fb) 512 { 513 struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0); 514 struct repaper_epd *epd = drm_to_epd(fb->dev); 515 struct drm_rect clip; 516 int idx, ret = 0; 517 u8 *buf = NULL; 518 519 if (!drm_dev_enter(fb->dev, &idx)) 520 return -ENODEV; 521 522 /* repaper can't do partial updates */ 523 clip.x1 = 0; 524 clip.x2 = fb->width; 525 clip.y1 = 0; 526 clip.y2 = fb->height; 527 528 repaper_get_temperature(epd); 529 530 DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id, 531 epd->factored_stage_time); 532 533 buf = kmalloc_array(fb->width, fb->height, GFP_KERNEL); 534 if (!buf) { 535 ret = -ENOMEM; 536 goto out_exit; 537 } 538 539 ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE); 540 if (ret) 541 goto out_free; 542 543 drm_fb_xrgb8888_to_mono(buf, 0, cma_obj->vaddr, fb, &clip); 544 545 drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE); 546 547 if (epd->partial) { 548 repaper_frame_data_repeat(epd, buf, epd->current_frame, 549 REPAPER_NORMAL); 550 } else if (epd->cleared) { 551 repaper_frame_data_repeat(epd, epd->current_frame, NULL, 552 REPAPER_COMPENSATE); 553 repaper_frame_data_repeat(epd, epd->current_frame, NULL, 554 REPAPER_WHITE); 555 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE); 556 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL); 557 558 epd->partial = true; 559 } else { 560 /* Clear display (anything -> white) */ 561 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_COMPENSATE); 562 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_WHITE); 563 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_INVERSE); 564 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_NORMAL); 565 566 /* Assuming a clear (white) screen output an image */ 567 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_COMPENSATE); 568 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_WHITE); 569 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE); 570 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL); 571 572 epd->cleared = true; 573 epd->partial = true; 574 } 575 576 memcpy(epd->current_frame, buf, fb->width * fb->height / 8); 577 578 /* 579 * An extra frame write is needed if pixels are set in the bottom line, 580 * or else grey lines rises up from the pixels 581 */ 582 if (epd->pre_border_byte) { 583 unsigned int x; 584 585 for (x = 0; x < (fb->width / 8); x++) 586 if (buf[x + (fb->width * (fb->height - 1) / 8)]) { 587 repaper_frame_data_repeat(epd, buf, 588 epd->current_frame, 589 REPAPER_NORMAL); 590 break; 591 } 592 } 593 594 out_free: 595 kfree(buf); 596 out_exit: 597 drm_dev_exit(idx); 598 599 return ret; 600 } 601 602 static void power_off(struct repaper_epd *epd) 603 { 604 /* Turn off power and all signals */ 605 gpiod_set_value_cansleep(epd->reset, 0); 606 gpiod_set_value_cansleep(epd->panel_on, 0); 607 if (epd->border) 608 gpiod_set_value_cansleep(epd->border, 0); 609 610 /* Ensure SPI MOSI and CLOCK are Low before CS Low */ 611 repaper_spi_mosi_low(epd->spi); 612 613 /* Discharge pulse */ 614 gpiod_set_value_cansleep(epd->discharge, 1); 615 msleep(150); 616 gpiod_set_value_cansleep(epd->discharge, 