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_dma_helper.h> 29 #include <drm/drm_fb_helper.h> 30 #include <drm/drm_format_helper.h> 31 #include <drm/drm_framebuffer.h> 32 #include <drm/drm_gem_atomic_helper.h> 33 #include <drm/drm_gem_dma_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 int repaper_fb_dirty(struct drm_framebuffer *fb) 513 { 514 struct drm_gem_dma_object *dma_obj = drm_fb_dma_get_gem_obj(fb, 0); 515 struct repaper_epd *epd = drm_to_epd(fb->dev); 516 unsigned int dst_pitch = 0; 517 struct iosys_map dst, vmap; 518 struct drm_rect clip; 519 int idx, ret = 0; 520 u8 *buf = NULL; 521 522 if (!drm_dev_enter(fb->dev, &idx)) 523 return -ENODEV; 524 525 /* repaper can't do partial updates */ 526 clip.x1 = 0; 527 clip.x2 = fb->width; 528 clip.y1 = 0; 529 clip.y2 = fb->height; 530 531 repaper_get_temperature(epd); 532 533 DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id, 534 epd->factored_stage_time); 535 536 buf = kmalloc_array(fb->width, fb->height, GFP_KERNEL); 537 if (!buf) { 538 ret = -ENOMEM; 539 goto out_exit; 540 } 541 542 ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE); 543 if (ret) 544 goto out_free; 545 546 iosys_map_set_vaddr(&dst, buf); 547 iosys_map_set_vaddr(&vmap, dma_obj->vaddr); 548 drm_fb_xrgb8888_to_mono(&dst, &dst_pitch, &vmap, fb, &clip); 549 550 drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE); 551 552 if (epd->partial) { 553 repaper_frame_data_repeat(epd, buf, epd->current_frame, 554 REPAPER_NORMAL); 555 } else if (epd->cleared) { 556 repaper_frame_data_repeat(epd, epd->current_frame, NULL, 557 REPAPER_COMPENSATE); 558 repaper_frame_data_repeat(epd, epd->current_frame, NULL, 559 REPAPER_WHITE); 560 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE); 561 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL); 562 563 epd->partial = true; 564 } else { 565 /* Clear display (anything -> white) */ 566 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_COMPENSATE); 567 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_WHITE); 568 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_INVERSE); 569 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_NORMAL); 570 571 /* Assuming a clear (white) screen output an image */ 572 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_COMPENSATE); 573 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_WHITE); 574 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE); 575 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL); 576 577 epd->cleared = true; 578 epd->partial = true; 579 } 580 581 memcpy(epd->current_frame, buf, fb->width * fb->height / 8); 582 583 /* 584 * An extra frame write is needed if pixels are set in the bottom line, 585 * or else grey lines rises up from the pixels 586 */ 587 if (epd->pre_border_byte) { 588 unsigned int x; 589 590 for (x = 0; x < (fb->width / 8); x++) 591 if (buf[x + (fb->width * (fb->height - 1) / 8)]) { 592 repaper_frame_data_repeat(epd, buf, 593 epd->current_frame, 594 REPAPER_NORMAL); 595 break; 596 } 597 } 598 599 out_free: 600 kfree(buf); 601 out_exit: 602 drm_dev_exit(idx); 603 604 return ret; 605 } 606 607 static void power_off(struct repaper_epd *epd) 608 { 609 /* Turn