1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * DRM driver for Pervasive Displays RePaper branded e-ink panels
5 * Copyright 2013-2017 Pervasive Displays, Inc.
6 * Copyright 2017 Noralf Trønnes
9 * Material Film: Aurora Mb (V231)
12 * The controller code was taken from the userspace driver:
13 * https://github.com/repaper/gratis
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/of_device.h>
21 #include <linux/sched/clock.h>
22 #include <linux/spi/spi.h>
23 #include <linux/thermal.h>
25 #include <drm/drm_atomic_helper.h>
26 #include <drm/drm_damage_helper.h>
27 #include <drm/drm_drv.h>
28 #include <drm/drm_fb_cma_helper.h>
29 #include <drm/drm_fb_helper.h>
30 #include <drm/drm_format_helper.h>
31 #include <drm/drm_gem_cma_helper.h>
32 #include <drm/drm_gem_framebuffer_helper.h>
33 #include <drm/drm_rect.h>
34 #include <drm/drm_vblank.h>
35 #include <drm/drm_simple_kms_helper.h>
36 #include <drm/tinydrm/tinydrm-helpers.h>
38 #define REPAPER_RID_G2_COG_ID 0x12
47 enum repaper_stage { /* Image pixel -> Display pixel */
48 REPAPER_COMPENSATE, /* B -> W, W -> B (Current Image) */
49 REPAPER_WHITE, /* B -> N, W -> W (Current Image) */
50 REPAPER_INVERSE, /* B -> N, W -> B (New Image) */
51 REPAPER_NORMAL /* B -> B, W -> W (New Image) */
54 enum repaper_epd_border_byte {
55 REPAPER_BORDER_BYTE_NONE,
56 REPAPER_BORDER_BYTE_ZERO,
57 REPAPER_BORDER_BYTE_SET,
61 struct drm_device drm;
62 struct drm_simple_display_pipe pipe;
63 struct spi_device *spi;
65 struct gpio_desc *panel_on;
66 struct gpio_desc *border;
67 struct gpio_desc *discharge;
68 struct gpio_desc *reset;
69 struct gpio_desc *busy;
71 struct thermal_zone_device *thermal;
75 unsigned int bytes_per_scan;
76 const u8 *channel_select;
77 unsigned int stage_time;
78 unsigned int factored_stage_time;
81 enum repaper_epd_border_byte border_byte;
91 static inline struct repaper_epd *drm_to_epd(struct drm_device *drm)
93 return container_of(drm, struct repaper_epd, drm);
96 static int repaper_spi_transfer(struct spi_device *spi, u8 header,
97 const void *tx, void *rx, size_t len)
99 void *txbuf = NULL, *rxbuf = NULL;
100 struct spi_transfer tr[2] = {};
104 headerbuf = kmalloc(1, GFP_KERNEL);
108 headerbuf[0] = header;
109 tr[0].tx_buf = headerbuf;
112 /* Stack allocated tx? */
113 if (tx && len <= 32) {
114 txbuf = kmemdup(tx, len, GFP_KERNEL);
122 rxbuf = kmalloc(len, GFP_KERNEL);
129 tr[1].tx_buf = txbuf ? txbuf : tx;
130 tr[1].rx_buf = rxbuf;
134 ret = spi_sync_transfer(spi, tr, 2);
136 memcpy(rx, rxbuf, len);
146 static int repaper_write_buf(struct spi_device *spi, u8 reg,
147 const u8 *buf, size_t len)
151 ret = repaper_spi_transfer(spi, 0x70, ®, NULL, 1);
155 return repaper_spi_transfer(spi, 0x72, buf, NULL, len);
158 static int repaper_write_val(struct spi_device *spi, u8 reg, u8 val)
160 return repaper_write_buf(spi, reg, &val, 1);
163 static int repaper_read_val(struct spi_device *spi, u8 reg)
168 ret = repaper_spi_transfer(spi, 0x70, ®, NULL, 1);
172 ret = repaper_spi_transfer(spi, 0x73, NULL, &val, 1);
174 return ret ? ret : val;
177 static int repaper_read_id(struct spi_device *spi)
182 ret = repaper_spi_transfer(spi, 0x71, NULL, &id, 1);
