drivers: display: ssd16xx: Add support for the ssd1677 EPD driver chip

nisargjhaveri · nisargjhaveri · commit 2d446d9ac69f · 2025-08-10T22:47:59.000+05:30
Add support for the SSD1677 EPD driver chip with support for up to
960x680 pixel displays.

Tested with the Waveshare 4.26" 800x480 display with XIAO BLE board.
I believe it is the same as Good Display GDEQ0426T82.
Tested with the samples/drivers/display sample.

The SSD1677 requires x address to be full address, instead of the byte
address used by SSD16XX. Added a new quirk to handle this.

The display requires a different GDO control flag as the panel layout
might be different, add an option to set this.

The display also requires the scan direction for y axis to be reversed,
add an option to set this as well.

Signed-off-by: Nisarg Jhaveri &lt;nisargjhaveri@gmail.com&gt;
diff --git a/drivers/display/Kconfig.ssd16xx b/drivers/display/Kconfig.ssd16xx
@@ -10,6 +10,7 @@ config SSD16XX
 		DT_HAS_SOLOMON_SSD1608_ENABLED || \
 		DT_HAS_SOLOMON_SSD1673_ENABLED || \
 		DT_HAS_SOLOMON_SSD1675A_ENABLED || \
+		DT_HAS_SOLOMON_SSD1677_ENABLED || \
 		DT_HAS_SOLOMON_SSD1680_ENABLED || \
 		DT_HAS_SOLOMON_SSD1681_ENABLED
 	select MIPI_DBI
diff --git a/drivers/display/ssd16xx.c b/drivers/display/ssd16xx.c
@@ -60,6 +60,15 @@ struct ssd16xx_quirks {
 	 * SSD16XX_CMD_UPDATE_CTRL2 for a partial refresh.
 	 */
 	uint8_t ctrl2_partial;
+
+	/*
+	 * Device specific flag deciding whether to pass in the byte address or
+	 * the bit address when setting the RAM x position window or counter in
+	 * SSD16XX_CMD_RAM_XPOS_CTRL or SSD16XX_CMD_RAM_XPOS_CNTR. Expected to
+	 * be `true` for the devices that expects the byte address, `false`
+	 * otherwise.
+	 */
+	bool x_addr_in_bytes;
 };
 
 struct ssd16xx_data {
@@ -105,6 +114,8 @@ struct ssd16xx_config {
 	uint16_t height;
 	uint16_t width;
 	uint8_t tssv;
+	uint8_t gdo_flags;
+	bool scan_y_reverse;
 };
 
 static int ssd16xx_set_profile(const struct device *dev,
@@ -369,33 +380,69 @@ static int ssd16xx_set_window(const struct device *dev,
 		}
 	}
 
-	switch (data->orientation) {
-	case DISPLAY_ORIENTATION_NORMAL:
-		x_start = (panel_h - 1 - y) / SSD16XX_PIXELS_PER_BYTE;
-		x_end = (panel_h - 1 - (y + desc->height - 1)) / SSD16XX_PIXELS_PER_BYTE;
-		y_start = x;
-		y_end = (x + desc->width - 1);
-		break;
-	case DISPLAY_ORIENTATION_ROTATED_90:
-		x_start = (panel_h - 1 - x) / SSD16XX_PIXELS_PER_BYTE;
-		x_end = (panel_h - 1 - (x + desc->width - 1)) / SSD16XX_PIXELS_PER_BYTE;
-		y_start = (config->width - 1 - y);
-		y_end = (config->width - 1 - (y + desc->height - 1));
-		break;
-	case DISPLAY_ORIENTATION_ROTATED_180:
-		x_start = y / SSD16XX_PIXELS_PER_BYTE;
-		x_end = (y + desc->height - 1) / SSD16XX_PIXELS_PER_BYTE;
-		y_start = (x + desc->width - 1);
-		y_end = x;
-		break;
-	case DISPLAY_ORIENTATION_ROTATED_270:
-		x_start = x / SSD16XX_PIXELS_PER_BYTE;
-		x_end = (x + desc->width - 1) / SSD16XX_PIXELS_PER_BYTE;
-		y_start = y;
-		y_end = (y + desc->height - 1);
-		break;
-	default:
-		return -EINVAL;
+	if (config->scan_y_reverse) {
+		switch (data->orientation) {
+		case DISPLAY_ORIENTATION_NORMAL:
+			x_start = (panel_h - 1 - y);
+			x_end = (panel_h - 1 - (y + desc->height - 1));
+			y_start = (config->width - 1 - x);
+			y_end = (config->width - 1 - (x + desc->width - 1));
+			break;
+		case DISPLAY_ORIENTATION_ROTATED_90:
+			x_start = x;
+			x_end = (x + desc->width - 1);
+			y_start = (config->width - 1 - y);
+			y_end = (config->width - 1 - (y + desc->height - 1));
+			break;
+		case DISPLAY_ORIENTATION_ROTATED_180:
+			x_start = y;
+			x_end = (y + desc->height - 1);
+			y_start = x;
+			y_end = (x + desc->width - 1);
+			break;
+		case DISPLAY_ORIENTATION_ROTATED_270:
+			x_start = (panel_h - 1 - x);
+			x_end = (panel_h - 1 - (x + desc->width - 1));
+			y_start = y;
+			y_end = (y + desc->height - 1);
+			break;
+		default:
+			return -EINVAL;
+		}
+	} else {
+		switch (data->orientation) {
+		case DISPLAY_ORIENTATION_NORMAL:
+			x_start = (panel_h - 1 - y);
+			x_end = (panel_h - 1 - (y + desc->height - 1));
+			y_start = x;
+			y_end = (x + desc->width - 1);
+			break;
+		case DISPLAY_ORIENTATION_ROTATED_90:
+			x_start = (panel_h - 1 - x);
+			x_end = (panel_h - 1 - (x + desc->width - 1));
+			y_start = (config->width - 1 - y);
+			y_end = (config->width - 1 - (y + desc->height - 1));
+			break;
+		case DISPLAY_ORIENTATION_ROTATED_180:
+			x_start = y;
+			x_end = (y + desc->height - 1);
+			y_start = (x + desc->width - 1);
+			y_end = x;
+			break;
+		case DISPLAY_ORIENTATION_ROTATED_270:
+			x_start = x;
+			x_end = (x + desc->width - 1);
+			y_start = y;
+			y_end = (y + desc->height - 1);
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	if (config->quirks->x_addr_in_bytes) {
+		x_start /= SSD16XX_PIXELS_PER_BYTE;
+		x_end /= SSD16XX_PIXELS_PER_BYTE;
 	}
 
 	err = ssd16xx_set_ram_param(dev, x_start, x_end, y_start, y_end);
@@ -588,17 +635,30 @@ static int ssd16xx_set_pixel_format(const struct device *dev,
 static int ssd16xx_set_orientation(const struct device *dev,
 				   const enum display_orientation orientation)
 {
+	const struct ssd16xx_config *config = dev->config;
 	struct ssd16xx_data *data = dev->data;
 	int err;
 