off power and all signals */ 610 gpiod_set_value_cansleep(epd->reset, 0); 611 gpiod_set_value_cansleep(epd->panel_on, 0); 612 if (epd->border) 613 gpiod_set_value_cansleep(epd->border, 0); 614 615 /* Ensure SPI MOSI and CLOCK are Low before CS Low */ 616 repaper_spi_mosi_low(epd->spi); 617 618 /* Discharge pulse */ 619 gpiod_set_value_cansleep(epd->discharge, 1); 620 msleep(150); 621 gpiod_set_value_cansleep(epd->discharge, 0); 622 } 623 624 static enum drm_mode_status repaper_pipe_mode_valid(struct drm_simple_display_pipe *pipe, 625 const struct drm_display_mode *mode) 626 { 627 struct drm_crtc *crtc = &pipe->crtc; 628 struct repaper_epd *epd = drm_to_epd(crtc->dev); 629 630 return drm_crtc_helper_mode_valid_fixed(crtc, mode, epd->mode); 631 } 632 633 static void repaper_pipe_enable(struct drm_simple_display_pipe *pipe, 634 struct drm_crtc_state *crtc_state, 635 struct drm_plane_state *plane_state) 636 { 637 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev); 638 struct spi_device *spi = epd->spi; 639 struct device *dev = &spi->dev; 640 bool dc_ok = false; 641 int i, ret, idx; 642 643 if (!drm_dev_enter(pipe->crtc.dev, &idx)) 644 return; 645 646 DRM_DEBUG_DRIVER("\n"); 647 648 /* Power up sequence */ 649 gpiod_set_value_cansleep(epd->reset, 0); 650 gpiod_set_value_cansleep(epd->panel_on, 0); 651 gpiod_set_value_cansleep(epd->discharge, 0); 652 if (epd->border) 653 gpiod_set_value_cansleep(epd->border, 0); 654 repaper_spi_mosi_low(spi); 655 usleep_range(5000, 10000); 656 657 gpiod_set_value_cansleep(epd->panel_on, 1); 658 /* 659 * This delay comes from the repaper.org userspace driver, it's not 660 * mentioned in the datasheet. 661 */ 662 usleep_range(10000, 15000); 663 gpiod_set_value_cansleep(epd->reset, 1); 664 if (epd->border) 665 gpiod_set_value_cansleep(epd->border, 1); 666 usleep_range(5000, 10000); 667 gpiod_set_value_cansleep(epd->reset, 0); 668 usleep_range(5000, 10000); 669 gpiod_set_value_cansleep(epd->reset, 1); 670 usleep_range(5000, 10000); 671 672 /* Wait for COG to become ready */ 673 for (i = 100; i > 0; i--) { 674 if (!gpiod_get_value_cansleep(epd->busy)) 675 break; 676 677 usleep_range(10, 100); 678 } 679 680 if (!i) { 681 DRM_DEV_ERROR(dev, "timeout waiting for panel to become ready.\n"); 682 power_off(epd); 683 goto out_exit; 684 } 685 686 repaper_read_id(spi); 687 ret = repaper_read_id(spi); 688 if (ret != REPAPER_RID_G2_COG_ID) { 689 if (ret < 0) 690 dev_err(dev, "failed to read chip (%d)\n", ret); 691 else 692 dev_err(dev, "wrong COG ID 0x%02x\n", ret); 693 power_off(epd); 694 goto out_exit; 695 } 696 697 /* Disable OE */ 698 repaper_write_val(spi, 0x02, 0x40); 699 700 ret = repaper_read_val(spi, 0x0f); 701 if (ret < 0 || !(ret & 0x80)) { 702 if (ret < 0) 703 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret); 704 else 705 DRM_DEV_ERROR(dev, "panel is reported broken\n"); 706 power_off(epd); 707 goto out_exit; 708 } 709 710 /* Power saving mode */ 711 repaper_write_val(spi, 0x0b, 0x02); 712 /* Channel select */ 713 repaper_write_buf(spi, 0x01, epd->channel_select, 8); 714 /* High power mode osc */ 715 repaper_write_val(spi, 0x07, 0xd1); 716 /* Power setting */ 717 repaper_write_val(spi, 0x08, 