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/tinydrm/tinydrm.h>
30 #include <drm/tinydrm/tinydrm-helpers.h>
32 #define REPAPER_RID_G2_COG_ID 0x12
41 enum repaper_stage { /* Image pixel -> Display pixel */
42 REPAPER_COMPENSATE, /* B -> W, W -> B (Current Image) */
43 REPAPER_WHITE, /* B -> N, W -> W (Current Image) */
44 REPAPER_INVERSE, /* B -> N, W -> B (New Image) */
45 REPAPER_NORMAL /* B -> B, W -> W (New Image) */
48 enum repaper_epd_border_byte {
49 REPAPER_BORDER_BYTE_NONE,
50 REPAPER_BORDER_BYTE_ZERO,
51 REPAPER_BORDER_BYTE_SET,
55 struct tinydrm_device tinydrm;
56 struct spi_device *spi;
58 struct gpio_desc *panel_on;
59 struct gpio_desc *border;
60 struct gpio_desc *discharge;
61 struct gpio_desc *reset;
62 struct gpio_desc *busy;
64 struct thermal_zone_device *thermal;
68 unsigned int bytes_per_scan;
69 const u8 *channel_select;
70 unsigned int stage_time;
71 unsigned int factored_stage_time;
74 enum repaper_epd_border_byte border_byte;
84 static inline struct repaper_epd *
85 epd_from_tinydrm(struct tinydrm_device *tdev)
87 return container_of(tdev, struct repaper_epd, tinydrm);
90 static int repaper_spi_transfer(struct spi_device *spi, u8 header,
91 const void *tx, void *rx, size_t len)
93 void *txbuf = NULL, *rxbuf = NULL;
94 struct spi_transfer tr[2] = {};
98 headerbuf = kmalloc(1, GFP_KERNEL);
102 headerbuf[0] = header;
103 tr[0].tx_buf = headerbuf;
106 /* Stack allocated tx? */
107 if (tx && len <= 32) {
108 txbuf = kmalloc(len, GFP_KERNEL);
113 memcpy(txbuf, tx, len);
117 rxbuf = kmalloc(len, GFP_KERNEL);
124 tr[1].tx_buf = txbuf ? txbuf : tx;
125 tr[1].rx_buf = rxbuf;
129 ret = spi_sync_transfer(spi, tr, 2);
131 memcpy(rx, rxbuf, len);
141 static int repaper_write_buf(struct spi_device *spi, u8 reg,
142 const u8 *buf, size_t len)
146 ret = repaper_spi_transfer(spi, 0x70, ®, NULL, 1);
150 return repaper_spi_transfer(spi, 0x72, buf, NULL, len);
153 static int repaper_write_val(struct spi_device *spi, u8 reg, u8 val)
155 return repaper_write_buf(spi, reg, &val, 1);
158 static int repaper_read_val(struct spi_device *spi, u8 reg)
163 ret = repaper_spi_transfer(spi, 0x70, ®, NULL, 1);
167 ret = repaper_spi_transfer(spi, 0x73, NULL, &val, 1);
169 return ret ? ret : val;
172 static int repaper_read_id(struct spi_device *spi)
177 ret = repaper_spi_transfer(spi, 0x71, NULL, &id, 1);
179 return ret ? ret : id;
182 static void repaper_spi_mosi_low(struct spi_device *spi)
184 const u8 buf[1] = { 0 };
186 spi_write(spi, buf, 1);
189 /* pixels on display are numbered from 1 so even is actually bits 1,3,5,... */
190 static void repaper_even_pixels(struct repaper_epd *epd, u8 **pp,
191 const u8 *data, u8 fixed_value, const u8 *mask,
192 enum repaper_stage stage)
196 for (b = 0; b < (epd->width / 8); b++) {
198 u8 pixels = data[b] & 0xaa;
199 u8 pixel_mask = 0xff;
203 pixel_mask = (mask[b] ^ pixels) & 0xaa;
204 pixel_mask |= pixel_mask >> 1;
208 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */
209 pixels = 0xaa | ((pixels ^ 0xaa) >> 1);
