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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_connector.h>
26#include <drm/drm_damage_helper.h>
27#include <drm/drm_drv.h>
28#include <drm/drm_fb_dma_helper.h>
29#include <drm/drm_fbdev_generic.h>
30#include <drm/drm_format_helper.h>
31#include <drm/drm_framebuffer.h>
32#include <drm/drm_gem_atomic_helper.h>
33#include <drm/drm_gem_dma_helper.h>
34#include <drm/drm_gem_framebuffer_helper.h>
35#include <drm/drm_managed.h>
36#include <drm/drm_modes.h>
37#include <drm/drm_rect.h>
38#include <drm/drm_probe_helper.h>
39#include <drm/drm_simple_kms_helper.h>
40
41#define REPAPER_RID_G2_COG_ID 0x12
42
43enum repaper_model {
44 /* 0 is reserved to avoid clashing with NULL */
45 E1144CS021 = 1,
46 E1190CS021,
47 E2200CS021,
48 E2271CS021,
49};
50
51enum repaper_stage { /* Image pixel -> Display pixel */
52 REPAPER_COMPENSATE, /* B -> W, W -> B (Current Image) */
53 REPAPER_WHITE, /* B -> N, W -> W (Current Image) */
54 REPAPER_INVERSE, /* B -> N, W -> B (New Image) */
55 REPAPER_NORMAL /* B -> B, W -> W (New Image) */
56};
57
58enum repaper_epd_border_byte {
59 REPAPER_BORDER_BYTE_NONE,
60 REPAPER_BORDER_BYTE_ZERO,
61 REPAPER_BORDER_BYTE_SET,
62};
63
64struct repaper_epd {
65 struct drm_device drm;
66 struct drm_simple_display_pipe pipe;
67 const struct drm_display_mode *mode;
68 struct drm_connector connector;
69 struct spi_device *spi;
70
71 struct gpio_desc *panel_on;
72 struct gpio_desc *border;
73 struct gpio_desc *discharge;
74 struct gpio_desc *reset;
75 struct gpio_desc *busy;
76
77 struct thermal_zone_device *thermal;
78
79 unsigned int height;
80 unsigned int width;
81 unsigned int bytes_per_scan;
82 const u8 *channel_select;
83 unsigned int stage_time;
84 unsigned int factored_stage_time;
85 bool middle_scan;
86 bool pre_border_byte;
87 enum repaper_epd_border_byte border_byte;
88
89 u8 *line_buffer;
90 void *current_frame;
91
92 bool cleared;
93 bool partial;
94};
95
96static inline struct repaper_epd *drm_to_epd(struct drm_device *drm)
97{
98 return container_of(drm, struct repaper_epd, drm);
99}
100
101static int repaper_spi_transfer(struct spi_device *spi, u8 header,
102 const void *tx, void *rx, size_t len)
103{
104 void *txbuf = NULL, *rxbuf = NULL;
105 struct spi_transfer tr[2] = {};
106 u8 *headerbuf;
107 int ret;
108
109 headerbuf = kmalloc(1, GFP_KERNEL);
110 if (!headerbuf)
111 return -ENOMEM;
112
113 headerbuf[0] = header;
114 tr[0].tx_buf = headerbuf;
115 tr[0].len = 1;
116
117 /* Stack allocated tx? */
118 if (tx && len <= 32) {
119 txbuf = kmemdup(tx, len, GFP_KERNEL);
120 if (!txbuf) {
121 ret = -ENOMEM;
122 goto out_free;
123 }
124 }
125
126 if (rx) {
127 rxbuf = kmalloc(len, GFP_KERNEL);
128 if (!rxbuf) {
129 ret = -ENOMEM;
130 goto out_free;
131 }
132 }
133
134 tr[1].tx_buf = txbuf ? txbuf : tx;
135 tr[1].rx_buf = rxbuf;
136 tr[1].len = len;
137
138 ndelay(80);
139 ret = spi_sync_transfer(spi, tr, 2);
140 if (rx && !ret)
141 memcpy(rx, rxbuf, len);
142
143out_free:
144 kfree(headerbuf);
145 kfree(txbuf);
146 kfree(rxbuf);
147
148 return ret;
149}
150
151static int repaper_write_buf(struct spi_device *spi, u8 reg,
152 const u8 *buf, size_t len)
153{
154 int ret;
155
156 ret = repaper_spi_transfer(spi, 0x70, ®, NULL, 1);
157 if (ret)
158 return ret;
159
160 return repaper_spi_transfer(spi, 0x72, buf, NULL, len);
161}
162
163static int repaper_write_val(struct spi_device *spi, u8 reg, u8 val)
164{
165 return repaper_write_buf(spi, reg, &val, 1);
166}
167
168static int repaper_read_val(struct spi_device *spi, u8 reg)
169{
170 int ret;
171 u8 val;
172
173 ret = repaper_spi_transfer(spi, 0x70, ®, NULL, 1);
174 if (ret)
175 return ret;
176
177 ret = repaper_spi_transfer(spi, 0x73, NULL, &val, 1);
178
179 return ret ? ret : val;
180}
181
182static int repaper_read_id(struct spi_device *spi)
183{
184 int ret;
185 u8 id;
186
187 ret = repaper_spi_transfer(spi, 0x71, NULL, &id, 1);
188
189 return ret ? ret : id;
190}
191
192static void repaper_spi_mosi_low(struct spi_device *spi)