0); 617 } 618 619 static void repaper_pipe_enable(struct drm_simple_display_pipe *pipe, 620 struct drm_crtc_state *crtc_state, 621 struct drm_plane_state *plane_state) 622 { 623 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev); 624 struct spi_device *spi = epd->spi; 625 struct device *dev = &spi->dev; 626 bool dc_ok = false; 627 int i, ret, idx; 628 629 if (!drm_dev_enter(pipe->crtc.dev, &idx)) 630 return; 631 632 DRM_DEBUG_DRIVER("\n"); 633 634 /* Power up sequence */ 635 gpiod_set_value_cansleep(epd->reset, 0); 636 gpiod_set_value_cansleep(epd->panel_on, 0); 637 gpiod_set_value_cansleep(epd->discharge, 0); 638 if (epd->border) 639 gpiod_set_value_cansleep(epd->border, 0); 640 repaper_spi_mosi_low(spi); 641 usleep_range(5000, 10000); 642 643 gpiod_set_value_cansleep(epd->panel_on, 1); 644 /* 645 * This delay comes from the repaper.org userspace driver, it's not 646 * mentioned in the datasheet. 647 */ 648 usleep_range(10000, 15000); 649 gpiod_set_value_cansleep(epd->reset, 1); 650 if (epd->border) 651 gpiod_set_value_cansleep(epd->border, 1); 652 usleep_range(5000, 10000); 653 gpiod_set_value_cansleep(epd->reset, 0); 654 usleep_range(5000, 10000); 655 gpiod_set_value_cansleep(epd->reset, 1); 656 usleep_range(5000, 10000); 657 658 /* Wait for COG to become ready */ 659 for (i = 100; i > 0; i--) { 660 if (!gpiod_get_value_cansleep(epd->busy)) 661 break; 662 663 usleep_range(10, 100); 664 } 665 666 if (!i) { 667 DRM_DEV_ERROR(dev, "timeout waiting for panel to become ready.\n"); 668 power_off(epd); 669 goto out_exit; 670 } 671 672 repaper_read_id(spi); 673 ret = repaper_read_id(spi); 674 if (ret != REPAPER_RID_G2_COG_ID) { 675 if (ret < 0) 676 dev_err(dev, "failed to read chip (%d)\n", ret); 677 else 678 dev_err(dev, "wrong COG ID 0x%02x\n", ret); 679 power_off(epd); 680 goto out_exit; 681 } 682 683 /* Disable OE */ 684 repaper_write_val(spi, 0x02, 0x40); 685 686 ret = repaper_read_val(spi, 0x0f); 687 if (ret < 0 || !(ret & 0x80)) { 688 if (ret < 0) 689 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret); 690 else 691 DRM_DEV_ERROR(dev, "panel is reported broken\n"); 692 power_off(epd); 693 goto out_exit; 694 } 695 696 /* Power saving mode */ 697 repaper_write_val(spi, 0x0b, 0x02); 698 /* Channel select */ 699 repaper_write_buf(spi, 0x01, epd->channel_select, 8); 700 /* High power mode osc */ 701 repaper_write_val(spi, 0x07, 0xd1); 702 /* Power setting */ 703 repaper_write_val(spi, 0x08, 0x02); 704 /* Vcom level */ 705 repaper_write_val(spi, 0x09, 0xc2); 706 /* Power setting */ 707 repaper_write_val(spi, 0x04, 0x03); 708 /* Driver latch on */ 709 repaper_write_val(spi, 0x03, 0x01); 710 /* Driver latch off */ 711 repaper_write_val(spi, 0x03, 0x00); 712 usleep_range(5000, 10000); 713 714 /* Start chargepump */ 715 for (i = 0; i < 4; ++i) { 716 /* Charge pump positive voltage on - VGH/VDL on */ 717 repaper_write_val(spi, 0x05, 0x01); 718 msleep(240); 719 720 /* Charge pump negative voltage on - VGL/VDL on */ 721 repaper_write_val(spi, 0x05, 0x03); 722 msleep(40); 723 724 /* Charge pump Vcom on - Vcom driver on */ 725 repaper_write_val(spi, 