// SPDX-License-Identifier: GPL-2.0-or-later /* * DRM driver for Pervasive Displays RePaper branded e-ink panels * * Copyright 2013-2017 Pervasive Displays, Inc. * Copyright 2017 Noralf Trønnes * * The driver supports: * Material Film: Aurora Mb (V231) * Driver IC: G2 (eTC) * * The controller code was taken from the userspace driver: * https://github.com/repaper/gratis */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define REPAPER_RID_G2_COG_ID 0x12 enum repaper_model { /* 0 is reserved to avoid clashing with NULL */ E1144CS021 = 1, E1190CS021, E2200CS021, E2271CS021, }; enum repaper_stage { /* Image pixel -> Display pixel */ REPAPER_COMPENSATE, /* B -> W, W -> B (Current Image) */ REPAPER_WHITE, /* B -> N, W -> W (Current Image) */ REPAPER_INVERSE, /* B -> N, W -> B (New Image) */ REPAPER_NORMAL /* B -> B, W -> W (New Image) */ }; enum repaper_epd_border_byte { REPAPER_BORDER_BYTE_NONE, REPAPER_BORDER_BYTE_ZERO, REPAPER_BORDER_BYTE_SET, }; struct repaper_epd { struct drm_device drm; struct drm_simple_display_pipe pipe; const struct drm_display_mode *mode; struct drm_connector connector; struct spi_device *spi; struct gpio_desc *panel_on; struct gpio_desc *border; struct gpio_desc *discharge; struct gpio_desc *reset; struct gpio_desc *busy; struct thermal_zone_device *thermal; unsigned int height; unsigned int width; unsigned int bytes_per_scan; const u8 *channel_select; unsigned int stage_time; unsigned int factored_stage_time; bool middle_scan; bool pre_border_byte; enum repaper_epd_border_byte border_byte; u8 *line_buffer; void *current_frame; bool cleared; bool partial; }; static inline struct repaper_epd *drm_to_epd(struct drm_device *drm) { return container_of(drm, struct repaper_epd, drm); } static int repaper_spi_transfer(struct spi_device *spi, u8 header, const void *tx, void *rx, size_t len) { void *txbuf = NULL, *rxbuf = NULL; struct spi_transfer tr[2] = {}; u8 *headerbuf; int ret; headerbuf = kmalloc(1, GFP_KERNEL); if (!headerbuf) return -ENOMEM; headerbuf[0] = header; tr[0].tx_buf = headerbuf; tr[0].len = 1; /* Stack allocated tx? */ if (tx && len <= 32) { txbuf = kmemdup(tx, len, GFP_KERNEL); if (!txbuf) { ret = -ENOMEM; goto out_free; } } if (rx) { rxbuf = kmalloc(len, GFP_KERNEL); if (!rxbuf) { ret = -ENOMEM; goto out_free; } } tr[1].tx_buf = txbuf ? txbuf : tx; tr[1].rx_buf = rxbuf; tr[1].len = len; ndelay(80); ret = spi_sync_transfer(spi, tr, 2); if (rx && !ret) memcpy(rx, rxbuf, len); out_free: kfree(headerbuf); kfree(txbuf); kfree(rxbuf); return ret; } static int repaper_write_buf(struct spi_device *spi, u8 reg, const u8 *buf, size_t len) { int ret; ret = repaper_spi_transfer(spi, 0x70, ®, NULL, 1); if (ret) return ret; return repaper_spi_transfer(spi, 0x72, buf, NULL, len); } static int repaper_write_val(struct spi_device *spi, u8 reg, u8 val) { return repaper_write_buf(spi, reg, &val, 1); } static int repaper_read_val(struct spi_device *spi, u8 reg) { int ret; u8 val; ret = repaper_spi_transfer(spi, 0x70, ®, NULL, 1); if (ret) return ret; ret = repaper_spi_transfer(spi, 0x73, NULL, &val, 1); return ret ? ret : val; } static int repaper_read_id(struct spi_device *spi) { int ret; u8 id; ret = repaper_spi_transfer(spi, 0x71, NULL, &id, 1); return ret ? ret : id; } static void repaper_spi_mosi_low(struct spi_device *spi) { const u8 buf[1] = { 0 }; spi_write(spi, buf, 1); } /* pixels on display are numbered from 1 so even is actually bits 1,3,5,... */ static void repaper_even_pixels(struct repaper_epd *epd, u8 **pp, const u8 *data, u8 fixed_value, const u8 *mask, enum repaper_stage stage) { unsigned int b; for (b = 0; b < (epd->width / 8); b++) { if (data) { u8 pixels = data[b] & 0xaa; u8 pixel_mask = 0xff; u8 p1, p2, p3, p4; if (mask) { pixel_mask = (mask[b] ^ pixels) & 0xaa; pixel_mask |= pixel_mask >> 1; } switch (stage) { case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */ pixels = 0xaa | ((pixels ^ 0xaa) >> 1); break; case REPAPER_WHITE: /* B -> N, W -> W (Current) */ pixels = 0x55 + ((pixels ^ 0xaa) >> 1); break; case REPAPER_INVERSE: /* B -> N, W -> B (New) */ pixels = 0x55 | (pixels ^ 0xaa); break; case REPAPER_NORMAL: /* B -> B, W -> W (New) */ pixels = 0xaa | (pixels >> 1); break; } pixels = (pixels & pixel_mask) | (~pixel_mask & 0x55); p1 = (pixels >> 6) & 0x03; p2 = (pixels >> 4) & 0x03; p3 = (pixels >> 2) & 0x03; p4 = (pixels >> 0) & 0x03; pixels = (p1 << 0) | (p2 << 2) | (p3 << 4) | (p4 << 6); *(*pp)++ = pixels; } else { *(*pp)++ = fixed_value; } } } /* pixels on display are numbered from 1 so odd is actually bits 0,2,4,... */ static void repaper_odd_pixels(struct repaper_epd *epd, u8 **pp, const u8 *data, u8 fixed_value, const u8 *mask, enum repaper_stage stage) { unsigned int b; for (b = epd->width / 8; b > 0; b--) { if (data) { u8 pixels = data[b - 1] & 0x55; u8 pixel_mask = 0xff; if (mask) { pixel_mask = (mask[b - 1] ^ pixels) & 0x55; pixel_mask |= pixel_mask << 1; } switch (stage) { case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */ pixels = 0xaa | (pixels ^ 0x55); break; case REPAPER_WHITE: /* B -> N, W -> W (Current) */ pixels = 0x55 + (pixels ^ 0x55); break; case REPAPER_INVERSE: /* B -> N, W -> B (New) */ pixels = 0x55 | ((pixels ^ 0x55) << 1); break; case REPAPER_NORMAL: /* B -> B, W -> W (New) */ pixels = 0xaa | pixels; break; } pixels = (pixels & pixel_mask) | (~pixel_mask & 0x55); *(*pp)++ = pixels; } else { *(*pp)++ = fixed_value; } } } /* interleave bits: (byte)76543210 -> (16 bit).7.6.5.4.3.2.1 */ static inline u16 repaper_interleave_bits(u16 value) { value = (value | (value << 4)) & 0x0f0f; value = (value | (value << 2)) & 0x3333; value = (value | (value << 1)) & 0x5555; return value; } /* pixels on display are numbered from 1 */ static void repaper_all_pixels(struct repaper_epd *epd, u8 **pp, const u8 *data, u8 fixed_value, const u8 *mask, enum repaper_stage stage) { unsigned int b; for (b = epd->width / 8; b > 0; b--) { if (data) { u16 pixels = repaper_interleave_bits(data[b - 1]); u16 pixel_mask = 0xffff; if (mask) { pixel_mask = repaper_interleave_bits(mask[b - 1]); pixel_mask = (pixel_mask ^ pixels) & 0x5555; pixel_mask |= pixel_mask << 1; } switch (stage) { case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */ pixels = 0xaaaa | (pixels ^ 0x5555); break; case REPAPER_WHITE: /* B -> N, W -> W (Current) */ pixels = 0x5555 + (pixels ^ 0x5555); break; case REPAPER_INVERSE: /* B -> N, W -> B (New) */ pixels = 0x5555 | ((pixels ^ 0x5555) << 1); break; case REPAPER_NORMAL: /* B -> B, W -> W (New) */ pixels = 0xaaaa | pixels; break; } pixels = (pixels & pixel_mask) | (~pixel_mask & 0x5555); *(*pp)++ = pixels >> 8; *(*pp)++ = pixels; } else { *(*pp)++ = fixed_value; *(*pp)++ = fixed_value; } } } /* output one line of scan and data bytes to the display */ static void repaper_one_line(struct repaper_epd *epd, unsigned int line, const u8 *data, u8 fixed_value, const u8 *mask, enum repaper_stage stage) { u8 *p = epd->line_buffer; unsigned int b; repaper_spi_mosi_low(epd->spi); if (epd->pre_border_byte) *p++ = 0x00; if (epd->middle_scan) { /* data bytes */ repaper_odd_pixels(epd, &p, data, fixed_value, mask, stage); /* scan line */ for (b = epd->bytes_per_scan; b > 0; b--) { if (line / 4 == b - 1) *p++ = 0x03 << (2 * (line & 0x03)); else *p++ = 0x00; } /* data bytes */ repaper_even_pixels(epd, &p, data, fixed_value, mask, stage); } else { /* * even scan line, but as lines on display are numbered from 1, * line: 1,3,5,... */ for (b = 0; b < epd->bytes_per_scan; b++) { if (0 != (line & 0x01) && line / 8 == b) *p++ = 0xc0 >> (line & 0x06); else *p++ = 0x00; } /* data bytes */ repaper_all_pixels(epd, &p, data, fixed_value, mask, stage); /* * odd scan line, but as lines on display are numbered from 1, * line: 0,2,4,6,... */ for (b = epd->bytes_per_scan; b > 0; b--) { if (0 == (line & 0x01) && line / 8 == b - 1) *p++ = 0x03 << (line & 0x06); else *p++ = 0x00; } } switch (epd->border_byte) { case REPAPER_BORDER_BYTE_NONE: break; case REPAPER_BORDER_BYTE_ZERO: *p++ = 0x00; break; case REPAPER_BORDER_BYTE_SET: switch (stage) { case REPAPER_COMPENSATE: case REPAPER_WHITE: case REPAPER_INVERSE: *p++ = 0x00; break; case REPAPER_NORMAL: *p++ = 0xaa; break; } break; } repaper_write_buf(epd->spi, 0x0a, epd->line_buffer, p - epd->line_buffer); /* Output data to panel */ repaper_write_val(epd->spi, 0x02, 0x07); repaper_spi_mosi_low(epd->spi); } static void repaper_frame_fixed(struct repaper_epd *epd, u8 fixed_value, enum repaper_stage stage) { unsigned int line; for (line = 0; line < epd->height; line++) repaper_one_line(epd, line, NULL, fixed_value, NULL, stage); } static void repaper_frame_data(struct repaper_epd *epd, const u8 *image, const u8 *mask, enum repaper_stage stage) { unsigned int line; if (!mask) { for (line = 0; line < epd->height; line++) { repaper_one_line(epd, line, &image[line * (epd->width / 8)], 0, NULL, stage); } } else { for (line = 0; line < epd->height; line++) { size_t n = line * epd->width / 8; repaper_one_line(epd, line, &image[n], 0, &mask[n], stage); } } } static void repaper_frame_fixed_repeat(struct repaper_epd *epd, u8 fixed_value, enum repaper_stage stage) { u64 start = local_clock(); u64 end = start + (epd->factored_stage_time * 1000 * 1000); do { repaper_frame_fixed(epd, fixed_value, stage); } while (local_clock() < end); } static void repaper_frame_data_repeat(struct repaper_epd *epd, const u8 *image, const u8 *mask, enum repaper_stage stage) { u64 start = local_clock(); u64 end = start + (epd->factored_stage_time * 1000 * 1000); do { repaper_frame_data(epd, image, mask, stage); } while (local_clock() < end); } static void repaper_get_temperature(struct repaper_epd *epd) { int ret, temperature = 0; unsigned int factor10x; if (!epd->thermal) return; ret = thermal_zone_get_temp(epd->thermal, &temperature); if (ret) { DRM_DEV_ERROR(&epd->spi->dev, "Failed to get temperature (%d)\n", ret); return; } temperature /= 1000; if (temperature <= -10) factor10x = 170; else if (temperature <= -5) factor10x = 120; else if (temperature <= 5) factor10x = 80; else if (temperature <= 10) factor10x = 40; else if (temperature <= 15) factor10x = 30; else if (temperature <= 20) factor10x = 20; else if (temperature <= 40) factor10x = 10; else factor10x = 7; epd->factored_stage_time = epd->stage_time * factor10x / 10; } static void repaper_gray8_to_mono_reversed(u8 *buf, u32 width, u32 height) { u8 *gray8 = buf, *mono = buf; int y, xb, i; for (y = 0; y < height; y++) for (xb = 0; xb < width / 8; xb++) { u8 byte = 0x00; for (i = 0; i < 8; i++) { int x = xb * 8 + i; byte >>= 1; if (gray8[y * width + x] >> 7) byte |= BIT(7); } *mono++ = byte; } } static int repaper_fb_dirty(struct drm_framebuffer *fb) { struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0); struct repaper_epd *epd = drm_to_epd(fb->dev); struct drm_rect clip; int idx, ret = 0; u8 *buf = NULL; if (!drm_dev_enter(fb->dev, &idx)) return -ENODEV; /* repaper can't do partial updates */ clip.x1 = 0; clip.x2 = fb->width; clip.y1 = 0; clip.y2 = fb->height; repaper_get_temperature(epd); DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id, epd->factored_stage_time); buf = kmalloc_array(fb->width, fb->height, GFP_KERNEL); if (!buf) { ret = -ENOMEM; goto out_exit; } ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE); if (ret) goto out_free; drm_fb_xrgb8888_to_gray8(buf, cma_obj->vaddr, fb, &clip); drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE); repaper_gray8_to_mono_reversed(buf, fb->width, fb->height); if (epd->partial) { repaper_frame_data_repeat(epd, buf, epd->current_frame, REPAPER_NORMAL); } else if (epd->cleared) { repaper_frame_data_repeat(epd, epd->current_frame, NULL, REPAPER_COMPENSATE); repaper_frame_data_repeat(epd, epd->current_frame, NULL, REPAPER_WHITE); repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE); repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL); epd->partial = true; } else { /* Clear display (anything -> white) */ repaper_frame_fixed_repeat(epd, 0xff, REPAPER_COMPENSATE); repaper_frame_fixed_repeat(epd, 0xff, REPAPER_WHITE); repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_INVERSE); repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_NORMAL); /* Assuming a clear (white) screen output an image */ repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_COMPENSATE); repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_WHITE); repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE); repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL); epd->cleared = true; epd->partial = true; } memcpy(epd->current_frame, buf, fb->width * fb->height / 8); /* * An extra frame write is needed if pixels are set in the bottom line, * or else grey lines rises up from the pixels */ if (epd->pre_border_byte) { unsigned int x; for (x = 0; x < (fb->width / 8); x++) if (buf[x + (fb->width * (fb->height - 1) / 8)]) { repaper_frame_data_repeat(epd, buf, epd->current_frame, REPAPER_NORMAL); break; } } out_free: kfree(buf); out_exit: drm_dev_exit(idx); return ret; } static void power_off(struct repaper_epd *epd) { /* Turn off power and all signals */ gpiod_set_value_cansleep(epd->reset, 0); gpiod_set_value_cansleep(epd->panel_on, 0); if (epd->border) gpiod_set_value_cansleep(epd->border, 0); /* Ensure SPI MOSI and CLOCK are Low before CS Low */ repaper_spi_mosi_low(epd->spi); /* Discharge pulse */ gpiod_set_value_cansleep(epd->discharge, 1); msleep(150); gpiod_set_value_cansleep(epd->discharge, 0); } static void repaper_pipe_enable(struct drm_simple_display_pipe *pipe, struct drm_crtc_state *crtc_state, struct drm_plane_state *plane_state) { struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev); struct spi_device *spi = epd->spi; struct device *dev = &spi->dev; bool dc_ok = false; int i, ret, idx; if (!drm_dev_enter(pipe->crtc.dev, &idx)) return; DRM_DEBUG_DRIVER("\n"); /* Power up sequence */ gpiod_set_value_cansleep(epd->reset, 0); gpiod_set_value_cansleep(epd->panel_on, 0); gpiod_set_value_cansleep(epd->discharge, 0); if (epd->border) gpiod_set_value_cansleep(epd->border, 0); repaper_spi_mosi_low(spi); usleep_range(5000, 10000); gpiod_set_value_cansleep(epd->panel_on, 1); /* * This delay comes from the repaper.org userspace driver, it's not * mentioned in the datasheet. */ usleep_range(10000, 15000); gpiod_set_value_cansleep(epd->reset, 1); if (epd->border) gpiod_set_value_cansleep(epd->border, 1); usleep_range(5000, 10000); gpiod_set_value_cansleep(epd->reset, 0); usleep_range(5000, 10000); gpiod_set_value_cansleep(epd->reset, 1); usleep_range(5000, 10000); /* Wait for COG to become ready */ for (i = 100; i > 0; i--) { if (!gpiod_get_value_cansleep(epd->busy)) break; usleep_range(10, 100); } if (!i) { DRM_DEV_ERROR(dev, "timeout waiting for panel to become ready.\n"); power_off(epd); goto out_exit; } repaper_read_id(spi); ret = repaper_read_id(spi); if (ret != REPAPER_RID_G2_COG_ID) { if (ret < 0) dev_err(dev, "failed to read chip (%d)\n", ret); else dev_err(dev, "wrong COG ID 0x%02x\n", ret); power_off(epd); goto out_exit; } /* Disable OE */ repaper_write_val(spi, 0x02, 0x40); ret = repaper_read_val(spi, 0x0f); if (ret < 0 || !(ret & 0x80)) { if (ret < 0) DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret); else DRM_DEV_ERROR(dev, "panel is reported broken\n"); power_off(epd); goto out_exit; } /* Power saving mode */ repaper_write_val(spi, 0x0b, 0x02); /* Channel select */ repaper_write_buf(spi, 0x01, epd->channel_select, 8); /* High power mode osc */ repaper_write_val(spi, 0x07, 0xd1); /* Power setting */ repaper_write_val(spi, 0x08, 0x02); /* Vcom level */ repaper_write_val(spi, 0x09, 0xc2); /* Power setting */ repaper_write_val(spi, 0x04, 0x03); /* Driver latch on */ repaper_write_val(spi, 0x03, 0x01); /* Driver latch off */ repaper_write_val(spi, 0x03, 0x00); usleep_range(5000, 10000); /* Start chargepump */ for (i = 0; i < 4; ++i) { /* Charge pump positive voltage on - VGH/VDL on */ repaper_write_val(spi, 0x05, 0x01); msleep(240); /* Charge pump negative voltage on - VGL/VDL on */ repaper_write_val(spi, 0x05, 0x03); msleep(40); /* Charge pump Vcom on - Vcom driver on */ repaper_write_val(spi, 0x05, 0x0f); msleep(40); /* check DC/DC */ ret = repaper_read_val(spi, 0x0f); if (ret < 0) { DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret); power_off(epd); goto out_exit; } if (ret & 0x40) { dc_ok = true; break; } } if (!dc_ok) { DRM_DEV_ERROR(dev, "dc/dc failed\n"); power_off(epd); goto out_exit; } /* * Output enable to disable * The userspace driver sets this to 0x04, but the datasheet says 0x06 */ repaper_write_val(spi, 0x02, 0x04); epd->partial = false; out_exit: drm_dev_exit(idx); } static void repaper_pipe_disable(struct drm_simple_display_pipe *pipe) { struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev); struct spi_device *spi = epd->spi; unsigned int line; /* * This callback is not protected by drm_dev_enter/exit since we want to * turn off the display on regular driver unload. It's highly unlikely * that the underlying SPI controller is gone should this be called after * unplug. */ DRM_DEBUG_DRIVER("\n"); /* Nothing frame */ for (line = 0; line < epd->height; line++) repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL, REPAPER_COMPENSATE); /* 2.7" */ if (epd->border) { /* Dummy line */ repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL, REPAPER_COMPENSATE); msleep(25); gpiod_set_value_cansleep(epd->border, 0); msleep(200); gpiod_set_value_cansleep(epd->border, 1); } else { /* Border dummy line */ repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL, REPAPER_NORMAL); msleep(200); } /* not described in datasheet */ repaper_write_val(spi, 0x0b, 0x00); /* Latch reset turn on */ repaper_write_val(spi, 0x03, 0x01); /* Power off charge pump Vcom */ repaper_write_val(spi, 0x05, 0x03); /* Power off charge pump neg voltage */ repaper_write_val(spi, 0x05, 0x01); msleep(120); /* Discharge internal */ repaper_write_val(spi, 0x04, 0x80); /* turn off all charge pumps */ repaper_write_val(spi, 0x05, 0x00); /* Turn off osc */ repaper_write_val(spi, 0x07, 0x01); msleep(50); power_off(epd); } static void repaper_pipe_update(struct drm_simple_display_pipe *pipe, struct drm_plane_state *old_state) { struct drm_plane_state *state = pipe->plane.state; struct drm_rect rect; if (!pipe->crtc.state->active) return; if (drm_atomic_helper_damage_merged(old_state, state, &rect)) repaper_fb_dirty(state->fb); } static const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = { .enable = repaper_pipe_enable, .disable = repaper_pipe_disable, .update = repaper_pipe_update, }; static int repaper_connector_get_modes(struct drm_connector *connector) { struct repaper_epd *epd = drm_to_epd(connector->dev); struct drm_display_mode *mode; mode = drm_mode_duplicate(connector->dev, epd->mode); if (!mode) { DRM_ERROR("Failed to duplicate mode\n"); return 0; } drm_mode_set_name(mode); mode->type |= DRM_MODE_TYPE_PREFERRED; drm_mode_probed_add(connector, mode); connector->display_info.width_mm = mode->width_mm; connector->display_info.height_mm = mode->height_mm; return 1; } static const struct drm_connector_helper_funcs repaper_connector_hfuncs = { .get_modes = repaper_connector_get_modes, }; static const struct drm_connector_funcs repaper_connector_funcs = { .reset = drm_atomic_helper_connector_reset, .fill_modes = drm_helper_probe_single_connector_modes, .destroy = drm_connector_cleanup, .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, }; static const struct drm_mode_config_funcs repaper_mode_config_funcs = { .fb_create = drm_gem_fb_create_with_dirty, .atomic_check = drm_atomic_helper_check, .atomic_commit = drm_atomic_helper_commit, }; static const uint32_t repaper_formats[] = { DRM_FORMAT_XRGB8888, }; static const struct drm_display_mode repaper_e1144cs021_mode = { DRM_SIMPLE_MODE(128, 96, 29, 22), }; static const u8 repaper_e1144cs021_cs[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x0f, 0xff, 0x00 }; static const struct drm_display_mode repaper_e1190cs021_mode = { DRM_SIMPLE_MODE(144, 128, 36, 