211 case REPAPER_WHITE: /* B -> N, W -> W (Current) */
212 pixels = 0x55 + ((pixels ^ 0xaa) >> 1);
214 case REPAPER_INVERSE: /* B -> N, W -> B (New) */
215 pixels = 0x55 | (pixels ^ 0xaa);
217 case REPAPER_NORMAL: /* B -> B, W -> W (New) */
218 pixels = 0xaa | (pixels >> 1);
222 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x55);
223 p1 = (pixels >> 6) & 0x03;
224 p2 = (pixels >> 4) & 0x03;
225 p3 = (pixels >> 2) & 0x03;
226 p4 = (pixels >> 0) & 0x03;
227 pixels = (p1 << 0) | (p2 << 2) | (p3 << 4) | (p4 << 6);
230 *(*pp)++ = fixed_value;
235 /* pixels on display are numbered from 1 so odd is actually bits 0,2,4,... */
236 static void repaper_odd_pixels(struct repaper_epd *epd, u8 **pp,
237 const u8 *data, u8 fixed_value, const u8 *mask,
238 enum repaper_stage stage)
242 for (b = epd->width / 8; b > 0; b--) {
244 u8 pixels = data[b - 1] & 0x55;
245 u8 pixel_mask = 0xff;
248 pixel_mask = (mask[b - 1] ^ pixels) & 0x55;
249 pixel_mask |= pixel_mask << 1;
253 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */
254 pixels = 0xaa | (pixels ^ 0x55);
256 case REPAPER_WHITE: /* B -> N, W -> W (Current) */
257 pixels = 0x55 + (pixels ^ 0x55);
259 case REPAPER_INVERSE: /* B -> N, W -> B (New) */
260 pixels = 0x55 | ((pixels ^ 0x55) << 1);
262 case REPAPER_NORMAL: /* B -> B, W -> W (New) */
263 pixels = 0xaa | pixels;
267 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x55);
270 *(*pp)++ = fixed_value;
275 /* interleave bits: (byte)76543210 -> (16 bit).7.6.5.4.3.2.1 */
276 static inline u16 repaper_interleave_bits(u16 value)
278 value = (value | (value << 4)) & 0x0f0f;
279 value = (value | (value << 2)) & 0x3333;
280 value = (value | (value << 1)) & 0x5555;
285 /* pixels on display are numbered from 1 */
286 static void repaper_all_pixels(struct repaper_epd *epd, u8 **pp,
287 const u8 *data, u8 fixed_value, const u8 *mask,
288 enum repaper_stage stage)
292 for (b = epd->width / 8; b > 0; b--) {
294 u16 pixels = repaper_interleave_bits(data[b - 1]);
295 u16 pixel_mask = 0xffff;
298 pixel_mask = repaper_interleave_bits(mask[b - 1]);
300 pixel_mask = (pixel_mask ^ pixels) & 0x5555;
301 pixel_mask |= pixel_mask << 1;
305 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */
306 pixels = 0xaaaa | (pixels ^ 0x5555);
308 case REPAPER_WHITE: /* B -> N, W -> W (Current) */
309 pixels = 0x5555 + (pixels ^ 0x5555);
311 case REPAPER_INVERSE: /* B -> N, W -> B (New) */
312 pixels = 0x5555 | ((pixels ^ 0x5555) << 1);
314 case REPAPER_NORMAL: /* B -> B, W -> W (New) */
315 pixels = 0xaaaa | pixels;
319 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x5555);
320 *(*pp)++ = pixels >> 8;
323 *(*pp)++ = fixed_value;
324 *(*pp)++ = fixed_value;
329 /* output one line of scan and data bytes to the display */
330 static void repaper_one_line(struct repaper_epd *epd, unsigned int line,
331 const u8 *data, u8 fixed_value, const u8 *mask,
332 enum repaper_stage stage)
334 u8 *p = epd->line_buffer;
337 repaper_spi_mosi_low(epd->spi);