0x05, 0x0f); 726 msleep(40); 727 728 /* check DC/DC */ 729 ret = repaper_read_val(spi, 0x0f); 730 if (ret < 0) { 731 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret); 732 power_off(epd); 733 goto out_exit; 734 } 735 736 if (ret & 0x40) { 737 dc_ok = true; 738 break; 739 } 740 } 741 742 if (!dc_ok) { 743 DRM_DEV_ERROR(dev, "dc/dc failed\n"); 744 power_off(epd); 745 goto out_exit; 746 } 747 748 /* 749 * Output enable to disable 750 * The userspace driver sets this to 0x04, but the datasheet says 0x06 751 */ 752 repaper_write_val(spi, 0x02, 0x04); 753 754 epd->partial = false; 755 out_exit: 756 drm_dev_exit(idx); 757 } 758 759 static void repaper_pipe_disable(struct drm_simple_display_pipe *pipe) 760 { 761 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev); 762 struct spi_device *spi = epd->spi; 763 unsigned int line; 764 765 /* 766 * This callback is not protected by drm_dev_enter/exit since we want to 767 * turn off the display on regular driver unload. It's highly unlikely 768 * that the underlying SPI controller is gone should this be called after 769 * unplug. 770 */ 771 772 DRM_DEBUG_DRIVER("\n"); 773 774 /* Nothing frame */ 775 for (line = 0; line < epd->height; line++) 776 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL, 777 REPAPER_COMPENSATE); 778 779 /* 2.7" */ 780 if (epd->border) { 781 /* Dummy line */ 782 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL, 783 REPAPER_COMPENSATE); 784 msleep(25); 785 gpiod_set_value_cansleep(epd->border, 0); 786 msleep(200); 787 gpiod_set_value_cansleep(epd->border, 1); 788 } else { 789 /* Border dummy line */ 790 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL, 791 REPAPER_NORMAL); 792 msleep(200); 793 } 794 795 /* not described in datasheet */ 796 repaper_write_val(spi, 0x0b, 0x00); 797 /* Latch reset turn on */ 798 repaper_write_val(spi, 0x03, 0x01); 799 /* Power off charge pump Vcom */ 800 repaper_write_val(spi, 0x05, 0x03); 801 /* Power off charge pump neg voltage */ 802 repaper_write_val(spi, 0x05, 0x01); 803 msleep(120); 804 /* Discharge internal */ 805 repaper_write_val(spi, 0x04, 0x80); 806 /* turn off all charge pumps */ 807 repaper_write_val(spi, 0x05, 0x00); 808 /* Turn off osc */ 809 repaper_write_val(spi, 0x07, 0x01); 810 msleep(50); 811 812 power_off(epd); 813 } 814 815 static void repaper_pipe_update(struct drm_simple_display_pipe *pipe, 816 struct drm_plane_state *old_state) 817 { 818 struct drm_plane_state *state = pipe->plane.state; 819 struct drm_rect rect; 820 821 if (!pipe->crtc.state->active) 822 return; 823 824 if (drm_atomic_helper_damage_merged(old_state, state, &rect)) 825 repaper_fb_dirty(state->fb); 826 } 827 828 static const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = { 829 .enable = repaper_pipe_enable, 830 .disable = repaper_pipe_disable, 831 .update = repaper_pipe_update, 832 }; 833 834 static int repaper_connector_get_modes(struct drm_connector *connector) 835 { 836 struct repaper_epd *epd = drm_to_epd(connector->dev); 837 struct drm_display_mode *mode; 838 839 mode = drm_mode_duplicate(connector->dev, epd->mode); 840 