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/clients/drm_client_setup.h> 25 #include <drm/drm_atomic_helper.h> 26 #include <drm/drm_connector.h> 27 #include <drm/drm_damage_helper.h> 28 #include <drm/drm_drv.h> 29 #include <drm/drm_fb_dma_helper.h> 30 #include <drm/drm_fbdev_dma.h> 31 #include <drm/drm_format_helper.h> 32 #include <drm/drm_framebuffer.h> 33 #include <drm/drm_gem_atomic_helper.h> 34 #include <drm/drm_gem_dma_helper.h> 35 #include <drm/drm_gem_framebuffer_helper.h> 36 #include <drm/drm_managed.h> 37 #include <drm/drm_modes.h> 38 #include <drm/drm_rect.h> 39 #include <drm/drm_probe_helper.h> 40 #include <drm/drm_simple_kms_helper.h> 41 42 #define REPAPER_RID_G2_COG_ID 0x12 43 44 enum repaper_model { 45 /* 0 is reserved to avoid clashing with NULL */ 46 E1144CS021 = 1, 47 E1190CS021, 48 E2200CS021, 49 E2271CS021, 50 }; 51 52 enum repaper_stage { /* Image pixel -> Display pixel */ 53 REPAPER_COMPENSATE, /* B -> W, W -> B (Current Image) */ 54 REPAPER_WHITE, /* B -> N, W -> W (Current Image) */ 55 REPAPER_INVERSE, /* B -> N, W -> B (New Image) */ 56 REPAPER_NORMAL /* B -> B, W -> W (New Image) */ 57 }; 58 59 enum repaper_epd_border_byte { 60 REPAPER_BORDER_BYTE_NONE, 61 REPAPER_BORDER_BYTE_ZERO, 62 REPAPER_BORDER_BYTE_SET, 63 }; 64 65 struct repaper_epd { 66 struct drm_device drm; 67 struct drm_simple_display_pipe pipe; 68 const struct drm_display_mode *mode; 69 struct drm_connector connector; 70 struct spi_device *spi; 71 72 struct gpio_desc *panel_on; 73 struct gpio_desc *border; 74 struct gpio_desc *discharge; 75 struct gpio_desc *reset; 76 struct gpio_desc *busy; 77 78 struct thermal_zone_device *thermal; 79 80 unsigned int height; 81 unsigned int width; 82 unsigned int bytes_per_scan; 83 const u8 *channel_select; 84 unsigned int stage_time; 85 unsigned int factored_stage_time; 86 bool middle_scan; 87 bool pre_border_byte; 88 enum repaper_epd_border_byte border_byte; 89 90 u8 *line_buffer; 91 void *current_frame; 92 93 bool cleared; 94 bool partial; 95 }; 96 97 static inline struct repaper_epd *drm_to_epd(struct drm_device *drm) 98 { 99 return container_of(drm, struct repaper_epd, drm); 100 } 101 102 static int repaper_spi_transfer(struct spi_device *spi, u8 header, 103 const void *tx, void *rx, size_t len) 104 { 105 void *txbuf = NULL, *rxbuf = NULL; 106 struct spi_transfer tr[2] = {}; 107 u8 *headerbuf; 108 int ret; 109 110 headerbuf = kmalloc(1, GFP_KERNEL); 111 if (!headerbuf) 112 return -ENOMEM; 113 114 headerbuf[0] = header; 115 tr[0].tx_buf = headerbuf; 116 tr[0].len = 1; 117 118 /* Stack allocated tx? */ 119 if (tx && len <= 32) { 120 txbuf = kmemdup(tx, len, GFP_KERNEL); 121 if (!txbuf) { 122 ret = -ENOMEM; 123 goto out_free; 124 } 125 } 126 127 if (rx) { 128 rxbuf = kmalloc(len, GFP_KERNEL); 129 if (!rxbuf) { 130 ret = -ENOMEM; 131 goto out_free; 132 } 133 } 134 135 tr[1].tx_buf = txbuf ? txbuf : tx; 136 tr[1].rx_buf = rxbuf; 137 tr[1].len = len; 138 139 ndelay(80); 140 ret = spi_sync_transfer(spi, tr, 2); 141 if (rx && !ret) 142 memcpy(rx, rxbuf, len); 143 144 out_free: 145 kfree(headerbuf); 146 kfree(txbuf); 147 kfree(rxbuf); 148 149 return ret; 150 } 151 152 static int repaper_write_buf(struct spi_device *spi, u8 reg, 153 const u8 *buf, size_t len) 154 { 155 int ret; 156 157 ret = repaper_spi_transfer(spi, 