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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/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_client_setup.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
44enum repaper_model {
45 /* 0 is reserved to avoid clashing with NULL */
46 E1144CS021 = 1,
47 E1190CS021,
48 E2200CS021,
49 E2271CS021,
50};
51
52enum 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
59enum repaper_epd_border_byte {
60 REPAPER_BORDER_BYTE_NONE,
61 REPAPER_BORDER_BYTE_ZERO,
62 REPAPER_BORDER_BYTE_SET,
63};
64
65struct 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
97static inline struct repaper_epd *drm_to_epd(struct drm_device *drm)
98{
99 return container_of(drm, struct repaper_epd, drm);
100}
101
102static 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
144out_free:
145 kfree(headerbuf);
146 kfree(txbuf);
147 kfree(rxbuf);
148
149 return ret;
150}
151
152static 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
164static int repaper_write_val(struct spi_device *spi, u8 reg, u8 val)
165{
166 return repaper_write_buf(spi, reg, &val, 1);
167}
168
169static 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
183static 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
193static 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,... */
201static 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,... */
247static 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 */
287static 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 */
297static 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 */
341static 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
425static 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
434static 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
455static 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 + (epd->factored_stage_time * 1000 * 1000);
460
461 do {
462 repaper_frame_fixed(epd, fixed_value, stage);
463 } while (local_clock() < end);
464}
465
466static 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 + (epd->factored_stage_time * 1000 * 1000);
471
472 do {
473 repaper_frame_data(epd, image, mask, stage);
474 } while (local_clock() < end);
475}
476
477static 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
513static int repaper_fb_dirty(struct drm_framebuffer *fb,
514 struct drm_format_conv_state *fmtcnv_state)
515{
516 struct drm_gem_dma_object *dma_obj = drm_fb_dma_get_gem_obj(fb, 0);
517 struct repaper_epd *epd = drm_to_epd(fb->dev);
518 unsigned int dst_pitch = 0;
519 struct iosys_map dst, vmap;
520 struct drm_rect clip;
521 int idx, ret = 0;
522 u8 *buf = NULL;
523
524 if (!drm_dev_enter(fb->dev, &idx))
525 return -ENODEV;
526
527 /* repaper can't do partial updates */
528 clip.x1 = 0;
529 clip.x2 = fb->width;
530 clip.y1 = 0;
531 clip.y2 = fb->height;
532
533 repaper_get_temperature(epd);
534
535 DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id,
536 epd->factored_stage_time);
537
538 buf = kmalloc(fb->width * fb->height / 8, GFP_KERNEL);
539 if (!buf) {
540 ret = -ENOMEM;
541 goto out_exit;
542 }
543
544 ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
545 if (ret)
546 goto out_free;
547
548 iosys_map_set_vaddr(&dst, buf);
549 iosys_map_set_vaddr(&vmap, dma_obj->vaddr);
550 drm_fb_xrgb8888_to_mono(&dst, &dst_pitch, &vmap, fb, &clip, fmtcnv_state);
551
552 drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
553
554 if (epd->partial) {
555 repaper_frame_data_repeat(epd, buf, epd->current_frame,
556 REPAPER_NORMAL);