0x02); 718 /* Vcom level */ 719 repaper_write_val(spi, 0x09, 0xc2); 720 /* Power setting */ 721 repaper_write_val(spi, 0x04, 0x03); 722 /* Driver latch on */ 723 repaper_write_val(spi, 0x03, 0x01); 724 /* Driver latch off */ 725 repaper_write_val(spi, 0x03, 0x00); 726 usleep_range(5000, 10000); 727 728 /* Start chargepump */ 729 for (i = 0; i < 4; ++i) { 730 /* Charge pump positive voltage on - VGH/VDL on */ 731 repaper_write_val(spi, 0x05, 0x01); 732 msleep(240); 733 734 /* Charge pump negative voltage on - VGL/VDL on */ 735 repaper_write_val(spi, 0x05, 0x03); 736 msleep(40); 737 738 /* Charge pump Vcom on - Vcom driver on */ 739 repaper_write_val(spi, 0x05, 0x0f); 740 msleep(40); 741 742 /* check DC/DC */ 743 ret = repaper_read_val(spi, 0x0f); 744 if (ret < 0) { 745 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret); 746 power_off(epd); 747 goto out_exit; 748 } 749 750 if (ret & 0x40) { 751 dc_ok = true; 752 break; 753 } 754 } 755 756 if (!dc_ok) { 757 DRM_DEV_ERROR(dev, "dc/dc failed\n"); 758 power_off(epd); 759 goto out_exit; 760 } 761 762 /* 763 * Output enable to disable 764 * The userspace driver sets this to 0x04, but the datasheet says 0x06 765 */ 766 repaper_write_val(spi, 0x02, 0x04); 767 768 epd->partial = false; 769 out_exit: 770 drm_dev_exit(idx); 771 } 772 773 static void repaper_pipe_disable(struct drm_simple_display_pipe *pipe) 774 { 775 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev); 776 struct spi_device *spi = epd->spi; 777 unsigned int line; 778 779 /* 780 * This callback is not protected by drm_dev_enter/exit since we want to 781 * turn off the display on regular driver unload. It's highly unlikely 782 * that the underlying SPI controller is gone should this be called after 783 * unplug. 784 */ 785 786 DRM_DEBUG_DRIVER("\n"); 787 788 /* Nothing frame */ 789 for (line = 0; line < epd->height; line++) 790 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL, 791 REPAPER_COMPENSATE); 792 793 /* 2.7" */ 794 if (epd->border) { 795 /* Dummy line */ 796 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL, 797 REPAPER_COMPENSATE); 798 msleep(25); 799 gpiod_set_value_cansleep(epd->border, 0); 800 msleep(200); 801 gpiod_set_value_cansleep(epd->border, 1); 802 } else { 803 /* Border dummy line */ 804 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL, 805 REPAPER_NORMAL); 806 msleep(200); 807 } 808 809 /* not described in datasheet */ 810 repaper_write_val(spi, 0x0b, 0x00); 811 /* Latch reset turn on */ 812 repaper_write_val(spi, 0x03, 0x01); 813 /* Power off charge pump Vcom */ 814 repaper_write_val(spi, 0x05, 0x03); 815 /* Power off charge pump neg voltage */ 816 repaper_write_val(spi, 0x05, 0x01); 817 msleep(120); 818 /* Discharge internal */ 819 repaper_write_val(spi, 0x04, 0x80); 820 /* turn off all charge pumps */ 821 repaper_write_val(spi, 0x05, 0x00); 822 /* Turn off osc */ 823 repaper_write_val(spi, 0x07, 0x01); 824 msleep(50); 825 826 power_off(epd); 827 } 828 829 static void repaper_pipe_update(struct drm_simple_display_pipe *pipe, 830 struct drm_plane_state *old_state) 831 { 832 struct drm_plane_state *state = pipe->plane.state; 833 struct drm_rect rect; 834 835 if (!pipe->crtc.state->active) 