0x70, ®, NULL, 1); 158 if (ret) 159 return ret; 160 161 return repaper_spi_transfer(spi, 0x72, buf, NULL, len); 162 } 163 164 static int repaper_write_val(struct spi_device *spi, u8 reg, u8 val) 165 { 166 return repaper_write_buf(spi, reg, &val, 1); 167 } 168 169 static int repaper_read_val(struct spi_device *spi, u8 reg) 170 { 171 int ret; 172 u8 val; 173 174 ret = repaper_spi_transfer(spi, 0x70, ®, NULL, 1); 175 if (ret) 176 return ret; 177 178 ret = repaper_spi_transfer(spi, 0x73, NULL, &val, 1); 179 180 return ret ? ret : val; 181 } 182 183 static int repaper_read_id(struct spi_device *spi) 184 { 185 int ret; 186 u8 id; 187 188 ret = repaper_spi_transfer(spi, 0x71, NULL, &id, 1); 189 190 return ret ? ret : id; 191 } 192 193 static void repaper_spi_mosi_low(struct spi_device *spi) 194 { 195 const u8 buf[1] = { 0 }; 196 197 spi_write(spi, buf, 1); 198 } 199 200 /* pixels on display are numbered from 1 so even is actually bits 1,3,5,... */ 201 static void repaper_even_pixels(struct repaper_epd *epd, u8 **pp, 202 const u8 *data, u8 fixed_value, const u8 *mask, 203 enum repaper_stage stage) 204 { 205 unsigned int b; 206 207 for (b = 0; b < (epd->width / 8); b++) { 208 if (data) { 209 u8 pixels = data[b] & 0xaa; 210 u8 pixel_mask = 0xff; 211 u8 p1, p2, p3, p4; 212 213 if (mask) { 214 pixel_mask = (mask[b] ^ pixels) & 0xaa; 215 pixel_mask |= pixel_mask >> 1; 216 } 217 218 switch (stage) { 219 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */ 220 pixels = 0xaa | ((pixels ^ 0xaa) >> 1); 221 break; 222 case REPAPER_WHITE: /* B -> N, W -> W (Current) */ 223 pixels = 0x55 + ((pixels ^ 0xaa) >> 1); 224 break; 225 case REPAPER_INVERSE: /* B -> N, W -> B (New) */ 226 pixels = 0x55 | (pixels ^ 0xaa); 227 break; 228 case REPAPER_NORMAL: /* B -> B, W -> W (New) */ 229 pixels = 0xaa | (pixels >> 1); 230 break; 231 } 232 233 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x55); 234 p1 = (pixels >> 6) & 0x03; 235 p2 = (pixels >> 4) & 0x03; 236 p3 = (pixels >> 2) & 0x03; 237 p4 = (pixels >> 0) & 0x03; 238 pixels = (p1 << 0) | (p2 << 2) | (p3 << 4) | (p4 << 6); 239 *(*pp)++ = pixels; 240 } else { 241 *(*pp)++ = fixed_value; 242 } 243 } 244 } 245 246 /* pixels on display are numbered from 1 so odd is actually bits 0,2,4,... */ 247 static void repaper_odd_pixels(struct repaper_epd *epd, u8 **pp, 248 const u8 *data, u8 fixed_value, const u8 *mask, 249 enum repaper_stage stage) 250 { 251 unsigned int b; 252 253 for (b = epd->width / 8; b > 0; b--) { 254 if (data) { 255 u8 pixels = data[b - 1] & 0x55; 256 u8 pixel_mask = 0xff; 257 258 if (mask) { 259 pixel_mask = (mask[b - 1] ^ pixels) & 0x55; 260 pixel_mask |= pixel_mask << 1; 261 } 262 263 switch (stage) { 264 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */ 265 pixels = 0xaa | (pixels ^ 0x55); 266 break; 267 case REPAPER_WHITE: /* B -> N, W -> W (Current) */ 268 pixels = 0x55 + (pixels ^ 0x55); 269 break; 270 case REPAPER_INVERSE: /* B -> N, W -> B (New) */ 271 pixels = 0x55 | ((pixels ^ 0x55) << 1); 272 break; 273 case REPAPER_NORMAL: /* B -> B, W -> W (New) */ 274 pixels = 0xaa | pixels; 275 break; 276 } 277 278 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x55); 279 *(*pp)++ = pixels; 280 } else { 281 *(*pp)++ = fixed_value; 282 } 283 } 284 } 285 286 /* interleave bits: (byte)76543210 -> (16 