557 } else if (epd->cleared) {
558 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
559 REPAPER_COMPENSATE);
560 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
561 REPAPER_WHITE);
562 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
563 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
564
565 epd->partial = true;
566 } else {
567 /* Clear display (anything -> white) */
568 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_COMPENSATE);
569 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_WHITE);
570 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_INVERSE);
571 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_NORMAL);
572
573 /* Assuming a clear (white) screen output an image */
574 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_COMPENSATE);
575 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_WHITE);
576 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
577 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
578
579 epd->cleared = true;
580 epd->partial = true;
581 }
582
583 memcpy(epd->current_frame, buf, fb->width * fb->height / 8);
584
585 /*
586 * An extra frame write is needed if pixels are set in the bottom line,
587 * or else grey lines rises up from the pixels
588 */
589 if (epd->pre_border_byte) {
590 unsigned int x;
591
592 for (x = 0; x < (fb->width / 8); x++)
593 if (buf[x + (fb->width * (fb->height - 1) / 8)]) {
594 repaper_frame_data_repeat(epd, buf,
595 epd->current_frame,
596 REPAPER_NORMAL);
597 break;
598 }
599 }
600
601out_free:
602 kfree(buf);
603out_exit:
604 drm_dev_exit(idx);
605
606 return ret;
607}
608
609static void power_off(struct repaper_epd *epd)
610{
611 /* Turn off power and all signals */
612 gpiod_set_value_cansleep(epd->reset, 0);
613 gpiod_set_value_cansleep(epd->panel_on, 0);
614 if (epd->border)
615 gpiod_set_value_cansleep(epd->border, 0);
616
617 /* Ensure SPI MOSI and CLOCK are Low before CS Low */
618 repaper_spi_mosi_low(epd->spi);
619
620 /* Discharge pulse */
621 gpiod_set_value_cansleep(epd->discharge, 1);
622 msleep(150);
623 gpiod_set_value_cansleep(epd->discharge, 0);
624}
625
626static enum drm_mode_status repaper_pipe_mode_valid(struct drm_simple_display_pipe *pipe,
627 const struct drm_display_mode *mode)
628{
629 struct drm_crtc *crtc = &pipe->crtc;
630 struct repaper_epd *epd = drm_to_epd(crtc->dev);
631
632 return drm_crtc_helper_mode_valid_fixed(crtc, mode, epd->mode);
633}
634
635static void repaper_pipe_enable(struct drm_simple_display_pipe *pipe,
636 struct drm_crtc_state *crtc_state,
637 struct drm_plane_state *plane_state)
638{
639 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev);
640 struct spi_device *spi = epd->spi;
641 struct device *dev = &spi->dev;
642 bool dc_ok = false;
643 int i, ret, idx;
644
645 if (!drm_dev_enter(pipe->crtc.dev, &idx))
646 return;
647
648 DRM_DEBUG_DRIVER("\n");
649
650 /* Power up sequence */
651 gpiod_set_value_cansleep(epd->reset, 0);
652 gpiod_set_value_cansleep(epd->panel_on, 0);
653 gpiod_set_value_cansleep(epd->discharge, 0);
654 if (epd->border)
655 gpiod_set_value_cansleep(epd->border, 0);
656 repaper_spi_mosi_low(spi);
657 usleep_range(5000, 10000);
658
659 gpiod_set_value_cansleep(epd->panel_on, 1);
660 /*
661 * This delay comes from the repaper.org userspace driver, it's not
662 * mentioned in the datasheet.
663 */
664 usleep_range(10000, 15000);
665 gpiod_set_value_cansleep(epd->reset, 1);
666 if (epd->border)
667 gpiod_set_value_cansleep(epd->border, 1);
668 usleep_range(5000, 10000);
669 gpiod_set_value_cansleep(epd->reset, 0);
