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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * DRM driver for Pervasive Displays RePaper branded e-ink panels
4 *
5 * Copyright 2013-2017 Pervasive Displays, Inc.
6 * Copyright 2017 Noralf Trønnes
7 *
8 * The driver supports:
9 * Material Film: Aurora Mb (V231)
10 * Driver IC: G2 (eTC)
11 *
12 * The controller code was taken from the userspace driver:
13 * https://github.com/repaper/gratis
14 */
15
16#include <linux/delay.h>
17#include <linux/dma-buf.h>
18#include <linux/gpio/consumer.h>
19#include <linux/module.h>
20#include <linux/property.h>
21#include <linux/sched/clock.h>
22#include <linux/spi/spi.h>
23#include <linux/thermal.h>
24
25#include <drm/drm_atomic_helper.h>
26#include <drm/drm_connector.h>
27#include <drm/drm_damage_helper.h>
28#include <drm/drm_drv.h>
29#include <drm/drm_fb_cma_helper.h>
30#include <drm/drm_fb_helper.h>
31#include <drm/drm_format_helper.h>
32#include <drm/drm_gem_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
42enum repaper_model {
43 /* 0 is reserved to avoid clashing with NULL */
44 E1144CS021 = 1,
45 E1190CS021,
46 E2200CS021,
47 E2271CS021,
48};
49
50enum 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
57enum repaper_epd_border_byte {
58 REPAPER_BORDER_BYTE_NONE,
59 REPAPER_BORDER_BYTE_ZERO,
60 REPAPER_BORDER_BYTE_SET,
61};
62
63struct 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
95static inline struct repaper_epd *drm_to_epd(struct drm_device *drm)
96{
97 return container_of(drm, struct repaper_epd, drm);
98}
99
100static 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
142out_free:
143 kfree(headerbuf);
144 kfree(txbuf);
145 kfree(rxbuf);
146
147 return ret;
148}
149
150static 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
162static int repaper_write_val(struct spi_device *spi, u8 reg, u8 val)
163{
164 return repaper_write_buf(spi, reg, &val, 1);
165}
166
167static 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
181static 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
191static 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,... */
199static 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,... */
245static 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 */
285static 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 */
295static 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 */
339static 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
423static 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
432static 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
453static 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
464static 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
475static 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
511static void repaper_gray8_to_mono_reversed(u8 *buf, u32 width, u32 height)
512{
513 u8 *gray8 = buf, *mono = buf;
514 int y, xb, i;
515
516 for (y = 0; y < height; y++)
517 for (xb = 0; xb < width / 8; xb++) {
518 u8 byte = 0x00;
519
520 for (i = 0; i < 8; i++) {
521 int x = xb * 8 + i;
522
523 byte >>= 1;
524 if (gray8[y * width + x] >> 7)
525 byte |= BIT(7);
526 }
527 *mono++ = byte;
528 }
529}
530
531static int repaper_fb_dirty(struct drm_framebuffer *fb)
532{
533 struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
534 struct dma_buf_attachment *import_attach = cma_obj->base.import_attach;
535 struct repaper_epd *epd = drm_to_epd(fb->dev);
536 struct drm_rect clip;
537 int idx, ret = 0;
538 u8 *buf = NULL;
539
540 if (!drm_dev_enter(fb->dev, &idx))
541 return -ENODEV;
542
543 /* repaper can't do partial updates */
544 clip.x1 = 0;
545 clip.x2 = fb->width;
546 clip.y1 = 0;
547 clip.y2 = fb->height;
548
549 repaper_get_temperature(epd);
550
