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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/of_device.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_modes.h>
35#include <drm/drm_rect.h>
36#include <drm/drm_vblank.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 E1144CS021 = 1,
44 E1190CS021,
45 E2200CS021,
46 E2271CS021,
47};
48
49enum repaper_stage { /* Image pixel -> Display pixel */
50 REPAPER_COMPENSATE, /* B -> W, W -> B (Current Image) */
51 REPAPER_WHITE, /* B -> N, W -> W (Current Image) */
52 REPAPER_INVERSE, /* B -> N, W -> B (New Image) */
53 REPAPER_NORMAL /* B -> B, W -> W (New Image) */
54};
55
56enum repaper_epd_border_byte {
57 REPAPER_BORDER_BYTE_NONE,
58 REPAPER_BORDER_BYTE_ZERO,
59 REPAPER_BORDER_BYTE_SET,
60};
61
62struct repaper_epd {
63 struct drm_device drm;
64 struct drm_simple_display_pipe pipe;
65 const struct drm_display_mode *mode;
66 struct drm_connector connector;
67 struct spi_device *spi;
68
69 struct gpio_desc *panel_on;
70 struct gpio_desc *border;
71 struct gpio_desc *discharge;
72 struct gpio_desc *reset;
73 struct gpio_desc *busy;
74
75 struct thermal_zone_device *thermal;
76
77 unsigned int height;
78 unsigned int width;
79 unsigned int bytes_per_scan;
80 const u8 *channel_select;
81 unsigned int stage_time;
82 unsigned int factored_stage_time;
83 bool middle_scan;
84 bool pre_border_byte;
85 enum repaper_epd_border_byte border_byte;
86
87 u8 *line_buffer;
88 void *current_frame;
89
90 bool enabled;
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 (!epd->enabled)
541 return 0;
542
543 if (!drm_dev_enter(fb->dev, &idx))
544 return -ENODEV;
545
546 /* repaper can't do partial updates */
547 clip.x1 = 0;
548 clip.x2 = fb->width;
549 clip.y1 = 0;
550 clip.y2 = fb->height;
551
552 repaper_get_temperature(epd);
553
554 DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id,
555 epd->factored_stage_time);
556
557 buf = kmalloc_array(fb->width, fb->height, GFP_KERNEL);
558 if (!buf) {
559 ret = -ENOMEM;
560 goto out_exit;
561 }
562
563 if (import_attach) {
564 ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
565 DMA_FROM_DEVICE);
566 if (ret)
567 goto out_free;
568 }
569
570 drm_fb_xrgb8888_to_gray8(buf, cma_obj->vaddr, fb, &clip);
571
572 if (import_attach) {
573 ret = dma_buf_end_cpu_access(import_attach->dmabuf,
574 DMA_FROM_DEVICE);
575 if (ret)
576 goto out_free;
577 }
578
579 repaper_gray8_to_mono_reversed(buf, fb->width, fb->height);
580
581 if (epd->partial) {
582 repaper_frame_data_repeat(epd, buf, epd->current_frame,
583 REPAPER_NORMAL);
584 } else if (epd->cleared) {
585 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
586 REPAPER_COMPENSATE);
587 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
588 REPAPER_WHITE);
589 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
590 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
591
592 epd->partial = true;
593 } else {
594 /* Clear display (anything -> white) */
595 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_COMPENSATE);
596 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_WHITE);
597 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_INVERSE);
598 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_NORMAL);
599
600 /* Assuming a clear (white) screen output an image */
601 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_COMPENSATE);
602 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_WHITE);
603 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