if (!mode) { 841 DRM_ERROR("Failed to duplicate mode\n"); 842 return 0; 843 } 844 845 drm_mode_set_name(mode); 846 mode->type |= DRM_MODE_TYPE_PREFERRED; 847 drm_mode_probed_add(connector, mode); 848 849 connector->display_info.width_mm = mode->width_mm; 850 connector->display_info.height_mm = mode->height_mm; 851 852 return 1; 853 } 854 855 static const struct drm_connector_helper_funcs repaper_connector_hfuncs = { 856 .get_modes = repaper_connector_get_modes, 857 }; 858 859 static const struct drm_connector_funcs repaper_connector_funcs = { 860 .reset = drm_atomic_helper_connector_reset, 861 .fill_modes = drm_helper_probe_single_connector_modes, 862 .destroy = drm_connector_cleanup, 863 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, 864 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, 865 }; 866 867 static const struct drm_mode_config_funcs repaper_mode_config_funcs = { 868 .fb_create = drm_gem_fb_create_with_dirty, 869 .atomic_check = drm_atomic_helper_check, 870 .atomic_commit = drm_atomic_helper_commit, 871 }; 872 873 static const uint32_t repaper_formats[] = { 874 DRM_FORMAT_XRGB8888, 875 }; 876 877 static const struct drm_display_mode repaper_e1144cs021_mode = { 878 DRM_SIMPLE_MODE(128, 96, 29, 22), 879 }; 880 881 static const u8 repaper_e1144cs021_cs[] = { 0x00, 0x00, 0x00, 0x00, 882 0x00, 0x0f, 0xff, 0x00 }; 883 884 static const struct drm_display_mode repaper_e1190cs021_mode = { 885 DRM_SIMPLE_MODE(144, 128, 36, 32), 886 }; 887 888 static const u8 repaper_e1190cs021_cs[] = { 0x00, 0x00, 0x00, 0x03, 889 0xfc, 0x00, 0x00, 0xff }; 890 891 static const struct drm_display_mode repaper_e2200cs021_mode = { 892 DRM_SIMPLE_MODE(200, 96, 46, 22), 893 }; 894 895 static const u8 repaper_e2200cs021_cs[] = { 0x00, 0x00, 0x00, 0x00, 896 0x01, 0xff, 0xe0, 0x00 }; 897 898 static const struct drm_display_mode repaper_e2271cs021_mode = { 899 DRM_SIMPLE_MODE(264, 176, 57, 38), 900 }; 901 902 static const u8 repaper_e2271cs021_cs[] = { 0x00, 0x00, 0x00, 0x7f, 903 0xff, 0xfe, 0x00, 0x00 }; 904 905 DEFINE_DRM_GEM_CMA_FOPS(repaper_fops); 906 907 static const struct drm_driver repaper_driver = { 908 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 909 .fops = &repaper_fops, 910 DRM_GEM_CMA_DRIVER_OPS_VMAP, 911 .name = "repaper", 912 .desc = "Pervasive Displays RePaper e-ink panels", 913 .date = "20170405", 914 .major = 1, 915 .minor = 0, 916 }; 917 918 static const struct of_device_id repaper_of_match[] = { 919 { .compatible = "pervasive,e1144cs021", .data = (void *)E1144CS021 }, 920 { .compatible = "pervasive,e1190cs021", .data = (void *)E1190CS021 }, 921 { .compatible = "pervasive,e2200cs021", .data = (void *)E2200CS021 }, 922 { .compatible = "pervasive,e2271cs021", .data = (void *)E2271CS021 }, 923 {}, 924 }; 925 MODULE_DEVICE_TABLE(of, repaper_of_match); 926 927 static const struct spi_device_id repaper_id[] = { 928 { "e1144cs021", E1144CS021 }, 929 { "e1190cs021", E1190CS021 }, 930 { "e2200cs021", E2200CS021 }, 931 { "e2271cs021", E2271CS021 }, 932 { }, 933 }; 934 MODULE_DEVICE_TABLE(spi, repaper_id); 935 936 static int repaper_probe(struct