193{
194 const u8 buf[1] = { 0 };
195
196 spi_write(spi, buf, 1);
197}
198
199/* pixels on display are numbered from 1 so even is actually bits 1,3,5,... */
200static void repaper_even_pixels(struct repaper_epd *epd, u8 **pp,
201 const u8 *data, u8 fixed_value, const u8 *mask,
202 enum repaper_stage stage)
203{
204 unsigned int b;
205
206 for (b = 0; b < (epd->width / 8); b++) {
207 if (data) {
208 u8 pixels = data[b] & 0xaa;
209 u8 pixel_mask = 0xff;
210 u8 p1, p2, p3, p4;
211
212 if (mask) {
213 pixel_mask = (mask[b] ^ pixels) & 0xaa;
214 pixel_mask |= pixel_mask >> 1;
215 }
216
217 switch (stage) {
218 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */
219 pixels = 0xaa | ((pixels ^ 0xaa) >> 1);
220 break;
221 case REPAPER_WHITE: /* B -> N, W -> W (Current) */
222 pixels = 0x55 + ((pixels ^ 0xaa) >> 1);
223 break;
224 case REPAPER_INVERSE: /* B -> N, W -> B (New) */
225 pixels = 0x55 | (pixels ^ 0xaa);
226 break;
227 case REPAPER_NORMAL: /* B -> B, W -> W (New) */
228 pixels = 0xaa | (pixels >> 1);
229 break;
230 }
231
232 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x55);
233 p1 = (pixels >> 6) & 0x03;
234 p2 = (pixels >> 4) & 0x03;
235 p3 = (pixels >> 2) & 0x03;
236 p4 = (pixels >> 0) & 0x03;
237 pixels = (p1 << 0) | (p2 << 2) | (p3 << 4) | (p4 << 6);
238 *(*pp)++ = pixels;
239 } else {
240 *(*pp)++ = fixed_value;
241 }
242 }
243}
244
245/* pixels on display are numbered from 1 so odd is actually bits 0,2,4,... */
246static void repaper_odd_pixels(struct repaper_epd *epd, u8 **pp,
247 const u8 *data, u8 fixed_value, const u8 *mask,
248 enum repaper_stage stage)
249{
250 unsigned int b;
251
252 for (b = epd->width / 8; b > 0; b--) {
253 if (data) {
254 u8 pixels = data[b - 1] & 0x55;
255 u8 pixel_mask = 0xff;
256
257 if (mask) {
258 pixel_mask = (mask[b - 1] ^ pixels) & 0x55;
259 pixel_mask |= pixel_mask << 1;
260 }
261
262 switch (stage) {
263 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */
264 pixels = 0xaa | (pixels ^ 0x55);
265 break;
266 case REPAPER_WHITE: /* B -> N, W -> W (Current) */
267 pixels = 0x55 + (pixels ^ 0x55);
268 break;
269 case REPAPER_INVERSE: /* B -> N, W -> B (New) */
270 pixels = 0x55 | ((pixels ^ 0x55) << 1);
271 break;
272 case REPAPER_NORMAL: /* B -> B, W -> W (New) */
273 pixels = 0xaa | pixels;
274 break;
275 }
276
277 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x55);
278 *(*pp)++ = pixels;
279 } else {
280 *(*pp)++ = fixed_value;
281 }
282 }
283}
284
285/* interleave bits: (byte)76543210 -> (16 bit).7.6.5.4.3.2.1 */
286static inline u16 repaper_interleave_bits(u16 value)
287{
288 value = (value | (value << 4)) & 0x0f0f;
289 value = (value | (value << 2)) & 0x3333;
290 value = (value | (value << 1)) & 0x5555;
291
292 return value;
293}
294
295/* pixels on display are numbered from 1 */
296static void repaper_all_pixels(struct repaper_epd *epd, u8 **pp,
297 const u8 *data, u8 fixed_value, const u8 *mask,
298 enum repaper_stage stage)
299{
300 unsigned int b;
301
302 for (b = epd->width / 8; b > 0; b--) {
303 if (data) {
304 u16 pixels = repaper_interleave_bits(data[b - 1]);
305 u16 pixel_mask = 0xffff;
306
307 if (mask) {
308 pixel_mask = repaper_interleave_bits(mask[b - 1]);
309
310 pixel_mask = (pixel_mask ^ pixels) & 0x5555;
311 pixel_mask |= pixel_mask << 1;
312 }
313
314 switch (stage) {
315 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */
316 pixels = 0xaaaa | (pixels ^ 0x5555);
317 break;
318 case REPAPER_WHITE: /* B -> N, W -> W (Current) */
319 pixels = 0x5555 + (pixels ^ 0x5555);
320 break;
321 case REPAPER_INVERSE: /* B -> N, W -> B (New) */
322 pixels = 0x5555 | ((pixels ^ 0x5555) << 1);
323 break;
324 case REPAPER_NORMAL: /* B -> B, W -> W (New) */
325 pixels = 0xaaaa | pixels;
326 break;
327 }
328
329 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x5555);
330 *(*pp)++ = pixels >> 8;
331 *(*pp)++ = pixels;
332 } else {
333 *(*pp)++ = fixed_value;
334 *(*pp)++ = fixed_value;
335 }
336 }
337}
338
339/* output one line of scan and data bytes to the display */