836 return; 837 838 if (drm_atomic_helper_damage_merged(old_state, state, &rect)) 839 repaper_fb_dirty(state->fb); 840 } 841 842 static const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = { 843 .mode_valid = repaper_pipe_mode_valid, 844 .enable = repaper_pipe_enable, 845 .disable = repaper_pipe_disable, 846 .update = repaper_pipe_update, 847 }; 848 849 static int repaper_connector_get_modes(struct drm_connector *connector) 850 { 851 struct repaper_epd *epd = drm_to_epd(connector->dev); 852 853 return drm_connector_helper_get_modes_fixed(connector, epd->mode); 854 } 855 856 static const struct drm_connector_helper_funcs repaper_connector_hfuncs = { 857 .get_modes = repaper_connector_get_modes, 858 }; 859 860 static const struct drm_connector_funcs repaper_connector_funcs = { 861 .reset = drm_atomic_helper_connector_reset, 862 .fill_modes = drm_helper_probe_single_connector_modes, 863 .destroy = drm_connector_cleanup, 864 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, 865 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, 866 }; 867 868 static const struct drm_mode_config_funcs repaper_mode_config_funcs = { 869 .fb_create = drm_gem_fb_create_with_dirty, 870 .atomic_check = drm_atomic_helper_check, 871 .atomic_commit = drm_atomic_helper_commit, 872 }; 873 874 static const uint32_t repaper_formats[] = { 875 DRM_FORMAT_XRGB8888, 876 }; 877 878 static const struct drm_display_mode repaper_e1144cs021_mode = { 879 DRM_SIMPLE_MODE(128, 96, 29, 22), 880 }; 881 882 static const u8 repaper_e1144cs021_cs[] = { 0x00, 0x00, 0x00, 0x00, 883 0x00, 0x0f, 0xff, 0x00 }; 884 885 static const struct drm_display_mode repaper_e1190cs021_mode = { 886 DRM_SIMPLE_MODE(144, 128, 36, 32), 887 }; 888 889 static const u8 repaper_e1190cs021_cs[] = { 0x00, 0x00, 0x00, 0x03, 890 0xfc, 0x00, 0x00, 0xff }; 891 892 static const struct drm_display_mode repaper_e2200cs021_mode = { 893 DRM_SIMPLE_MODE(200, 96, 46, 22), 894 }; 895 896 static const u8 repaper_e2200cs021_cs[] = { 0x00, 0x00, 0x00, 0x00, 897 0x01, 0xff, 0xe0, 0x00 }; 898 899 static const struct drm_display_mode repaper_e2271cs021_mode = { 900 DRM_SIMPLE_MODE(264, 176, 57, 38), 901 }; 902 903 static const u8 repaper_e2271cs021_cs[] = { 0x00, 0x00, 0x00, 0x7f, 904 0xff, 0xfe, 0x00, 0x00 }; 905 906 DEFINE_DRM_GEM_DMA_FOPS(repaper_fops); 907 908 static const struct drm_driver repaper_driver = { 909 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 910 .fops = &repaper_fops, 911 DRM_GEM_DMA_DRIVER_OPS_VMAP, 912 .name = "repaper", 913 .desc = "Pervasive Displays RePaper e-ink panels", 914 .date = "20170405", 915 .major = 1, 916 .minor = 0, 917 }; 918 919 static const struct of_device_id repaper_of_match[] = { 920 { .compatible = "pervasive,e1144cs021", .data = (void *)E1144CS021 }, 921 { .compatible = "pervasive,e1190cs021", .data = (void *)E1190CS021 }, 922 { .compatible = "pervasive,e2200cs021", .data = (void *)E2200CS021 }, 923 { .compatible = "pervasive,e2271cs021", .data = (void *)E2271CS021 }, 924 {}, 925 }; 926 MODULE_DEVICE_TABLE(of, repaper_of_match); 927 928 static const struct spi_device_id repaper_id[] = { 929 { "e1144cs021", E1144CS021 }, 930 { "e1190cs021", E1190CS021 }, 931 { "e2200cs021", E2200CS021 }, 932 { "e2271cs021", E2271CS021 }, 933 { }, 934 }; 935 MODULE_DEVICE_TABLE(spi, repaper_id); 936 937 static int repaper_probe(struct spi_device *spi) 938 { 939 const struct drm_display_mode *mode; 940 const struct spi_device_id *spi_id; 941 struct device *dev = &spi->dev; 942 enum repaper_model model; 943 const char *thermal_zone; 944 struct repaper_epd *epd; 945 size_t line_buffer_size; 946 struct drm_device *drm; 947 const void *match; 948 int ret; 949 950 match = device_get_match_data(dev); 951 if (match) { 952 model = (enum repaper_model)match; 953 } else { 954 spi_id = spi_get_device_id(spi); 955 model = (enum repaper_model)spi_id->driver_data; 956 } 957 958 /* The SPI device is used to allocate dma memory */ 959 if (!dev->coherent_dma_mask) { 960 ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32)); 961 if (ret) { 962 dev_warn(dev, "Failed to set dma mask %d\n", ret); 963 return ret; 964 } 965 } 966 967 epd = devm_drm_dev_alloc(dev, &repaper_driver, 968 struct repaper_epd, drm); 969 if (IS_ERR(epd)) 970 return PTR_ERR(epd); 971 972 drm = &epd->drm; 973 974 ret = drmm_mode_config_init(drm); 975 if (ret) 976 return ret; 977 drm->mode_config.funcs = &repaper_mode_config_funcs; 978 979 epd->spi = spi; 980 981 epd->panel_on = devm_gpiod_get(dev, "panel-on", GPIOD_OUT_LOW); 982 if (IS_ERR(epd->panel_on)) { 983 ret = PTR_ERR(epd->panel_on); 984 if (ret != -EPROBE_DEFER) 985 DRM_DEV_ERROR(dev, "Failed to get gpio 'panel-on'\n"); 986 return ret; 987 } 988 989 epd->discharge = devm_gpiod_get(dev, "discharge", GPIOD_OUT_LOW); 990 if (IS_ERR(epd->discharge)) { 991 ret = PTR_ERR(epd->discharge); 992 if (ret != -EPROBE_DEFER) 993 DRM_DEV_ERROR(dev, "Failed to get gpio 'discharge'\n"); 994 return ret; 995 } 996 997 epd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW); 998 if (IS_ERR(epd->reset)) { 999 ret = PTR_ERR(epd->reset); 1000 if (ret != -EPROBE_DEFER) 1001 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n"); 1002 return ret; 1003 } 1004 1005 epd->busy = devm_gpiod_get(dev, "busy", GPIOD_IN); 1006 if (IS_ERR(epd->busy)) { 1007 ret = PTR_ERR(epd->busy); 1008 if (ret != -EPROBE_DEFER) 1009 DRM_DEV_ERROR(dev, "Failed to get gpio 'busy'\n"); 1010 return ret; 1011 } 1012 1013 if (!device_property_read_string(dev, "pervasive,thermal-zone", 1014 &thermal_zone)) { 1015 epd->thermal = thermal_zone_get_zone_by_name(thermal_zone); 1016 if (IS_ERR(epd->thermal)) { 1017 DRM_DEV_ERROR(dev, "Failed to get thermal zone: %s\n", thermal_zone); 1018 return PTR_ERR(epd->thermal); 1019 } 1020 } 1021 1022 switch (model) { 1023 case E1144CS021: 1024 mode = &repaper_e1144cs021_mode; 1025 epd->channel_select = repaper_e1144cs021_cs; 1026 epd->stage_time = 480; 1027 epd->bytes_per_scan = 96 / 4; 1028 epd->middle_scan = true; /* data-scan-data */ 1029 epd->pre_border_byte = false; 1030 epd->border_byte = REPAPER_BORDER_BYTE_ZERO; 1031 break; 1032 1033 case E1190CS021: 1034 mode = &repaper_e1190cs021_mode; 1035 epd->channel_select = repaper_e1190cs021_cs; 1036 epd->stage_time = 480; 1037 epd->bytes_per_scan = 128 / 4 / 2; 1038 epd->middle_scan = false; /* scan-data-scan */ 1039 epd->pre_border_byte = false; 1040 