551 DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id,
552 epd->factored_stage_time);
553
554 buf = kmalloc_array(fb->width, fb->height, GFP_KERNEL);
555 if (!buf) {
556 ret = -ENOMEM;
557 goto out_exit;
558 }
559
560 if (import_attach) {
561 ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
562 DMA_FROM_DEVICE);
563 if (ret)
564 goto out_free;
565 }
566
567 drm_fb_xrgb8888_to_gray8(buf, cma_obj->vaddr, fb, &clip);
568
569 if (import_attach) {
570 ret = dma_buf_end_cpu_access(import_attach->dmabuf,
571 DMA_FROM_DEVICE);
572 if (ret)
573 goto out_free;
574 }
575
576 repaper_gray8_to_mono_reversed(buf, fb->width, fb->height);
577
578 if (epd->partial) {
579 repaper_frame_data_repeat(epd, buf, epd->current_frame,
580 REPAPER_NORMAL);
581 } else if (epd->cleared) {
582 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
583 REPAPER_COMPENSATE);
584 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
585 REPAPER_WHITE);
586 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
587 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
588
589 epd->partial = true;
590 } else {
591 /* Clear display (anything -> white) */
592 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_COMPENSATE);
593 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_WHITE);
594 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_INVERSE);
595 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_NORMAL);
596
597 /* Assuming a clear (white) screen output an image */
598 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_COMPENSATE);
599 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_WHITE);
600 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
601 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
602
603 epd->cleared = true;
604 epd->partial = true;
605 }
606
607 memcpy(epd->current_frame, buf, fb->width * fb->height / 8);
608
609 /*
610 * An extra frame write is needed if pixels are set in the bottom line,
611 * or else grey lines rises up from the pixels
612 */
613 if (epd->pre_border_byte) {
614 unsigned int x;
615
616 for (x = 0; x < (fb->width / 8); x++)
617 if (buf[x + (fb->width * (fb->height - 1) / 8)]) {
618 repaper_frame_data_repeat(epd, buf,
619 epd->current_frame,
620 REPAPER_NORMAL);
621 break;
622 }
623 }
624
625out_free:
626 kfree(buf);
627out_exit:
628 drm_dev_exit(idx);
629
630 return ret;
631}
632
633static void power_off(struct repaper_epd *epd)
634{
635 /* Turn off power and all signals */
636 gpiod_set_value_cansleep(epd->reset, 0);
637 gpiod_set_value_cansleep(epd->panel_on, 0);
638 if (epd->border)
639 gpiod_set_value_cansleep(epd->border, 0);
640
641 /* Ensure SPI MOSI and CLOCK are Low before CS Low */
642 repaper_spi_mosi_low(epd->spi);
643
644 /* Discharge pulse */
645 gpiod_set_value_cansleep(epd->discharge, 1);
646 msleep(150);
647 gpiod_set_value_cansleep(epd->discharge, 0);
648}
649
650static void repaper_pipe_enable(struct drm_simple_display_pipe *pipe,
651 struct drm_crtc_state *crtc_state,
652 struct drm_plane_state *plane_state)
653{
654 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev);
655 struct spi_device *spi = epd->spi;
656 struct device *dev = &spi->dev;
657 bool dc_ok = false;
658 int i, ret, idx;
659
660 if (!drm_dev_enter(pipe->crtc.dev, &idx))
661 return;
662
663 DRM_DEBUG_DRIVER("\n");
664
665 /* Power up sequence */
666 gpiod_set_value_cansleep(epd->reset, 0);
667 gpiod_set_value_cansleep(epd->panel_on, 0);
668 gpiod_set_value_cansleep(epd->discharge, 0);
669 if (epd->border)
670 gpiod_set_value_cansleep(epd->border, 0);
671 repaper_spi_mosi_low(spi);
672 usleep_range(5000, 10000);
673
674 gpiod_set_value_cansleep(epd->panel_on, 1);
675 /*
676 * This delay comes from the repaper.org userspace driver, it's not
677 * mentioned in the datasheet.