184 return ret ? ret : id;
187 static void repaper_spi_mosi_low(struct spi_device *spi)
189 const u8 buf[1] = { 0 };
191 spi_write(spi, buf, 1);
194 /* pixels on display are numbered from 1 so even is actually bits 1,3,5,... */
195 static void repaper_even_pixels(struct repaper_epd *epd, u8 **pp,
196 const u8 *data, u8 fixed_value, const u8 *mask,
197 enum repaper_stage stage)
201 for (b = 0; b < (epd->width / 8); b++) {
203 u8 pixels = data[b] & 0xaa;
204 u8 pixel_mask = 0xff;
208 pixel_mask = (mask[b] ^ pixels) & 0xaa;
209 pixel_mask |= pixel_mask >> 1;
213 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */
214 pixels = 0xaa | ((pixels ^ 0xaa) >> 1);
216 case REPAPER_WHITE: /* B -> N, W -> W (Current) */
217 pixels = 0x55 + ((pixels ^ 0xaa) >> 1);
219 case REPAPER_INVERSE: /* B -> N, W -> B (New) */
220 pixels = 0x55 | (pixels ^ 0xaa);
222 case REPAPER_NORMAL: /* B -> B, W -> W (New) */
223 pixels = 0xaa | (pixels >> 1);
227 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x55);
228 p1 = (pixels >> 6) & 0x03;
229 p2 = (pixels >> 4) & 0x03;
230 p3 = (pixels >> 2) & 0x03;
231 p4 = (pixels >> 0) & 0x03;
232 pixels = (p1 << 0) | (p2 << 2) | (p3 << 4) | (p4 << 6);
235 *(*pp)++ = fixed_value;
240 /* pixels on display are numbered from 1 so odd is actually bits 0,2,4,... */
241 static void repaper_odd_pixels(struct repaper_epd *epd, u8 **pp,
242 const u8 *data, u8 fixed_value, const u8 *mask,
243 enum repaper_stage stage)
247 for (b = epd->width / 8; b > 0; b--) {
249 u8 pixels = data[b - 1] & 0x55;
250 u8 pixel_mask = 0xff;
253 pixel_mask = (mask[b - 1] ^ pixels) & 0x55;
254 pixel_mask |= pixel_mask << 1;
258 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */
259 pixels = 0xaa | (pixels ^ 0x55);
261 case REPAPER_WHITE: /* B -> N, W -> W (Current) */
262 pixels = 0x55 + (pixels ^ 0x55);
264 case REPAPER_INVERSE: /* B -> N, W -> B (New) */
265 pixels = 0x55 | ((pixels ^ 0x55) << 1);
267 case REPAPER_NORMAL: /* B -> B, W -> W (New) */
268 pixels = 0xaa | pixels;
272 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x55);
275 *(*pp)++ = fixed_value;
280 /* interleave bits: (byte)76543210 -> (16 bit).7.6.5.4.3.2.1 */
281 static inline u16 repaper_interleave_bits(u16 value)
283 value = (value | (value << 4)) & 0x0f0f;
284 value = (value | (value << 2)) & 0x3333;
285 value = (value | (value << 1)) & 0x5555;
290 /* pixels on display are numbered from 1 */
291 static void repaper_all_pixels(struct repaper_epd *epd, u8 **pp,
292 const u8 *data, u8 fixed_value, const u8 *mask,
293 enum repaper_stage stage)
297 for (b = epd->width / 8; b > 0; b--) {
299 u16 pixels = repaper_interleave_bits(data[b - 1]);
300 u16 pixel_mask = 0xffff;
303 pixel_mask = repaper_interleave_bits(mask[b - 1]);
305 pixel_mask = (pixel_mask ^ pixels) & 0x5555;
306 pixel_mask |= pixel_mask << 1;
310 case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */
311 pixels = 0xaaaa | (pixels ^ 0x5555);
313 case REPAPER_WHITE: /* B -> N, W -> W (Current) */
314 pixels = 0x5555 + (pixels ^ 0x5555);
316 case REPAPER_INVERSE: /* B -> N, W -> B (New) */
317 pixels = 0x5555 | ((pixels ^ 0x5555) << 1);
319 case REPAPER_NORMAL: /* B -> B, W -> W (New) */