340static void repaper_one_line(struct repaper_epd *epd, unsigned int line,
341 const u8 *data, u8 fixed_value, const u8 *mask,
342 enum repaper_stage stage)
343{
344 u8 *p = epd->line_buffer;
345 unsigned int b;
346
347 repaper_spi_mosi_low(epd->spi);
348
349 if (epd->pre_border_byte)
350 *p++ = 0x00;
351
352 if (epd->middle_scan) {
353 /* data bytes */
354 repaper_odd_pixels(epd, &p, data, fixed_value, mask, stage);
355
356 /* scan line */
357 for (b = epd->bytes_per_scan; b > 0; b--) {
358 if (line / 4 == b - 1)
359 *p++ = 0x03 << (2 * (line & 0x03));
360 else
361 *p++ = 0x00;
362 }
363
364 /* data bytes */
365 repaper_even_pixels(epd, &p, data, fixed_value, mask, stage);
366 } else {
367 /*
368 * even scan line, but as lines on display are numbered from 1,
369 * line: 1,3,5,...
370 */
371 for (b = 0; b < epd->bytes_per_scan; b++) {
372 if (0 != (line & 0x01) && line / 8 == b)
373 *p++ = 0xc0 >> (line & 0x06);
374 else
375 *p++ = 0x00;
376 }
377
378 /* data bytes */
379 repaper_all_pixels(epd, &p, data, fixed_value, mask, stage);
380
381 /*
382 * odd scan line, but as lines on display are numbered from 1,
383 * line: 0,2,4,6,...
384 */
385 for (b = epd->bytes_per_scan; b > 0; b--) {
386 if (0 == (line & 0x01) && line / 8 == b - 1)
387 *p++ = 0x03 << (line & 0x06);
388 else
389 *p++ = 0x00;
390 }
391 }
392
393 switch (epd->border_byte) {
394 case REPAPER_BORDER_BYTE_NONE:
395 break;
396
397 case REPAPER_BORDER_BYTE_ZERO:
398 *p++ = 0x00;
399 break;
400
401 case REPAPER_BORDER_BYTE_SET:
402 switch (stage) {
403 case REPAPER_COMPENSATE:
404 case REPAPER_WHITE:
405 case REPAPER_INVERSE:
406 *p++ = 0x00;
407 break;
408 case REPAPER_NORMAL:
409 *p++ = 0xaa;
410 break;
411 }
412 break;
413 }
414
415 repaper_write_buf(epd->spi, 0x0a, epd->line_buffer,
416 p - epd->line_buffer);
417
418 /* Output data to panel */
419 repaper_write_val(epd->spi, 0x02, 0x07);
420
421 repaper_spi_mosi_low(epd->spi);
422}
423
424static void repaper_frame_fixed(struct repaper_epd *epd, u8 fixed_value,
425 enum repaper_stage stage)
426{
427 unsigned int line;
428
429 for (line = 0; line < epd->height; line++)
430 repaper_one_line(epd, line, NULL, fixed_value, NULL, stage);
431}
432
433static void repaper_frame_data(struct repaper_epd *epd, const u8 *image,
434 const u8 *mask, enum repaper_stage stage)
435{
436 unsigned int line;
437
438 if (!mask) {
439 for (line = 0; line < epd->height; line++) {
440 repaper_one_line(epd, line,
441 &image[line * (epd->width / 8)],
442 0, NULL, stage);
443 }
444 } else {
445 for (line = 0; line < epd->height; line++) {
446 size_t n = line * epd->width / 8;
447
448 repaper_one_line(epd, line, &image[n], 0, &mask[n],
449 stage);
450 }
451 }
452}
453
454static void repaper_frame_fixed_repeat(struct repaper_epd *epd, u8 fixed_value,
455 enum repaper_stage stage)
456{
457 u64 start = local_clock();
458 u64 end = start + (epd->factored_stage_time * 1000 * 1000);
459
460 do {
461 repaper_frame_fixed(epd, fixed_value, stage);
462 } while (local_clock() < end);
463}
464
465static void repaper_frame_data_repeat(struct repaper_epd *epd, const u8 *image,
466 const u8 *mask, enum repaper_stage stage)
467{
468 u64 start = local_clock();
469 u64 end = start + (epd->factored_stage_time * 1000 * 1000);
470
471 do {
472 repaper_frame_data(epd, image, mask, stage);
473 } while (local_clock() < end);
474}
475
476static void repaper_get_temperature(struct repaper_epd *epd)
477{
478 int ret, temperature = 0;
479 unsigned int factor10x;
480
481 if (!epd->thermal)
482 return;
483
484 ret = thermal_zone_get_temp(epd->thermal, &temperature);
485 if (ret) {
486 DRM_DEV_ERROR(&epd->spi->dev, "Failed to get temperature (%d)\n", ret);
487 return;
488 }
489
490 temperature /= 1000;
491
492 if (temperature <= -10)
493 factor10x = 170;
494 else if (temperature <= -5)
495 factor10x = 120;
496 else if (temperature <= 5)
497 factor10x = 80;
498 else if (temperature <= 10)
499 factor10x = 40;
500 else if (temperature <= 15)
501 factor10x = 30;
502 else if (temperature <= 20)