339 if (epd->pre_border_byte)
342 if (epd->middle_scan) {
344 repaper_odd_pixels(epd, &p, data, fixed_value, mask, stage);
347 for (b = epd->bytes_per_scan; b > 0; b--) {
348 if (line / 4 == b - 1)
349 *p++ = 0x03 << (2 * (line & 0x03));
355 repaper_even_pixels(epd, &p, data, fixed_value, mask, stage);
358 * even scan line, but as lines on display are numbered from 1,
361 for (b = 0; b < epd->bytes_per_scan; b++) {
362 if (0 != (line & 0x01) && line / 8 == b)
363 *p++ = 0xc0 >> (line & 0x06);
369 repaper_all_pixels(epd, &p, data, fixed_value, mask, stage);
372 * odd scan line, but as lines on display are numbered from 1,
375 for (b = epd->bytes_per_scan; b > 0; b--) {
376 if (0 == (line & 0x01) && line / 8 == b - 1)
377 *p++ = 0x03 << (line & 0x06);
383 switch (epd->border_byte) {
384 case REPAPER_BORDER_BYTE_NONE:
387 case REPAPER_BORDER_BYTE_ZERO:
391 case REPAPER_BORDER_BYTE_SET:
393 case REPAPER_COMPENSATE:
395 case REPAPER_INVERSE:
405 repaper_write_buf(epd->spi, 0x0a, epd->line_buffer,
406 p - epd->line_buffer);
408 /* Output data to panel */
409 repaper_write_val(epd->spi, 0x02, 0x07);
411 repaper_spi_mosi_low(epd->spi);
414 static void repaper_frame_fixed(struct repaper_epd *epd, u8 fixed_value,
415 enum repaper_stage stage)
419 for (line = 0; line < epd->height; line++)
420 repaper_one_line(epd, line, NULL, fixed_value, NULL, stage);
423 static void repaper_frame_data(struct repaper_epd *epd, const u8 *image,
424 const u8 *mask, enum repaper_stage stage)
429 for (line = 0; line < epd->height; line++) {
430 repaper_one_line(epd, line,
431 &image[line * (epd->width / 8)],
435 for (line = 0; line < epd->height; line++) {
436 size_t n = line * epd->width / 8;
438 repaper_one_line(epd, line, &image[n], 0, &mask[n],
444 static void repaper_frame_fixed_repeat(struct repaper_epd *epd, u8 fixed_value,
445 enum repaper_stage stage)
447 u64 start = local_clock();
448 u64 end = start + (epd->factored_stage_time * 1000 * 1000);
451 repaper_frame_fixed(epd, fixed_value, stage);
452 } while (local_clock() < end);
455 static void repaper_frame_data_repeat(struct repaper_epd *epd, const u8 *image,
456 const u8 *mask, enum repaper_stage stage)
458 u64 start = local_clock();
459 u64 end = start + (epd->factored_stage_time * 1000 * 1000);
462 repaper_frame_data(epd, image, mask, stage);
463 } while (local_clock() < end);
466 static void repaper_get_temperature(struct repaper_epd *epd)
468 int ret, temperature = 0;
469 unsigned int factor10x;
474 ret = thermal_zone_get_temp(epd->thermal, &temperature);
476 dev_err(&epd->spi->dev, "Failed to get temperature (%d)\n",
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;
543 mutex_lock(&tdev->dirty_lock);
548 /* fbdev can flush even when we're not interested */
549 if (tdev->pipe.plane.fb != fb)
552 repaper_get_temperature(epd);
554 DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id,
555 epd->factored_stage_time);
557 buf = kmalloc(fb->width * fb->height, GFP_KERNEL);
564 ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