320 pixels = 0xaaaa | pixels;
324 pixels = (pixels & pixel_mask) | (~pixel_mask & 0x5555);
325 *(*pp)++ = pixels >> 8;
328 *(*pp)++ = fixed_value;
329 *(*pp)++ = fixed_value;
334 /* output one line of scan and data bytes to the display */
335 static void repaper_one_line(struct repaper_epd *epd, unsigned int line,
336 const u8 *data, u8 fixed_value, const u8 *mask,
337 enum repaper_stage stage)
339 u8 *p = epd->line_buffer;
342 repaper_spi_mosi_low(epd->spi);
344 if (epd->pre_border_byte)
347 if (epd->middle_scan) {
349 repaper_odd_pixels(epd, &p, data, fixed_value, mask, stage);
352 for (b = epd->bytes_per_scan; b > 0; b--) {
353 if (line / 4 == b - 1)
354 *p++ = 0x03 << (2 * (line & 0x03));
360 repaper_even_pixels(epd, &p, data, fixed_value, mask, stage);
363 * even scan line, but as lines on display are numbered from 1,
366 for (b = 0; b < epd->bytes_per_scan; b++) {
367 if (0 != (line & 0x01) && line / 8 == b)
368 *p++ = 0xc0 >> (line & 0x06);
374 repaper_all_pixels(epd, &p, data, fixed_value, mask, stage);
377 * odd scan line, but as lines on display are numbered from 1,
380 for (b = epd->bytes_per_scan; b > 0; b--) {
381 if (0 == (line & 0x01) && line / 8 == b - 1)
382 *p++ = 0x03 << (line & 0x06);
388 switch (epd->border_byte) {
389 case REPAPER_BORDER_BYTE_NONE:
392 case REPAPER_BORDER_BYTE_ZERO:
396 case REPAPER_BORDER_BYTE_SET:
398 case REPAPER_COMPENSATE:
400 case REPAPER_INVERSE:
410 repaper_write_buf(epd->spi, 0x0a, epd->line_buffer,
411 p - epd->line_buffer);
413 /* Output data to panel */
414 repaper_write_val(epd->spi, 0x02, 0x07);
416 repaper_spi_mosi_low(epd->spi);
419 static void repaper_frame_fixed(struct repaper_epd *epd, u8 fixed_value,
420 enum repaper_stage stage)
424 for (line = 0; line < epd->height; line++)
425 repaper_one_line(epd, line, NULL, fixed_value, NULL, stage);
428 static void repaper_frame_data(struct repaper_epd *epd, const u8 *image,
429 const u8 *mask, enum repaper_stage stage)
434 for (line = 0; line < epd->height; line++) {
435 repaper_one_line(epd, line,
436 &image[line * (epd->width / 8)],
440 for (line = 0; line < epd->height; line++) {
441 size_t n = line * epd->width / 8;
443 repaper_one_line(epd, line, &image[n], 0, &mask[n],
449 static void repaper_frame_fixed_repeat(struct repaper_epd *epd, u8 fixed_value,
450 enum repaper_stage stage)
452 u64 start = local_clock();
453 u64 end = start + (epd->factored_stage_time * 1000 * 1000);
456 repaper_frame_fixed(epd, fixed_value, stage);
457 } while (local_clock() < end);
460 static void repaper_frame_data_repeat(struct repaper_epd *epd, const u8 *image,
461 const u8 *mask, enum repaper_stage stage)
463 u64 start = local_clock();
464 u64 end = start + (epd->factored_stage_time * 1000 * 1000);
467 repaper_frame_data(epd, image, mask, stage);
468 } while (local_clock() < end);
471 static void repaper_get_temperature(struct repaper_epd *epd)
473 int ret, temperature = 0;
474 unsigned int factor10x;
479 ret = thermal_zone_get_temp(epd->thermal, &temperature);
481 DRM_DEV_ERROR(&epd->spi->dev, "Failed to get temperature (%d)\n", ret);
487 if (temperature <= -10)
489 else if (temperature <= -5)
491 else if (temperature <= 5)