spi_device *spi) 937 { 938 const struct drm_display_mode *mode; 939 const struct spi_device_id *spi_id; 940 struct device *dev = &spi->dev; 941 enum repaper_model model; 942 const char *thermal_zone; 943 struct repaper_epd *epd; 944 size_t line_buffer_size; 945 struct drm_device *drm; 946 const void *match; 947 int ret; 948 949 match = device_get_match_data(dev); 950 if (match) { 951 model = (enum repaper_model)match; 952 } else { 953 spi_id = spi_get_device_id(spi); 954 model = (enum repaper_model)spi_id->driver_data; 955 } 956 957 /* The SPI device is used to allocate dma memory */ 958 if (!dev->coherent_dma_mask) { 959 ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32)); 960 if (ret) { 961 dev_warn(dev, "Failed to set dma mask %d\n", ret); 962 return ret; 963 } 964 } 965 966 epd = devm_drm_dev_alloc(dev, &repaper_driver, 967 struct repaper_epd, drm); 968 if (IS_ERR(epd)) 969 return PTR_ERR(epd); 970 971 drm = &epd->drm; 972 973 ret = drmm_mode_config_init(drm); 974 if (ret) 975 return ret; 976 drm->mode_config.funcs = &repaper_mode_config_funcs; 977 978 epd->spi = spi; 979 980 epd->panel_on = devm_gpiod_get(dev, "panel-on", GPIOD_OUT_LOW); 981 if (IS_ERR(epd->panel_on)) { 982 ret = PTR_ERR(epd->panel_on); 983 if (ret != -EPROBE_DEFER) 984 DRM_DEV_ERROR(dev, "Failed to get gpio 'panel-on'\n"); 985 return ret; 986 } 987 988 epd->discharge = devm_gpiod_get(dev, "discharge", GPIOD_OUT_LOW); 989 if (IS_ERR(epd->discharge)) { 990 ret = PTR_ERR(epd->discharge); 991 if (ret != -EPROBE_DEFER) 992 DRM_DEV_ERROR(dev, "Failed to get gpio 'discharge'\n"); 993 return ret; 994 } 995 996 epd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW); 997 if (IS_ERR(epd->reset)) { 998 ret = PTR_ERR(epd->reset); 999 if (ret != -EPROBE_DEFER) 1000 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n"); 1001 return ret; 1002 } 1003 1004 epd->busy = devm_gpiod_get(dev, "busy", GPIOD_IN); 1005 if (IS_ERR(epd->busy)) { 1006 ret = PTR_ERR(epd->busy); 1007 if (ret != -EPROBE_DEFER) 1008 DRM_DEV_ERROR(dev, "Failed to get gpio 'busy'\n"); 1009 return ret; 1010 } 1011 1012 if (!device_property_read_string(dev, "pervasive,thermal-zone", 1013 &thermal_zone)) { 1014 epd->thermal = thermal_zone_get_zone_by_name(thermal_zone); 1015 if (IS_ERR(epd->thermal)) { 1016 DRM_DEV_ERROR(dev, "Failed to get thermal zone: %s\n", thermal_zone); 1017 return PTR_ERR(epd->thermal); 1018 } 1019 } 1020 1021 switch (model) { 1022 case E1144CS021: 1023 mode = &repaper_e1144cs021_mode; 1024 epd->channel_select = repaper_e1144cs021_cs; 1025 epd->stage_time = 480; 1026 epd->bytes_per_scan = 96 / 4; 1027 epd->middle_scan = true; /* data-scan-data */ 1028 epd->pre_border_byte = false; 1029 epd->border_byte = REPAPER_BORDER_BYTE_ZERO; 1030 break; 1031 1032 case E1190CS021: 1033 mode = &repaper_e1190cs021_mode; 1034 epd->channel_select = repaper_e1190cs021_cs; 1035 epd->stage_time = 480; 1036 epd->bytes_per_scan = 128 / 4 / 2; 1037 epd->middle_scan = false; /* scan-data-scan */ 1038 epd->pre_border_byte = false; 1039 epd->border_byte = REPAPER_BORDER_BYTE_SET; 1040 break; 1041 1042 case E2200CS021: 1043 