670 usleep_range(5000, 10000);
671 gpiod_set_value_cansleep(epd->reset, 1);
672 usleep_range(5000, 10000);
673
674 /* Wait for COG to become ready */
675 for (i = 100; i > 0; i--) {
676 if (!gpiod_get_value_cansleep(epd->busy))
677 break;
678
679 usleep_range(10, 100);
680 }
681
682 if (!i) {
683 DRM_DEV_ERROR(dev, "timeout waiting for panel to become ready.\n");
684 power_off(epd);
685 goto out_exit;
686 }
687
688 repaper_read_id(spi);
689 ret = repaper_read_id(spi);
690 if (ret != REPAPER_RID_G2_COG_ID) {
691 if (ret < 0)
692 dev_err(dev, "failed to read chip (%d)\n", ret);
693 else
694 dev_err(dev, "wrong COG ID 0x%02x\n", ret);
695 power_off(epd);
696 goto out_exit;
697 }
698
699 /* Disable OE */
700 repaper_write_val(spi, 0x02, 0x40);
701
702 ret = repaper_read_val(spi, 0x0f);
703 if (ret < 0 || !(ret & 0x80)) {
704 if (ret < 0)
705 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
706 else
707 DRM_DEV_ERROR(dev, "panel is reported broken\n");
708 power_off(epd);
709 goto out_exit;
710 }
711
712 /* Power saving mode */
713 repaper_write_val(spi, 0x0b, 0x02);
714 /* Channel select */
715 repaper_write_buf(spi, 0x01, epd->channel_select, 8);
716 /* High power mode osc */
717 repaper_write_val(spi, 0x07, 0xd1);
718 /* Power setting */
719 repaper_write_val(spi, 0x08, 0x02);
720 /* Vcom level */
721 repaper_write_val(spi, 0x09, 0xc2);
722 /* Power setting */
723 repaper_write_val(spi, 0x04, 0x03);
724 /* Driver latch on */
725 repaper_write_val(spi, 0x03, 0x01);
726 /* Driver latch off */
727 repaper_write_val(spi, 0x03, 0x00);
728 usleep_range(5000, 10000);
729
730 /* Start chargepump */
731 for (i = 0; i < 4; ++i) {
732 /* Charge pump positive voltage on - VGH/VDL on */
733 repaper_write_val(spi, 0x05, 0x01);
734 msleep(240);
735
736 /* Charge pump negative voltage on - VGL/VDL on */
737 repaper_write_val(spi, 0x05, 0x03);
738 msleep(40);
739
740 /* Charge pump Vcom on - Vcom driver on */
741 repaper_write_val(spi, 0x05, 0x0f);
742 msleep(40);
743
744 /* check DC/DC */
745 ret = repaper_read_val(spi, 0x0f);
746 if (ret < 0) {
747 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
748 power_off(epd);
749 goto out_exit;
750 }
751
752 if (ret & 0x40) {
753 dc_ok = true;
754 break;
755 }
756 }
757
758 if (!dc_ok) {
759 DRM_DEV_ERROR(dev, "dc/dc failed\n");
760 power_off(epd);
761 goto out_exit;
762 }
763
764 /*
765 * Output enable to disable
766 * The userspace driver sets this to 0x04, but the datasheet says 0x06
767 */
768 repaper_write_val(spi, 0x02, 0x04);
769
770 epd->partial = false;
771out_exit:
772 drm_dev_exit(idx);
773}
774
775static void repaper_pipe_disable(struct drm_simple_display_pipe *pipe)
776{
777 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev);
778 struct spi_device *spi = epd->spi;
779 unsigned int line;
780
781 /*
782 * This callback is not protected by drm_dev_enter/exit since we want to
783 * turn off the display on regular driver unload. It's highly unlikely
784 * that the underlying SPI controller is gone should this be called after
785 * unplug.
786 */
787
788 DRM_DEBUG_DRIVER("\n");
789
790 /* Nothing frame */
791 for (line = 0; line < epd->height; line++)
792 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
793 REPAPER_COMPENSATE);
794
795 /* 2.7" */
796 if (epd->border) {
797 /* Dummy line */
798 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
799 REPAPER_COMPENSATE);
800 msleep(25);
801 gpiod_set_value_cansleep(epd->border, 0);
802 msleep(200);
803 gpiod_set_value_cansleep(epd->border, 1);
804 } else {
805 /* Border dummy line */