493 else if (temperature <= 10)
495 else if (temperature <= 15)
497 else if (temperature <= 20)
499 else if (temperature <= 40)
504 epd->factored_stage_time = epd->stage_time * factor10x / 10;
507 static void repaper_gray8_to_mono_reversed(u8 *buf, u32 width, u32 height)
509 u8 *gray8 = buf, *mono = buf;
512 for (y = 0; y < height; y++)
513 for (xb = 0; xb < width / 8; xb++) {
516 for (i = 0; i < 8; i++) {
520 if (gray8[y * width + x] >> 7)
527 static int repaper_fb_dirty(struct drm_framebuffer *fb)
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 repaper_epd *epd = drm_to_epd(fb->dev);
532 struct drm_rect clip;
539 if (!drm_dev_enter(fb->dev, &idx))
542 /* repaper can't do partial updates */
546 clip.y2 = fb->height;
548 repaper_get_temperature(epd);
550 DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id,
551 epd->factored_stage_time);
553 buf = kmalloc_array(fb->width, fb->height, GFP_KERNEL);
560 ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
566 drm_fb_xrgb8888_to_gray8(buf, cma_obj->vaddr, fb, &clip);
569 ret = dma_buf_end_cpu_access(import_attach->dmabuf,
575 repaper_gray8_to_mono_reversed(buf, fb->width, fb->height);
578 repaper_frame_data_repeat(epd, buf, epd->current_frame,
580 } else if (epd->cleared) {
581 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
583 repaper_frame_data_repeat(epd, epd->current_frame, NULL,
585 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
586 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
590 /* Clear display (anything -> white) */
591 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_COMPENSATE);
592 repaper_frame_fixed_repeat(epd, 0xff, REPAPER_WHITE);
593 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_INVERSE);
594 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_NORMAL);
596 /* Assuming a clear (white) screen output an image */
597 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_COMPENSATE);
598 repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_WHITE);
599 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
600 repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
606 memcpy(epd->current_frame, buf, fb->width * fb->height / 8);
609 * An extra frame write is needed if pixels are set in the bottom line,
610 * or else grey lines rises up from the pixels
612 if (epd->pre_border_byte) {
615 for (x = 0; x < (fb->width / 8); x++)
616 if (buf[x + (fb->width * (fb->height - 1) / 8)]) {
617 repaper_frame_data_repeat(epd, buf,
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 repaper_epd *epd = drm_to_epd(pipe->crtc.dev);
654 struct spi_device *spi = epd->spi;
655 struct device *dev = &spi->dev;
659 if (!drm_dev_enter(pipe->crtc.dev, &idx))
662 DRM_DEBUG_DRIVER("\n");
664 /* Power up sequence */
665 gpiod_set_value_cansleep(epd->reset, 0);
666 gpiod_set_value_cansleep(epd->panel_on, 0);
667 gpiod_set_value_cansleep(epd->discharge, 0);
669 gpiod_set_value_cansleep(epd->border, 0);
670 repaper_spi_mosi_low(spi);
671 usleep_range(5000, 10000);
673 gpiod_set_value_cansleep(epd->panel_on, 1);
675 * This delay comes from the repaper.org userspace driver, it's not
676 * mentioned in the datasheet.
