2 * DRM driver for Pervasive Displays RePaper branded e-ink panels
4 * Copyright 2013-2017 Pervasive Displays, Inc.
5 * Copyright 2017 Noralf Trønnes
8 * Material Film: Aurora Mb (V231)
11 * The controller code was taken from the userspace driver:
12 * https://github.com/repaper/gratis
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
20 #include <linux/delay.h>
21 #include <linux/dma-buf.h>
22 #include <linux/gpio/consumer.h>
23 #include <linux/module.h>
24 #include <linux/of_device.h>
25 #include <linux/sched/clock.h>
26 #include <linux/spi/spi.h>
27 #include <linux/thermal.h>
29 #include <drm/drm_gem_framebuffer_helper.h>
30 #include <drm/tinydrm/tinydrm.h>
31 #include <drm/tinydrm/tinydrm-helpers.h>
33 #define REPAPER_RID_G2_COG_ID 0x12
42 enum repaper_stage { /* Image pixel -> Display pixel */
43 REPAPER_COMPENSATE, /* B -> W, W -> B (Current Image) */
44 REPAPER_WHITE, /* B -> N, W -> W (Current Image) */
45 REPAPER_INVERSE, /* B -> N, W -> B (New Image) */
46 REPAPER_NORMAL /* B -> B, W -> W (New Image) */
49 enum repaper_epd_border_byte {
50 REPAPER_BORDER_BYTE_NONE,
51 REPAPER_BORDER_BYTE_ZERO,
52 REPAPER_BORDER_BYTE_SET,
56 struct tinydrm_device tinydrm;
57 struct spi_device *spi;
59 struct gpio_desc *panel_on;
60 struct gpio_desc *border;
61 struct gpio_desc *discharge;
62 struct gpio_desc *reset;
63 struct gpio_desc *busy;
65 struct thermal_zone_device *thermal;
69 unsigned int bytes_per_scan;
70 const u8 *channel_select;
71 unsigned int stage_time;
72 unsigned int factored_stage_time;
75 enum repaper_epd_border_byte border_byte;
85 static inline struct repaper_epd *
86 epd_from_tinydrm(struct tinydrm_device *tdev)
88 return container_of(tdev, struct repaper_epd, tinydrm);
91 static int repaper_spi_transfer(struct spi_device *spi, u8 header,
92 const void *tx, void *rx, size_t len)
94 void *txbuf = NULL, *rxbuf = NULL;
95 struct spi_transfer tr[2] = {};
99 headerbuf = kmalloc(1, GFP_KERNEL);
103 headerbuf[0] = header;
104 tr[0].tx_buf = headerbuf;
107 /* Stack allocated tx? */
108 if (tx && len <= 32) {
109 txbuf = kmalloc(len, GFP_KERNEL);
114 memcpy(txbuf, tx, len);
118 rxbuf = kmalloc(len, GFP_KERNEL);
125 tr[1].tx_buf = txbuf ? txbuf : tx;
126 tr[1].rx_buf = rxbuf;
130 ret = spi_sync_transfer(spi, tr, 2);
132 memcpy(rx, rxbuf, len);
142 static int repaper_write_buf(struct spi_device *spi, u8 reg,
143 const u8 *buf, size_t len)
147 ret = repaper_spi_transfer(spi, 0x70, ®, NULL, 1);
151 return repaper_spi_transfer(spi, 0x72, buf, NULL, len);
154 static int repaper_write_val(struct spi_device *spi, u8 reg, u8 val)
156 return repaper_write_buf(spi, reg, &val, 1);
159 static int repaper_read_val(struct spi_device *spi, u8 reg)
164 ret = repaper_spi_transfer(spi, 0x70, ®, NULL, 1);
168 ret = repaper_spi_transfer(spi, 0x73, NULL, &val, 1);
170 return ret ? ret : val;
173 static int repaper_read_id(struct spi_device *spi)
178 ret = repaper_spi_transfer(spi, 0x71, NULL, &id, 1);
180 return ret ? ret : id;
183 static void repaper_spi_mosi_low(struct spi_device *spi)
185 const u8 buf[1] = { 0 };
187 spi_write(spi, buf, 1);
190 /* pixels on display are numbered from 1 so even is actually bits 1,3,5,... */
191 static void repaper_even_pixels(struct repaper_epd *epd, u8 **pp,
192 const u8 *data, u8 fixed_value, const u8 *mask,
193 enum repaper_stage stage)
197 for (b = 0; b < (epd->width / 8); b++) {