epd->border_byte = REPAPER_BORDER_BYTE_SET; 1041 break; 1042 1043 case E2200CS021: 1044 mode = &repaper_e2200cs021_mode; 1045 epd->channel_select = repaper_e2200cs021_cs; 1046 epd->stage_time = 480; 1047 epd->bytes_per_scan = 96 / 4; 1048 epd->middle_scan = true; /* data-scan-data */ 1049 epd->pre_border_byte = true; 1050 epd->border_byte = REPAPER_BORDER_BYTE_NONE; 1051 break; 1052 1053 case E2271CS021: 1054 epd->border = devm_gpiod_get(dev, "border", GPIOD_OUT_LOW); 1055 if (IS_ERR(epd->border)) { 1056 ret = PTR_ERR(epd->border); 1057 if (ret != -EPROBE_DEFER) 1058 DRM_DEV_ERROR(dev, "Failed to get gpio 'border'\n"); 1059 return ret; 1060 } 1061 1062 mode = &repaper_e2271cs021_mode; 1063 epd->channel_select = repaper_e2271cs021_cs; 1064 epd->stage_time = 630; 1065 epd->bytes_per_scan = 176 / 4; 1066 epd->middle_scan = true; /* data-scan-data */ 1067 epd->pre_border_byte = true; 1068 epd->border_byte = REPAPER_BORDER_BYTE_NONE; 1069 break; 1070 1071 default: 1072 return -ENODEV; 1073 } 1074 1075 epd->mode = mode; 1076 epd->width = mode->hdisplay; 1077 epd->height = mode->vdisplay; 1078 epd->factored_stage_time = epd->stage_time; 1079 1080 line_buffer_size = 2 * epd->width / 8 + epd->bytes_per_scan + 2; 1081 epd->line_buffer = devm_kzalloc(dev, line_buffer_size, GFP_KERNEL); 1082 if (!epd->line_buffer) 1083 return -ENOMEM; 1084 1085 epd->current_frame = devm_kzalloc(dev, epd->width * epd->height / 8, 1086 GFP_KERNEL); 1087 if (!epd->current_frame) 1088 return -ENOMEM; 1089 1090 drm->mode_config.min_width = mode->hdisplay; 1091 drm->mode_config.max_width = mode->hdisplay; 1092 drm->mode_config.min_height = mode->vdisplay; 1093 drm->mode_config.max_height = mode->vdisplay; 1094 1095 drm_connector_helper_add(&epd->connector, &repaper_connector_hfuncs); 1096 ret = drm_connector_init(drm, &epd->connector, &repaper_connector_funcs, 1097 DRM_MODE_CONNECTOR_SPI); 1098 if (ret) 1099 return ret; 1100 1101 ret = drm_simple_display_pipe_init(drm, &epd->pipe, &repaper_pipe_funcs, 1102 repaper_formats, ARRAY_SIZE(repaper_formats), 1103 NULL, &epd->connector); 1104 if (ret) 1105 return ret; 1106 1107 drm_mode_config_reset(drm); 1108 1109 ret = drm_dev_register(drm, 0); 1110 if (ret) 1111 return ret; 1112 1113 spi_set_drvdata(spi, drm); 1114 1115 DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000); 1116 1117 drm_fbdev_generic_setup(drm, 0); 1118 1119 return 0; 1120 } 1121 1122 static void repaper_remove(struct spi_device *spi) 1123 { 1124 struct drm_device *drm = spi_get_drvdata(spi); 1125 1126 drm_dev_unplug(drm); 1127 drm_atomic_helper_shutdown(drm); 1128 } 1129 1130 static void repaper_shutdown(struct spi_device *spi) 1131 { 1132 drm_atomic_helper_shutdown(spi_get_drvdata(spi)); 1133 } 1134 1135 static struct spi_driver repaper_spi_driver = { 1136 .driver = { 1137 .name = "repaper", 1138 .of_match_table = repaper_of_match, 1139 }, 1140 .id_table = repaper_id, 1141 .probe = repaper_probe, 1142 .remove = repaper_remove, 1143 .shutdown = repaper_shutdown, 1144 }; 1145 module_spi_driver(repaper_spi_driver); 1146 1147 MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver"); 1148 MODULE_AUTHOR("Noralf Trønnes"); 1149 MODULE_LICENSE("GPL"); 1150