678 usleep_range(10000, 15000);
679 gpiod_set_value_cansleep(epd->reset, 1);
681 gpiod_set_value_cansleep(epd->border, 1);
682 usleep_range(5000, 10000);
683 gpiod_set_value_cansleep(epd->reset, 0);
684 usleep_range(5000, 10000);
685 gpiod_set_value_cansleep(epd->reset, 1);
686 usleep_range(5000, 10000);
688 /* Wait for COG to become ready */
689 for (i = 100; i > 0; i--) {
690 if (!gpiod_get_value_cansleep(epd->busy))
693 usleep_range(10, 100);
697 DRM_DEV_ERROR(dev, "timeout waiting for panel to become ready.\n");
702 repaper_read_id(spi);
703 ret = repaper_read_id(spi);
704 if (ret != REPAPER_RID_G2_COG_ID) {
706 dev_err(dev, "failed to read chip (%d)\n", ret);
708 dev_err(dev, "wrong COG ID 0x%02x\n", ret);
714 repaper_write_val(spi, 0x02, 0x40);
716 ret = repaper_read_val(spi, 0x0f);
717 if (ret < 0 || !(ret & 0x80)) {
719 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
721 DRM_DEV_ERROR(dev, "panel is reported broken\n");
726 /* Power saving mode */
727 repaper_write_val(spi, 0x0b, 0x02);
729 repaper_write_buf(spi, 0x01, epd->channel_select, 8);
730 /* High power mode osc */
731 repaper_write_val(spi, 0x07, 0xd1);
733 repaper_write_val(spi, 0x08, 0x02);
735 repaper_write_val(spi, 0x09, 0xc2);
737 repaper_write_val(spi, 0x04, 0x03);
738 /* Driver latch on */
739 repaper_write_val(spi, 0x03, 0x01);
740 /* Driver latch off */
741 repaper_write_val(spi, 0x03, 0x00);
742 usleep_range(5000, 10000);
744 /* Start chargepump */
745 for (i = 0; i < 4; ++i) {
746 /* Charge pump positive voltage on - VGH/VDL on */
747 repaper_write_val(spi, 0x05, 0x01);
750 /* Charge pump negative voltage on - VGL/VDL on */
751 repaper_write_val(spi, 0x05, 0x03);
754 /* Charge pump Vcom on - Vcom driver on */
755 repaper_write_val(spi, 0x05, 0x0f);
759 ret = repaper_read_val(spi, 0x0f);
761 DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
773 DRM_DEV_ERROR(dev, "dc/dc failed\n");
779 * Output enable to disable
780 * The userspace driver sets this to 0x04, but the datasheet says 0x06
782 repaper_write_val(spi, 0x02, 0x04);
785 epd->partial = false;
790 static void repaper_pipe_disable(struct drm_simple_display_pipe *pipe)
792 struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev);
793 struct spi_device *spi = epd->spi;
797 * This callback is not protected by drm_dev_enter/exit since we want to
798 * turn off the display on regular driver unload. It's highly unlikely
799 * that the underlying SPI controller is gone should this be called after
806 DRM_DEBUG_DRIVER("\n");
808 epd->enabled = false;
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 void repaper_pipe_update(struct drm_simple_display_pipe *pipe,
852 struct drm_plane_state *old_state)
854 struct drm_plane_state *state = pipe->plane.state;
855 struct drm_crtc *crtc = &pipe->crtc;
856 struct drm_rect rect;
858 if (drm_atomic_helper_damage_merged(old_state, state, &rect))
859 repaper_fb_dirty(state->fb);
861 if (crtc->state->event) {
862 spin_lock_irq(&crtc->dev->event_lock);
863 drm_crtc_send_vblank_event(crtc, crtc->state->event);
864 spin_unlock_irq(&crtc->dev->event_lock);
865 crtc->state->event = NULL;
869 static const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = {
870 .enable = repaper_pipe_enable,
871 .disable = repaper_pipe_disable,
872 .update = repaper_pipe_update,
873 .prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
876 static const struct drm_mode_config_funcs repaper_mode_config_funcs = {
877 .fb_create = drm_gem_fb_create_with_dirty,