199 u8 pixels = data[b] & 0xaa;
200 u8 pixel_mask = 0xff;
204 pixel_mask = (mask[b] ^ pixels) & 0xaa;
205 pixel_mask |= pixel_mask >> 1;
209 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */
210 pixels = 0xaa | ((pixels ^ 0xaa) >> 1);
212 case REPAPER_WHITE: /* B -> N, W -> W (Current) */
213 pixels = 0x55 + ((pixels ^ 0xaa) >> 1);
215 case REPAPER_INVERSE: /* B -> N, W -> B (New) */
216 pixels = 0x55 | (pixels ^ 0xaa);
218 case REPAPER_NORMAL: /* B -> B, W -> W (New) */
219 pixels = 0xaa | (pixels >> 1);
223 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x55);
224 p1 = (pixels >> 6) & 0x03;
225 p2 = (pixels >> 4) & 0x03;
226 p3 = (pixels >> 2) & 0x03;
227 p4 = (pixels >> 0) & 0x03;
228 pixels = (p1 << 0) | (p2 << 2) | (p3 << 4) | (p4 << 6);
231 *(*pp)++ = fixed_value;
236 /* pixels on display are numbered from 1 so odd is actually bits 0,2,4,... */
237 static void repaper_odd_pixels(struct repaper_epd *epd, u8 **pp,
238 const u8 *data, u8 fixed_value, const u8 *mask,
239 enum repaper_stage stage)
243 for (b = epd->width / 8; b > 0; b--) {
245 u8 pixels = data[b - 1] & 0x55;
246 u8 pixel_mask = 0xff;
249 pixel_mask = (mask[b - 1] ^ pixels) & 0x55;
250 pixel_mask |= pixel_mask << 1;
254 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */
255 pixels = 0xaa | (pixels ^ 0x55);
257 case REPAPER_WHITE: /* B -> N, W -> W (Current) */
258 pixels = 0x55 + (pixels ^ 0x55);
260 case REPAPER_INVERSE: /* B -> N, W -> B (New) */
261 pixels = 0x55 | ((pixels ^ 0x55) << 1);
263 case REPAPER_NORMAL: /* B -> B, W -> W (New) */
264 pixels = 0xaa | pixels;
268 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x55);
271 *(*pp)++ = fixed_value;
276 /* interleave bits: (byte)76543210 -> (16 bit).7.6.5.4.3.2.1 */
277 static inline u16 repaper_interleave_bits(u16 value)
279 value = (value | (value << 4)) & 0x0f0f;
280 value = (value | (value << 2)) & 0x3333;
281 value = (value | (value << 1)) & 0x5555;
286 /* pixels on display are numbered from 1 */
287 static void repaper_all_pixels(struct repaper_epd *epd, u8 **pp,
288 const u8 *data, u8 fixed_value, const u8 *mask,
289 enum repaper_stage stage)
293 for (b = epd->width / 8; b > 0; b--) {
295 u16 pixels = repaper_interleave_bits(data[b - 1]);
296 u16 pixel_mask = 0xffff;
299 pixel_mask = repaper_interleave_bits(mask[b - 1]);
301 pixel_mask = (pixel_mask ^ pixels) & 0x5555;
302 pixel_mask |= pixel_mask << 1;
306 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */
307 pixels = 0xaaaa | (pixels ^ 0x5555);
309 case REPAPER_WHITE: /* B -> N, W -> W (Current) */
310 pixels = 0x5555 + (pixels ^ 0x5555);
312 case REPAPER_INVERSE: /* B -> N, W -> B (New) */
313 pixels = 0x5555 | ((pixels ^ 0x5555) << 1);
315 case REPAPER_NORMAL: /* B -> B, W -> W (New) */
316 pixels = 0xaaaa | pixels;
320 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x5555);
321 *(*pp)++ = pixels >> 8;
324 *(*pp)++ = fixed_value;
325 *(*pp)++ = fixed_value;
330 /* output one line of scan and data bytes to the display */
331 static void repaper_one_line(struct repaper_epd *epd, unsigned int line,
332 const u8 *data, u8 fixed_value, const u8 *mask,
333 enum repaper_stage stage)
335 u8 *p = epd->line_buffer;
338 repaper_spi_mosi_low(epd->spi);
340 if (epd->pre_border_byte)
343 if (epd->middle_scan) {
345 repaper_odd_pixels(epd, &p, data, fixed_value, mask, stage);
