Loading...
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");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * DRM driver for Pervasive Displays RePaper branded e-ink panels
4 *
5 * Copyright 2013-2017 Pervasive Displays, Inc.
6 * Copyright 2017 Noralf Trønnes
7 *
8 * The driver supports:
9 * Material Film: Aurora Mb (V231)
10 * Driver IC: G2 (eTC)
11 *
12 * The controller code was taken from the userspace driver:
13 * https://github.com/repaper/gratis
14 */
15
16#include <linux/delay.h>
17#include <linux/dma-buf.h>
18#include <linux/gpio/consumer.h>
19#include <linux/module.h>
20#include <linux/property.h>
21#include <linux/sched/clock.h>
22#include <linux/spi/spi.h>
23#include <linux/thermal.h>
24
25#include <drm/drm_atomic_helper.h>
26#include <drm/drm_connector.h>
27#include <drm/drm_damage_helper.h>
28#include <drm/drm_drv.h>
29#include <drm/drm_fb_cma_helper.h>
30#include <drm/drm_fb_helper.h>
31#include <drm/drm_format_helper.h>
32#include <drm/drm_gem_atomic_helper.h>
33#include <drm/drm_gem_cma_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 void repaper_gray8_to_mono_reversed(u8 *buf, u32 width, u32 height)
513{
514 u8 *gray8 = buf, *mono = buf;
515 int y, xb, i;
516
517 for (y = 0; y < height; y++)
518 for (xb = 0; xb < width / 8; xb++) {
519 u8 byte = 0x00;
520
521 for (i = 0; i < 8; i++) {
522 int x = xb * 8 + i;
523
524 byte >>= 1;
525 if (gray8[y * width + x] >> 7)
526 byte |= BIT(7);
527 }
528 *mono++ = byte;
529 }
530}
531
532static int repaper_fb_dirty(struct drm_framebuffer *fb)
533{
534 struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
535 struct dma_buf_attachment *import_attach = cma_obj->base.import_attach;
536 struct repaper_epd *epd = drm_to_epd(fb->dev);
537 struct drm_rect clip;
538 int idx, ret = 0;
539 u8 *buf = NULL;
540
541 if (!drm_dev_enter(fb->dev, &idx))
542 return -ENODEV;
543
544 /* repaper can't do partial updates */
545 clip.x1 = 0;
546 clip.x2 = fb->width;
547 clip.y1 = 0;
548 clip.y2 = fb->height;
549
550 repaper_get_temperature(epd);
551
552 DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id,
553 epd->factored_stage_time);
554
555 buf = kmalloc_array(fb->width, fb->height, GFP_KERNEL);
556 if (!buf) {
557 ret = -ENOMEM;
558 goto out_exit;
559 }
560
561 if (import_attach) {
562 ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
563 DMA_FROM_DEVICE);
564 if (ret)
565 goto out_free;
566 }
567
568 drm_fb_xrgb8888_to_gray8(buf, cma_obj->vaddr, fb, &clip);
569
570 if (import_attach) {
571 ret = dma_buf_end_cpu_access(import_attach->dmabuf,
572 DMA_FROM_DEVICE);
573 if (ret)
574 goto out_free;
575 }
576
577 repaper_gray8_to_mono_reversed(buf, fb->width, fb->height);
578
579 if (epd->partial) {
580 repaper_frame_data_repeat(epd, buf, epd->current_frame,
581 REPAPER_NORMAL);
582 } else if (epd->cleared) {
583 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
584 REPAPER_COMPENSATE);
585 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
586 REPAPER_WHITE);
587 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
588 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
589
590 epd->partial = true;
591 } else {
592 /* Clear display (anything -> white) */
593 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_COMPENSATE);
594 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_WHITE);
595 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_INVERSE);
596 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_NORMAL);
597
598 /* Assuming a clear (white) screen output an image */
599 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_COMPENSATE);
600 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_WHITE);
601 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
602 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
603
604 epd->cleared = true;
605 epd->partial = true;
606 }
607
608 memcpy(epd->current_frame, buf, fb->width * fb->height / 8);
609
610 /*
611 * An extra frame write is needed if pixels are set in the bottom line,
612 * or else grey lines rises up from the pixels
613 */
614 if (epd->pre_border_byte) {
615 unsigned int x;
616
617 for (x = 0; x < (fb->width / 8); x++)
618 if (buf[x + (fb->width * (fb->height - 1) / 8)]) {
619 repaper_frame_data_repeat(epd, buf,
620 epd->current_frame,
621 REPAPER_NORMAL);
622 break;
623 }
624 }
625
626out_free:
627 kfree(buf);
628out_exit:
629 drm_dev_exit(idx);
630
631 return ret;
632}
633
634static void power_off(struct repaper_epd *epd)
635{
636 /* Turn off power and all signals */
637 gpiod_set_value_cansleep(epd->reset, 0);
638 gpiod_set_value_cansleep(epd->panel_on, 0);
639 if (epd->border)
640 gpiod_set_value_cansleep(epd->border, 0);
641
642 /* Ensure SPI MOSI and CLOCK are Low before CS Low */
643 repaper_spi_mosi_low(epd->spi);
644
645 /* Discharge pulse */
646 gpiod_set_value_cansleep(epd->discharge, 1);
647 msleep(150);
648 gpiod_set_value_cansleep(epd->discharge, 0);
649}
650
651static void repaper_pipe_enable(struct drm_simple_display_pipe *pipe,
652 struct drm_crtc_state *crtc_state,
653 struct drm_plane_state *plane_state)
654{
655 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev);
656 struct spi_device *spi = epd->spi;
657 struct device *dev = &spi->dev;
658 bool dc_ok = false;
659 int i, ret, idx;
660
661 if (!drm_dev_enter(pipe->crtc.dev, &idx))
662 return;
663
664 DRM_DEBUG_DRIVER("\n");
665
666 /* Power up sequence */
667 gpiod_set_value_cansleep(epd->reset, 0);
668 gpiod_set_value_cansleep(epd->panel_on, 0);
669 gpiod_set_value_cansleep(epd->discharge, 0);
670 if (epd->border)
671 gpiod_set_value_cansleep(epd->border, 0);
672 repaper_spi_mosi_low(spi);
673 usleep_range(5000, 10000);
674
675 gpiod_set_value_cansleep(epd->panel_on, 1);
676 /*
677 * This delay comes from the repaper.org userspace driver, it's not
678 * mentioned in the datasheet.
679 */
680 usleep_range(10000, 15000);
681 gpiod_set_value_cansleep(epd->reset, 1);
682 if (epd->border)
683 gpiod_set_value_cansleep(epd->border, 1);
684 usleep_range(5000, 10000);
685 gpiod_set_value_cansleep(epd->reset, 0);
686 usleep_range(5000, 10000);
687 gpiod_set_value_cansleep(epd->reset, 1);
688 usleep_range(5000, 10000);
689
690 /* Wait for COG to become ready */
691 for (i = 100; i > 0; i--) {
692 if (!gpiod_get_value_cansleep(epd->busy))
693 break;
694
695 usleep_range(10, 100);
696 }
697
698 if (!i) {
699 DRM_DEV_ERROR(dev, "timeout waiting for panel to become ready.\n");
700 power_off(epd);
701 goto out_exit;
702 }
703
704 repaper_read_id(spi);
705 ret = repaper_read_id(spi);
706 if (ret != REPAPER_RID_G2_COG_ID) {
707 if (ret < 0)
708 dev_err(dev, "failed to read chip (%d)\n", ret);
709 else
710 dev_err(dev, "wrong COG ID 0x%02x\n", ret);
711 power_off(epd);
712 goto out_exit;
713 }
714
715 /* Disable OE */
716 repaper_write_val(spi, 0x02, 0x40);
717
718 ret = repaper_read_val(spi, 0x0f);
719 if (ret < 0 || !(ret & 0x80)) {
720 if (ret < 0)
721 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
722 else
723 DRM_DEV_ERROR(dev, "panel is reported broken\n");
724 power_off(epd);
725 goto out_exit;
726 }
727
728 /* Power saving mode */
729 repaper_write_val(spi, 0x0b, 0x02);
730 /* Channel select */
731 repaper_write_buf(spi, 0x01, epd->channel_select, 8);
732 /* High power mode osc */
733 repaper_write_val(spi, 0x07, 0xd1);
734 /* Power setting */
735 repaper_write_val(spi, 0x08, 0x02);
736 /* Vcom level */
737 repaper_write_val(spi, 0x09, 0xc2);
738 /* Power setting */
739 repaper_write_val(spi, 0x04, 0x03);
740 /* Driver latch on */
741 repaper_write_val(spi, 0x03, 0x01);
742 /* Driver latch off */
743 repaper_write_val(spi, 0x03, 0x00);
744 usleep_range(5000, 10000);
745
746 /* Start chargepump */
747 for (i = 0; i < 4; ++i) {
748 /* Charge pump positive voltage on - VGH/VDL on */
749 repaper_write_val(spi, 0x05, 0x01);
750 msleep(240);
751
752 /* Charge pump negative voltage on - VGL/VDL on */
753 repaper_write_val(spi, 0x05, 0x03);
754 msleep(40);
755
756 /* Charge pump Vcom on - Vcom driver on */
757 repaper_write_val(spi, 0x05, 0x0f);
758 msleep(40);
759
760 /* check DC/DC */
761 ret = repaper_read_val(spi, 0x0f);
762 if (ret < 0) {
763 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
764 power_off(epd);
765 goto out_exit;
766 }
767
768 if (ret & 0x40) {
769 dc_ok = true;
770 break;
771 }
772 }
773
774 if (!dc_ok) {
775 DRM_DEV_ERROR(dev, "dc/dc failed\n");
776 power_off(epd);
777 goto out_exit;
778 }
779
780 /*
781 * Output enable to disable
782 * The userspace driver sets this to 0x04, but the datasheet says 0x06
783 */
784 repaper_write_val(spi, 0x02, 0x04);
785
786 epd->partial = false;
787out_exit:
788 drm_dev_exit(idx);
789}
790
791static void repaper_pipe_disable(struct drm_simple_display_pipe *pipe)
792{
793 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev);
794 struct spi_device *spi = epd->spi;
795 unsigned int line;
796
797 /*
798 * This callback is not protected by drm_dev_enter/exit since we want to
799 * turn off the display on regular driver unload. It's highly unlikely
800 * that the underlying SPI controller is gone should this be called after
801 * unplug.
802 */
803
804 DRM_DEBUG_DRIVER("\n");
805
806 /* Nothing frame */
807 for (line = 0; line < epd->height; line++)
808 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
809 REPAPER_COMPENSATE);
810
811 /* 2.7" */
812 if (epd->border) {
813 /* Dummy line */
814 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
815 REPAPER_COMPENSATE);
816 msleep(25);
817 gpiod_set_value_cansleep(epd->border, 0);
818 msleep(200);
819 gpiod_set_value_cansleep(epd->border, 1);
820 } else {
821 /* Border dummy line */
822 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
823 REPAPER_NORMAL);
824 msleep(200);
825 }
826
827 /* not described in datasheet */
828 repaper_write_val(spi, 0x0b, 0x00);
829 /* Latch reset turn on */
830 repaper_write_val(spi, 0x03, 0x01);
831 /* Power off charge pump Vcom */
832 repaper_write_val(spi, 0x05, 0x03);
833 /* Power off charge pump neg voltage */
834 repaper_write_val(spi, 0x05, 0x01);
835 msleep(120);
836 /* Discharge internal */
837 repaper_write_val(spi, 0x04, 0x80);
838 /* turn off all charge pumps */
839 repaper_write_val(spi, 0x05, 0x00);
840 /* Turn off osc */
841 repaper_write_val(spi, 0x07, 0x01);
842 msleep(50);
843
844 power_off(epd);
845}
846
847static void repaper_pipe_update(struct drm_simple_display_pipe *pipe,
848 struct drm_plane_state *old_state)
849{
850 struct drm_plane_state *state = pipe->plane.state;
851 struct drm_rect rect;
852
853 if (!pipe->crtc.state->active)
854 return;
855
856 if (drm_atomic_helper_damage_merged(old_state, state, &rect))
857 repaper_fb_dirty(state->fb);
858}
859
860static const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = {
861 .enable = repaper_pipe_enable,
862 .disable = repaper_pipe_disable,
863 .update = repaper_pipe_update,
864 .prepare_fb = drm_gem_simple_display_pipe_prepare_fb,
865};
866
867static int repaper_connector_get_modes(struct drm_connector *connector)
868{
869 struct repaper_epd *epd = drm_to_epd(connector->dev);
870 struct drm_display_mode *mode;
871
872 mode = drm_mode_duplicate(connector->dev, epd->mode);
873 if (!mode) {
874 DRM_ERROR("Failed to duplicate mode\n");
875 return 0;
876 }
877
878 drm_mode_set_name(mode);
879 mode->type |= DRM_MODE_TYPE_PREFERRED;
880 drm_mode_probed_add(connector, mode);
881
882 connector->display_info.width_mm = mode->width_mm;
883 connector->display_info.height_mm = mode->height_mm;
884
885 return 1;
886}
887
888static const struct drm_connector_helper_funcs repaper_connector_hfuncs = {
889 .get_modes = repaper_connector_get_modes,
890};
891
892static const struct drm_connector_funcs repaper_connector_funcs = {
893 .reset = drm_atomic_helper_connector_reset,
894 .fill_modes = drm_helper_probe_single_connector_modes,
895 .destroy = drm_connector_cleanup,
896 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
897 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
898};
899
900static const struct drm_mode_config_funcs repaper_mode_config_funcs = {
901 .fb_create = drm_gem_fb_create_with_dirty,
902 .atomic_check = drm_atomic_helper_check,
903 .atomic_commit = drm_atomic_helper_commit,
904};
905
906static const uint32_t repaper_formats[] = {
907 DRM_FORMAT_XRGB8888,
908};
909
910static const struct drm_display_mode repaper_e1144cs021_mode = {
911 DRM_SIMPLE_MODE(128, 96, 29, 22),
912};
913
914static const u8 repaper_e1144cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
915 0x00, 0x0f, 0xff, 0x00 };
916
917static const struct drm_display_mode repaper_e1190cs021_mode = {
918 DRM_SIMPLE_MODE(144, 128, 36, 32),
919};
920
921static const u8 repaper_e1190cs021_cs[] = { 0x00, 0x00, 0x00, 0x03,
922 0xfc, 0x00, 0x00, 0xff };
923
924static const struct drm_display_mode repaper_e2200cs021_mode = {
925 DRM_SIMPLE_MODE(200, 96, 46, 22),
926};
927
928static const u8 repaper_e2200cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
929 0x01, 0xff, 0xe0, 0x00 };
930
931static const struct drm_display_mode repaper_e2271cs021_mode = {
932 DRM_SIMPLE_MODE(264, 176, 57, 38),
933};
934
935static const u8 repaper_e2271cs021_cs[] = { 0x00, 0x00, 0x00, 0x7f,
936 0xff, 0xfe, 0x00, 0x00 };
937
938DEFINE_DRM_GEM_CMA_FOPS(repaper_fops);
939
940static const struct drm_driver repaper_driver = {
941 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
942 .fops = &repaper_fops,
943 DRM_GEM_CMA_DRIVER_OPS_VMAP,
944 .name = "repaper",
945 .desc = "Pervasive Displays RePaper e-ink panels",
946 .date = "20170405",
947 .major = 1,
948 .minor = 0,
949};
950
951static const struct of_device_id repaper_of_match[] = {
952 { .compatible = "pervasive,e1144cs021", .data = (void *)E1144CS021 },
953 { .compatible = "pervasive,e1190cs021", .data = (void *)E1190CS021 },
954 { .compatible = "pervasive,e2200cs021", .data = (void *)E2200CS021 },
955 { .compatible = "pervasive,e2271cs021", .data = (void *)E2271CS021 },
956 {},
957};
958MODULE_DEVICE_TABLE(of, repaper_of_match);
959
960static const struct spi_device_id repaper_id[] = {
961 { "e1144cs021", E1144CS021 },
962 { "e1190cs021", E1190CS021 },
963 { "e2200cs021", E2200CS021 },
964 { "e2271cs021", E2271CS021 },
965 { },
966};
967MODULE_DEVICE_TABLE(spi, repaper_id);
968
969static int repaper_probe(struct spi_device *spi)
970{
971 const struct drm_display_mode *mode;
972 const struct spi_device_id *spi_id;
973 struct device *dev = &spi->dev;
974 enum repaper_model model;
975 const char *thermal_zone;
976 struct repaper_epd *epd;
977 size_t line_buffer_size;
978 struct drm_device *drm;
979 const void *match;
980 int ret;
981
982 match = device_get_match_data(dev);
983 if (match) {
984 model = (enum repaper_model)match;
985 } else {
986 spi_id = spi_get_device_id(spi);
987 model = (enum repaper_model)spi_id->driver_data;
988 }
989
990 /* The SPI device is used to allocate dma memory */
991 if (!dev->coherent_dma_mask) {
992 ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
993 if (ret) {
994 dev_warn(dev, "Failed to set dma mask %d\n", ret);
995 return ret;
996 }
997 }
998
999 epd = devm_drm_dev_alloc(dev, &repaper_driver,
1000 struct repaper_epd, drm);
1001 if (IS_ERR(epd))
1002 return PTR_ERR(epd);
1003
1004 drm = &epd->drm;
1005
1006 ret = drmm_mode_config_init(drm);
1007 if (ret)
1008 return ret;
1009 drm->mode_config.funcs = &repaper_mode_config_funcs;
1010
1011 epd->spi = spi;
1012
1013 epd->panel_on = devm_gpiod_get(dev, "panel-on", GPIOD_OUT_LOW);
1014 if (IS_ERR(epd->panel_on)) {
1015 ret = PTR_ERR(epd->panel_on);
1016 if (ret != -EPROBE_DEFER)
1017 DRM_DEV_ERROR(dev, "Failed to get gpio 'panel-on'\n");
1018 return ret;
1019 }
1020
1021 epd->discharge = devm_gpiod_get(dev, "discharge", GPIOD_OUT_LOW);
1022 if (IS_ERR(epd->discharge)) {
1023 ret = PTR_ERR(epd->discharge);
1024 if (ret != -EPROBE_DEFER)
1025 DRM_DEV_ERROR(dev, "Failed to get gpio 'discharge'\n");
1026 return ret;
1027 }
1028
1029 epd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
1030 if (IS_ERR(epd->reset)) {
1031 ret = PTR_ERR(epd->reset);
1032 if (ret != -EPROBE_DEFER)
1033 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
1034 return ret;
1035 }
1036
1037 epd->busy = devm_gpiod_get(dev, "busy", GPIOD_IN);
1038 if (IS_ERR(epd->busy)) {
1039 ret = PTR_ERR(epd->busy);
1040 if (ret != -EPROBE_DEFER)
1041 DRM_DEV_ERROR(dev, "Failed to get gpio 'busy'\n");
1042 return ret;
1043 }
1044
1045 if (!device_property_read_string(dev, "pervasive,thermal-zone",
1046 &thermal_zone)) {
1047 epd->thermal = thermal_zone_get_zone_by_name(thermal_zone);
1048 if (IS_ERR(epd->thermal)) {
1049 DRM_DEV_ERROR(dev, "Failed to get thermal zone: %s\n", thermal_zone);
1050 return PTR_ERR(epd->thermal);
1051 }
1052 }
1053
1054 switch (model) {
1055 case E1144CS021:
1056 mode = &repaper_e1144cs021_mode;
1057 epd->channel_select = repaper_e1144cs021_cs;
1058 epd->stage_time = 480;
1059 epd->bytes_per_scan = 96 / 4;
1060 epd->middle_scan = true; /* data-scan-data */
1061 epd->pre_border_byte = false;
1062 epd->border_byte = REPAPER_BORDER_BYTE_ZERO;
1063 break;
1064
1065 case E1190CS021:
1066 mode = &repaper_e1190cs021_mode;
1067 epd->channel_select = repaper_e1190cs021_cs;
1068 epd->stage_time = 480;
1069 epd->bytes_per_scan = 128 / 4 / 2;
1070 epd->middle_scan = false; /* scan-data-scan */
1071 epd->pre_border_byte = false;
1072 epd->border_byte = REPAPER_BORDER_BYTE_SET;
1073 break;
1074
1075 case E2200CS021:
1076 mode = &repaper_e2200cs021_mode;
1077 epd->channel_select = repaper_e2200cs021_cs;
1078 epd->stage_time = 480;
1079 epd->bytes_per_scan = 96 / 4;
1080 epd->middle_scan = true; /* data-scan-data */
1081 epd->pre_border_byte = true;
1082 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1083 break;
1084
1085 case E2271CS021:
1086 epd->border = devm_gpiod_get(dev, "border", GPIOD_OUT_LOW);
1087 if (IS_ERR(epd->border)) {
1088 ret = PTR_ERR(epd->border);
1089 if (ret != -EPROBE_DEFER)
1090 DRM_DEV_ERROR(dev, "Failed to get gpio 'border'\n");
1091 return ret;
1092 }
1093
1094 mode = &repaper_e2271cs021_mode;
1095 epd->channel_select = repaper_e2271cs021_cs;
1096 epd->stage_time = 630;
1097 epd->bytes_per_scan = 176 / 4;
1098 epd->middle_scan = true; /* data-scan-data */
1099 epd->pre_border_byte = true;
1100 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1101 break;
1102
1103 default:
1104 return -ENODEV;
1105 }
1106
1107 epd->mode = mode;
1108 epd->width = mode->hdisplay;
1109 epd->height = mode->vdisplay;
1110 epd->factored_stage_time = epd->stage_time;
1111
1112 line_buffer_size = 2 * epd->width / 8 + epd->bytes_per_scan + 2;
1113 epd->line_buffer = devm_kzalloc(dev, line_buffer_size, GFP_KERNEL);
1114 if (!epd->line_buffer)
1115 return -ENOMEM;
1116
1117 epd->current_frame = devm_kzalloc(dev, epd->width * epd->height / 8,
1118 GFP_KERNEL);
1119 if (!epd->current_frame)
1120 return -ENOMEM;
1121
1122 drm->mode_config.min_width = mode->hdisplay;
1123 drm->mode_config.max_width = mode->hdisplay;
1124 drm->mode_config.min_height = mode->vdisplay;
1125 drm->mode_config.max_height = mode->vdisplay;
1126
1127 drm_connector_helper_add(&epd->connector, &repaper_connector_hfuncs);
1128 ret = drm_connector_init(drm, &epd->connector, &repaper_connector_funcs,
1129 DRM_MODE_CONNECTOR_SPI);
1130 if (ret)
1131 return ret;
1132
1133 ret = drm_simple_display_pipe_init(drm, &epd->pipe, &repaper_pipe_funcs,
1134 repaper_formats, ARRAY_SIZE(repaper_formats),
1135 NULL, &epd->connector);
1136 if (ret)
1137 return ret;
1138
1139 drm_mode_config_reset(drm);
1140
1141 ret = drm_dev_register(drm, 0);
1142 if (ret)
1143 return ret;
1144
1145 spi_set_drvdata(spi, drm);
1146
1147 DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000);
1148
1149 drm_fbdev_generic_setup(drm, 0);
1150
1151 return 0;
1152}
1153
1154static int repaper_remove(struct spi_device *spi)
1155{
1156 struct drm_device *drm = spi_get_drvdata(spi);
1157
1158 drm_dev_unplug(drm);
1159 drm_atomic_helper_shutdown(drm);
1160
1161 return 0;
1162}
1163
1164static void repaper_shutdown(struct spi_device *spi)
1165{
1166 drm_atomic_helper_shutdown(spi_get_drvdata(spi));
1167}
1168
1169static struct spi_driver repaper_spi_driver = {
1170 .driver = {
1171 .name = "repaper",
1172 .of_match_table = repaper_of_match,
1173 },
1174 .id_table = repaper_id,
1175 .probe = repaper_probe,
1176 .remove = repaper_remove,
1177 .shutdown = repaper_shutdown,
1178};
1179module_spi_driver(repaper_spi_driver);
1180
1181MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver");
1182MODULE_AUTHOR("Noralf Trønnes");
1183MODULE_LICENSE("GPL");