570 tinydrm_xrgb8888_to_gray8(buf, cma_obj->vaddr, fb, &clip);
573 ret = dma_buf_end_cpu_access(import_attach->dmabuf,
579 repaper_gray8_to_mono_reversed(buf, fb->width, fb->height);
582 repaper_frame_data_repeat(epd, buf, epd->current_frame,
584 } else if (epd->cleared) {
585 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
587 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
589 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
590 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
594 /* Clear display (anything -> white) */
595 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_COMPENSATE);
596 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_WHITE);
597 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_INVERSE);
598 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_NORMAL);
600 /* Assuming a clear (white) screen output an image */
601 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_COMPENSATE);
602 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_WHITE);
603 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
604 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
610 memcpy(epd->current_frame, buf, fb->width * fb->height / 8);
613 * An extra frame write is needed if pixels are set in the bottom line,
614 * or else grey lines rises up from the pixels
616 if (epd->pre_border_byte) {
619 for (x = 0; x < (fb->width / 8); x++)
620 if (buf[x + (fb->width * (fb->height - 1) / 8)]) {
621 repaper_frame_data_repeat(epd, buf,
629 mutex_unlock(&tdev->dirty_lock);
632 dev_err(fb->dev->dev, "Failed to update display (%d)\n", ret);
638 static const struct drm_framebuffer_funcs repaper_fb_funcs = {
639 .destroy = drm_fb_cma_destroy,
640 .create_handle = drm_fb_cma_create_handle,
641 .dirty = repaper_fb_dirty,
644 static void power_off(struct repaper_epd *epd)
646 /* Turn off power and all signals */
647 gpiod_set_value_cansleep(epd->reset, 0);
648 gpiod_set_value_cansleep(epd->panel_on, 0);
650 gpiod_set_value_cansleep(epd->border, 0);
652 /* Ensure SPI MOSI and CLOCK are Low before CS Low */
653 repaper_spi_mosi_low(epd->spi);
655 /* Discharge pulse */
656 gpiod_set_value_cansleep(epd->discharge, 1);
658 gpiod_set_value_cansleep(epd->discharge, 0);
661 static void repaper_pipe_enable(struct drm_simple_display_pipe *pipe,
662 struct drm_crtc_state *crtc_state)
664 struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
665 struct repaper_epd *epd = epd_from_tinydrm(tdev);
666 struct spi_device *spi = epd->spi;
667 struct device *dev = &spi->dev;
671 DRM_DEBUG_DRIVER("\n");
673 /* Power up sequence */
674 gpiod_set_value_cansleep(epd->reset, 0);
675 gpiod_set_value_cansleep(epd->panel_on, 0);
676 gpiod_set_value_cansleep(epd->discharge, 0);
678 gpiod_set_value_cansleep(epd->border, 0);
679 repaper_spi_mosi_low(spi);
680 usleep_range(5000, 10000);
682 gpiod_set_value_cansleep(epd->panel_on, 1);
684 * This delay comes from the repaper.org userspace driver, it's not
685 * mentioned in the datasheet.