bit).7.6.5.4.3.2.1 */ 287 static inline u16 repaper_interleave_bits(u16 value) 288 { 289 value = (value | (value << 4)) & 0x0f0f; 290 value = (value | (value << 2)) & 0x3333; 291 value = (value | (value << 1)) & 0x5555; 292 293 return value; 294 } 295 296 /* pixels on display are numbered from 1 */ 297 static void repaper_all_pixels(struct repaper_epd *epd, u8 **pp, 298 const u8 *data, u8 fixed_value, const u8 *mask, 299 enum repaper_stage stage) 300 { 301 unsigned int b; 302 303 for (b = epd->width / 8; b > 0; b--) { 304 if (data) { 305 u16 pixels = repaper_interleave_bits(data[b - 1]); 306 u16 pixel_mask = 0xffff; 307 308 if (mask) { 309 pixel_mask = repaper_interleave_bits(mask[b - 1]); 310 311 pixel_mask = (pixel_mask ^ pixels) & 0x5555; 312 pixel_mask |= pixel_mask << 1; 313 } 314 315 switch (stage) { 316 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */ 317 pixels = 0xaaaa | (pixels ^ 0x5555); 318 break; 319 case REPAPER_WHITE: /* B -> N, W -> W (Current) */ 320 pixels = 0x5555 + (pixels ^ 0x5555); 321 break; 322 case REPAPER_INVERSE: /* B -> N, W -> B (New) */ 323 pixels = 0x5555 | ((pixels ^ 0x5555) << 1); 324 break; 325 case REPAPER_NORMAL: /* B -> B, W -> W (New) */ 326 pixels = 0xaaaa | pixels; 327 break; 328 } 329 330 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x5555); 331 *(*pp)++ = pixels >> 8; 332 *(*pp)++ = pixels; 333 } else { 334 *(*pp)++ = fixed_value; 335 *(*pp)++ = fixed_value; 336 } 337 } 338 } 339 340 /* output one line of scan and data bytes to the display */ 341 static void repaper_one_line(struct repaper_epd *epd, unsigned int line, 342 const u8 *data, u8 fixed_value, const u8 *mask, 343 enum repaper_stage stage) 344 { 345 u8 *p = epd->line_buffer; 346 unsigned int b; 347 348 repaper_spi_mosi_low(epd->spi); 349 350 if (epd->pre_border_byte) 351 *p++ = 0x00; 352 353 if (epd->middle_scan) { 354 /* data bytes */ 355 repaper_odd_pixels(epd, &p, data, fixed_value, mask, stage); 356 357 /* scan line */ 358 for (b = epd->bytes_per_scan; b > 0; b--) { 359 if (line / 4 == b - 1) 360 *p++ = 0x03 << (2 * (line & 0x03)); 361 else 362 *p++ = 0x00; 363 } 364 365 /* data bytes */ 366 repaper_even_pixels(epd, &p, data, fixed_value, mask, stage); 367 } else { 368 /* 369 * even scan line, but as lines on display are numbered from 1, 370 * line: 1,3,5,... 371 */ 372 for (b = 0; b < epd->bytes_per_scan; b++) { 373 if (0 != (line & 0x01) && line / 8 == b) 374 *p++ = 0xc0 >> (line & 0x06); 375 else 376 *p++ = 0x00; 377 } 378 379 /* data bytes */ 380 repaper_all_pixels(epd, &p, data, fixed_value, mask, stage); 381 382 /* 383 * odd scan line, but as lines on display are numbered from 1, 384 * line: 0,2,4,6,... 385 */ 386 for (b = epd->bytes_per_scan; b > 0; b--) { 387 if (0 == (line & 0x01) && line / 8 == b - 1) 388 *p++ = 0x03 << (line & 0x06); 389 else 390 *p++ = 0x00; 391 } 392 } 393 394 switch (epd->border_byte) { 395 case REPAPER_BORDER_BYTE_NONE: 396 break; 397 398 case REPAPER_BORDER_BYTE_ZERO: 399 *p++ = 0x00; 400 break; 401 402 case REPAPER_BORDER_BYTE_SET: 403 switch (stage) { 404 case REPAPER_COMPENSATE: 405 case REPAPER_WHITE: 406 case REPAPER_INVERSE: 407 *p++ = 0x00; 408 break; 409 case REPAPER_NORMAL: 410 *p++ = 0xaa; 411 break; 412 } 413 break; 414 } 415 416 repaper_write_buf(epd->spi, 0x0a, epd->line_buffer, 