678 */
679 usleep_range(10000, 15000);
680 gpiod_set_value_cansleep(epd->reset, 1);
681 if (epd->border)
682 gpiod_set_value_cansleep(epd->border, 1);
683 usleep_range(5000, 10000);
684 gpiod_set_value_cansleep(epd->reset, 0);
685 usleep_range(5000, 10000);
686 gpiod_set_value_cansleep(epd->reset, 1);
687 usleep_range(5000, 10000);
688
689 /* Wait for COG to become ready */
690 for (i = 100; i > 0; i--) {
691 if (!gpiod_get_value_cansleep(epd->busy))
692 break;
693
694 usleep_range(10, 100);
695 }
696
697 if (!i) {
698 DRM_DEV_ERROR(dev, "timeout waiting for panel to become ready.\n");
699 power_off(epd);
700 goto out_exit;
701 }
702
703 repaper_read_id(spi);
704 ret = repaper_read_id(spi);
705 if (ret != REPAPER_RID_G2_COG_ID) {
706 if (ret < 0)
707 dev_err(dev, "failed to read chip (%d)\n", ret);
708 else
709 dev_err(dev, "wrong COG ID 0x%02x\n", ret);
710 power_off(epd);
711 goto out_exit;
712 }
713
714 /* Disable OE */
715 repaper_write_val(spi, 0x02, 0x40);
716
717 ret = repaper_read_val(spi, 0x0f);
718 if (ret < 0 || !(ret & 0x80)) {
719 if (ret < 0)
720 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
721 else
722 DRM_DEV_ERROR(dev, "panel is reported broken\n");
723 power_off(epd);
724 goto out_exit;
725 }
726
727 /* Power saving mode */
728 repaper_write_val(spi, 0x0b, 0x02);
729 /* Channel select */
730 repaper_write_buf(spi, 0x01, epd->channel_select, 8);
731 /* High power mode osc */
732 repaper_write_val(spi, 0x07, 0xd1);
733 /* Power setting */
734 repaper_write_val(spi, 0x08, 0x02);
735 /* Vcom level */
736 repaper_write_val(spi, 0x09, 0xc2);
737 /* Power setting */
738 repaper_write_val(spi, 0x04, 0x03);
739 /* Driver latch on */
740 repaper_write_val(spi, 0x03, 0x01);
741 /* Driver latch off */
742 repaper_write_val(spi, 0x03, 0x00);
743 usleep_range(5000, 10000);
744
745 /* Start chargepump */
746 for (i = 0; i < 4; ++i) {
747 /* Charge pump positive voltage on - VGH/VDL on */
748 repaper_write_val(spi, 0x05, 0x01);
749 msleep(240);
750
751 /* Charge pump negative voltage on - VGL/VDL on */
752 repaper_write_val(spi, 0x05, 0x03);
753 msleep(40);
754
755 /* Charge pump Vcom on - Vcom driver on */
756 repaper_write_val(spi, 0x05, 0x0f);
757 msleep(40);
758
759 /* check DC/DC */
760 ret = repaper_read_val(spi, 0x0f);
761 if (ret < 0) {
762 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
763 power_off(epd);
764 goto out_exit;
765 }
766
767 if (ret & 0x40) {
768 dc_ok = true;
769 break;
770 }
771 }
772
773 if (!dc_ok) {
774 DRM_DEV_ERROR(dev, "dc/dc failed\n");
775 power_off(epd);
776 goto out_exit;
777 }
778
779 /*
780 * Output enable to disable
781 * The userspace driver sets this to 0x04, but the datasheet says 0x06
782 */
783 repaper_write_val(spi, 0x02, 0x04);
784
785 epd->partial = false;
786out_exit:
787 drm_dev_exit(idx);
788}
789
790static void repaper_pipe_disable(struct drm_simple_display_pipe *pipe)
791{
792 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev);
793 struct spi_device *spi = epd->spi;
794 unsigned int line;
795
796 /*
797 * This callback is not protected by drm_dev_enter/exit since we want to
798 * turn off the display on regular driver unload. It's highly unlikely
799 * that the underlying SPI controller is gone should this be called after
800 * unplug.