604 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
605
606 epd->cleared = true;
607 epd->partial = true;
608 }
609
610 memcpy(epd->current_frame, buf, fb->width * fb->height / 8);
611
612 /*
613 * An extra frame write is needed if pixels are set in the bottom line,
614 * or else grey lines rises up from the pixels
615 */
616 if (epd->pre_border_byte) {
617 unsigned int x;
618
619 for (x = 0; x < (fb->width / 8); x++)
620 if (buf[x + (fb->width * (fb->height - 1) / 8)]) {
621 repaper_frame_data_repeat(epd, buf,
622 epd->current_frame,
623 REPAPER_NORMAL);
624 break;
625 }
626 }
627
628out_free:
629 kfree(buf);
630out_exit:
631 drm_dev_exit(idx);
632
633 return ret;
634}
635
636static void power_off(struct repaper_epd *epd)
637{
638 /* Turn off power and all signals */
639 gpiod_set_value_cansleep(epd->reset, 0);
640 gpiod_set_value_cansleep(epd->panel_on, 0);
641 if (epd->border)
642 gpiod_set_value_cansleep(epd->border, 0);
643
644 /* Ensure SPI MOSI and CLOCK are Low before CS Low */
645 repaper_spi_mosi_low(epd->spi);
646
647 /* Discharge pulse */
648 gpiod_set_value_cansleep(epd->discharge, 1);
649 msleep(150);
650 gpiod_set_value_cansleep(epd->discharge, 0);
651}
652
653static void repaper_pipe_enable(struct drm_simple_display_pipe *pipe,
654 struct drm_crtc_state *crtc_state,
655 struct drm_plane_state *plane_state)
656{
657 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev);
658 struct spi_device *spi = epd->spi;
659 struct device *dev = &spi->dev;
660 bool dc_ok = false;
661 int i, ret, idx;
662
663 if (!drm_dev_enter(pipe->crtc.dev, &idx))
664 return;
665
666 DRM_DEBUG_DRIVER("\n");
667
668 /* Power up sequence */
669 gpiod_set_value_cansleep(epd->reset, 0);
670 gpiod_set_value_cansleep(epd->panel_on, 0);
671 gpiod_set_value_cansleep(epd->discharge, 0);
672 if (epd->border)
673 gpiod_set_value_cansleep(epd->border, 0);
674 repaper_spi_mosi_low(spi);
675 usleep_range(5000, 10000);
676
677 gpiod_set_value_cansleep(epd->panel_on, 1);
678 /*
679 * This delay comes from the repaper.org userspace driver, it's not
680 * mentioned in the datasheet.
681 */
682 usleep_range(10000, 15000);
683 gpiod_set_value_cansleep(epd->reset, 1);
684 if (epd->border)
685 gpiod_set_value_cansleep(epd->border, 1);
686 usleep_range(5000, 10000);
687 gpiod_set_value_cansleep(epd->reset, 0);
688 usleep_range(5000, 10000);
689 gpiod_set_value_cansleep(epd->reset, 1);
690 usleep_range(5000, 10000);
691
692 /* Wait for COG to become ready */
693 for (i = 100; i > 0; i--) {
694 if (!gpiod_get_value_cansleep(epd->busy))
695 break;
696
697 usleep_range(10, 100);
698 }
699
700 if (!i) {
701 DRM_DEV_ERROR(dev, "timeout waiting for panel to become ready.\n");
702 power_off(epd);
703 goto out_exit;
704 }
705
706 repaper_read_id(spi);
707 ret = repaper_read_id(spi);
708 if (ret != REPAPER_RID_G2_COG_ID) {
709 if (ret < 0)
710 dev_err(dev, "failed to read chip (%d)\n", ret);
711 else
712 dev_err(dev, "wrong COG ID 0x%02x\n", ret);
713 power_off(epd);
714 goto out_exit;
715 }
716
717 /* Disable OE */
718 repaper_write_val(spi, 0x02, 0x40);
719
720 ret = repaper_read_val(spi, 0x0f);
721 if (ret < 0 || !(ret & 0x80)) {
722 if (ret < 0)
723 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
724 else
725 DRM_DEV_ERROR(dev, "panel is reported broken\n");
726 power_off(epd);
727 goto out_exit;
728 }
729
730 /* Power saving mode */
731 repaper_write_val(spi, 0x0b, 0x02);
732 /* Channel select */
733 repaper_write_buf(spi, 0x01, epd->channel_select, 8);
