--- /dev/null
+/*
+ * 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
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/sched/clock.h>
+#include <linux/spi/spi.h>
+#include <linux/thermal.h>
+
+#include <drm/tinydrm/tinydrm.h>
+#include <drm/tinydrm/tinydrm-helpers.h>
+
+#define REPAPER_RID_G2_COG_ID 0x12
+
+enum repaper_model {
+ 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 tinydrm_device tinydrm;
+ 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 enabled;
+ bool cleared;
+ bool partial;
+};
+
+static inline struct repaper_epd *
+epd_from_tinydrm(struct tinydrm_device *tdev)
+{
+ return container_of(tdev, struct repaper_epd, tinydrm);
+}
+
+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 = kmalloc(len, GFP_KERNEL);
+ if (!txbuf) {
+ ret = -ENOMEM;
+ goto out_free;
+ }
+ memcpy(txbuf, tx, len);
+ }
+
+ 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) {
+ dev_err(&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_file *file_priv,
+ unsigned int flags, unsigned int color,
+ struct drm_clip_rect *clips,
+ unsigned int num_clips)
+{
+ struct tinydrm_device *tdev = fb->dev->dev_private;
+ struct repaper_epd *epd = epd_from_tinydrm(tdev);
+ u8 *buf = NULL;
+ int ret = 0;
+
+ mutex_lock(&tdev->dirty_lock);
+
+ if (!epd->enabled)
+ goto out_unlock;
+
+ /* fbdev can flush even when we're not interested */
+ if (tdev->pipe.plane.fb != fb)
+ goto out_unlock;
+
+ repaper_get_temperature(epd);
+
+ DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id,
+ epd->factored_stage_time);
+
+ buf = kmalloc(fb->width * fb->height, GFP_KERNEL);
+ if (!buf) {
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
+
+ ret = tinydrm_xrgb8888_to_gray8(buf, fb);
+ if (ret)
+ goto out_unlock;
+
+ 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_unlock:
+ mutex_unlock(&tdev->dirty_lock);
+
+ if (ret)
+ dev_err(fb->dev->dev, "Failed to update display (%d)\n", ret);
+ kfree(buf);
+
+ return ret;
+}
+
+static const struct drm_framebuffer_funcs repaper_fb_funcs = {
+ .destroy = drm_fb_cma_destroy,
+ .create_handle = drm_fb_cma_create_handle,
+ .dirty = repaper_fb_dirty,
+};
+
+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 tinydrm_device *tdev = pipe_to_tinydrm(pipe);
+ struct repaper_epd *epd = epd_from_tinydrm(tdev);
+ struct spi_device *spi = epd->spi;
+ struct device *dev = &spi->dev;
+ bool dc_ok = false;
+ int i, ret;
+
+ 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) {
+ dev_err(dev, "timeout waiting for panel to become ready.\n");
+ power_off(epd);
+ return;
+ }
+
+ 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);
+ return;
+ }
+
+ /* Disable OE */
+ repaper_write_val(spi, 0x02, 0x40);
+
+ ret = repaper_read_val(spi, 0x0f);
+ if (ret < 0 || !(ret & 0x80)) {
+ if (ret < 0)
+ dev_err(dev, "failed to read chip (%d)\n", ret);
+ else
+ dev_err(dev, "panel is reported broken\n");
+ power_off(epd);
+ return;
+ }
+
+ /* 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) {
+ dev_err(dev, "failed to read chip (%d)\n", ret);
+ power_off(epd);
+ return;
+ }
+
+ if (ret & 0x40) {
+ dc_ok = true;
+ break;
+ }
+ }
+
+ if (!dc_ok) {
+ dev_err(dev, "dc/dc failed\n");
+ power_off(epd);
+ return;
+ }
+
+ /*
+ * Output enable to disable
+ * The userspace driver sets this to 0x04, but the datasheet says 0x06
+ */
+ repaper_write_val(spi, 0x02, 0x04);
+
+ epd->enabled = true;
+ epd->partial = false;
+}
+
+static void repaper_pipe_disable(struct drm_simple_display_pipe *pipe)
+{
+ struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
+ struct repaper_epd *epd = epd_from_tinydrm(tdev);
+ struct spi_device *spi = epd->spi;
+ unsigned int line;
+
+ DRM_DEBUG_DRIVER("\n");
+
+ mutex_lock(&tdev->dirty_lock);
+ epd->enabled = false;
+ mutex_unlock(&tdev->dirty_lock);
+
+ /* 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 const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = {
+ .enable = repaper_pipe_enable,
+ .disable = repaper_pipe_disable,
+ .update = tinydrm_display_pipe_update,
+ .prepare_fb = tinydrm_display_pipe_prepare_fb,
+};
+
+static const uint32_t repaper_formats[] = {
+ DRM_FORMAT_XRGB8888,
+};
+
+static const struct drm_display_mode repaper_e1144cs021_mode = {
+ TINYDRM_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 = {
+ TINYDRM_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 = {
+ TINYDRM_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 = {
+ TINYDRM_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 struct drm_driver repaper_driver = {
+ .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
+ DRIVER_ATOMIC,
+ .fops = &repaper_fops,
+ TINYDRM_GEM_DRIVER_OPS,
+ .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;
+ const struct of_device_id *match;
+ struct device *dev = &spi->dev;
+ struct tinydrm_device *tdev;
+ enum repaper_model model;
+ const char *thermal_zone;
+ struct repaper_epd *epd;
+ size_t line_buffer_size;
+ int ret;
+
+ match = of_match_device(repaper_of_match, dev);
+ if (match) {
+ model = (enum repaper_model)match->data;
+ } else {
+ spi_id = spi_get_device_id(spi);
+ 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_kzalloc(dev, sizeof(*epd), GFP_KERNEL);
+ if (!epd)
+ return -ENOMEM;
+
+ 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)
+ dev_err(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)
+ dev_err(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)
+ dev_err(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)
+ dev_err(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)) {
+ dev_err(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)
+ dev_err(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->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;
+
+ tdev = &epd->tinydrm;
+
+ ret = devm_tinydrm_init(dev, tdev, &repaper_fb_funcs, &repaper_driver);
+ if (ret)
+ return ret;
+
+ ret = tinydrm_display_pipe_init(tdev, &repaper_pipe_funcs,
+ DRM_MODE_CONNECTOR_VIRTUAL,
+ repaper_formats,
+ ARRAY_SIZE(repaper_formats), mode, 0);
+ if (ret)
+ return ret;
+
+ drm_mode_config_reset(tdev->drm);
+
+ ret = devm_tinydrm_register(tdev);
+ if (ret)
+ return ret;
+
+ spi_set_drvdata(spi, tdev);
+
+ DRM_DEBUG_DRIVER("Initialized %s:%s @%uMHz on minor %d\n",
+ tdev->drm->driver->name, dev_name(dev),
+ spi->max_speed_hz / 1000000,
+ tdev->drm->primary->index);
+
+ return 0;
+}
+
+static void repaper_shutdown(struct spi_device *spi)
+{
+ struct tinydrm_device *tdev = spi_get_drvdata(spi);
+
+ tinydrm_shutdown(tdev);
+}
+
+static struct spi_driver repaper_spi_driver = {
+ .driver = {
+ .name = "repaper",
+ .owner = THIS_MODULE,
+ .of_match_table = repaper_of_match,
+ },
+ .id_table = repaper_id,
+ .probe = repaper_probe,
+ .shutdown = repaper_shutdown,
+};
+module_spi_driver(repaper_spi_driver);
+
+MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver");
+MODULE_AUTHOR("Noralf Trønnes");
+MODULE_LICENSE("GPL");
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff