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_fb_helper.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
43 enum repaper_model {
44 /* 0 is reserved to avoid clashing with NULL */
45 E1144CS021 = 1,
46 E1190CS021,
47 E2200CS021,
48 E2271CS021,
49 };
50
51 enum 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
58 enum repaper_epd_border_byte {
59 REPAPER_BORDER_BYTE_NONE,
60 REPAPER_BORDER_BYTE_ZERO,
61 REPAPER_BORDER_BYTE_SET,
62 };
63
64 struct 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
drm_to_epd(struct drm_device * drm)96 static inline struct repaper_epd *drm_to_epd(struct drm_device *drm)
97 {
98 return container_of(drm, struct repaper_epd, drm);
99 }
100
repaper_spi_transfer(struct spi_device * spi,u8 header,const void * tx,void * rx,size_t len)101 static 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
143 out_free:
144 kfree(headerbuf);
145 kfree(txbuf);
146 kfree(rxbuf);
147
148 return ret;
149 }
150
repaper_write_buf(struct spi_device * spi,u8 reg,const u8 * buf,size_t len)151 static 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
repaper_write_val(struct spi_device * spi,u8 reg,u8 val)163 static int repaper_write_val(struct spi_device *spi, u8 reg, u8 val)
164 {
165 return repaper_write_buf(spi, reg, &val, 1);
166 }
167
repaper_read_val(struct spi_device * spi,u8 reg)168 static 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
repaper_read_id(struct spi_device * spi)182 static 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
repaper_spi_mosi_low(struct spi_device * spi)192 static 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,... */
repaper_even_pixels(struct repaper_epd * epd,u8 ** pp,const u8 * data,u8 fixed_value,const u8 * mask,enum repaper_stage stage)200 static 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,... */
repaper_odd_pixels(struct repaper_epd * epd,u8 ** pp,const u8 * data,u8 fixed_value,const u8 * mask,enum repaper_stage stage)246 static 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 */
repaper_interleave_bits(u16 value)286 static 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 */
repaper_all_pixels(struct repaper_epd * epd,u8 ** pp,const u8 * data,u8 fixed_value,const u8 * mask,enum repaper_stage stage)296 static 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 */
repaper_one_line(struct repaper_epd * epd,unsigned int line,const u8 * data,u8 fixed_value,const u8 * mask,enum repaper_stage stage)340 static 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
repaper_frame_fixed(struct repaper_epd * epd,u8 fixed_value,enum repaper_stage stage)424 static 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
repaper_frame_data(struct repaper_epd * epd,const u8 * image,const u8 * mask,enum repaper_stage stage)433 static 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
repaper_frame_fixed_repeat(struct repaper_epd * epd,u8 fixed_value,enum repaper_stage stage)454 static 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
repaper_frame_data_repeat(struct repaper_epd * epd,const u8 * image,const u8 * mask,enum repaper_stage stage)465 static 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
repaper_get_temperature(struct repaper_epd * epd)476 static 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
repaper_fb_dirty(struct drm_framebuffer * fb)512 static int repaper_fb_dirty(struct drm_framebuffer *fb)
513 {
514 struct drm_gem_dma_object *dma_obj = drm_fb_dma_get_gem_obj(fb, 0);
515 struct repaper_epd *epd = drm_to_epd(fb->dev);
516 unsigned int dst_pitch = 0;
517 struct iosys_map dst, vmap;
518 struct drm_rect clip;
519 int idx, ret = 0;
520 u8 *buf = NULL;
521
522 if (!drm_dev_enter(fb->dev, &idx))
523 return -ENODEV;
524
525 /* repaper can't do partial updates */
526 clip.x1 = 0;
527 clip.x2 = fb->width;
528 clip.y1 = 0;
529 clip.y2 = fb->height;
530
531 repaper_get_temperature(epd);
532
533 DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id,
534 epd->factored_stage_time);
535
536 buf = kmalloc_array(fb->width, fb->height, GFP_KERNEL);
537 if (!buf) {
538 ret = -ENOMEM;
539 goto out_exit;
540 }
541
542 ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
543 if (ret)
544 goto out_free;
545
546 iosys_map_set_vaddr(&dst, buf);
547 iosys_map_set_vaddr(&vmap, dma_obj->vaddr);
548 drm_fb_xrgb8888_to_mono(&dst, &dst_pitch, &vmap, fb, &clip);
549
550 drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
551
552 if (epd->partial) {
553 repaper_frame_data_repeat(epd, buf, epd->current_frame,
554 REPAPER_NORMAL);
555 } else if (epd->cleared) {
556 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
557 REPAPER_COMPENSATE);
558 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
559 REPAPER_WHITE);
560 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
561 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
562
563 epd->partial = true;
564 } else {
565 /* Clear display (anything -> white) */
566 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_COMPENSATE);
567 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_WHITE);
568 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_INVERSE);
569 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_NORMAL);
570
571 /* Assuming a clear (white) screen output an image */
572 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_COMPENSATE);
573 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_WHITE);
574 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
575 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
576
577 epd->cleared = true;
578 epd->partial = true;
579 }
580
581 memcpy(epd->current_frame, buf, fb->width * fb->height / 8);
582
583 /*
584 * An extra frame write is needed if pixels are set in the bottom line,
585 * or else grey lines rises up from the pixels
586 */
587 if (epd->pre_border_byte) {
588 unsigned int x;
589
590 for (x = 0; x < (fb->width / 8); x++)
591 if (buf[x + (fb->width * (fb->height - 1) / 8)]) {
592 repaper_frame_data_repeat(epd, buf,
593 epd->current_frame,
594 REPAPER_NORMAL);
595 break;
596 }
597 }
598
599 out_free:
600 kfree(buf);
601 out_exit:
602 drm_dev_exit(idx);
603
604 return ret;
605 }
606
power_off(struct repaper_epd * epd)607 static void power_off(struct repaper_epd *epd)
608 {
609 /* Turn off power and all signals */
610 gpiod_set_value_cansleep(epd->reset, 0);
611 gpiod_set_value_cansleep(epd->panel_on, 0);
612 if (epd->border)
613 gpiod_set_value_cansleep(epd->border, 0);
614
615 /* Ensure SPI MOSI and CLOCK are Low before CS Low */
616 repaper_spi_mosi_low(epd->spi);
617
618 /* Discharge pulse */
619 gpiod_set_value_cansleep(epd->discharge, 1);
620 msleep(150);
621 gpiod_set_value_cansleep(epd->discharge, 0);
622 }
623
repaper_pipe_mode_valid(struct drm_simple_display_pipe * pipe,const struct drm_display_mode * mode)624 static enum drm_mode_status repaper_pipe_mode_valid(struct drm_simple_display_pipe *pipe,
625 const struct drm_display_mode *mode)
626 {
627 struct drm_crtc *crtc = &pipe->crtc;
628 struct repaper_epd *epd = drm_to_epd(crtc->dev);
629
630 return drm_crtc_helper_mode_valid_fixed(crtc, mode, epd->mode);
631 }
632
repaper_pipe_enable(struct drm_simple_display_pipe * pipe,struct drm_crtc_state * crtc_state,struct drm_plane_state * plane_state)633 static void repaper_pipe_enable(struct drm_simple_display_pipe *pipe,
634 struct drm_crtc_state *crtc_state,
635 struct drm_plane_state *plane_state)
636 {
637 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev);
638 struct spi_device *spi = epd->spi;
639 struct device *dev = &spi->dev;
640 bool dc_ok = false;
641 int i, ret, idx;
642
643 if (!drm_dev_enter(pipe->crtc.dev, &idx))
644 return;
645
646 DRM_DEBUG_DRIVER("\n");
647
648 /* Power up sequence */
649 gpiod_set_value_cansleep(epd->reset, 0);
650 gpiod_set_value_cansleep(epd->panel_on, 0);
651 gpiod_set_value_cansleep(epd->discharge, 0);
652 if (epd->border)
653 gpiod_set_value_cansleep(epd->border, 0);
654 repaper_spi_mosi_low(spi);
655 usleep_range(5000, 10000);
656
657 gpiod_set_value_cansleep(epd->panel_on, 1);
658 /*
659 * This delay comes from the repaper.org userspace driver, it's not
660 * mentioned in the datasheet.
661 */
662 usleep_range(10000, 15000);
663 gpiod_set_value_cansleep(epd->reset, 1);
664 if (epd->border)
665 gpiod_set_value_cansleep(epd->border, 1);
666 usleep_range(5000, 10000);
667 gpiod_set_value_cansleep(epd->reset, 0);
668 usleep_range(5000, 10000);
669 gpiod_set_value_cansleep(epd->reset, 1);
670 usleep_range(5000, 10000);
671
672 /* Wait for COG to become ready */
673 for (i = 100; i > 0; i--) {
674 if (!gpiod_get_value_cansleep(epd->busy))
675 break;
676
677 usleep_range(10, 100);
678 }
679
680 if (!i) {
681 DRM_DEV_ERROR(dev, "timeout waiting for panel to become ready.\n");
682 power_off(epd);
683 goto out_exit;
684 }
685
686 repaper_read_id(spi);
687 ret = repaper_read_id(spi);
688 if (ret != REPAPER_RID_G2_COG_ID) {
689 if (ret < 0)
690 dev_err(dev, "failed to read chip (%d)\n", ret);
691 else
692 dev_err(dev, "wrong COG ID 0x%02x\n", ret);
693 power_off(epd);
694 goto out_exit;
695 }
696
697 /* Disable OE */
698 repaper_write_val(spi, 0x02, 0x40);
699
700 ret = repaper_read_val(spi, 0x0f);
701 if (ret < 0 || !(ret & 0x80)) {
702 if (ret < 0)
703 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
704 else
705 DRM_DEV_ERROR(dev, "panel is reported broken\n");
706 power_off(epd);
707 goto out_exit;
708 }
709
710 /* Power saving mode */
711 repaper_write_val(spi, 0x0b, 0x02);
712 /* Channel select */
713 repaper_write_buf(spi, 0x01, epd->channel_select, 8);
714 /* High power mode osc */
715 repaper_write_val(spi, 0x07, 0xd1);
716 /* Power setting */
717 repaper_write_val(spi, 0x08, 0x02);
718 /* Vcom level */
719 repaper_write_val(spi, 0x09, 0xc2);
720 /* Power setting */
721 repaper_write_val(spi, 0x04, 0x03);
722 /* Driver latch on */
723 repaper_write_val(spi, 0x03, 0x01);
724 /* Driver latch off */
725 repaper_write_val(spi, 0x03, 0x00);
726 usleep_range(5000, 10000);
727
728 /* Start chargepump */
729 for (i = 0; i < 4; ++i) {
730 /* Charge pump positive voltage on - VGH/VDL on */
731 repaper_write_val(spi, 0x05, 0x01);
732 msleep(240);
733
734 /* Charge pump negative voltage on - VGL/VDL on */
735 repaper_write_val(spi, 0x05, 0x03);
736 msleep(40);
737
738 /* Charge pump Vcom on - Vcom driver on */
739 repaper_write_val(spi, 0x05, 0x0f);
740 msleep(40);
741
742 /* check DC/DC */
743 ret = repaper_read_val(spi, 0x0f);
744 if (ret < 0) {
745 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
746 power_off(epd);
747 goto out_exit;
748 }
749
750 if (ret & 0x40) {
751 dc_ok = true;
752 break;
753 }
754 }
755
756 if (!dc_ok) {
757 DRM_DEV_ERROR(dev, "dc/dc failed\n");
758 power_off(epd);
759 goto out_exit;
760 }
761
762 /*
763 * Output enable to disable
764 * The userspace driver sets this to 0x04, but the datasheet says 0x06
765 */
766 repaper_write_val(spi, 0x02, 0x04);
767
768 epd->partial = false;
769 out_exit:
770 drm_dev_exit(idx);
771 }
772
repaper_pipe_disable(struct drm_simple_display_pipe * pipe)773 static void repaper_pipe_disable(struct drm_simple_display_pipe *pipe)
774 {
775 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev);
776 struct spi_device *spi = epd->spi;
777 unsigned int line;
778
779 /*
780 * This callback is not protected by drm_dev_enter/exit since we want to
781 * turn off the display on regular driver unload. It's highly unlikely
782 * that the underlying SPI controller is gone should this be called after
783 * unplug.