734 /* High power mode osc */
735 repaper_write_val(spi, 0x07, 0xd1);
736 /* Power setting */
737 repaper_write_val(spi, 0x08, 0x02);
738 /* Vcom level */
739 repaper_write_val(spi, 0x09, 0xc2);
740 /* Power setting */
741 repaper_write_val(spi, 0x04, 0x03);
742 /* Driver latch on */
743 repaper_write_val(spi, 0x03, 0x01);
744 /* Driver latch off */
745 repaper_write_val(spi, 0x03, 0x00);
746 usleep_range(5000, 10000);
747
748 /* Start chargepump */
749 for (i = 0; i < 4; ++i) {
750 /* Charge pump positive voltage on - VGH/VDL on */
751 repaper_write_val(spi, 0x05, 0x01);
752 msleep(240);
753
754 /* Charge pump negative voltage on - VGL/VDL on */
755 repaper_write_val(spi, 0x05, 0x03);
756 msleep(40);
757
758 /* Charge pump Vcom on - Vcom driver on */
759 repaper_write_val(spi, 0x05, 0x0f);
760 msleep(40);
761
762 /* check DC/DC */
763 ret = repaper_read_val(spi, 0x0f);
764 if (ret < 0) {
765 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
766 power_off(epd);
767 goto out_exit;
768 }
769
770 if (ret & 0x40) {
771 dc_ok = true;
772 break;
773 }
774 }
775
776 if (!dc_ok) {
777 DRM_DEV_ERROR(dev, "dc/dc failed\n");
778 power_off(epd);
779 goto out_exit;
780 }
781
782 /*
783 * Output enable to disable
784 * The userspace driver sets this to 0x04, but the datasheet says 0x06
785 */
786 repaper_write_val(spi, 0x02, 0x04);
787
788 epd->enabled = true;
789 epd->partial = false;
790out_exit:
791 drm_dev_exit(idx);
792}
793
794static void repaper_pipe_disable(struct drm_simple_display_pipe *pipe)
795{
796 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev);
797 struct spi_device *spi = epd->spi;
798 unsigned int line;
799
800 /*
801 * This callback is not protected by drm_dev_enter/exit since we want to
802 * turn off the display on regular driver unload. It's highly unlikely
803 * that the underlying SPI controller is gone should this be called after
804 * unplug.
805 */
806
807 if (!epd->enabled)
808 return;
809
810 DRM_DEBUG_DRIVER("\n");
811
812 epd->enabled = false;
813
814 /* Nothing frame */
815 for (line = 0; line < epd->height; line++)
816 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
817 REPAPER_COMPENSATE);
818
819 /* 2.7" */
820 if (epd->border) {
821 /* Dummy line */
822 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
823 REPAPER_COMPENSATE);
824 msleep(25);
825 gpiod_set_value_cansleep(epd->border, 0);
826 msleep(200);
827 gpiod_set_value_cansleep(epd->border, 1);
828 } else {
829 /* Border dummy line */
830 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
831 REPAPER_NORMAL);
832 msleep(200);
833 }
834
835 /* not described in datasheet */
836 repaper_write_val(spi, 0x0b, 0x00);
837 /* Latch reset turn on */
838 repaper_write_val(spi, 0x03, 0x01);
839 /* Power off charge pump Vcom */
840 repaper_write_val(spi, 0x05, 0x03);
841 /* Power off charge pump neg voltage */
842 repaper_write_val(spi, 0x05, 0x01);
843 msleep(120);
844 /* Discharge internal */
845 repaper_write_val(spi, 0x04, 0x80);
846 /* turn off all charge pumps */
847 repaper_write_val(spi, 0x05, 0x00);
848 /* Turn off osc */
849 repaper_write_val(spi, 0x07, 0x01);
850 msleep(50);
851
852 power_off(epd);
853}
854
855static void repaper_pipe_update(struct drm_simple_display_pipe *pipe,
856 struct drm_plane_state *old_state)
857{
858 struct drm_plane_state *state = pipe->plane.state;
859 struct drm_crtc *crtc = &pipe->crtc;
860 struct drm_rect rect;
861
862 if (drm_atomic_helper_damage_merged(old_state, state, &rect))