801 */
802
803 DRM_DEBUG_DRIVER("\n");
804
805 /* Nothing frame */
806 for (line = 0; line < epd->height; line++)
807 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
808 REPAPER_COMPENSATE);
809
810 /* 2.7" */
811 if (epd->border) {
812 /* Dummy line */
813 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
814 REPAPER_COMPENSATE);
815 msleep(25);
816 gpiod_set_value_cansleep(epd->border, 0);
817 msleep(200);
818 gpiod_set_value_cansleep(epd->border, 1);
819 } else {
820 /* Border dummy line */
821 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
822 REPAPER_NORMAL);
823 msleep(200);
824 }
825
826 /* not described in datasheet */
827 repaper_write_val(spi, 0x0b, 0x00);
828 /* Latch reset turn on */
829 repaper_write_val(spi, 0x03, 0x01);
830 /* Power off charge pump Vcom */
831 repaper_write_val(spi, 0x05, 0x03);
832 /* Power off charge pump neg voltage */
833 repaper_write_val(spi, 0x05, 0x01);
834 msleep(120);
835 /* Discharge internal */
836 repaper_write_val(spi, 0x04, 0x80);
837 /* turn off all charge pumps */
838 repaper_write_val(spi, 0x05, 0x00);
839 /* Turn off osc */
840 repaper_write_val(spi, 0x07, 0x01);
841 msleep(50);
842
843 power_off(epd);
844}
845
846static void repaper_pipe_update(struct drm_simple_display_pipe *pipe,
847 struct drm_plane_state *old_state)
848{
849 struct drm_plane_state *state = pipe->plane.state;
850 struct drm_rect rect;
851
852 if (!pipe->crtc.state->active)
853 return;
854
855 if (drm_atomic_helper_damage_merged(old_state, state, &rect))
856 repaper_fb_dirty(state->fb);
857}
858
859static const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = {
860 .enable = repaper_pipe_enable,
861 .disable = repaper_pipe_disable,
862 .update = repaper_pipe_update,
863 .prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
864};
865
866static int repaper_connector_get_modes(struct drm_connector *connector)
867{
868 struct repaper_epd *epd = drm_to_epd(connector->dev);
869 struct drm_display_mode *mode;
870
871 mode = drm_mode_duplicate(connector->dev, epd->mode);
872 if (!mode) {
873 DRM_ERROR("Failed to duplicate mode\n");
874 return 0;
875 }
876
877 drm_mode_set_name(mode);
878 mode->type |= DRM_MODE_TYPE_PREFERRED;
879 drm_mode_probed_add(connector, mode);
880
881 connector->display_info.width_mm = mode->width_mm;
882 connector->display_info.height_mm = mode->height_mm;
883
884 return 1;
885}
886
887static const struct drm_connector_helper_funcs repaper_connector_hfuncs = {
888 .get_modes = repaper_connector_get_modes,
889};
890
891static const struct drm_connector_funcs repaper_connector_funcs = {
892 .reset = drm_atomic_helper_connector_reset,
893 .fill_modes = drm_helper_probe_single_connector_modes,
894 .destroy = drm_connector_cleanup,
895 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
896 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
897};
898
899static const struct drm_mode_config_funcs repaper_mode_config_funcs = {
900 .fb_create = drm_gem_fb_create_with_dirty,
901 .atomic_check = drm_atomic_helper_check,
902 .atomic_commit = drm_atomic_helper_commit,
903};
904
905static const uint32_t repaper_formats[] = {
906 DRM_FORMAT_XRGB8888,
907};
908
909static const struct drm_display_mode repaper_e1144cs021_mode = {
910 DRM_SIMPLE_MODE(128, 96, 29, 22),
911};
912
913static const u8 repaper_e1144cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
914 0x00, 0x0f, 0xff, 0x00 };
915
916static const struct drm_display_mode repaper_e1190cs021_mode = {
917 DRM_SIMPLE_MODE(144, 128, 36, 32),
918};
919
920static const u8 repaper_e1190cs021_cs[] = { 0x00, 0x00, 0x00, 0x03,
921 0xfc, 0x00, 0x00, 0xff };
922
923static const struct drm_display_mode repaper_e2200cs021_mode = {
924 DRM_SIMPLE_MODE(200, 96, 46, 22),
925};
926
927static const u8 repaper_e2200cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