417 p - epd->line_buffer); 418 419 /* Output data to panel */ 420 repaper_write_val(epd->spi, 0x02, 0x07); 421 422 repaper_spi_mosi_low(epd->spi); 423 } 424 425 static void repaper_frame_fixed(struct repaper_epd *epd, u8 fixed_value, 426 enum repaper_stage stage) 427 { 428 unsigned int line; 429 430 for (line = 0; line < epd->height; line++) 431 repaper_one_line(epd, line, NULL, fixed_value, NULL, stage); 432 } 433 434 static void repaper_frame_data(struct repaper_epd *epd, const u8 *image, 435 const u8 *mask, enum repaper_stage stage) 436 { 437 unsigned int line; 438 439 if (!mask) { 440 for (line = 0; line < epd->height; line++) { 441 repaper_one_line(epd, line, 442 &image[line * (epd->width / 8)], 443 0, NULL, stage); 444 } 445 } else { 446 for (line = 0; line < epd->height; line++) { 447 size_t n = line * epd->width / 8; 448 449 repaper_one_line(epd, line, &image[n], 0, &mask[n], 450 stage); 451 } 452 } 453 } 454 455 static void repaper_frame_fixed_repeat(struct repaper_epd *epd, u8 fixed_value, 456 enum repaper_stage stage) 457 { 458 u64 start = local_clock(); 459 u64 end = start + ((u64)epd->factored_stage_time * 1000 * 1000); 460 461 do { 462 repaper_frame_fixed(epd, fixed_value, stage); 463 } while (local_clock() < end); 464 } 465 466 static void repaper_frame_data_repeat(struct repaper_epd *epd, const u8 *image, 467 const u8 *mask, enum repaper_stage stage) 468 { 469 u64 start = local_clock(); 470 u64 end = start + ((u64)epd->factored_stage_time * 1000 * 1000); 471 472 do { 473 repaper_frame_data(epd, image, mask, stage); 474 } while (local_clock() < end); 475 } 476 477 static void repaper_get_temperature(struct repaper_epd *epd) 478 { 479 int ret, temperature = 0; 480 unsigned int factor10x; 481 482 if (!epd->thermal) 483 return; 484 485 ret = thermal_zone_get_temp(epd->thermal, &temperature); 486 if (ret) { 487 DRM_DEV_ERROR(&epd->spi->dev, "Failed to get temperature (%d)\n", ret); 488 return; 489 } 490 491 temperature /= 1000; 492 493 if (temperature <= -10) 494 factor10x = 170; 495 else if (temperature <= -5) 496 factor10x = 120; 497 else if (temperature <= 5) 498 factor10x = 80; 499 else if (temperature <= 10) 500 factor10x = 40; 501 else if (temperature <= 15) 502 factor10x = 30; 503 else if (temperature <= 20) 504 factor10x = 20; 505 else if (temperature <= 40) 506 factor10x = 10; 507 else 508 factor10x = 7; 509 510 epd->factored_stage_time = epd->stage_time * factor10x / 10; 511 } 512 513 static int repaper_fb_dirty(struct drm_framebuffer *fb, const struct iosys_map *vmap, 514 struct drm_format_conv_state *fmtcnv_state) 515 { 516 struct repaper_epd *epd = drm_to_epd(fb->dev); 517 unsigned int dst_pitch = 0; 518 struct iosys_map dst; 519 struct drm_rect clip; 520 int idx, ret = 0; 521 u8 *buf = NULL; 522 523 if (!drm_dev_enter(fb->dev, &idx)) 524 return -ENODEV; 525 526 /* repaper can't do partial updates */ 527 clip.x1 = 0; 528 clip.x2 = fb->width; 529 clip.y1 = 0; 530 clip.y2 = fb->height; 531 532 repaper_get_temperature(epd); 533 534 DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id, 535 epd->factored_stage_time); 536 537 buf = kmalloc(fb->width * fb->height / 8, GFP_KERNEL); 538 if (!buf) { 539 ret = -ENOMEM; 540 goto out_exit; 541 } 542 543 ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE); 544 if (ret) 545 goto