32), }; static const u8 repaper_e1190cs021_cs[] = { 0x00, 0x00, 0x00, 0x03, 0xfc, 0x00, 0x00, 0xff }; static const struct drm_display_mode repaper_e2200cs021_mode = { DRM_SIMPLE_MODE(200, 96, 46, 22), }; static const u8 repaper_e2200cs021_cs[] = { 0x00, 0x00, 0x00, 0x00, 0x01, 0xff, 0xe0, 0x00 }; static const struct drm_display_mode repaper_e2271cs021_mode = { DRM_SIMPLE_MODE(264, 176, 57, 38), }; static const u8 repaper_e2271cs021_cs[] = { 0x00, 0x00, 0x00, 0x7f, 0xff, 0xfe, 0x00, 0x00 }; DEFINE_DRM_GEM_CMA_FOPS(repaper_fops); static const struct drm_driver repaper_driver = { .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, .fops = &repaper_fops, DRM_GEM_CMA_DRIVER_OPS_VMAP, .name = "repaper", .desc = "Pervasive Displays RePaper e-ink panels", .date = "20170405", .major = 1, .minor = 0, }; static const struct of_device_id repaper_of_match[] = { { .compatible = "pervasive,e1144cs021", .data = (void *)E1144CS021 }, { .compatible = "pervasive,e1190cs021", .data = (void *)E1190CS021 }, { .compatible = "pervasive,e2200cs021", .data = (void *)E2200CS021 }, { .compatible = "pervasive,e2271cs021", .data = (void *)E2271CS021 }, {}, }; MODULE_DEVICE_TABLE(of, repaper_of_match); static const struct spi_device_id repaper_id[] = { { "e1144cs021", E1144CS021 }, { "e1190cs021", E1190CS021 }, { "e2200cs021", E2200CS021 }, { "e2271cs021", E2271CS021 }, { }, }; MODULE_DEVICE_TABLE(spi, repaper_id); static int repaper_probe(struct spi_device *spi) { const struct drm_display_mode *mode; const struct spi_device_id *spi_id; struct device *dev = &spi->dev; enum repaper_model model; const char *thermal_zone; struct repaper_epd *epd; size_t line_buffer_size; struct drm_device *drm; const void *match; int ret; match = device_get_match_data(dev); if (match) { model = (enum repaper_model)match; } else { spi_id = spi_get_device_id(spi); model = (enum repaper_model)spi_id->driver_data; } /* The SPI device is used to allocate dma memory */ if (!dev->coherent_dma_mask) { ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32)); if (ret) { dev_warn(dev, "Failed to set dma mask %d\n", ret); return ret; } } epd = devm_drm_dev_alloc(dev, &repaper_driver, struct repaper_epd, drm); if (IS_ERR(epd)) return PTR_ERR(epd); drm = &epd->drm; ret = drmm_mode_config_init(drm); if (ret) return ret; drm->mode_config.funcs = &repaper_mode_config_funcs; epd->spi = spi; epd->panel_on = devm_gpiod_get(dev, "panel-on", GPIOD_OUT_LOW); if (IS_ERR(epd->panel_on)) { ret = PTR_ERR(epd->panel_on); if (ret != -EPROBE_DEFER) DRM_DEV_ERROR(dev, "Failed to get gpio 'panel-on'\n"); return ret; } epd->discharge = devm_gpiod_get(dev, "discharge", GPIOD_OUT_LOW); if (IS_ERR(epd->discharge)) { ret = PTR_ERR(epd->discharge); if (ret != -EPROBE_DEFER) DRM_DEV_ERROR(dev, "Failed to get gpio 'discharge'\n"); return ret; } epd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW); if (IS_ERR(epd->reset)) { ret = PTR_ERR(epd->reset); if (ret != -EPROBE_DEFER) DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n"); return ret; } epd->busy = devm_gpiod_get(dev, "busy", GPIOD_IN); if (IS_ERR(epd->busy)) { ret = PTR_ERR(epd->busy); if (ret != -EPROBE_DEFER) DRM_DEV_ERROR(dev, "Failed to get gpio 'busy'\n"); return ret; } if (!device_property_read_string(dev, "pervasive,thermal-zone", &thermal_zone)) { epd->thermal = thermal_zone_get_zone_by_name(thermal_zone); if (IS_ERR(epd->thermal)) { DRM_DEV_ERROR(dev, "Failed to get thermal zone: %s\n", thermal_zone); return PTR_ERR(epd->thermal); } } switch (model) { case E1144CS021: mode = &repaper_e1144cs021_mode; epd->channel_select = repaper_e1144cs021_cs; epd->stage_time = 480; epd->bytes_per_scan = 96 / 4; epd->middle_scan = true; /* data-scan-data */ epd->pre_border_byte = false; epd->border_byte = REPAPER_BORDER_BYTE_ZERO; break; case E1190CS021: mode = &repaper_e1190cs021_mode; epd->channel_select = repaper_e1190cs021_cs; epd->stage_time = 480; epd->bytes_per_scan = 128 / 4 / 2; epd->middle_scan = false; /* scan-data-scan */ epd->pre_border_byte = false; epd->border_byte = REPAPER_BORDER_BYTE_SET; break; case E2200CS021: mode = &repaper_e2200cs021_mode; epd->channel_select = repaper_e2200cs021_cs; epd->stage_time = 480; epd->bytes_per_scan = 96 / 4; epd->middle_scan = true; /* data-scan-data */ epd->pre_border_byte = true; epd->border_byte = REPAPER_BORDER_BYTE_NONE; break; case E2271CS021: epd->border = devm_gpiod_get(dev, "border", GPIOD_OUT_LOW); if (IS_ERR(epd->border)) { ret = PTR_ERR(epd->border); if (ret != -EPROBE_DEFER) DRM_DEV_ERROR(dev, "Failed to get gpio 'border'\n"); return ret; } mode = &repaper_e2271cs021_mode; epd->channel_select = repaper_e2271cs021_cs; epd->stage_time = 630; epd->bytes_per_scan = 176 / 4; epd->middle_scan = true; /* data-scan-data */ epd->pre_border_byte = true; epd->border_byte = REPAPER_BORDER_BYTE_NONE; break; default: return -ENODEV; } epd->mode = mode; epd->width = mode->hdisplay; epd->height = mode->vdisplay; epd->factored_stage_time = epd->stage_time; line_buffer_size = 2 * epd->width / 8 + epd->bytes_per_scan + 2; epd->line_buffer = devm_kzalloc(dev, line_buffer_size, GFP_KERNEL); if (!epd->line_buffer) return -ENOMEM; epd->current_frame = devm_kzalloc(dev, epd->width * epd->height / 8, GFP_KERNEL); if (!epd->current_frame) return -ENOMEM; drm->mode_config.min_width = mode->hdisplay; drm->mode_config.max_width = mode->hdisplay; drm->mode_config.min_height = mode->vdisplay; drm->mode_config.max_height = mode->vdisplay; drm_connector_helper_add(&epd->connector, &repaper_connector_hfuncs); ret = drm_connector_init(drm, &epd->connector, &repaper_connector_funcs, DRM_MODE_CONNECTOR_SPI); if (ret) return ret; ret = drm_simple_display_pipe_init(drm, &epd->pipe, &repaper_pipe_funcs, repaper_formats, ARRAY_SIZE(repaper_formats), NULL, &epd->connector); if (ret) return ret; drm_mode_config_reset(drm); ret = drm_dev_register(drm, 0); if (ret) return ret; spi_set_drvdata(spi, drm); DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000); drm_fbdev_generic_setup(drm, 0); return 0; } static int repaper_remove(struct spi_device *spi) { struct drm_device *drm = spi_get_drvdata(spi); drm_dev_unplug(drm); drm_atomic_helper_shutdown(drm); return 0; } static void repaper_shutdown(struct spi_device *spi) { drm_atomic_helper_shutdown(spi_get_drvdata(spi)); } static struct spi_driver repaper_spi_driver = { .driver = { .name = "repaper", .of_match_table = repaper_of_match, }, .id_table = repaper_id, .probe = repaper_probe, .remove = repaper_remove, .shutdown = repaper_shutdown, }; module_spi_driver(repaper_spi_driver); MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver"); MODULE_AUTHOR("Noralf Trønnes"); MODULE_LICENSE("GPL");