348 for (b = epd->bytes_per_scan; b > 0; b--) {
349 if (line / 4 == b - 1)
350 *p++ = 0x03 << (2 * (line & 0x03));
356 repaper_even_pixels(epd, &p, data, fixed_value, mask, stage);
359 * even scan line, but as lines on display are numbered from 1,
362 for (b = 0; b < epd->bytes_per_scan; b++) {
363 if (0 != (line & 0x01) && line / 8 == b)
364 *p++ = 0xc0 >> (line & 0x06);
370 repaper_all_pixels(epd, &p, data, fixed_value, mask, stage);
373 * odd scan line, but as lines on display are numbered from 1,
376 for (b = epd->bytes_per_scan; b > 0; b--) {
377 if (0 == (line & 0x01) && line / 8 == b - 1)
378 *p++ = 0x03 << (line & 0x06);
384 switch (epd->border_byte) {
385 case REPAPER_BORDER_BYTE_NONE:
388 case REPAPER_BORDER_BYTE_ZERO:
392 case REPAPER_BORDER_BYTE_SET:
394 case REPAPER_COMPENSATE:
396 case REPAPER_INVERSE:
406 repaper_write_buf(epd->spi, 0x0a, epd->line_buffer,
407 p - epd->line_buffer);
409 /* Output data to panel */
410 repaper_write_val(epd->spi, 0x02, 0x07);
412 repaper_spi_mosi_low(epd->spi);
415 static void repaper_frame_fixed(struct repaper_epd *epd, u8 fixed_value,
416 enum repaper_stage stage)
420 for (line = 0; line < epd->height; line++)
421 repaper_one_line(epd, line, NULL, fixed_value, NULL, stage);
424 static void repaper_frame_data(struct repaper_epd *epd, const u8 *image,
425 const u8 *mask, enum repaper_stage stage)
430 for (line = 0; line < epd->height; line++) {
431 repaper_one_line(epd, line,
432 &image[line * (epd->width / 8)],
436 for (line = 0; line < epd->height; line++) {
437 size_t n = line * epd->width / 8;
439 repaper_one_line(epd, line, &image[n], 0, &mask[n],
445 static void repaper_frame_fixed_repeat(struct repaper_epd *epd, u8 fixed_value,
446 enum repaper_stage stage)
448 u64 start = local_clock();
449 u64 end = start + (epd->factored_stage_time * 1000 * 1000);
452 repaper_frame_fixed(epd, fixed_value, stage);
453 } while (local_clock() < end);
456 static void repaper_frame_data_repeat(struct repaper_epd *epd, const u8 *image,
457 const u8 *mask, enum repaper_stage stage)
459 u64 start = local_clock();
460 u64 end = start + (epd->factored_stage_time * 1000 * 1000);
463 repaper_frame_data(epd, image, mask, stage);
464 } while (local_clock() < end);
467 static void repaper_get_temperature(struct repaper_epd *epd)
469 int ret, temperature = 0;
470 unsigned int factor10x;
475 ret = thermal_zone_get_temp(epd->thermal, &temperature);
477 DRM_DEV_ERROR(&epd->spi->dev, "Failed to get temperature (%d)\n", ret);
483 if (temperature <= -10)
485 else if (temperature <= -5)
487 else if (temperature <= 5)
489 else if (temperature <= 10)
491 else if (temperature <= 15)
493 else if (temperature <= 20)
495 else if (temperature <= 40)
500 epd->factored_stage_time = epd->stage_time * factor10x / 10;
503 static void repaper_gray8_to_mono_reversed(u8 *buf, u32 width, u32 height)
505 u8 *gray8 = buf, *mono = buf;
508 for (y = 0; y < height; y++)
509 for (xb = 0; xb < width / 8; xb++) {
512 for (i = 0; i < 8; i++) {
516 if (gray8[y * width + x] >> 7)
523 static int repaper_fb_dirty(struct drm_framebuffer *fb,
524 struct drm_file *file_priv,
525 unsigned int flags, unsigned int color,
526 struct drm_clip_rect *clips,
527 unsigned int num_clips)
529 struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
530 struct dma_buf_attachment *import_attach = cma_obj->base.import_attach;