806 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
807 REPAPER_NORMAL);
808 msleep(200);
809 }
810
811 /* not described in datasheet */
812 repaper_write_val(spi, 0x0b, 0x00);
813 /* Latch reset turn on */
814 repaper_write_val(spi, 0x03, 0x01);
815 /* Power off charge pump Vcom */
816 repaper_write_val(spi, 0x05, 0x03);
817 /* Power off charge pump neg voltage */
818 repaper_write_val(spi, 0x05, 0x01);
819 msleep(120);
820 /* Discharge internal */
821 repaper_write_val(spi, 0x04, 0x80);
822 /* turn off all charge pumps */
823 repaper_write_val(spi, 0x05, 0x00);
824 /* Turn off osc */
825 repaper_write_val(spi, 0x07, 0x01);
826 msleep(50);
827
828 power_off(epd);
829}
830
831static void repaper_pipe_update(struct drm_simple_display_pipe *pipe,
832 struct drm_plane_state *old_state)
833{
834 struct drm_plane_state *state = pipe->plane.state;
835 struct drm_format_conv_state fmtcnv_state = DRM_FORMAT_CONV_STATE_INIT;
836 struct drm_rect rect;
837
838 if (!pipe->crtc.state->active)
839 return;
840
841 if (drm_atomic_helper_damage_merged(old_state, state, &rect))
842 repaper_fb_dirty(state->fb, &fmtcnv_state);
843
844 drm_format_conv_state_release(&fmtcnv_state);
845}
846
847static const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = {
848 .mode_valid = repaper_pipe_mode_valid,
849 .enable = repaper_pipe_enable,
850 .disable = repaper_pipe_disable,
851 .update = repaper_pipe_update,
852};
853
854static int repaper_connector_get_modes(struct drm_connector *connector)
855{
856 struct repaper_epd *epd = drm_to_epd(connector->dev);
857
858 return drm_connector_helper_get_modes_fixed(connector, epd->mode);
859}
860
861static const struct drm_connector_helper_funcs repaper_connector_hfuncs = {
862 .get_modes = repaper_connector_get_modes,
863};
864
865static const struct drm_connector_funcs repaper_connector_funcs = {
866 .reset = drm_atomic_helper_connector_reset,
867 .fill_modes = drm_helper_probe_single_connector_modes,
868 .destroy = drm_connector_cleanup,
869 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
870 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
871};
872
873static const struct drm_mode_config_funcs repaper_mode_config_funcs = {
874 .fb_create = drm_gem_fb_create_with_dirty,
875 .atomic_check = drm_atomic_helper_check,
876 .atomic_commit = drm_atomic_helper_commit,
877};
878
879static const uint32_t repaper_formats[] = {
880 DRM_FORMAT_XRGB8888,
881};
882
883static const struct drm_display_mode repaper_e1144cs021_mode = {
884 DRM_SIMPLE_MODE(128, 96, 29, 22),
885};
886
887static const u8 repaper_e1144cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
888 0x00, 0x0f, 0xff, 0x00 };
889
890static const struct drm_display_mode repaper_e1190cs021_mode = {
891 DRM_SIMPLE_MODE(144, 128, 36, 32),
892};
893
894static const u8 repaper_e1190cs021_cs[] = { 0x00, 0x00, 0x00, 0x03,
895 0xfc, 0x00, 0x00, 0xff };
896
897static const struct drm_display_mode repaper_e2200cs021_mode = {
898 DRM_SIMPLE_MODE(200, 96, 46, 22),
899};
900
901static const u8 repaper_e2200cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
902 0x01, 0xff, 0xe0, 0x00 };
903
904static const struct drm_display_mode repaper_e2271cs021_mode = {
905 DRM_SIMPLE_MODE(264, 176, 57, 38),
906};
907
908static const u8 repaper_e2271cs021_cs[] = { 0x00, 0x00, 0x00, 0x7f,
909 0xff, 0xfe, 0x00, 0x00 };
910
911DEFINE_DRM_GEM_DMA_FOPS(repaper_fops);
912
913static const struct drm_driver repaper_driver = {
914 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
915 .fops = &repaper_fops,
916 DRM_GEM_DMA_DRIVER_OPS_VMAP,