503 factor10x = 20;
504 else if (temperature <= 40)
505 factor10x = 10;
506 else
507 factor10x = 7;
508
509 epd->factored_stage_time = epd->stage_time * factor10x / 10;
510}
511
512static int repaper_fb_dirty(struct drm_framebuffer *fb,
513 struct drm_format_conv_state *fmtcnv_state)
514{
515 struct drm_gem_dma_object *dma_obj = drm_fb_dma_get_gem_obj(fb, 0);
516 struct repaper_epd *epd = drm_to_epd(fb->dev);
517 unsigned int dst_pitch = 0;
518 struct iosys_map dst, vmap;
519 struct drm_rect clip;
520 int idx, ret = 0;
521 u8 *buf = NULL;
522
523 if (!drm_dev_enter(fb->dev, &idx))
524 return -ENODEV;
525
526 /* repaper can't do partial updates */
527 clip.x1 = 0;
528 clip.x2 = fb->width;
529 clip.y1 = 0;
530 clip.y2 = fb->height;
531
532 repaper_get_temperature(epd);
533
534 DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id,
535 epd->factored_stage_time);
536
537 buf = kmalloc(fb->width * fb->height / 8, GFP_KERNEL);
538 if (!buf) {
539 ret = -ENOMEM;
540 goto out_exit;
541 }
542
543 ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
544 if (ret)
545 goto out_free;
546
547 iosys_map_set_vaddr(&dst, buf);
548 iosys_map_set_vaddr(&vmap, dma_obj->vaddr);
549 drm_fb_xrgb8888_to_mono(&dst, &dst_pitch, &vmap, fb, &clip, fmtcnv_state);
550
551 drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
552
553 if (epd->partial) {
554 repaper_frame_data_repeat(epd, buf, epd->current_frame,
555 REPAPER_NORMAL);
556 } else if (epd->cleared) {
557 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
558 REPAPER_COMPENSATE);
559 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
560 REPAPER_WHITE);
561 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
562 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
563
564 epd->partial = true;
565 } else {
566 /* Clear display (anything -> white) */
567 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_COMPENSATE);
568 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_WHITE);
569 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_INVERSE);
570 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_NORMAL);
571
572 /* Assuming a clear (white) screen output an image */
573 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_COMPENSATE);
574 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_WHITE);
575 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
576 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
577
578 epd->cleared = true;
579 epd->partial = true;
580 }
581
582 memcpy(epd->current_frame, buf, fb->width * fb->height / 8);
583
584 /*
585 * An extra frame write is needed if pixels are set in the bottom line,
586 * or else grey lines rises up from the pixels
587 */
588 if (epd->pre_border_byte) {
589 unsigned int x;
590
591 for (x = 0; x < (fb->width / 8); x++)
592 if (buf[x + (fb->width * (fb->height - 1) / 8)]) {
593 repaper_frame_data_repeat(epd, buf,
594 epd->current_frame,
595 REPAPER_NORMAL);
596 break;
597 }
598 }
599
600out_free:
601 kfree(buf);
602out_exit:
603 drm_dev_exit(idx);
604
605 return ret;
606}
607
608static void power_off(struct repaper_epd *epd)
609{
610 /* Turn off power and all signals */
611 gpiod_set_value_cansleep(epd->reset, 0);
612 gpiod_set_value_cansleep(epd->panel_on, 0);
613 if (epd->border)
614 gpiod_set_value_cansleep(epd->border, 0);
615
616 /* Ensure SPI MOSI and CLOCK are Low before CS Low */
617 repaper_spi_mosi_low(epd->spi);
618
619 /* Discharge pulse */
620 gpiod_set_value_cansleep(epd->discharge, 1);
621 msleep(150);
622 gpiod_set_value_cansleep(epd->discharge, 0);
623}
624
625static enum drm_mode_status repaper_pipe_mode_valid(struct drm_simple_display_pipe *pipe,
626 const struct drm_display_mode *mode)
627{
628 struct drm_crtc *crtc = &pipe->crtc;
629 struct repaper_epd *epd = drm_to_epd(crtc->dev);
630
631 return drm_crtc_helper_mode_valid_fixed(crtc, mode, epd->mode);
632}
633
634static void repaper_pipe_enable(struct drm_simple_display_pipe *pipe,
635 struct drm_crtc_state *crtc_state,
636 struct drm_plane_state *plane_state)