878 .atomic_check = drm_atomic_helper_check,
879 .atomic_commit = drm_atomic_helper_commit,
882 static void repaper_release(struct drm_device *drm)
884 struct repaper_epd *epd = drm_to_epd(drm);
886 DRM_DEBUG_DRIVER("\n");
888 drm_mode_config_cleanup(drm);
893 static const uint32_t repaper_formats[] = {
897 static const struct drm_display_mode repaper_e1144cs021_mode = {
898 DRM_SIMPLE_MODE(128, 96, 29, 22),
901 static const u8 repaper_e1144cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
902 0x00, 0x0f, 0xff, 0x00 };
904 static const struct drm_display_mode repaper_e1190cs021_mode = {
905 DRM_SIMPLE_MODE(144, 128, 36, 32),
908 static const u8 repaper_e1190cs021_cs[] = { 0x00, 0x00, 0x00, 0x03,
909 0xfc, 0x00, 0x00, 0xff };
911 static const struct drm_display_mode repaper_e2200cs021_mode = {
912 DRM_SIMPLE_MODE(200, 96, 46, 22),
915 static const u8 repaper_e2200cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
916 0x01, 0xff, 0xe0, 0x00 };
918 static const struct drm_display_mode repaper_e2271cs021_mode = {
919 DRM_SIMPLE_MODE(264, 176, 57, 38),
922 static const u8 repaper_e2271cs021_cs[] = { 0x00, 0x00, 0x00, 0x7f,
923 0xff, 0xfe, 0x00, 0x00 };
925 DEFINE_DRM_GEM_CMA_FOPS(repaper_fops);
927 static struct drm_driver repaper_driver = {
928 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
930 .fops = &repaper_fops,
931 .release = repaper_release,
932 DRM_GEM_CMA_VMAP_DRIVER_OPS,
934 .desc = "Pervasive Displays RePaper e-ink panels",
940 static const struct of_device_id repaper_of_match[] = {
941 { .compatible = "pervasive,e1144cs021", .data = (void *)E1144CS021 },
942 { .compatible = "pervasive,e1190cs021", .data = (void *)E1190CS021 },
943 { .compatible = "pervasive,e2200cs021", .data = (void *)E2200CS021 },
944 { .compatible = "pervasive,e2271cs021", .data = (void *)E2271CS021 },
947 MODULE_DEVICE_TABLE(of, repaper_of_match);
949 static const struct spi_device_id repaper_id[] = {
950 { "e1144cs021", E1144CS021 },
951 { "e1190cs021", E1190CS021 },
952 { "e2200cs021", E2200CS021 },
953 { "e2271cs021", E2271CS021 },
956 MODULE_DEVICE_TABLE(spi, repaper_id);
958 static int repaper_probe(struct spi_device *spi)
960 const struct drm_display_mode *mode;
961 const struct spi_device_id *spi_id;
962 const struct of_device_id *match;
963 struct device *dev = &spi->dev;
964 enum repaper_model model;
965 const char *thermal_zone;
966 struct repaper_epd *epd;
967 size_t line_buffer_size;
968 struct drm_device *drm;
971 match = of_match_device(repaper_of_match, dev);
973 model = (enum repaper_model)match->data;
975 spi_id = spi_get_device_id(spi);
976 model = spi_id->driver_data;
979 /* The SPI device is used to allocate dma memory */
980 if (!dev->coherent_dma_mask) {
981 ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
983 dev_warn(dev, "Failed to set dma mask %d\n", ret);
988 epd = kzalloc(sizeof(*epd), GFP_KERNEL);
994 ret = devm_drm_dev_init(dev, drm, &repaper_driver);
1000 drm_mode_config_init(drm);
1001 drm->mode_config.funcs = &repaper_mode_config_funcs;
1005 epd->panel_on = devm_gpiod_get(dev, "panel-on", GPIOD_OUT_LOW);
1006 if (IS_ERR(epd->panel_on)) {
1007 ret = PTR_ERR(epd->panel_on);
1008 if (ret != -EPROBE_DEFER)
1009 DRM_DEV_ERROR(dev, "Failed to get gpio 'panel-on'\n");
1013 epd->discharge = devm_gpiod_get(dev, "discharge", GPIOD_OUT_LOW);
1014 if (IS_ERR(epd->discharge)) {
1015 ret = PTR_ERR(epd->discharge);
1016 if (ret != -EPROBE_DEFER)
1017 DRM_DEV_ERROR(dev, "Failed to get gpio 'discharge'\n");