917 DRM_FBDEV_DMA_DRIVER_OPS,
918 .name = "repaper",
919 .desc = "Pervasive Displays RePaper e-ink panels",
920 .date = "20170405",
921 .major = 1,
922 .minor = 0,
923};
924
925static const struct of_device_id repaper_of_match[] = {
926 { .compatible = "pervasive,e1144cs021", .data = (void *)E1144CS021 },
927 { .compatible = "pervasive,e1190cs021", .data = (void *)E1190CS021 },
928 { .compatible = "pervasive,e2200cs021", .data = (void *)E2200CS021 },
929 { .compatible = "pervasive,e2271cs021", .data = (void *)E2271CS021 },
930 {},
931};
932MODULE_DEVICE_TABLE(of, repaper_of_match);
933
934static const struct spi_device_id repaper_id[] = {
935 { "e1144cs021", E1144CS021 },
936 { "e1190cs021", E1190CS021 },
937 { "e2200cs021", E2200CS021 },
938 { "e2271cs021", E2271CS021 },
939 { },
940};
941MODULE_DEVICE_TABLE(spi, repaper_id);
942
943static int repaper_probe(struct spi_device *spi)
944{
945 const struct drm_display_mode *mode;
946 const struct spi_device_id *spi_id;
947 struct device *dev = &spi->dev;
948 enum repaper_model model;
949 const char *thermal_zone;
950 struct repaper_epd *epd;
951 size_t line_buffer_size;
952 struct drm_device *drm;
953 const void *match;
954 int ret;
955
956 match = device_get_match_data(dev);
957 if (match) {
958 model = (enum repaper_model)(uintptr_t)match;
959 } else {
960 spi_id = spi_get_device_id(spi);
961 model = (enum repaper_model)spi_id->driver_data;
962 }
963
964 /* The SPI device is used to allocate dma memory */
965 if (!dev->coherent_dma_mask) {
966 ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
967 if (ret) {
968 dev_warn(dev, "Failed to set dma mask %d\n", ret);
969 return ret;
970 }
971 }
972
973 epd = devm_drm_dev_alloc(dev, &repaper_driver,
974 struct repaper_epd, drm);
975 if (IS_ERR(epd))
976 return PTR_ERR(epd);
977
978 drm = &epd->drm;
979
980 ret = drmm_mode_config_init(drm);
981 if (ret)
982 return ret;
983 drm->mode_config.funcs = &repaper_mode_config_funcs;
984
985 epd->spi = spi;
986
987 epd->panel_on = devm_gpiod_get(dev, "panel-on", GPIOD_OUT_LOW);
988 if (IS_ERR(epd->panel_on)) {
989 ret = PTR_ERR(epd->panel_on);
990 if (ret != -EPROBE_DEFER)
991 DRM_DEV_ERROR(dev, "Failed to get gpio 'panel-on'\n");
992 return ret;
993 }
994
995 epd->discharge = devm_gpiod_get(dev, "discharge", GPIOD_OUT_LOW);
996 if (IS_ERR(epd->discharge)) {
997 ret = PTR_ERR(epd->discharge);
998 if (ret != -EPROBE_DEFER)
999 DRM_DEV_ERROR(dev, "Failed to get gpio 'discharge'\n");
1000 return ret;
1001 }
1002
1003 epd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
1004 if (IS_ERR(epd->reset)) {
1005 ret = PTR_ERR(epd->reset);
1006 if (ret != -EPROBE_DEFER)
1007 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
1008 return ret;
1009 }
1010
1011 epd->busy = devm_gpiod_get(dev, "busy", GPIOD_IN);
1012 if (IS_ERR(epd->busy)) {
1013 ret = PTR_ERR(epd->busy);
1014 if (ret != -EPROBE_DEFER)
1015 DRM_DEV_ERROR(dev, "Failed to get gpio 'busy'\n");
1016 return ret;
1017 }
1018
1019 if (!device_property_read_string(dev, "pervasive,thermal-zone",
1020 &thermal_zone)) {
1021 epd->thermal = thermal_zone_get_zone_by_name(thermal_zone);
1022 if (IS_ERR(epd->thermal)) {
1023 DRM_DEV_ERROR(dev, "Failed to get thermal zone: %s\n", thermal_zone);
1024 return PTR_ERR(epd->thermal);
1025 }
1026 }
1027
1028 switch (model) {
1029 case E1144CS021:
1030 mode = &repaper_e1144cs021_mode;
1031 epd->channel_select = repaper_e1144cs021_cs;
1032 epd->stage_time = 480;
1033 epd->bytes_per_scan = 96 / 4;
1034 epd->middle_scan = true; /* data-scan-data */