out_free; 546 547 iosys_map_set_vaddr(&dst, buf); 548 drm_fb_xrgb8888_to_mono(&dst, &dst_pitch, vmap, fb, &clip, fmtcnv_state); 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_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(state); 834 struct drm_rect rect; 835 836 if (!pipe->crtc.state->active) 837 return; 838 839 if (drm_atomic_helper_damage_merged(old_state, state, &rect)) 840 repaper_fb_dirty(state->fb, shadow_plane_state->data, 841 &shadow_plane_state->fmtcnv_state); 842 } 843 844 static const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = { 845 .mode_valid = repaper_pipe_mode_valid, 846 .enable = repaper_pipe_enable, 847 .disable = repaper_pipe_disable, 848 .update = repaper_pipe_update, 849 DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS, 850 }; 851 852 static int repaper_connector_get_modes(struct drm_connector *connector) 853 { 854 struct repaper_epd *epd = drm_to_epd(connector->dev); 855 856 return drm_connector_helper_get_modes_fixed(connector, epd->mode); 857 } 858 859 static const struct drm_connector_helper_funcs repaper_connector_hfuncs = { 860 .get_modes = repaper_connector_get_modes, 861 }; 862 863 static const struct drm_connector_funcs repaper_connector_funcs = { 864 .reset = drm_atomic_helper_connector_reset, 865 .fill_modes = drm_helper_probe_single_connector_modes, 866 .destroy = drm_connector_cleanup, 867 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, 868 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, 869 }; 870 871 static const struct drm_mode_config_funcs repaper_mode_config_funcs = { 872 .fb_create = drm_gem_fb_create_with_dirty, 873 .atomic_check = drm_atomic_helper_check, 874 .atomic_commit = drm_atomic_helper_commit, 875 }; 876 877 static const uint32_t repaper_formats[] = { 878 DRM_FORMAT_XRGB8888, 879 }; 880 881 static const struct drm_display_mode repaper_e1144cs021_mode = { 882 DRM_SIMPLE_MODE(128, 96, 29, 22), 883 }; 884 885 static const u8 repaper_e1144cs021_cs[] = { 0x00, 0x00, 0x00, 0x00, 886 0x00, 0x0f, 0xff, 0x00 }; 887 888 static const struct drm_display_mode repaper_e1190cs021_mode = { 889 DRM_SIMPLE_MODE(144, 128, 36, 32), 890 }; 891 892 static const u8 repaper_e1190cs021_cs[] = { 0x00, 0x00, 0x00, 0x03, 893 0xfc, 0x00, 0x00, 0xff }; 894 895 static const struct drm_display_mode repaper_e2200cs021_mode = { 896 DRM_SIMPLE_MODE(200, 96, 46, 22), 897 }; 898 899 static const u8 repaper_e2200cs021_cs[] = { 0x00, 0x00, 0x00, 0x00, 900 0x01, 0xff, 0xe0, 0x00 }; 901 902 static const struct drm_display_mode repaper_e2271cs021_mode = { 903 DRM_SIMPLE_MODE(264, 176, 57, 38), 904 }; 905 906 static const u8 repaper_e2271cs021_cs[] = { 0x00, 0x00, 0x00, 0x7f, 907 0xff, 0xfe, 0x00, 0x00 }; 908 909 DEFINE_DRM_GEM_DMA_FOPS(repaper_fops); 910 911 static const struct drm_driver repaper_driver = { 912 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 913 .fops = &repaper_fops, 914 DRM_GEM_DMA_DRIVER_OPS_VMAP, 915 DRM_FBDEV_DMA_DRIVER_OPS, 916 .name = "repaper", 917 .desc = "Pervasive Displays RePaper e-ink panels", 918 .major = 1, 919 .minor = 0, 920 }; 921 922 static const struct of_device_id repaper_of_match[] = { 923 { .compatible = "pervasive,e1144cs021", .data = (void *)E1144CS021 }, 924 { .compatible = "pervasive,e1190cs021", .data = (void *)E1190CS021 }, 925 { .compatible = "pervasive,e2200cs021", .data = (void *)E2200CS021 }, 926 { .compatible = "pervasive,e2271cs021", .data = (void *)E2271CS021 }, 927 {}, 928 }; 929 MODULE_DEVICE_TABLE(of, repaper_of_match); 930 931 static const struct spi_device_id repaper_id[] = { 932 { "e1144cs021", E1144CS021 }, 933 { "e1190cs021", E1190CS021 }, 934 { "e2200cs021", E2200CS021 }, 935 { "e2271cs021", E2271CS021 }, 936 { }, 937 }; 938 MODULE_DEVICE_TABLE(spi, repaper_id); 939 940 static int repaper_probe(struct spi_device *spi) 941 { 942 const struct drm_display_mode *mode; 943 const struct spi_device_id *spi_id; 944 struct device *dev = &spi->dev; 945 enum repaper_model model; 946 const char *thermal_zone; 947 struct repaper_epd *epd; 948 size_t line_buffer_size; 949 struct drm_device *drm; 950 const void *match; 951 int ret; 952 953 match = device_get_match_data(dev); 954 if (match) { 955 model = (enum repaper_model)(uintptr_t)match; 956 } else { 957 spi_id = spi_get_device_id(spi); 958 model = (enum repaper_model)spi_id->driver_data; 959 } 960 961 /* The SPI device is used to allocate dma memory */ 962 if (!dev->coherent_dma_mask) { 963 ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32)); 964 if (ret) { 965 dev_warn(dev, "Failed to set dma mask %d\n", ret); 966 return ret; 967 } 968 } 969 970 epd = devm_drm_dev_alloc(dev, &repaper_driver, 971 struct repaper_epd, drm); 972 if (IS_ERR(epd)) 973 return PTR_ERR(epd); 974 975 drm = &epd->drm; 976 977 ret = drmm_mode_config_init(drm); 978 if (ret) 979 return ret; 980 drm->mode_config.funcs = &repaper_mode_config_funcs; 981 982 epd->spi = spi; 983 984 epd->panel_on = devm_gpiod_get(dev, "panel-on", GPIOD_OUT_LOW); 985 if (IS_ERR(epd->panel_on)) { 986 ret = PTR_ERR(epd->panel_on); 987 if (ret != -EPROBE_DEFER) 988 DRM_DEV_ERROR(dev, "Failed to get gpio 'panel-on'\n"); 989 return ret; 990 } 991 992 epd->discharge = devm_gpiod_get(dev, "discharge", GPIOD_OUT_LOW); 993 if (IS_ERR(epd->discharge)) { 994 ret = PTR_ERR(epd->discharge); 995 if (ret != -EPROBE_DEFER) 996 DRM_DEV_ERROR(dev, "Failed to get gpio 'discharge'\n"); 997 return ret; 998 } 999 1000 epd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW); 1001 if (IS_ERR(epd->reset)) { 1002 ret = PTR_ERR(epd->reset); 1003 if (ret != -EPROBE_DEFER) 1004 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n"); 1005 return ret; 1006 } 1007 1008 epd->busy = devm_gpiod_get(dev, "busy", GPIOD_IN); 1009 if (IS_ERR(epd->busy)) { 1010 ret = PTR_ERR(epd->busy); 1011 if (ret != -EPROBE_DEFER) 1012 DRM_DEV_ERROR(dev, "Failed to get gpio 'busy'\n"); 1013 return ret; 1014 } 1015 1016 if (!device_property_read_string(dev, "pervasive,thermal-zone", 1017 &thermal_zone)) { 1018 epd->thermal = thermal_zone_get_zone_by_name(thermal_zone); 1019 if (IS_ERR(epd->thermal)) { 1020 DRM_DEV_ERROR(dev, "Failed to get thermal zone: %s\n", thermal_zone); 1021 return PTR_ERR(epd->thermal); 1022 } 1023 } 1024 1025 switch (model) { 1026 case E1144CS021: 1027 mode = &repaper_e1144cs021_mode; 1028 epd->channel_select = repaper_e1144cs021_cs; 1029 epd->stage_time = 480; 1030 epd->bytes_per_scan = 96 / 4; 1031 epd->middle_scan = true; /* data-scan-data */ 1032 epd->pre_border_byte = false; 1033 epd->border_byte = REPAPER_BORDER_BYTE_ZERO; 1034 break; 1035 1036 case E1190CS021: 1037 mode = &repaper_e1190cs021_mode; 