687 usleep_range(10000, 15000);
688 gpiod_set_value_cansleep(epd->reset, 1);
690 gpiod_set_value_cansleep(epd->border, 1);
691 usleep_range(5000, 10000);
692 gpiod_set_value_cansleep(epd->reset, 0);
693 usleep_range(5000, 10000);
694 gpiod_set_value_cansleep(epd->reset, 1);
695 usleep_range(5000, 10000);
697 /* Wait for COG to become ready */
698 for (i = 100; i > 0; i--) {
699 if (!gpiod_get_value_cansleep(epd->busy))
702 usleep_range(10, 100);
706 dev_err(dev, "timeout waiting for panel to become ready.\n");
711 repaper_read_id(spi);
712 ret = repaper_read_id(spi);
713 if (ret != REPAPER_RID_G2_COG_ID) {
715 dev_err(dev, "failed to read chip (%d)\n", ret);
717 dev_err(dev, "wrong COG ID 0x%02x\n", ret);
723 repaper_write_val(spi, 0x02, 0x40);
725 ret = repaper_read_val(spi, 0x0f);
726 if (ret < 0 || !(ret & 0x80)) {
728 dev_err(dev, "failed to read chip (%d)\n", ret);
730 dev_err(dev, "panel is reported broken\n");
735 /* Power saving mode */
736 repaper_write_val(spi, 0x0b, 0x02);
738 repaper_write_buf(spi, 0x01, epd->channel_select, 8);
739 /* High power mode osc */
740 repaper_write_val(spi, 0x07, 0xd1);
742 repaper_write_val(spi, 0x08, 0x02);
744 repaper_write_val(spi, 0x09, 0xc2);
746 repaper_write_val(spi, 0x04, 0x03);
747 /* Driver latch on */
748 repaper_write_val(spi, 0x03, 0x01);
749 /* Driver latch off */
750 repaper_write_val(spi, 0x03, 0x00);
751 usleep_range(5000, 10000);
753 /* Start chargepump */
754 for (i = 0; i < 4; ++i) {
755 /* Charge pump positive voltage on - VGH/VDL on */
756 repaper_write_val(spi, 0x05, 0x01);
759 /* Charge pump negative voltage on - VGL/VDL on */
760 repaper_write_val(spi, 0x05, 0x03);
763 /* Charge pump Vcom on - Vcom driver on */
764 repaper_write_val(spi, 0x05, 0x0f);
768 ret = repaper_read_val(spi, 0x0f);
770 dev_err(dev, "failed to read chip (%d)\n", ret);
782 dev_err(dev, "dc/dc failed\n");
788 * Output enable to disable
789 * The userspace driver sets this to 0x04, but the datasheet says 0x06
791 repaper_write_val(spi, 0x02, 0x04);
794 epd->partial = false;
797 static void repaper_pipe_disable(struct drm_simple_display_pipe *pipe)
799 struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
800 struct repaper_epd *epd = epd_from_tinydrm(tdev);
801 struct spi_device *spi = epd->spi;
804 DRM_DEBUG_DRIVER("\n");
806 mutex_lock(&tdev->dirty_lock);
807 epd->enabled = false;
808 mutex_unlock(&tdev->dirty_lock);
811 for (line = 0; line < epd->height; line++)
812 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
818 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
821 gpiod_set_value_cansleep(epd->border, 0);
823 gpiod_set_value_cansleep(epd->border, 1);
825 /* Border dummy line */
826 repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
831 /* not described in datasheet */
832 repaper_write_val(spi, 0x0b, 0x00);
833 /* Latch reset turn on */
834 repaper_write_val(spi, 0x03, 0x01);
835 /* Power off charge pump Vcom */
836 repaper_write_val(spi, 0x05, 0x03);
837 /* Power off charge pump neg voltage */
838 repaper_write_val(spi, 0x05, 0x01);
840 /* Discharge internal */
841 repaper_write_val(spi, 0x04, 0x80);
842 /* turn off all charge pumps */
843 repaper_write_val(spi, 0x05, 0x00);
845 repaper_write_val(spi, 0x07, 0x01);
851 static const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = {
852 .enable = repaper_pipe_enable,