637{
638 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev);
639 struct spi_device *spi = epd->spi;
640 struct device *dev = &spi->dev;
641 bool dc_ok = false;
642 int i, ret, idx;
643
644 if (!drm_dev_enter(pipe->crtc.dev, &idx))
645 return;
646
647 DRM_DEBUG_DRIVER("\n");
648
649 /* Power up sequence */
650 gpiod_set_value_cansleep(epd->reset, 0);
651 gpiod_set_value_cansleep(epd->panel_on, 0);
652 gpiod_set_value_cansleep(epd->discharge, 0);
653 if (epd->border)
654 gpiod_set_value_cansleep(epd->border, 0);
655 repaper_spi_mosi_low(spi);
656 usleep_range(5000, 10000);
657
658 gpiod_set_value_cansleep(epd->panel_on, 1);
659 /*
660 * This delay comes from the repaper.org userspace driver, it's not
661 * mentioned in the datasheet.
662 */
663 usleep_range(10000, 15000);
664 gpiod_set_value_cansleep(epd->reset, 1);
665 if (epd->border)
666 gpiod_set_value_cansleep(epd->border, 1);
667 usleep_range(5000, 10000);
668 gpiod_set_value_cansleep(epd->reset, 0);
669 usleep_range(5000, 10000);
670 gpiod_set_value_cansleep(epd->reset, 1);
671 usleep_range(5000, 10000);
672
673 /* Wait for COG to become ready */
674 for (i = 100; i > 0; i--) {
675 if (!gpiod_get_value_cansleep(epd->busy))
676 break;
677
678 usleep_range(10, 100);
679 }
680
681 if (!i) {
682 DRM_DEV_ERROR(dev, "timeout waiting for panel to become ready.\n");
683 power_off(epd);
684 goto out_exit;
685 }
686
687 repaper_read_id(spi);
688 ret = repaper_read_id(spi);
689 if (ret != REPAPER_RID_G2_COG_ID) {
690 if (ret < 0)
691 dev_err(dev, "failed to read chip (%d)\n", ret);
692 else
693 dev_err(dev, "wrong COG ID 0x%02x\n", ret);
694 power_off(epd);
695 goto out_exit;
696 }
697
698 /* Disable OE */
699 repaper_write_val(spi, 0x02, 0x40);
700
701 ret = repaper_read_val(spi, 0x0f);
702 if (ret < 0 || !(ret & 0x80)) {
703 if (ret < 0)
704 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
705 else
706 DRM_DEV_ERROR(dev, "panel is reported broken\n");
707 power_off(epd);
708 goto out_exit;
709 }
710
711 /* Power saving mode */
712 repaper_write_val(spi, 0x0b, 0x02);
713 /* Channel select */
714 repaper_write_buf(spi, 0x01, epd->channel_select, 8);
715 /* High power mode osc */
716 repaper_write_val(spi, 0x07, 0xd1);
717 /* Power setting */
718 repaper_write_val(spi, 0x08, 0x02);
719 /* Vcom level */
720 repaper_write_val(spi, 0x09, 0xc2);
721 /* Power setting */
722 repaper_write_val(spi, 0x04, 0x03);
723 /* Driver latch on */
724 repaper_write_val(spi, 0x03, 0x01);
725 /* Driver latch off */
726 repaper_write_val(spi, 0x03, 0x00);
727 usleep_range(5000, 10000);
728
729 /* Start chargepump */
730 for (i = 0; i < 4; ++i) {
731 /* Charge pump positive voltage on - VGH/VDL on */
732 repaper_write_val(spi, 0x05, 0x01);
733 msleep(240);
734
735 /* Charge pump negative voltage on - VGL/VDL on */
736 repaper_write_val(spi, 0x05, 0x03);
737 msleep(40);
738
739 /* Charge pump Vcom on - Vcom driver on */
740 repaper_write_val(spi, 0x05, 0x0f);
741 msleep(40);
742
743 /* check DC/DC */
744 ret = repaper_read_val(spi, 0x0f);
745 if (ret < 0) {
746 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
747 power_off(epd);
748 goto out_exit;
749 }
750
751 if (ret & 0x40) {
752 dc_ok = true;
753 break;
754 }
755 }
756
757 if (!dc_ok) {
758 DRM_DEV_ERROR(dev, "dc/dc failed\n");
759 power_off(epd);
760 goto out_exit;
761 }
762
763 /*
764 * Output enable to disable
765 * The userspace driver sets this to 0x04, but the datasheet says 0x06
766 */
767 repaper_write_val(spi, 0x02, 0x04);
768
769 epd->partial = false;
770out_exit:
771 drm_dev_exit(idx);
772}
773
774static void repaper_pipe_disable(struct drm_simple_display_pipe *pipe)
775{
776 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev);
777 struct spi_device *spi = epd->spi;
778 unsigned int line;
779
780 /*
781 * This callback is not protected by drm_dev_enter/exit since we want to
782 * turn off the display on regular driver unload. It's highly unlikely
783 * that the underlying SPI controller is gone should this be called after
784 * unplug.