784 */
785
786 DRM_DEBUG_DRIVER("\n");
787
788 /* Nothing frame */
789 for (line = 0; line < epd->height; line++)
790 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
791 REPAPER_COMPENSATE);
792
793 /* 2.7" */
794 if (epd->border) {
795 /* Dummy line */
796 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
797 REPAPER_COMPENSATE);
798 msleep(25);
799 gpiod_set_value_cansleep(epd->border, 0);
800 msleep(200);
801 gpiod_set_value_cansleep(epd->border, 1);
802 } else {
803 /* Border dummy line */
804 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
805 REPAPER_NORMAL);
806 msleep(200);
807 }
808
809 /* not described in datasheet */
810 repaper_write_val(spi, 0x0b, 0x00);
811 /* Latch reset turn on */
812 repaper_write_val(spi, 0x03, 0x01);
813 /* Power off charge pump Vcom */
814 repaper_write_val(spi, 0x05, 0x03);
815 /* Power off charge pump neg voltage */
816 repaper_write_val(spi, 0x05, 0x01);
817 msleep(120);
818 /* Discharge internal */
819 repaper_write_val(spi, 0x04, 0x80);
820 /* turn off all charge pumps */
821 repaper_write_val(spi, 0x05, 0x00);
822 /* Turn off osc */
823 repaper_write_val(spi, 0x07, 0x01);
824 msleep(50);
825
826 power_off(epd);
827 }
828
repaper_pipe_update(struct drm_simple_display_pipe * pipe,struct drm_plane_state * old_state)829 static void repaper_pipe_update(struct drm_simple_display_pipe *pipe,
830 struct drm_plane_state *old_state)
831 {
832 struct drm_plane_state *state = pipe->plane.state;
833 struct drm_rect rect;
834
835 if (!pipe->crtc.state->active)
836 return;
837
838 if (drm_atomic_helper_damage_merged(old_state, state, &rect))
839 repaper_fb_dirty(state->fb);
840 }
841
842 static const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = {
843 .mode_valid = repaper_pipe_mode_valid,
844 .enable = repaper_pipe_enable,
845 .disable = repaper_pipe_disable,
846 .update = repaper_pipe_update,
847 };
848
repaper_connector_get_modes(struct drm_connector * connector)849 static int repaper_connector_get_modes(struct drm_connector *connector)
850 {
851 struct repaper_epd *epd = drm_to_epd(connector->dev);
852
853 return drm_connector_helper_get_modes_fixed(connector, epd->mode);
854 }
855
856 static const struct drm_connector_helper_funcs repaper_connector_hfuncs = {
857 .get_modes = repaper_connector_get_modes,
858 };
859
860 static const struct drm_connector_funcs repaper_connector_funcs = {
861 .reset = drm_atomic_helper_connector_reset,
862 .fill_modes = drm_helper_probe_single_connector_modes,
863 .destroy = drm_connector_cleanup,
864 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
865 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
866 };
867
868 static const struct drm_mode_config_funcs repaper_mode_config_funcs = {
869 .fb_create = drm_gem_fb_create_with_dirty,
870 .atomic_check = drm_atomic_helper_check,
871 .atomic_commit = drm_atomic_helper_commit,
872 };
873
874 static const uint32_t repaper_formats[] = {
875 DRM_FORMAT_XRGB8888,
876 };
877
878 static const struct drm_display_mode repaper_e1144cs021_mode = {
879 DRM_SIMPLE_MODE(128, 96, 29, 22),
880 };
881
882 static const u8 repaper_e1144cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
883 0x00, 0x0f, 0xff, 0x00 };
884
885 static const struct drm_display_mode repaper_e1190cs021_mode = {
886 DRM_SIMPLE_MODE(144, 128, 36, 32),
887 };
888
889 static const u8 repaper_e1190cs021_cs[] = { 0x00, 0x00, 0x00, 0x03,
890 0xfc, 0x00, 0x00, 0xff };
891
892 static const struct drm_display_mode repaper_e2200cs021_mode = {
893 DRM_SIMPLE_MODE(200, 96, 46, 22),
894 };
895
896 static const u8 repaper_e2200cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
897 0x01, 0xff, 0xe0, 0x00 };
898
899 static const struct drm_display_mode repaper_e2271cs021_mode = {
900 DRM_SIMPLE_MODE(264, 176, 57, 38),