1021 epd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
1022 if (IS_ERR(epd->reset)) {
1023 ret = PTR_ERR(epd->reset);
1024 if (ret != -EPROBE_DEFER)
1025 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
1029 epd->busy = devm_gpiod_get(dev, "busy", GPIOD_IN);
1030 if (IS_ERR(epd->busy)) {
1031 ret = PTR_ERR(epd->busy);
1032 if (ret != -EPROBE_DEFER)
1033 DRM_DEV_ERROR(dev, "Failed to get gpio 'busy'\n");
1037 if (!device_property_read_string(dev, "pervasive,thermal-zone",
1039 epd->thermal = thermal_zone_get_zone_by_name(thermal_zone);
1040 if (IS_ERR(epd->thermal)) {
1041 DRM_DEV_ERROR(dev, "Failed to get thermal zone: %s\n", thermal_zone);
1042 return PTR_ERR(epd->thermal);
1048 mode = &repaper_e1144cs021_mode;
1049 epd->channel_select = repaper_e1144cs021_cs;
1050 epd->stage_time = 480;
1051 epd->bytes_per_scan = 96 / 4;
1052 epd->middle_scan = true; /* data-scan-data */
1053 epd->pre_border_byte = false;
1054 epd->border_byte = REPAPER_BORDER_BYTE_ZERO;
1058 mode = &repaper_e1190cs021_mode;
1059 epd->channel_select = repaper_e1190cs021_cs;
1060 epd->stage_time = 480;
1061 epd->bytes_per_scan = 128 / 4 / 2;
1062 epd->middle_scan = false; /* scan-data-scan */
1063 epd->pre_border_byte = false;
1064 epd->border_byte = REPAPER_BORDER_BYTE_SET;
1068 mode = &repaper_e2200cs021_mode;
1069 epd->channel_select = repaper_e2200cs021_cs;
1070 epd->stage_time = 480;
1071 epd->bytes_per_scan = 96 / 4;
1072 epd->middle_scan = true; /* data-scan-data */
1073 epd->pre_border_byte = true;
1074 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1078 epd->border = devm_gpiod_get(dev, "border", GPIOD_OUT_LOW);
1079 if (IS_ERR(epd->border)) {
1080 ret = PTR_ERR(epd->border);
1081 if (ret != -EPROBE_DEFER)
1082 DRM_DEV_ERROR(dev, "Failed to get gpio 'border'\n");
1086 mode = &repaper_e2271cs021_mode;
1087 epd->channel_select = repaper_e2271cs021_cs;
1088 epd->stage_time = 630;
1089 epd->bytes_per_scan = 176 / 4;
1090 epd->middle_scan = true; /* data-scan-data */
1091 epd->pre_border_byte = true;
1092 epd->border_byte = REPAPER_BORDER_BYTE_NONE;
1099 epd->width = mode->hdisplay;
1100 epd->height = mode->vdisplay;
1101 epd->factored_stage_time = epd->stage_time;
1103 line_buffer_size = 2 * epd->width / 8 + epd->bytes_per_scan + 2;
1104 epd->line_buffer = devm_kzalloc(dev, line_buffer_size, GFP_KERNEL);
1105 if (!epd->line_buffer)
1108 epd->current_frame = devm_kzalloc(dev, epd->width * epd->height / 8,
1110 if (!epd->current_frame)
1113 ret = tinydrm_display_pipe_init(drm, &epd->pipe, &repaper_pipe_funcs,
1114 DRM_MODE_CONNECTOR_VIRTUAL,
1116 ARRAY_SIZE(repaper_formats), mode, 0);
1120 drm_mode_config_reset(drm);
1122 ret = drm_dev_register(drm, 0);
1126 spi_set_drvdata(spi, drm);
1128 DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000);
1130 drm_fbdev_generic_setup(drm, 0);
1135 static int repaper_remove(struct spi_device *spi)
1137 struct drm_device *drm = spi_get_drvdata(spi);
1139 drm_dev_unplug(drm);
1140 drm_atomic_helper_shutdown(drm);
1145 static void repaper_shutdown(struct spi_device *spi)
1147 drm_atomic_helper_shutdown(spi_get_drvdata(spi));
1150 static struct spi_driver repaper_spi_driver = {
1153 .owner = THIS_MODULE,
1154 .of_match_table = repaper_of_match,
1156 .id_table = repaper_id,
1157 .probe = repaper_probe,
1158 .remove = repaper_remove,
1159 .shutdown = repaper_shutdown,
1161 module_spi_driver(repaper_spi_driver);
1163 MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver");
1164 MODULE_AUTHOR("Noralf Trønnes");
1165 MODULE_LICENSE("GPL");