853 .disable = repaper_pipe_disable,
854 .update = tinydrm_display_pipe_update,
855 .prepare_fb = tinydrm_display_pipe_prepare_fb,
858 static const uint32_t repaper_formats[] = {
862 static const struct drm_display_mode repaper_e1144cs021_mode = {
863 TINYDRM_MODE(128, 96, 29, 22),
866 static const u8 repaper_e1144cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
867 0x00, 0x0f, 0xff, 0x00 };
869 static const struct drm_display_mode repaper_e1190cs021_mode = {
870 TINYDRM_MODE(144, 128, 36, 32),
873 static const u8 repaper_e1190cs021_cs[] = { 0x00, 0x00, 0x00, 0x03,
874 0xfc, 0x00, 0x00, 0xff };
876 static const struct drm_display_mode repaper_e2200cs021_mode = {
877 TINYDRM_MODE(200, 96, 46, 22),
880 static const u8 repaper_e2200cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
881 0x01, 0xff, 0xe0, 0x00 };
883 static const struct drm_display_mode repaper_e2271cs021_mode = {
884 TINYDRM_MODE(264, 176, 57, 38),
887 static const u8 repaper_e2271cs021_cs[] = { 0x00, 0x00, 0x00, 0x7f,
888 0xff, 0xfe, 0x00, 0x00 };
890 DEFINE_DRM_GEM_CMA_FOPS(repaper_fops);
892 static struct drm_driver repaper_driver = {
893 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
895 .fops = &repaper_fops,
896 TINYDRM_GEM_DRIVER_OPS,
898 .desc = "Pervasive Displays RePaper e-ink panels",
904 static const struct of_device_id repaper_of_match[] = {
905 { .compatible = "pervasive,e1144cs021", .data = (void *)E1144CS021 },
906 { .compatible = "pervasive,e1190cs021", .data = (void *)E1190CS021 },
907 { .compatible = "pervasive,e2200cs021", .data = (void *)E2200CS021 },
908 { .compatible = "pervasive,e2271cs021", .data = (void *)E2271CS021 },
911 MODULE_DEVICE_TABLE(of, repaper_of_match);
913 static const struct spi_device_id repaper_id[] = {
914 { "e1144cs021", E1144CS021 },
915 { "e1190cs021", E1190CS021 },
916 { "e2200cs021", E2200CS021 },
917 { "e2271cs021", E2271CS021 },
920 MODULE_DEVICE_TABLE(spi, repaper_id);
922 static int repaper_probe(struct spi_device *spi)
924 const struct drm_display_mode *mode;
925 const struct spi_device_id *spi_id;
926 const struct of_device_id *match;
927 struct device *dev = &spi->dev;
928 struct tinydrm_device *tdev;
929 enum repaper_model model;
930 const char *thermal_zone;
931 struct repaper_epd *epd;
932 size_t line_buffer_size;
935 match = of_match_device(repaper_of_match, dev);
937 model = (enum repaper_model)match->data;
939 spi_id = spi_get_device_id(spi);
940 model = spi_id->driver_data;
943 /* The SPI device is used to allocate dma memory */
944 if (!dev->coherent_dma_mask) {
945 ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
947 dev_warn(dev, "Failed to set dma mask %d\n", ret);
952 epd = devm_kzalloc(dev, sizeof(*epd), GFP_KERNEL);
958 epd->panel_on = devm_gpiod_get(dev, "panel-on", GPIOD_OUT_LOW);
959 if (IS_ERR(epd->panel_on)) {
960 ret = PTR_ERR(epd->panel_on);
961 if (ret != -EPROBE_DEFER)
962 dev_err(dev, "Failed to get gpio 'panel-on'\n");
966 epd->discharge = devm_gpiod_get(dev, "discharge", GPIOD_OUT_LOW);
967 if (IS_ERR(epd->discharge)) {
968 ret = PTR_ERR(epd->discharge);
969 if (ret != -EPROBE_DEFER)
970 dev_err(dev, "Failed to get gpio 'discharge'\n");
974 epd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
975 if (IS_ERR(epd->reset)) {
976 ret = PTR_ERR(epd->reset);
977 if (ret != -EPROBE_DEFER)