1038 epd->channel_select = repaper_e1190cs021_cs; 1039 epd->stage_time = 480; 1040 epd->bytes_per_scan = 128 / 4 / 2; 1041 epd->middle_scan = false; /* scan-data-scan */ 1042 epd->pre_border_byte = false; 1043 epd->border_byte = REPAPER_BORDER_BYTE_SET; 1044 break; 1045 1046 case E2200CS021: 1047 mode = &repaper_e2200cs021_mode; 1048 epd->channel_select = repaper_e2200cs021_cs; 1049 epd->stage_time = 480; 1050 epd->bytes_per_scan = 96 / 4; 1051 epd->middle_scan = true; /* data-scan-data */ 1052 epd->pre_border_byte = true; 1053 epd->border_byte = REPAPER_BORDER_BYTE_NONE; 1054 break; 1055 1056 case E2271CS021: 1057 epd->border = devm_gpiod_get(dev, "border", GPIOD_OUT_LOW); 1058 if (IS_ERR(epd->border)) { 1059 ret = PTR_ERR(epd->border); 1060 if (ret != -EPROBE_DEFER) 1061 DRM_DEV_ERROR(dev, "Failed to get gpio 'border'\n"); 1062 return ret; 1063 } 1064 1065 mode = &repaper_e2271cs021_mode; 1066 epd->channel_select = repaper_e2271cs021_cs; 1067 epd->stage_time = 630; 1068 epd->bytes_per_scan = 176 / 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 default: 1075 return -ENODEV; 1076 } 1077 1078 epd->mode = mode; 1079 epd->width = mode->hdisplay; 1080 epd->height = mode->vdisplay; 1081 epd->factored_stage_time = epd->stage_time; 1082 1083 line_buffer_size = 2 * epd->width / 8 + epd->bytes_per_scan + 2; 1084 epd->line_buffer = devm_kzalloc(dev, line_buffer_size, GFP_KERNEL); 1085 if (!epd->line_buffer) 1086 return -ENOMEM; 1087 1088 epd->current_frame = devm_kzalloc(dev, epd->width * epd->height / 8, 1089 GFP_KERNEL); 1090 if (!epd->current_frame) 1091 return -ENOMEM; 1092 1093 drm->mode_config.min_width = mode->hdisplay; 1094 drm->mode_config.max_width = mode->hdisplay; 1095 drm->mode_config.min_height = mode->vdisplay; 1096 drm->mode_config.max_height = mode->vdisplay; 1097 1098 drm_connector_helper_add(&epd->connector, &repaper_connector_hfuncs); 1099 ret = drm_connector_init(drm, &epd->connector, &repaper_connector_funcs, 1100 DRM_MODE_CONNECTOR_SPI); 1101 if (ret) 1102 return ret; 1103 1104 ret = drm_simple_display_pipe_init(drm, &epd->pipe, &repaper_pipe_funcs, 1105 repaper_formats, ARRAY_SIZE(repaper_formats), 1106 NULL, &epd->connector); 1107 if (ret) 1108 return ret; 1109 1110 drm_mode_config_reset(drm); 1111 1112 ret = drm_dev_register(drm, 0); 1113 if (ret) 1114 return ret; 1115 1116 spi_set_drvdata(spi, drm); 1117 1118 DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000); 1119 1120 drm_client_setup(drm, NULL); 1121 1122 return 0; 1123 } 1124 1125 static void repaper_remove(struct spi_device *spi) 1126 { 1127 struct drm_device *drm = spi_get_drvdata(spi); 1128 1129 drm_dev_unplug(drm); 1130 drm_atomic_helper_shutdown(drm); 1131 } 1132 1133 static void repaper_shutdown(struct spi_device *spi) 1134 { 1135 drm_atomic_helper_shutdown(spi_get_drvdata(spi)); 1136 } 1137 1138 static struct spi_driver repaper_spi_driver = { 1139 .driver = { 1140 .name = "repaper", 1141 .of_match_table = repaper_of_match, 1142 }, 1143 .id_table = repaper_id, 1144 .probe = repaper_probe, 1145 .remove = repaper_remove, 1146 .shutdown = repaper_shutdown, 1147 }; 1148 module_spi_driver(repaper_spi_driver); 1149 1150 MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver"); 1151 MODULE_AUTHOR("Noralf Trønnes"); 1152 MODULE_LICENSE("GPL"); 1153