863 repaper_fb_dirty(state->fb);
864
865 if (crtc->state->event) {
866 spin_lock_irq(&crtc->dev->event_lock);
867 drm_crtc_send_vblank_event(crtc, crtc->state->event);
868 spin_unlock_irq(&crtc->dev->event_lock);
869 crtc->state->event = NULL;
870 }
871}
872
873static const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = {
874 .enable = repaper_pipe_enable,
875 .disable = repaper_pipe_disable,
876 .update = repaper_pipe_update,
877 .prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
878};
879
880static int repaper_connector_get_modes(struct drm_connector *connector)
881{
882 struct repaper_epd *epd = drm_to_epd(connector->dev);
883 struct drm_display_mode *mode;
884
885 mode = drm_mode_duplicate(connector->dev, epd->mode);
886 if (!mode) {
887 DRM_ERROR("Failed to duplicate mode\n");
888 return 0;
889 }
890
891 drm_mode_set_name(mode);
892 mode->type |= DRM_MODE_TYPE_PREFERRED;
893 drm_mode_probed_add(connector, mode);
894
895 connector->display_info.width_mm = mode->width_mm;
896 connector->display_info.height_mm = mode->height_mm;
897
898 return 1;
899}
900
901static const struct drm_connector_helper_funcs repaper_connector_hfuncs = {
902 .get_modes = repaper_connector_get_modes,
903};
904
905static const struct drm_connector_funcs repaper_connector_funcs = {
906 .reset = drm_atomic_helper_connector_reset,
907 .fill_modes = drm_helper_probe_single_connector_modes,
908 .destroy = drm_connector_cleanup,
909 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
910 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
911};
912
913static const struct drm_mode_config_funcs repaper_mode_config_funcs = {
914 .fb_create = drm_gem_fb_create_with_dirty,
915 .atomic_check = drm_atomic_helper_check,
916 .atomic_commit = drm_atomic_helper_commit,
917};
918
919static void repaper_release(struct drm_device *drm)
920{
921 struct repaper_epd *epd = drm_to_epd(drm);
922
923 DRM_DEBUG_DRIVER("\n");
924
925 drm_mode_config_cleanup(drm);
926 drm_dev_fini(drm);
927 kfree(epd);
928}
929
930static const uint32_t repaper_formats[] = {
931 DRM_FORMAT_XRGB8888,
932};
933
934static const struct drm_display_mode repaper_e1144cs021_mode = {
935 DRM_SIMPLE_MODE(128, 96, 29, 22),
936};
937
938static const u8 repaper_e1144cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
939 0x00, 0x0f, 0xff, 0x00 };
940
941static const struct drm_display_mode repaper_e1190cs021_mode = {
942 DRM_SIMPLE_MODE(144, 128, 36, 32),
943};
944
945static const u8 repaper_e1190cs021_cs[] = { 0x00, 0x00, 0x00, 0x03,
946 0xfc, 0x00, 0x00, 0xff };
947
948static const struct drm_display_mode repaper_e2200cs021_mode = {
949 DRM_SIMPLE_MODE(200, 96, 46, 22),
950};
951
952static const u8 repaper_e2200cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
953 0x01, 0xff, 0xe0, 0x00 };
954
955static const struct drm_display_mode repaper_e2271cs021_mode = {
956 DRM_SIMPLE_MODE(264, 176, 57, 38),
957};
958
959static const u8 repaper_e2271cs021_cs[] = { 0x00, 0x00, 0x00, 0x7f,
960 0xff, 0xfe, 0x00, 0x00 };
961
962DEFINE_DRM_GEM_CMA_FOPS(repaper_fops);
963
964static struct drm_driver repaper_driver = {
965 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
966 .fops = &repaper_fops,
967 .release = repaper_release,
968 DRM_GEM_CMA_VMAP_DRIVER_OPS,
969 .name = "repaper",
970 .desc = "Pervasive Displays RePaper e-ink panels",
971 .date = "20170405",
972 .major = 1,
973 .minor = 0,
974};
975
976static const struct of_device_id repaper_of_match[] = {