531 struct tinydrm_device *tdev = fb->dev->dev_private;
532 struct repaper_epd *epd = epd_from_tinydrm(tdev);
533 struct drm_clip_rect clip;
537 /* repaper can't do partial updates */
541 clip.y2 = fb->height;
546 repaper_get_temperature(epd);
548 DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id,
549 epd->factored_stage_time);
551 buf = kmalloc_array(fb->width, fb->height, GFP_KERNEL);
556 ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
562 tinydrm_xrgb8888_to_gray8(buf, cma_obj->vaddr, fb, &clip);
565 ret = dma_buf_end_cpu_access(import_attach->dmabuf,
571 repaper_gray8_to_mono_reversed(buf, fb->width, fb->height);
574 repaper_frame_data_repeat(epd, buf, epd->current_frame,
576 } else if (epd->cleared) {
577 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
579 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
581 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
582 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
586 /* Clear display (anything -> white) */
587 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_COMPENSATE);
588 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_WHITE);
589 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_INVERSE);
590 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_NORMAL);
592 /* Assuming a clear (white) screen output an image */
593 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_COMPENSATE);
594 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_WHITE);
595 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
596 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
602 memcpy(epd->current_frame, buf, fb->width * fb->height / 8);
605 * An extra frame write is needed if pixels are set in the bottom line,
606 * or else grey lines rises up from the pixels
608 if (epd->pre_border_byte) {
611 for (x = 0; x < (fb->width / 8); x++)
612 if (buf[x + (fb->width * (fb->height - 1) / 8)]) {
613 repaper_frame_data_repeat(epd, buf,
626 static const struct drm_framebuffer_funcs repaper_fb_funcs = {
627 .destroy = drm_gem_fb_destroy,
628 .create_handle = drm_gem_fb_create_handle,
629 .dirty = tinydrm_fb_dirty,
632 static void power_off(struct repaper_epd *epd)
634 /* Turn off power and all signals */
635 gpiod_set_value_cansleep(epd->reset, 0);
636 gpiod_set_value_cansleep(epd->panel_on, 0);
638 gpiod_set_value_cansleep(epd->border, 0);
640 /* Ensure SPI MOSI and CLOCK are Low before CS Low */
641 repaper_spi_mosi_low(epd->spi);
643 /* Discharge pulse */
644 gpiod_set_value_cansleep(epd->discharge, 1);
646 gpiod_set_value_cansleep(epd->discharge, 0);
649 static void repaper_pipe_enable(struct drm_simple_display_pipe *pipe,
650 struct drm_crtc_state *crtc_state,
651 struct drm_plane_state *plane_state)
653 struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
654 struct repaper_epd *epd = epd_from_tinydrm(tdev);
655 struct spi_device *spi = epd->spi;
656 struct device *dev = &spi->dev;
660 DRM_DEBUG_DRIVER("\n");
662 /* Power up sequence */
663 gpiod_set_value_cansleep(epd->reset, 0);
664 gpiod_set_value_cansleep(epd->panel_on, 0);
665 gpiod_set_value_cansleep(epd->discharge, 0);
667 gpiod_set_value_cansleep(epd->border, 0);
668 repaper_spi_mosi_low(spi);
669 usleep_range(5000, 10000);
671 gpiod_set_value_cansleep(epd->panel_on, 1);
673 * This delay comes from the repaper.org userspace driver, it's not
674 * mentioned in the datasheet.