901 };
902
903 static const u8 repaper_e2271cs021_cs[] = { 0x00, 0x00, 0x00, 0x7f,
904 0xff, 0xfe, 0x00, 0x00 };
905
906 DEFINE_DRM_GEM_DMA_FOPS(repaper_fops);
907
908 static const struct drm_driver repaper_driver = {
909 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
910 .fops = &repaper_fops,
911 DRM_GEM_DMA_DRIVER_OPS_VMAP,
912 .name = "repaper",
913 .desc = "Pervasive Displays RePaper e-ink panels",
914 .date = "20170405",
915 .major = 1,
916 .minor = 0,
917 };
918
919 static const struct of_device_id repaper_of_match[] = {
920 { .compatible = "pervasive,e1144cs021", .data = (void *)E1144CS021 },
921 { .compatible = "pervasive,e1190cs021", .data = (void *)E1190CS021 },
922 { .compatible = "pervasive,e2200cs021", .data = (void *)E2200CS021 },
923 { .compatible = "pervasive,e2271cs021", .data = (void *)E2271CS021 },
924 {},
925 };
926 MODULE_DEVICE_TABLE(of, repaper_of_match);
927
928 static const struct spi_device_id repaper_id[] = {
929 { "e1144cs021", E1144CS021 },
930 { "e1190cs021", E1190CS021 },
931 { "e2200cs021", E2200CS021 },
932 { "e2271cs021", E2271CS021 },
933 { },
934 };
935 MODULE_DEVICE_TABLE(spi, repaper_id);
936
repaper_probe(struct spi_device * spi)937 static int repaper_probe(struct spi_device *spi)
938 {
939 const struct drm_display_mode *mode;
940 const struct spi_device_id *spi_id;
941 struct device *dev = &spi->dev;
942 enum repaper_model model;
943 const char *thermal_zone;
944 struct repaper_epd *epd;
945 size_t line_buffer_size;
946 struct drm_device *drm;
947 const void *match;
948 int ret;
949
950 match = device_get_match_data(dev);
951 if (match) {
952 model = (enum repaper_model)match;
953 } else {
954 spi_id = spi_get_device_id(spi);
955 model = (enum repaper_model)spi_id->driver_data;
956 }
957
958 /* The SPI device is used to allocate dma memory */
959 if (!dev->coherent_dma_mask) {
960 ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
961 if (ret) {
962 dev_warn(dev, "Failed to set dma mask %d\n", ret);
963 return ret;
964 }
965 }
966
967 epd = devm_drm_dev_alloc(dev, &repaper_driver,
968 struct repaper_epd, drm);
969 if (IS_ERR(epd))
970 return PTR_ERR(epd);
971
972 drm = &epd->drm;
973
974 ret = drmm_mode_config_init(drm);
975 if (ret)
976 return ret;
977 drm->mode_config.funcs = &repaper_mode_config_funcs;
978
979 epd->spi = spi;
980
981 epd->panel_on = devm_gpiod_get(dev, "panel-on", GPIOD_OUT_LOW);
982 if (IS_ERR(epd->panel_on)) {
983 ret = PTR_ERR(epd->panel_on);
984 if (ret != -EPROBE_DEFER)
985 DRM_DEV_ERROR(dev, "Failed to get gpio 'panel-on'\n");
986 return ret;
987 }
988
989 epd->discharge = devm_gpiod_get(dev, "discharge", GPIOD_OUT_LOW);
990 if (IS_ERR(epd->discharge)) {
991 ret = PTR_ERR(epd->discharge);
992 if (ret != -EPROBE_DEFER)
993 DRM_DEV_ERROR(dev, "Failed to get gpio 'discharge'\n");
994 return ret;
995 }
996
997 epd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
998 if (IS_ERR(epd->reset)) {
999 ret = PTR_ERR(epd->reset);
1000 if (ret != -EPROBE_DEFER)
1001 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
1002 return ret;
1003 }
1004
1005 epd->busy = devm_gpiod_get(dev, "busy", GPIOD_IN);
1006 if (IS_ERR(epd->busy)) {
1007 ret = PTR_ERR(epd->busy);
1008 if (ret != -EPROBE_DEFER)
1009 DRM_DEV_ERROR(dev, "Failed to get gpio 'busy'\n");
1010 return ret;
1011 }
1012
1013 if (!device_property_read_string(dev, "pervasive,thermal-zone",
1014 &thermal_zone)) {
1015 epd->thermal = thermal_zone_get_zone_by_name(thermal_zone);
1016 if (IS_ERR(epd->thermal)) {
1017 DRM_DEV_ERROR(dev, "Failed to get thermal zone: %s\n", thermal_zone);
1018 return PTR_ERR(epd->thermal);
1019 }
1020 }
1021
1022 switch (model) {
1023 case E1144CS021:
1024 mode = &repaper_e1144cs021_mode;
1025 epd->channel_select = repaper_e1144cs021_cs;