785 */
786
787 DRM_DEBUG_DRIVER("\n");
788
789 /* Nothing frame */
790 for (line = 0; line < epd->height; line++)
791 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
792 REPAPER_COMPENSATE);
793
794 /* 2.7" */
795 if (epd->border) {
796 /* Dummy line */
797 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
798 REPAPER_COMPENSATE);
799 msleep(25);
800 gpiod_set_value_cansleep(epd->border, 0);
801 msleep(200);
802 gpiod_set_value_cansleep(epd->border, 1);
803 } else {
804 /* Border dummy line */
805 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
806 REPAPER_NORMAL);
807 msleep(200);
808 }
809
810 /* not described in datasheet */
811 repaper_write_val(spi, 0x0b, 0x00);
812 /* Latch reset turn on */
813 repaper_write_val(spi, 0x03, 0x01);
814 /* Power off charge pump Vcom */
815 repaper_write_val(spi, 0x05, 0x03);
816 /* Power off charge pump neg voltage */
817 repaper_write_val(spi, 0x05, 0x01);
818 msleep(120);
819 /* Discharge internal */
820 repaper_write_val(spi, 0x04, 0x80);
821 /* turn off all charge pumps */
822 repaper_write_val(spi, 0x05, 0x00);
823 /* Turn off osc */
824 repaper_write_val(spi, 0x07, 0x01);
825 msleep(50);
826
827 power_off(epd);
828}
829
830static void repaper_pipe_update(struct drm_simple_display_pipe *pipe,
831 struct drm_plane_state *old_state)
832{
833 struct drm_plane_state *state = pipe->plane.state;
834 struct drm_format_conv_state fmtcnv_state = DRM_FORMAT_CONV_STATE_INIT;
835 struct drm_rect rect;
836
837 if (!pipe->crtc.state->active)
838 return;
839
840 if (drm_atomic_helper_damage_merged(old_state, state, &rect))
841 repaper_fb_dirty(state->fb, &fmtcnv_state);
842
843 drm_format_conv_state_release(&fmtcnv_state);
844}
845
846static const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = {
847 .mode_valid = repaper_pipe_mode_valid,
848 .enable = repaper_pipe_enable,
849 .disable = repaper_pipe_disable,
850 .update = repaper_pipe_update,
851};
852
853static int repaper_connector_get_modes(struct drm_connector *connector)
854{
855 struct repaper_epd *epd = drm_to_epd(connector->dev);
856
857 return drm_connector_helper_get_modes_fixed(connector, epd->mode);
858}
859
860static const struct drm_connector_helper_funcs repaper_connector_hfuncs = {
861 .get_modes = repaper_connector_get_modes,
862};
863
864static const struct drm_connector_funcs repaper_connector_funcs = {
865 .reset = drm_atomic_helper_connector_reset,
866 .fill_modes = drm_helper_probe_single_connector_modes,
867 .destroy = drm_connector_cleanup,
868 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
869 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
870};
871
872static const struct drm_mode_config_funcs repaper_mode_config_funcs = {
873 .fb_create = drm_gem_fb_create_with_dirty,
874 .atomic_check = drm_atomic_helper_check,
875 .atomic_commit = drm_atomic_helper_commit,
876};
877
878static const uint32_t repaper_formats[] = {
879 DRM_FORMAT_XRGB8888,
880};
881
882static const struct drm_display_mode repaper_e1144cs021_mode = {
883 DRM_SIMPLE_MODE(128, 96, 29, 22),
884};
885
886static const u8 repaper_e1144cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
887 0x00, 0x0f, 0xff, 0x00 };
888
889static const struct drm_display_mode repaper_e1190cs021_mode = {
890 DRM_SIMPLE_MODE(144, 128, 36, 32),
891};
892
893static const u8 repaper_e1190cs021_cs[] = { 0x00, 0x00, 0x00, 0x03,
894 0xfc, 0x00, 0x00, 0xff };
895
896static const struct drm_display_mode repaper_e2200cs021_mode = {
897 DRM_SIMPLE_MODE(200, 96, 46, 22),
898};
899
900static const u8 repaper_e2200cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
901 0x01, 0xff, 0xe0, 0x00 };
902
903static const struct drm_display_mode repaper_e2271cs021_mode = {
904 DRM_SIMPLE_MODE(264, 176, 57, 38),
905};
906
907static const u8 repaper_e2271cs021_cs[] = { 0x00, 0x00, 0x00, 0x7f,
908 0xff, 0xfe, 0x00, 0x00 };
909
910DEFINE_DRM_GEM_DMA_FOPS(repaper_fops);
911
912static const struct drm_driver repaper_driver = {
913 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
914 .fops = &repaper_fops,
915 DRM_GEM_DMA_DRIVER_OPS_VMAP,
916 .name = "repaper",
917 .desc = "Pervasive Displays RePaper e-ink panels",
918 .date = "20170405",
919 .major = 1,
920 .minor = 0,
921};
922
923static const struct of_device_id repaper_of_match[] = {
924 { .compatible = "pervasive,e1144cs021", .data = (void *)E1144CS021 },
925 { .compatible = "pervasive,e1190cs021", .data = (void *)E1190CS021 },
926 { .compatible = "pervasive,e2200cs021", .data = (void *)E2200CS021 },
927 { .compatible = "pervasive,e2271cs021", .data = (void *)E2271CS021 },
928 {},
929};
930MODULE_DEVICE_TABLE(of, repaper_of_match);
931
932static const struct spi_device_id repaper_id[] = {
933 { "e1144cs021", E1144CS021 },
934 { "e1190cs021", E1190CS021 },
935 { "e2200cs021", E2200CS021 },
936 { "e2271cs021", E2271CS021 },
937 { },
938};
939MODULE_DEVICE_TABLE(spi, repaper_id);
940
941static int repaper_probe(struct spi_device *spi)
942{
943 const struct drm_display_mode *mode;
944 const struct spi_device_id *spi_id;
945 struct device *dev = &spi->dev;
946 enum repaper_model model;
947 const char *thermal_zone;
948 struct repaper_epd *epd;
949 size_t line_buffer_size;
950 struct drm_device *drm;
951 const void *match;
952 int ret;
953
954 match = device_get_match_data(dev);
955 if (match) {
956 model = (enum repaper_model)(uintptr_t)match;
957 } else {
958 spi_id = spi_get_device_id(spi);
959 model = (enum repaper_model)spi_id->driver_data;
960 }
961
962 /* The SPI device is used to allocate dma memory */
963 if (!dev->coherent_dma_mask) {
964 ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
965 if (ret) {
966 dev_warn(dev, "Failed to set dma mask %d\n", ret);
967 return ret;
968 }
969 }
970
971 epd = devm_drm_dev_alloc(dev, &repaper_driver,
972 struct repaper_epd, drm);
973 if (IS_ERR(epd))
974 return PTR_ERR(epd);
975
976 drm = &epd->drm;
977
978 ret = drmm_mode_config_init(drm);
979 if (ret)
980 return ret;
981 drm->mode_config.funcs = &repaper_mode_config_funcs;
982
983 epd->spi = spi;
984
985 epd->panel_on = devm_gpiod_get(dev, "panel-on", GPIOD_OUT_LOW);
986 if (IS_ERR(epd->panel_on)) {
987 ret = PTR_ERR(epd->panel_on);
988 if (ret != -EPROBE_DEFER)
989 DRM_DEV_ERROR(dev, "Failed to get gpio 'panel-on'\n");
990 return ret;
991 }
992
993 epd->discharge = devm_gpiod_get(dev, "discharge", GPIOD_OUT_LOW);
994 if (IS_ERR(epd->discharge)) {
995 ret = PTR_ERR(epd->discharge);
996 if (ret != -EPROBE_DEFER)
997 DRM_DEV_ERROR(dev, "Failed to get gpio 'discharge'\n");
998 return ret;
999 }
1000
1001 epd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
1002 if (IS_ERR(epd->reset)) {
1003 ret = PTR_ERR(epd->reset);
1004 if (ret != -EPROBE_DEFER)
1005 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
1006 return ret;
1007 }
1008
1009 epd->busy = devm_gpiod_get(dev, "busy", GPIOD_IN);
1010 if (IS_ERR(epd->busy)) {
1011 ret = PTR_ERR(epd->busy);
1012 if (ret != -EPROBE_DEFER)
1013 DRM_DEV_ERROR(dev, "Failed to get gpio 'busy'\n");
1014 return ret;
1015 }
1016
1017 if (!device_property_read_string(dev, "pervasive,thermal-zone",
1018 &thermal_zone)) {
1019 epd->thermal = thermal_zone_get_zone_by_name(thermal_zone);
1020 if (IS_ERR(epd->thermal)) {
1021 DRM_DEV_ERROR(dev, "Failed to get thermal zone: %s\n", thermal_zone);
1022 return PTR_ERR(epd->thermal);
1023 }
1024 }
1025
1026 switch (model) {
1027 case E1144CS021:
1028 mode = &repaper_e1144cs021_mode;
1029 epd->channel_select = repaper_e1144cs021_cs;
1030 epd->stage_time = 480;
1031 epd->bytes_per_scan = 96 / 4;
1032 epd->middle_scan = true; /* data-scan-data */
1033 epd->pre_border_byte = false;
1034 epd->border_byte = REPAPER_BORDER_BYTE_ZERO;
1035 break;
1036
1037 case E1190CS021:
1038 mode = &repaper_e1190cs021_mode;
1039 epd->channel_select = repaper_e1190cs021_cs;
1040 epd->stage_time = 480;
1041 epd->bytes_per_scan = 128 / 4 / 2;
1042 epd->middle_scan = false; /* scan-data-scan */
1043 epd->pre_border_byte = false;
1044 epd->border_byte = REPAPER_BORDER_BYTE_SET;
1045 break;
1046
1047 case E2200CS021:
1048 mode = &repaper_e2200cs021_mode;
1049 epd->channel_select = repaper_e2200cs021_cs;
1050 epd->stage_time = 480;
1051 epd->bytes_per_scan = 96 / 4;
1052 epd->middle_scan = true; /* data-scan-data */
1053 epd->pre_border_byte = true;
1054 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1055 break;
1056
1057 case E2271CS021:
1058 epd->border = devm_gpiod_get(dev, "border", GPIOD_OUT_LOW);
1059 if (IS_ERR(epd->border)) {
1060 ret = PTR_ERR(epd->border);
1061 if (ret != -EPROBE_DEFER)
1062 DRM_DEV_ERROR(dev, "Failed to get gpio 'border'\n");
1063 return ret;
1064 }
1065
1066 mode = &repaper_e2271cs021_mode;
1067 epd->channel_select = repaper_e2271cs021_cs;
1068 epd->stage_time = 630;
1069 epd->bytes_per_scan = 176 / 4;
1070 epd->middle_scan = true; /* data-scan-data */
1071 epd->pre_border_byte = true;
1072 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1073 break;
1074
1075 default:
1076 return -ENODEV;
1077 }
1078
1079 epd->mode = mode;
1080 epd->width = mode->hdisplay;
1081 epd->height = mode->vdisplay;
1082 epd->factored_stage_time = epd->stage_time;
1083
1084 line_buffer_size = 2 * epd->width / 8 + epd->bytes_per_scan + 2;
1085 epd->line_buffer = devm_kzalloc(dev, line_buffer_size, GFP_KERNEL);
1086 if (!epd->line_buffer)
1087 return -ENOMEM;
1088
1089 epd->current_frame = devm_kzalloc(dev, epd->width * epd->height / 8,
1090 GFP_KERNEL);
1091 if (!epd->current_frame)
1092 return -ENOMEM;
1093
1094 drm->mode_config.min_width = mode->hdisplay;
1095 drm->mode_config.max_width = mode->hdisplay;
1096 drm->mode_config.min_height = mode->vdisplay;
1097 drm->mode_config.max_height = mode->vdisplay;
1098
1099 drm_connector_helper_add(&epd->connector, &repaper_connector_hfuncs);
1100 ret = drm_connector_init(drm, &epd->connector, &repaper_connector_funcs,
1101 DRM_MODE_CONNECTOR_SPI);
1102 if (ret)
1103 return ret;
1104
1105 ret = drm_simple_display_pipe_init(drm, &epd->pipe, &repaper_pipe_funcs,
1106 repaper_formats, ARRAY_SIZE(repaper_formats),
1107 NULL, &epd->connector);
1108 if (ret)
1109 return ret;
1110
1111 drm_mode_config_reset(drm);
1112
1113 ret = drm_dev_register(drm, 0);
1114 if (ret)
1115 return ret;
1116
1117 spi_set_drvdata(spi, drm);
1118
1119 DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000);
1120
1121 drm_fbdev_generic_setup(drm, 0);
1122
1123 return 0;
1124}
1125
1126static void repaper_remove(struct spi_device *spi)
1127{
1128 struct drm_device *drm = spi_get_drvdata(spi);
1129
1130 drm_dev_unplug(drm);
1131 drm_atomic_helper_shutdown(drm);
1132}
1133
1134static void repaper_shutdown(struct spi_device *spi)
1135{
1136 drm_atomic_helper_shutdown(spi_get_drvdata(spi));
1137}
1138
1139static struct spi_driver repaper_spi_driver = {
1140 .driver = {
1141 .name = "repaper",
1142 .of_match_table = repaper_of_match,
1143 },
1144 .id_table = repaper_id,
1145 .probe = repaper_probe,
1146 .remove = repaper_remove,
1147 .shutdown = repaper_shutdown,
1148};
1149module_spi_driver(repaper_spi_driver);
1150
1151MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver");
1152MODULE_AUTHOR("Noralf Trønnes");
1153MODULE_LICENSE("GPL");