676 usleep_range(10000, 15000);
677 gpiod_set_value_cansleep(epd->reset, 1);
679 gpiod_set_value_cansleep(epd->border, 1);
680 usleep_range(5000, 10000);
681 gpiod_set_value_cansleep(epd->reset, 0);
682 usleep_range(5000, 10000);
683 gpiod_set_value_cansleep(epd->reset, 1);
684 usleep_range(5000, 10000);
686 /* Wait for COG to become ready */
687 for (i = 100; i > 0; i--) {
688 if (!gpiod_get_value_cansleep(epd->busy))
691 usleep_range(10, 100);
695 DRM_DEV_ERROR(dev, "timeout waiting for panel to become ready.\n");
700 repaper_read_id(spi);
701 ret = repaper_read_id(spi);
702 if (ret != REPAPER_RID_G2_COG_ID) {
704 dev_err(dev, "failed to read chip (%d)\n", ret);
706 dev_err(dev, "wrong COG ID 0x%02x\n", ret);
712 repaper_write_val(spi, 0x02, 0x40);
714 ret = repaper_read_val(spi, 0x0f);
715 if (ret < 0 || !(ret & 0x80)) {
717 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
719 DRM_DEV_ERROR(dev, "panel is reported broken\n");
724 /* Power saving mode */
725 repaper_write_val(spi, 0x0b, 0x02);
727 repaper_write_buf(spi, 0x01, epd->channel_select, 8);
728 /* High power mode osc */
729 repaper_write_val(spi, 0x07, 0xd1);
731 repaper_write_val(spi, 0x08, 0x02);
733 repaper_write_val(spi, 0x09, 0xc2);
735 repaper_write_val(spi, 0x04, 0x03);
736 /* Driver latch on */
737 repaper_write_val(spi, 0x03, 0x01);
738 /* Driver latch off */
739 repaper_write_val(spi, 0x03, 0x00);
740 usleep_range(5000, 10000);
742 /* Start chargepump */
743 for (i = 0; i < 4; ++i) {
744 /* Charge pump positive voltage on - VGH/VDL on */
745 repaper_write_val(spi, 0x05, 0x01);
748 /* Charge pump negative voltage on - VGL/VDL on */
749 repaper_write_val(spi, 0x05, 0x03);
752 /* Charge pump Vcom on - Vcom driver on */
753 repaper_write_val(spi, 0x05, 0x0f);
757 ret = repaper_read_val(spi, 0x0f);
759 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
771 DRM_DEV_ERROR(dev, "dc/dc failed\n");
777 * Output enable to disable
778 * The userspace driver sets this to 0x04, but the datasheet says 0x06
780 repaper_write_val(spi, 0x02, 0x04);
783 epd->partial = false;
786 static void repaper_pipe_disable(struct drm_simple_display_pipe *pipe)
788 struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
789 struct repaper_epd *epd = epd_from_tinydrm(tdev);
790 struct spi_device *spi = epd->spi;
793 DRM_DEBUG_DRIVER("\n");
795 mutex_lock(&tdev->dirty_lock);
796 epd->enabled = false;
797 mutex_unlock(&tdev->dirty_lock);
800 for (line = 0; line < epd->height; line++)
801 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
807 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
810 gpiod_set_value_cansleep(epd->border, 0);
812 gpiod_set_value_cansleep(epd->border, 1);
814 /* Border dummy line */
815 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
820 /* not described in datasheet */
821 repaper_write_val(spi, 0x0b, 0x00);
822 /* Latch reset turn on */
823 repaper_write_val(spi, 0x03, 0x01);
824 /* Power off charge pump Vcom */
825 repaper_write_val(spi, 0x05, 0x03);
826 /* Power off charge pump neg voltage */
827 repaper_write_val(spi, 0x05, 0x01);
829 /* Discharge internal */
830 repaper_write_val(spi, 0x04, 0x80);
831 /* turn off all charge pumps */
832 repaper_write_val(spi, 0x05, 0x00);
834 repaper_write_val(spi, 0x07, 0x01);
840 static const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = {
841 .enable = repaper_pipe_enable,
842 .disable = repaper_pipe_disable,
843 .update = tinydrm_display_pipe_update,
844 .prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
847 static const uint32_t repaper_formats[] = {
851 static const struct drm_display_mode repaper_e1144cs021_mode = {
852 TINYDRM_MODE(128, 96, 29, 22),
855 static const u8 repaper_e1144cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
856 0x00, 0x0f, 0xff, 0x00 };
858 static const struct drm_display_mode repaper_e1190cs021_mode = {
859 TINYDRM_MODE(144, 128, 36, 32),
862 static const u8 repaper_e1190cs021_cs[] = { 0x00, 0x00, 0x00, 0x03,
863 0xfc, 0x00, 0x00, 0xff };
865 static const struct drm_display_mode repaper_e2200cs021_mode = {
866 TINYDRM_MODE(200, 96, 46, 22),
869 static const u8 repaper_e2200cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
870 0x01, 0xff, 0xe0, 0x00 };
872 static const struct drm_display_mode repaper_e2271cs021_mode = {
873 TINYDRM_MODE(264, 176, 57, 38),
876 static const u8 repaper_e2271cs021_cs[] = { 0x00, 0x00, 0x00, 0x7f,
877 0xff, 0xfe, 0x00, 0x00 };
879 DEFINE_DRM_GEM_CMA_FOPS(repaper_fops);
881 static struct drm_driver repaper_driver = {
882 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
884 .fops = &repaper_fops,
885 TINYDRM_GEM_DRIVER_OPS,
887 .desc = "Pervasive Displays RePaper e-ink panels",
893 static const struct of_device_id repaper_of_match[] = {
894 { .compatible = "pervasive,e1144cs021", .data = (void *)E1144CS021 },
895 { .compatible = "pervasive,e1190cs021", .data = (void *)E1190CS021 },
896 { .compatible = "pervasive,e2200cs021", .data = (void *)E2200CS021 },
897 { .compatible = "pervasive,e2271cs021", .data = (void *)E2271CS021 },
900 MODULE_DEVICE_TABLE(of, repaper_of_match);
902 static const struct spi_device_id repaper_id[] = {
903 { "e1144cs021", E1144CS021 },
904 { "e1190cs021", E1190CS021 },
905 { "e2200cs021", E2200CS021 },
906 { "e2271cs021", E2271CS021 },
909 MODULE_DEVICE_TABLE(spi, repaper_id);
911 static int repaper_probe(struct spi_device *spi)
913 const struct drm_display_mode *mode;
914 const struct spi_device_id *spi_id;
915 const struct of_device_id *match;
916 struct device *dev = &spi->dev;
917 struct tinydrm_device *tdev;
918 enum repaper_model model;
919 const char *thermal_zone;
920 struct repaper_epd *epd;
921 size_t line_buffer_size;
924 match = of_match_device(repaper_of_match, dev);
926 model = (enum repaper_model)match->data;
928 spi_id = spi_get_device_id(spi);
929 model = spi_id->driver_data;
932 /* The SPI device is used to allocate dma memory */
933 if (!dev->coherent_dma_mask) {
934 ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
936 dev_warn(dev, "Failed to set dma mask %d\n", ret);
941 epd = devm_kzalloc(dev, sizeof(*epd), GFP_KERNEL);
947 epd->panel_on = devm_gpiod_get(dev, "panel-on", GPIOD_OUT_LOW);
948 if (IS_ERR(epd->panel_on)) {
949 ret = PTR_ERR(epd->panel_on);
950 if (ret != -EPROBE_DEFER)
951 DRM_DEV_ERROR(dev, "Failed to get gpio 'panel-on'\n");
955 epd->discharge = devm_gpiod_get(dev, "discharge", GPIOD_OUT_LOW);
956 if (IS_ERR(epd->discharge)) {
957 ret = PTR_ERR(epd->discharge);
958 if (ret != -EPROBE_DEFER)
959 DRM_DEV_ERROR(dev, "Failed to get gpio 'discharge'\n");
963 epd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
964 if (IS_ERR(epd->reset)) {
965 ret = PTR_ERR(epd->reset);