1026 epd->stage_time = 480;
1027 epd->bytes_per_scan = 96 / 4;
1028 epd->middle_scan = true; /* data-scan-data */
1029 epd->pre_border_byte = false;
1030 epd->border_byte = REPAPER_BORDER_BYTE_ZERO;
1031 break;
1032
1033 case E1190CS021:
1034 mode = &repaper_e1190cs021_mode;
1035 epd->channel_select = repaper_e1190cs021_cs;
1036 epd->stage_time = 480;
1037 epd->bytes_per_scan = 128 / 4 / 2;
1038 epd->middle_scan = false; /* scan-data-scan */
1039 epd->pre_border_byte = false;
1040 epd->border_byte = REPAPER_BORDER_BYTE_SET;
1041 break;
1042
1043 case E2200CS021:
1044 mode = &repaper_e2200cs021_mode;
1045 epd->channel_select = repaper_e2200cs021_cs;
1046 epd->stage_time = 480;
1047 epd->bytes_per_scan = 96 / 4;
1048 epd->middle_scan = true; /* data-scan-data */
1049 epd->pre_border_byte = true;
1050 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1051 break;
1052
1053 case E2271CS021:
1054 epd->border = devm_gpiod_get(dev, "border", GPIOD_OUT_LOW);
1055 if (IS_ERR(epd->border)) {
1056 ret = PTR_ERR(epd->border);
1057 if (ret != -EPROBE_DEFER)
1058 DRM_DEV_ERROR(dev, "Failed to get gpio 'border'\n");
1059 return ret;
1060 }
1061
1062 mode = &repaper_e2271cs021_mode;
1063 epd->channel_select = repaper_e2271cs021_cs;
1064 epd->stage_time = 630;
1065 epd->bytes_per_scan = 176 / 4;
1066 epd->middle_scan = true; /* data-scan-data */
1067 epd->pre_border_byte = true;
1068 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1069 break;
1070
1071 default:
1072 return -ENODEV;
1073 }
1074
1075 epd->mode = mode;
1076 epd->width = mode->hdisplay;
1077 epd->height = mode->vdisplay;
1078 epd->factored_stage_time = epd->stage_time;
1079
1080 line_buffer_size = 2 * epd->width / 8 + epd->bytes_per_scan + 2;
1081 epd->line_buffer = devm_kzalloc(dev, line_buffer_size, GFP_KERNEL);
1082 if (!epd->line_buffer)
1083 return -ENOMEM;
1084
1085 epd->current_frame = devm_kzalloc(dev, epd->width * epd->height / 8,
1086 GFP_KERNEL);
1087 if (!epd->current_frame)
1088 return -ENOMEM;
1089
1090 drm->mode_config.min_width = mode->hdisplay;
1091 drm->mode_config.max_width = mode->hdisplay;
1092 drm->mode_config.min_height = mode->vdisplay;
1093 drm->mode_config.max_height = mode->vdisplay;
1094
1095 drm_connector_helper_add(&epd->connector, &repaper_connector_hfuncs);
1096 ret = drm_connector_init(drm, &epd->connector, &repaper_connector_funcs,
1097 DRM_MODE_CONNECTOR_SPI);
1098 if (ret)
1099 return ret;
1100
1101 ret = drm_simple_display_pipe_init(drm, &epd->pipe, &repaper_pipe_funcs,
1102 repaper_formats, ARRAY_SIZE(repaper_formats),
1103 NULL, &epd->connector);
1104 if (ret)
1105 return ret;
1106
1107 drm_mode_config_reset(drm);
1108
1109 ret = drm_dev_register(drm, 0);
1110 if (ret)
1111 return ret;
1112
1113 spi_set_drvdata(spi, drm);
1114
1115 DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000);
1116
1117 drm_fbdev_generic_setup(drm, 0);
1118
1119 return 0;
1120 }
1121
repaper_remove(struct spi_device * spi)1122 static void repaper_remove(struct spi_device *spi)
1123 {
1124 struct drm_device *drm = spi_get_drvdata(spi);
1125
1126 drm_dev_unplug(drm);
1127 drm_atomic_helper_shutdown(drm);
1128 }
1129
repaper_shutdown(struct spi_device * spi)1130 static void repaper_shutdown(struct spi_device *spi)
1131 {
1132 drm_atomic_helper_shutdown(spi_get_drvdata(spi));
1133 }
1134
1135 static struct spi_driver repaper_spi_driver = {
1136 .driver = {
1137 .name = "repaper",
1138 .of_match_table = repaper_of_match,
1139 },
1140 .id_table = repaper_id,
1141 .probe = repaper_probe,
1142 .remove = repaper_remove,
1143 .shutdown = repaper_shutdown,
1144 };
1145 module_spi_driver(repaper_spi_driver);
1146
1147 MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver");
1148 MODULE_AUTHOR("Noralf Trønnes");
1149 MODULE_LICENSE("GPL");
1150