977 { .compatible = "pervasive,e1144cs021", .data = (void *)E1144CS021 },
978 { .compatible = "pervasive,e1190cs021", .data = (void *)E1190CS021 },
979 { .compatible = "pervasive,e2200cs021", .data = (void *)E2200CS021 },
980 { .compatible = "pervasive,e2271cs021", .data = (void *)E2271CS021 },
981 {},
982};
983MODULE_DEVICE_TABLE(of, repaper_of_match);
984
985static const struct spi_device_id repaper_id[] = {
986 { "e1144cs021", E1144CS021 },
987 { "e1190cs021", E1190CS021 },
988 { "e2200cs021", E2200CS021 },
989 { "e2271cs021", E2271CS021 },
990 { },
991};
992MODULE_DEVICE_TABLE(spi, repaper_id);
993
994static int repaper_probe(struct spi_device *spi)
995{
996 const struct drm_display_mode *mode;
997 const struct spi_device_id *spi_id;
998 const struct of_device_id *match;
999 struct device *dev = &spi->dev;
1000 enum repaper_model model;
1001 const char *thermal_zone;
1002 struct repaper_epd *epd;
1003 size_t line_buffer_size;
1004 struct drm_device *drm;
1005 int ret;
1006
1007 match = of_match_device(repaper_of_match, dev);
1008 if (match) {
1009 model = (enum repaper_model)match->data;
1010 } else {
1011 spi_id = spi_get_device_id(spi);
1012 model = spi_id->driver_data;
1013 }
1014
1015 /* The SPI device is used to allocate dma memory */
1016 if (!dev->coherent_dma_mask) {
1017 ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
1018 if (ret) {
1019 dev_warn(dev, "Failed to set dma mask %d\n", ret);
1020 return ret;
1021 }
1022 }
1023
1024 epd = kzalloc(sizeof(*epd), GFP_KERNEL);
1025 if (!epd)
1026 return -ENOMEM;
1027
1028 drm = &epd->drm;
1029
1030 ret = devm_drm_dev_init(dev, drm, &repaper_driver);
1031 if (ret) {
1032 kfree(epd);
1033 return ret;
1034 }
1035
1036 drm_mode_config_init(drm);
1037 drm->mode_config.funcs = &repaper_mode_config_funcs;
1038
1039 epd->spi = spi;
1040
1041 epd->panel_on = devm_gpiod_get(dev, "panel-on", GPIOD_OUT_LOW);
1042 if (IS_ERR(epd->panel_on)) {
1043 ret = PTR_ERR(epd->panel_on);
1044 if (ret != -EPROBE_DEFER)
1045 DRM_DEV_ERROR(dev, "Failed to get gpio 'panel-on'\n");
1046 return ret;
1047 }
1048
1049 epd->discharge = devm_gpiod_get(dev, "discharge", GPIOD_OUT_LOW);
1050 if (IS_ERR(epd->discharge)) {
1051 ret = PTR_ERR(epd->discharge);
1052 if (ret != -EPROBE_DEFER)
1053 DRM_DEV_ERROR(dev, "Failed to get gpio 'discharge'\n");
1054 return ret;
1055 }
1056
1057 epd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
1058 if (IS_ERR(epd->reset)) {
1059 ret = PTR_ERR(epd->reset);
1060 if (ret != -EPROBE_DEFER)
1061 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
1062 return ret;
1063 }
1064
1065 epd->busy = devm_gpiod_get(dev, "busy", GPIOD_IN);
1066 if (IS_ERR(epd->busy)) {
1067 ret = PTR_ERR(epd->busy);
1068 if (ret != -EPROBE_DEFER)
1069 DRM_DEV_ERROR(dev, "Failed to get gpio 'busy'\n");
1070 return ret;
1071 }
1072
1073 if (!device_property_read_string(dev, "pervasive,thermal-zone",
1074 &thermal_zone)) {
1075 epd->thermal = thermal_zone_get_zone_by_name(thermal_zone);
1076 if (IS_ERR(epd->thermal)) {
1077 DRM_DEV_ERROR(dev, "Failed to get thermal zone: %s\n", thermal_zone);
1078 return PTR_ERR(epd->thermal);
1079 }
1080 }
1081
1082 switch (model) {
1083 case E1144CS021:
1084 mode = &repaper_e1144cs021_mode;
1085 epd->channel_select = repaper_e1144cs021_cs;
1086 epd->stage_time = 480;
1087 epd->bytes_per_scan = 96 / 4;
1088 epd->middle_scan = true; /* data-scan-data */
1089 epd->pre_border_byte = false;
1090 epd->border_byte = REPAPER_BORDER_BYTE_ZERO;
1091 break;
1092
1093 case E1190CS021:
1094 mode = &repaper_e1190cs021_mode;
1095 epd->channel_select = repaper_e1190cs021_cs;
1096 epd->stage_time = 480;
1097 epd->bytes_per_scan = 128 / 4 / 2;
1098 epd->middle_scan = false; /* scan-data-scan */
1099 epd->pre_border_byte = false;
1100 epd->border_byte = REPAPER_BORDER_BYTE_SET;
1101 break;
1102
1103 case E2200CS021:
1104 mode = &repaper_e2200cs021_mode;
1105 epd->channel_select = repaper_e2200cs021_cs;
1106 epd->stage_time = 480;
1107 epd->bytes_per_scan = 96 / 4;
1108 epd->middle_scan = true; /* data-scan-data */
1109 epd->pre_border_byte = true;
1110 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1111 break;
1112
1113 case E2271CS021:
1114 epd->border = devm_gpiod_get(dev, "border", GPIOD_OUT_LOW);
1115 if (IS_ERR(epd->border)) {
1116 ret = PTR_ERR(epd->border);
1117 if (ret != -EPROBE_DEFER)
1118 DRM_DEV_ERROR(dev, "Failed to get gpio 'border'\n");
1119 return ret;
1120 }
1121
1122 mode = &repaper_e2271cs021_mode;
1123 epd->channel_select = repaper_e2271cs021_cs;
1124 epd->stage_time = 630;
1125 epd->bytes_per_scan = 176 / 4;
1126 epd->middle_scan = true; /* data-scan-data */
1127 epd->pre_border_byte = true;
1128 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1129 break;
1130
1131 default:
1132 return -ENODEV;
1133 }
1134
1135 epd->mode = mode;
1136 epd->width = mode->hdisplay;
1137 epd->height = mode->vdisplay;
1138 epd->factored_stage_time = epd->stage_time;
1139
1140 line_buffer_size = 2 * epd->width / 8 + epd->bytes_per_scan + 2;
1141 epd->line_buffer = devm_kzalloc(dev, line_buffer_size, GFP_KERNEL);
1142 if (!epd->line_buffer)
1143 return -ENOMEM;
1144
1145 epd->current_frame = devm_kzalloc(dev, epd->width * epd->height / 8,
1146 GFP_KERNEL);
1147 if (!epd->current_frame)
1148 return -ENOMEM;
1149
1150 drm->mode_config.min_width = mode->hdisplay;
1151 drm->mode_config.max_width = mode->hdisplay;
1152 drm->mode_config.min_height = mode->vdisplay;
1153 drm->mode_config.max_height = mode->vdisplay;
1154
1155 drm_connector_helper_add(&epd->connector, &repaper_connector_hfuncs);
1156 ret = drm_connector_init(drm, &epd->connector, &repaper_connector_funcs,
1157 DRM_MODE_CONNECTOR_SPI);
1158 if (ret)
1159 return ret;
1160
1161 ret = drm_simple_display_pipe_init(drm, &epd->pipe, &repaper_pipe_funcs,
1162 repaper_formats, ARRAY_SIZE(repaper_formats),
1163 NULL, &epd->connector);
1164 if (ret)
1165 return ret;
1166
1167 drm_mode_config_reset(drm);
1168
1169 ret = drm_dev_register(drm, 0);
1170 if (ret)
1171 return ret;
1172
1173 spi_set_drvdata(spi, drm);
1174
1175 DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000);
1176
1177 drm_fbdev_generic_setup(drm, 0);
1178
1179 return 0;
1180}
1181
1182static int repaper_remove(struct spi_device *spi)
1183{
1184 struct drm_device *drm = spi_get_drvdata(spi);
1185
1186 drm_dev_unplug(drm);
1187 drm_atomic_helper_shutdown(drm);
1188
1189 return 0;
1190}
1191
1192static void repaper_shutdown(struct spi_device *spi)
1193{
1194 drm_atomic_helper_shutdown(spi_get_drvdata(spi));
1195}
1196
1197static struct spi_driver repaper_spi_driver = {
1198 .driver = {
1199 .name = "repaper",
1200 .owner = THIS_MODULE,
1201 .of_match_table = repaper_of_match,
1202 },
1203 .id_table = repaper_id,
1204 .probe = repaper_probe,
1205 .remove = repaper_remove,
1206 .shutdown = repaper_shutdown,
1207};
1208module_spi_driver(repaper_spi_driver);
1209
1210MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver");
1211MODULE_AUTHOR("Noralf Trønnes");
1212MODULE_LICENSE("GPL");