928 0x01, 0xff, 0xe0, 0x00 };
929
930static const struct drm_display_mode repaper_e2271cs021_mode = {
931 DRM_SIMPLE_MODE(264, 176, 57, 38),
932};
933
934static const u8 repaper_e2271cs021_cs[] = { 0x00, 0x00, 0x00, 0x7f,
935 0xff, 0xfe, 0x00, 0x00 };
936
937DEFINE_DRM_GEM_CMA_FOPS(repaper_fops);
938
939static struct drm_driver repaper_driver = {
940 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
941 .fops = &repaper_fops,
942 DRM_GEM_CMA_DRIVER_OPS_VMAP,
943 .name = "repaper",
944 .desc = "Pervasive Displays RePaper e-ink panels",
945 .date = "20170405",
946 .major = 1,
947 .minor = 0,
948};
949
950static const struct of_device_id repaper_of_match[] = {
951 { .compatible = "pervasive,e1144cs021", .data = (void *)E1144CS021 },
952 { .compatible = "pervasive,e1190cs021", .data = (void *)E1190CS021 },
953 { .compatible = "pervasive,e2200cs021", .data = (void *)E2200CS021 },
954 { .compatible = "pervasive,e2271cs021", .data = (void *)E2271CS021 },
955 {},
956};
957MODULE_DEVICE_TABLE(of, repaper_of_match);
958
959static const struct spi_device_id repaper_id[] = {
960 { "e1144cs021", E1144CS021 },
961 { "e1190cs021", E1190CS021 },
962 { "e2200cs021", E2200CS021 },
963 { "e2271cs021", E2271CS021 },
964 { },
965};
966MODULE_DEVICE_TABLE(spi, repaper_id);
967
968static int repaper_probe(struct spi_device *spi)
969{
970 const struct drm_display_mode *mode;
971 const struct spi_device_id *spi_id;
972 struct device *dev = &spi->dev;
973 enum repaper_model model;
974 const char *thermal_zone;
975 struct repaper_epd *epd;
976 size_t line_buffer_size;
977 struct drm_device *drm;
978 const void *match;
979 int ret;
980
981 match = device_get_match_data(dev);
982 if (match) {
983 model = (enum repaper_model)match;
984 } else {
985 spi_id = spi_get_device_id(spi);
986 model = (enum repaper_model)spi_id->driver_data;
987 }
988
989 /* The SPI device is used to allocate dma memory */
990 if (!dev->coherent_dma_mask) {
991 ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
992 if (ret) {
993 dev_warn(dev, "Failed to set dma mask %d\n", ret);
994 return ret;
995 }
996 }
997
998 epd = devm_drm_dev_alloc(dev, &repaper_driver,
999 struct repaper_epd, drm);
1000 if (IS_ERR(epd))
1001 return PTR_ERR(epd);
1002
1003 drm = &epd->drm;
1004
1005 ret = drmm_mode_config_init(drm);
1006 if (ret)
1007 return ret;
1008 drm->mode_config.funcs = &repaper_mode_config_funcs;
1009
1010 epd->spi = spi;
1011
1012 epd->panel_on = devm_gpiod_get(dev, "panel-on", GPIOD_OUT_LOW);
1013 if (IS_ERR(epd->panel_on)) {
1014 ret = PTR_ERR(epd->panel_on);
1015 if (ret != -EPROBE_DEFER)
1016 DRM_DEV_ERROR(dev, "Failed to get gpio 'panel-on'\n");
1017 return ret;
1018 }
1019
1020 epd->discharge = devm_gpiod_get(dev, "discharge", GPIOD_OUT_LOW);
1021 if (IS_ERR(epd->discharge)) {
1022 ret = PTR_ERR(epd->discharge);
1023 if (ret != -EPROBE_DEFER)
1024 DRM_DEV_ERROR(dev, "Failed to get gpio 'discharge'\n");
1025 return ret;
1026 }
1027
1028 epd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
1029 if (IS_ERR(epd->reset)) {
1030 ret = PTR_ERR(epd->reset);
1031 if (ret != -EPROBE_DEFER)
1032 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
1033 return ret;
1034 }
1035
1036 epd->busy = devm_gpiod_get(dev, "busy", GPIOD_IN);
1037 if (IS_ERR(epd->busy)) {
1038 ret = PTR_ERR(epd->busy);
1039 if (ret != -EPROBE_DEFER)
1040 DRM_DEV_ERROR(dev, "Failed to get gpio 'busy'\n");
1041 return ret;
1042 }
1043
1044 if (!device_property_read_string(dev, "pervasive,thermal-zone",
1045 &thermal_zone)) {
1046 epd->thermal = thermal_zone_get_zone_by_name(thermal_zone);
1047 if (IS_ERR(epd->thermal)) {
1048 DRM_DEV_ERROR(dev, "Failed to get thermal zone: %s\n", thermal_zone);
1049 return PTR_ERR(epd->thermal);
1050 }
1051 }
1052
1053 switch (model) {