978 dev_err(dev, "Failed to get gpio 'reset'\n");
982 epd->busy = devm_gpiod_get(dev, "busy", GPIOD_IN);
983 if (IS_ERR(epd->busy)) {
984 ret = PTR_ERR(epd->busy);
985 if (ret != -EPROBE_DEFER)
986 dev_err(dev, "Failed to get gpio 'busy'\n");
990 if (!device_property_read_string(dev, "pervasive,thermal-zone",
992 epd->thermal = thermal_zone_get_zone_by_name(thermal_zone);
993 if (IS_ERR(epd->thermal)) {
994 dev_err(dev, "Failed to get thermal zone: %s\n",
996 return PTR_ERR(epd->thermal);
1002 mode = &repaper_e1144cs021_mode;
1003 epd->channel_select = repaper_e1144cs021_cs;
1004 epd->stage_time = 480;
1005 epd->bytes_per_scan = 96 / 4;
1006 epd->middle_scan = true; /* data-scan-data */
1007 epd->pre_border_byte = false;
1008 epd->border_byte = REPAPER_BORDER_BYTE_ZERO;
1012 mode = &repaper_e1190cs021_mode;
1013 epd->channel_select = repaper_e1190cs021_cs;
1014 epd->stage_time = 480;
1015 epd->bytes_per_scan = 128 / 4 / 2;
1016 epd->middle_scan = false; /* scan-data-scan */
1017 epd->pre_border_byte = false;
1018 epd->border_byte = REPAPER_BORDER_BYTE_SET;
1022 mode = &repaper_e2200cs021_mode;
1023 epd->channel_select = repaper_e2200cs021_cs;
1024 epd->stage_time = 480;
1025 epd->bytes_per_scan = 96 / 4;
1026 epd->middle_scan = true; /* data-scan-data */
1027 epd->pre_border_byte = true;
1028 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1032 epd->border = devm_gpiod_get(dev, "border", GPIOD_OUT_LOW);
1033 if (IS_ERR(epd->border)) {
1034 ret = PTR_ERR(epd->border);
1035 if (ret != -EPROBE_DEFER)
1036 dev_err(dev, "Failed to get gpio 'border'\n");
1040 mode = &repaper_e2271cs021_mode;
1041 epd->channel_select = repaper_e2271cs021_cs;
1042 epd->stage_time = 630;
1043 epd->bytes_per_scan = 176 / 4;
1044 epd->middle_scan = true; /* data-scan-data */
1045 epd->pre_border_byte = true;
1046 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1053 epd->width = mode->hdisplay;
1054 epd->height = mode->vdisplay;
1055 epd->factored_stage_time = epd->stage_time;
1057 line_buffer_size = 2 * epd->width / 8 + epd->bytes_per_scan + 2;
1058 epd->line_buffer = devm_kzalloc(dev, line_buffer_size, GFP_KERNEL);
1059 if (!epd->line_buffer)
1062 epd->current_frame = devm_kzalloc(dev, epd->width * epd->height / 8,
1064 if (!epd->current_frame)
1067 tdev = &epd->tinydrm;
1069 ret = devm_tinydrm_init(dev, tdev, &repaper_fb_funcs, &repaper_driver);
1073 ret = tinydrm_display_pipe_init(tdev, &repaper_pipe_funcs,
1074 DRM_MODE_CONNECTOR_VIRTUAL,
1076 ARRAY_SIZE(repaper_formats), mode, 0);
1080 drm_mode_config_reset(tdev->drm);
1082 ret = devm_tinydrm_register(tdev);
1086 spi_set_drvdata(spi, tdev);
1088 DRM_DEBUG_DRIVER("Initialized %s:%s @%uMHz on minor %d\n",
1089 tdev->drm->driver->name, dev_name(dev),
1090 spi->max_speed_hz / 1000000,
1091 tdev->drm->primary->index);
1096 static void repaper_shutdown(struct spi_device *spi)
1098 struct tinydrm_device *tdev = spi_get_drvdata(spi);
1100 tinydrm_shutdown(tdev);
1103 static struct spi_driver repaper_spi_driver = {
1106 .owner = THIS_MODULE,
1107 .of_match_table = repaper_of_match,
1109 .id_table = repaper_id,
1110 .probe = repaper_probe,
1111 .shutdown = repaper_shutdown,
1113 module_spi_driver(repaper_spi_driver);
1115 MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver");
1116 MODULE_AUTHOR("Noralf Trønnes");
1117 MODULE_LICENSE("GPL");