mode = &repaper_e2200cs021_mode; 1044 epd->channel_select = repaper_e2200cs021_cs; 1045 epd->stage_time = 480; 1046 epd->bytes_per_scan = 96 / 4; 1047 epd->middle_scan = true; /* data-scan-data */ 1048 epd->pre_border_byte = true; 1049 epd->border_byte = REPAPER_BORDER_BYTE_NONE; 1050 break; 1051 1052 case E2271CS021: 1053 epd->border = devm_gpiod_get(dev, "border", GPIOD_OUT_LOW); 1054 if (IS_ERR(epd->border)) { 1055 ret = PTR_ERR(epd->border); 1056 if (ret != -EPROBE_DEFER) 1057 DRM_DEV_ERROR(dev, "Failed to get gpio 'border'\n"); 1058 return ret; 1059 } 1060 1061 mode = &repaper_e2271cs021_mode; 1062 epd->channel_select = repaper_e2271cs021_cs; 1063 epd->stage_time = 630; 1064 epd->bytes_per_scan = 176 / 4; 1065 epd->middle_scan = true; /* data-scan-data */ 1066 epd->pre_border_byte = true; 1067 epd->border_byte = REPAPER_BORDER_BYTE_NONE; 1068 break; 1069 1070 default: 1071 return -ENODEV; 1072 } 1073 1074 epd->mode = mode; 1075 epd->width = mode->hdisplay; 1076 epd->height = mode->vdisplay; 1077 epd->factored_stage_time = epd->stage_time; 1078 1079 line_buffer_size = 2 * epd->width / 8 + epd->bytes_per_scan + 2; 1080 epd->line_buffer = devm_kzalloc(dev, line_buffer_size, GFP_KERNEL); 1081 if (!epd->line_buffer) 1082 return -ENOMEM; 1083 1084 epd->current_frame = devm_kzalloc(dev, epd->width * epd->height / 8, 1085 GFP_KERNEL); 1086 if (!epd->current_frame) 1087 return -ENOMEM; 1088 1089 drm->mode_config.min_width = mode->hdisplay; 1090 drm->mode_config.max_width = mode->hdisplay; 1091 drm->mode_config.min_height = mode->vdisplay; 1092 drm->mode_config.max_height = mode->vdisplay; 1093 1094 drm_connector_helper_add(&epd->connector, &repaper_connector_hfuncs); 1095 ret = drm_connector_init(drm, &epd->connector, &repaper_connector_funcs, 1096 DRM_MODE_CONNECTOR_SPI); 1097 if (ret) 1098 return ret; 1099 1100 ret = drm_simple_display_pipe_init(drm, &epd->pipe, &repaper_pipe_funcs, 1101 repaper_formats, ARRAY_SIZE(repaper_formats), 1102 NULL, &epd->connector); 1103 if (ret) 1104 return ret; 1105 1106 drm_mode_config_reset(drm); 1107 1108 ret = drm_dev_register(drm, 0); 1109 if (ret) 1110 return ret; 1111 1112 spi_set_drvdata(spi, drm); 1113 1114 DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000); 1115 1116 drm_fbdev_generic_setup(drm, 0); 1117 1118 return 0; 1119 } 1120 1121 static void repaper_remove(struct spi_device *spi) 1122 { 1123 struct drm_device *drm = spi_get_drvdata(spi); 1124 1125 drm_dev_unplug(drm); 1126 drm_atomic_helper_shutdown(drm); 1127 } 1128 1129 static void repaper_shutdown(struct spi_device *spi) 1130 { 1131 drm_atomic_helper_shutdown(spi_get_drvdata(spi)); 1132 } 1133 1134 static struct spi_driver repaper_spi_driver = { 1135 .driver = { 1136 .name = "repaper", 1137 .of_match_table = repaper_of_match, 1138 }, 1139 .id_table = repaper_id, 1140 .probe = repaper_probe, 1141 .remove = repaper_remove, 1142 .shutdown = repaper_shutdown, 1143 }; 1144 module_spi_driver(repaper_spi_driver); 1145 1146 MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver"); 1147 MODULE_AUTHOR("Noralf Trønnes"); 1148 MODULE_LICENSE("GPL"); 1149