1035 epd->pre_border_byte = false;
1036 epd->border_byte = REPAPER_BORDER_BYTE_ZERO;
1037 break;
1038
1039 case E1190CS021:
1040 mode = &repaper_e1190cs021_mode;
1041 epd->channel_select = repaper_e1190cs021_cs;
1042 epd->stage_time = 480;
1043 epd->bytes_per_scan = 128 / 4 / 2;
1044 epd->middle_scan = false; /* scan-data-scan */
1045 epd->pre_border_byte = false;
1046 epd->border_byte = REPAPER_BORDER_BYTE_SET;
1047 break;
1048
1049 case E2200CS021:
1050 mode = &repaper_e2200cs021_mode;
1051 epd->channel_select = repaper_e2200cs021_cs;
1052 epd->stage_time = 480;
1053 epd->bytes_per_scan = 96 / 4;
1054 epd->middle_scan = true; /* data-scan-data */
1055 epd->pre_border_byte = true;
1056 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1057 break;
1058
1059 case E2271CS021:
1060 epd->border = devm_gpiod_get(dev, "border", GPIOD_OUT_LOW);
1061 if (IS_ERR(epd->border)) {
1062 ret = PTR_ERR(epd->border);
1063 if (ret != -EPROBE_DEFER)
1064 DRM_DEV_ERROR(dev, "Failed to get gpio 'border'\n");
1065 return ret;
1066 }
1067
1068 mode = &repaper_e2271cs021_mode;
1069 epd->channel_select = repaper_e2271cs021_cs;
1070 epd->stage_time = 630;
1071 epd->bytes_per_scan = 176 / 4;
1072 epd->middle_scan = true; /* data-scan-data */
1073 epd->pre_border_byte = true;
1074 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1075 break;
1076
1077 default:
1078 return -ENODEV;
1079 }
1080
1081 epd->mode = mode;
1082 epd->width = mode->hdisplay;
1083 epd->height = mode->vdisplay;
1084 epd->factored_stage_time = epd->stage_time;
1085
1086 line_buffer_size = 2 * epd->width / 8 + epd->bytes_per_scan + 2;
1087 epd->line_buffer = devm_kzalloc(dev, line_buffer_size, GFP_KERNEL);
1088 if (!epd->line_buffer)
1089 return -ENOMEM;
1090
1091 epd->current_frame = devm_kzalloc(dev, epd->width * epd->height / 8,
1092 GFP_KERNEL);
1093 if (!epd->current_frame)
1094 return -ENOMEM;
1095
1096 drm->mode_config.min_width = mode->hdisplay;
1097 drm->mode_config.max_width = mode->hdisplay;
1098 drm->mode_config.min_height = mode->vdisplay;
1099 drm->mode_config.max_height = mode->vdisplay;
1100
1101 drm_connector_helper_add(&epd->connector, &repaper_connector_hfuncs);
1102 ret = drm_connector_init(drm, &epd->connector, &repaper_connector_funcs,
1103 DRM_MODE_CONNECTOR_SPI);
1104 if (ret)
1105 return ret;
1106
1107 ret = drm_simple_display_pipe_init(drm, &epd->pipe, &repaper_pipe_funcs,
1108 repaper_formats, ARRAY_SIZE(repaper_formats),
1109 NULL, &epd->connector);
1110 if (ret)
1111 return ret;
1112
1113 drm_mode_config_reset(drm);
1114
1115 ret = drm_dev_register(drm, 0);
1116 if (ret)
1117 return ret;
1118
1119 spi_set_drvdata(spi, drm);
1120
1121 DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000);
1122
1123 drm_client_setup(drm, NULL);
1124
1125 return 0;
1126}
1127
1128static void repaper_remove(struct spi_device *spi)
1129{
1130 struct drm_device *drm = spi_get_drvdata(spi);
1131
1132 drm_dev_unplug(drm);
1133 drm_atomic_helper_shutdown(drm);
1134}
1135
1136static void repaper_shutdown(struct spi_device *spi)
1137{
1138 drm_atomic_helper_shutdown(spi_get_drvdata(spi));
1139}
1140
1141static struct spi_driver repaper_spi_driver = {
1142 .driver = {
1143 .name = "repaper",
1144 .of_match_table = repaper_of_match,
1145 },
1146 .id_table = repaper_id,
1147 .probe = repaper_probe,
1148 .remove = repaper_remove,
1149 .shutdown = repaper_shutdown,
1150};
1151module_spi_driver(repaper_spi_driver);
1152
1153MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver");
1154MODULE_AUTHOR("Noralf Trønnes");
1155MODULE_LICENSE("GPL");