1054 case E1144CS021:
1055 mode = &repaper_e1144cs021_mode;
1056 epd->channel_select = repaper_e1144cs021_cs;
1057 epd->stage_time = 480;
1058 epd->bytes_per_scan = 96 / 4;
1059 epd->middle_scan = true; /* data-scan-data */
1060 epd->pre_border_byte = false;
1061 epd->border_byte = REPAPER_BORDER_BYTE_ZERO;
1062 break;
1063
1064 case E1190CS021:
1065 mode = &repaper_e1190cs021_mode;
1066 epd->channel_select = repaper_e1190cs021_cs;
1067 epd->stage_time = 480;
1068 epd->bytes_per_scan = 128 / 4 / 2;
1069 epd->middle_scan = false; /* scan-data-scan */
1070 epd->pre_border_byte = false;
1071 epd->border_byte = REPAPER_BORDER_BYTE_SET;
1072 break;
1073
1074 case E2200CS021:
1075 mode = &repaper_e2200cs021_mode;
1076 epd->channel_select = repaper_e2200cs021_cs;
1077 epd->stage_time = 480;
1078 epd->bytes_per_scan = 96 / 4;
1079 epd->middle_scan = true; /* data-scan-data */
1080 epd->pre_border_byte = true;
1081 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1082 break;
1083
1084 case E2271CS021:
1085 epd->border = devm_gpiod_get(dev, "border", GPIOD_OUT_LOW);
1086 if (IS_ERR(epd->border)) {
1087 ret = PTR_ERR(epd->border);
1088 if (ret != -EPROBE_DEFER)
1089 DRM_DEV_ERROR(dev, "Failed to get gpio 'border'\n");
1090 return ret;
1091 }
1092
1093 mode = &repaper_e2271cs021_mode;
1094 epd->channel_select = repaper_e2271cs021_cs;
1095 epd->stage_time = 630;
1096 epd->bytes_per_scan = 176 / 4;
1097 epd->middle_scan = true; /* data-scan-data */
1098 epd->pre_border_byte = true;
1099 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1100 break;
1101
1102 default:
1103 return -ENODEV;
1104 }
1105
1106 epd->mode = mode;
1107 epd->width = mode->hdisplay;
1108 epd->height = mode->vdisplay;
1109 epd->factored_stage_time = epd->stage_time;
1110
1111 line_buffer_size = 2 * epd->width / 8 + epd->bytes_per_scan + 2;
1112 epd->line_buffer = devm_kzalloc(dev, line_buffer_size, GFP_KERNEL);
1113 if (!epd->line_buffer)
1114 return -ENOMEM;
1115
1116 epd->current_frame = devm_kzalloc(dev, epd->width * epd->height / 8,
1117 GFP_KERNEL);
1118 if (!epd->current_frame)
1119 return -ENOMEM;
1120
1121 drm->mode_config.min_width = mode->hdisplay;
1122 drm->mode_config.max_width = mode->hdisplay;
1123 drm->mode_config.min_height = mode->vdisplay;
1124 drm->mode_config.max_height = mode->vdisplay;
1125
1126 drm_connector_helper_add(&epd->connector, &repaper_connector_hfuncs);
1127 ret = drm_connector_init(drm, &epd->connector, &repaper_connector_funcs,
1128 DRM_MODE_CONNECTOR_SPI);
1129 if (ret)
1130 return ret;
1131
1132 ret = drm_simple_display_pipe_init(drm, &epd->pipe, &repaper_pipe_funcs,
1133 repaper_formats, ARRAY_SIZE(repaper_formats),
1134 NULL, &epd->connector);
1135 if (ret)
1136 return ret;
1137
1138 drm_mode_config_reset(drm);
1139
1140 ret = drm_dev_register(drm, 0);
1141 if (ret)
1142 return ret;
1143
1144 spi_set_drvdata(spi, drm);
1145
1146 DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000);
1147
1148 drm_fbdev_generic_setup(drm, 0);
1149
1150 return 0;
1151}
1152
1153static int repaper_remove(struct spi_device *spi)
1154{
1155 struct drm_device *drm = spi_get_drvdata(spi);
1156
1157 drm_dev_unplug(drm);
1158 drm_atomic_helper_shutdown(drm);
1159
1160 return 0;
1161}
1162
1163static void repaper_shutdown(struct spi_device *spi)
1164{
1165 drm_atomic_helper_shutdown(spi_get_drvdata(spi));
1166}
1167
1168static struct spi_driver repaper_spi_driver = {
1169 .driver = {
1170 .name = "repaper",
1171 .of_match_table = repaper_of_match,
1172 },
1173 .id_table = repaper_id,
1174 .probe = repaper_probe,
1175 .remove = repaper_remove,
1176 .shutdown = repaper_shutdown,
1177};
1178module_spi_driver(repaper_spi_driver);
1179
1180MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver");
1181MODULE_AUTHOR("Noralf Trønnes");
1182MODULE_LICENSE("GPL");