966 if (ret != -EPROBE_DEFER)
967 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
971 epd->busy = devm_gpiod_get(dev, "busy", GPIOD_IN);
972 if (IS_ERR(epd->busy)) {
973 ret = PTR_ERR(epd->busy);
974 if (ret != -EPROBE_DEFER)
975 DRM_DEV_ERROR(dev, "Failed to get gpio 'busy'\n");
979 if (!device_property_read_string(dev, "pervasive,thermal-zone",
981 epd->thermal = thermal_zone_get_zone_by_name(thermal_zone);
982 if (IS_ERR(epd->thermal)) {
983 DRM_DEV_ERROR(dev, "Failed to get thermal zone: %s\n", thermal_zone);
984 return PTR_ERR(epd->thermal);
990 mode = &repaper_e1144cs021_mode;
991 epd->channel_select = repaper_e1144cs021_cs;
992 epd->stage_time = 480;
993 epd->bytes_per_scan = 96 / 4;
994 epd->middle_scan = true; /* data-scan-data */
995 epd->pre_border_byte = false;
996 epd->border_byte = REPAPER_BORDER_BYTE_ZERO;
1000 mode = &repaper_e1190cs021_mode;
1001 epd->channel_select = repaper_e1190cs021_cs;
1002 epd->stage_time = 480;
1003 epd->bytes_per_scan = 128 / 4 / 2;
1004 epd->middle_scan = false; /* scan-data-scan */
1005 epd->pre_border_byte = false;
1006 epd->border_byte = REPAPER_BORDER_BYTE_SET;
1010 mode = &repaper_e2200cs021_mode;
1011 epd->channel_select = repaper_e2200cs021_cs;
1012 epd->stage_time = 480;
1013 epd->bytes_per_scan = 96 / 4;
1014 epd->middle_scan = true; /* data-scan-data */
1015 epd->pre_border_byte = true;
1016 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1020 epd->border = devm_gpiod_get(dev, "border", GPIOD_OUT_LOW);
1021 if (IS_ERR(epd->border)) {
1022 ret = PTR_ERR(epd->border);
1023 if (ret != -EPROBE_DEFER)
1024 DRM_DEV_ERROR(dev, "Failed to get gpio 'border'\n");
1028 mode = &repaper_e2271cs021_mode;
1029 epd->channel_select = repaper_e2271cs021_cs;
1030 epd->stage_time = 630;
1031 epd->bytes_per_scan = 176 / 4;
1032 epd->middle_scan = true; /* data-scan-data */
1033 epd->pre_border_byte = true;
1034 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1041 epd->width = mode->hdisplay;
1042 epd->height = mode->vdisplay;
1043 epd->factored_stage_time = epd->stage_time;
1045 line_buffer_size = 2 * epd->width / 8 + epd->bytes_per_scan + 2;
1046 epd->line_buffer = devm_kzalloc(dev, line_buffer_size, GFP_KERNEL);
1047 if (!epd->line_buffer)
1050 epd->current_frame = devm_kzalloc(dev, epd->width * epd->height / 8,
1052 if (!epd->current_frame)
1055 tdev = &epd->tinydrm;
1057 ret = devm_tinydrm_init(dev, tdev, &repaper_fb_funcs, &repaper_driver);
1061 tdev->fb_dirty = repaper_fb_dirty;
1063 ret = tinydrm_display_pipe_init(tdev, &repaper_pipe_funcs,
1064 DRM_MODE_CONNECTOR_VIRTUAL,
1066 ARRAY_SIZE(repaper_formats), mode, 0);
1070 drm_mode_config_reset(tdev->drm);
1071 spi_set_drvdata(spi, tdev);
1073 DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000);
1075 return devm_tinydrm_register(tdev);
1078 static void repaper_shutdown(struct spi_device *spi)
1080 struct tinydrm_device *tdev = spi_get_drvdata(spi);
1082 tinydrm_shutdown(tdev);
1085 static struct spi_driver repaper_spi_driver = {
1088 .owner = THIS_MODULE,
1089 .of_match_table = repaper_of_match,
1091 .id_table = repaper_id,
1092 .probe = repaper_probe,
1093 .shutdown = repaper_shutdown,
1095 module_spi_driver(repaper_spi_driver);
1097 MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver");
1098 MODULE_AUTHOR("Noralf Trønnes");
1099 MODULE_LICENSE("GPL");