-	if (orientation == DISPLAY_ORIENTATION_NORMAL) {
-		data->scan_mode = SSD16XX_DATA_ENTRY_XDYIY;
-	} else if (orientation == DISPLAY_ORIENTATION_ROTATED_90) {
-		data->scan_mode = SSD16XX_DATA_ENTRY_XDYDX;
-	} else if (orientation == DISPLAY_ORIENTATION_ROTATED_180) {
-		data->scan_mode = SSD16XX_DATA_ENTRY_XIYDY;
-	} else if (orientation == DISPLAY_ORIENTATION_ROTATED_270) {
-		data->scan_mode = SSD16XX_DATA_ENTRY_XIYIX;
+	if (config->scan_y_reverse) {
+		if (orientation == DISPLAY_ORIENTATION_NORMAL) {
+			data->scan_mode = SSD16XX_DATA_ENTRY_XDYDY;
+		} else if (orientation == DISPLAY_ORIENTATION_ROTATED_90) {
+			data->scan_mode = SSD16XX_DATA_ENTRY_XIYDX;
+		} else if (orientation == DISPLAY_ORIENTATION_ROTATED_180) {
+			data->scan_mode = SSD16XX_DATA_ENTRY_XIYIY;
+		} else if (orientation == DISPLAY_ORIENTATION_ROTATED_270) {
+			data->scan_mode = SSD16XX_DATA_ENTRY_XDYIX;
+		}
+	} else {
+		if (orientation == DISPLAY_ORIENTATION_NORMAL) {
+			data->scan_mode = SSD16XX_DATA_ENTRY_XDYIY;
+		} else if (orientation == DISPLAY_ORIENTATION_ROTATED_90) {
+			data->scan_mode = SSD16XX_DATA_ENTRY_XDYDX;
+		} else if (orientation == DISPLAY_ORIENTATION_ROTATED_180) {
+			data->scan_mode = SSD16XX_DATA_ENTRY_XIYDY;
+		} else if (orientation == DISPLAY_ORIENTATION_ROTATED_270) {
+			data->scan_mode = SSD16XX_DATA_ENTRY_XIYIX;
+		}
 	}
 
 	err = ssd16xx_write_uint8(dev, SSD16XX_CMD_ENTRY_MODE, data->scan_mode);
@@ -614,7 +674,7 @@ static int ssd16xx_set_orientation(const struct device *dev,
 static int ssd16xx_clear_cntlr_mem(const struct device *dev, uint8_t ram_cmd)
 {
 	const struct ssd16xx_config *config = dev->config;
-	uint16_t panel_h = config->height / EPD_PANEL_NUMOF_ROWS_PER_PAGE;
+	uint16_t panel_h = config->height;
 	uint16_t last_gate = config->width - 1;
 	uint8_t clear_page[64];
 	int err;
@@ -623,8 +683,9 @@ static int ssd16xx_clear_cntlr_mem(const struct device *dev, uint8_t ram_cmd)
 	 * Clear unusable memory area when the resolution of the panel is not
 	 * multiple of an octet.
 	 */
-	if (config->height % EPD_PANEL_NUMOF_ROWS_PER_PAGE) {
-		panel_h += 1;
+	if (config->quirks->x_addr_in_bytes) {
+		panel_h = (config->height + (EPD_PANEL_NUMOF_ROWS_PER_PAGE - 1)) /
+			  EPD_PANEL_NUMOF_ROWS_PER_PAGE;
 	}
 
 	err = ssd16xx_write_uint8(dev, SSD16XX_CMD_ENTRY_MODE,
@@ -771,7 +832,7 @@ static int ssd16xx_set_profile(const struct device *dev,
 	}
 
 	gdo_len = push_y_param(dev, gdo, last_gate);
-	gdo[gdo_len++] = 0U;
+	gdo[gdo_len++] = config->gdo_flags;
 	err = ssd16xx_write_cmd(dev, SSD16XX_CMD_GDO_CTRL, gdo, gdo_len);
 	if (err < 0) {
 		return err;
@@ -964,6 +1025,7 @@ static struct ssd16xx_quirks quirks_solomon_ssd1608 = {
 	.pp_height_bits = 16,
 	.ctrl2_full = SSD16XX_GEN1_CTRL2_TO_PATTERN,
 	.ctrl2_partial = SSD16XX_GEN1_CTRL2_TO_PATTERN,
+	.x_addr_in_bytes = true,
 };
 #endif
 
@@ -975,6 +1037,7 @@ static struct ssd16xx_quirks quirks_solomon_ssd1673 = {
 	.pp_height_bits = 8,
 	.ctrl2_full = SSD16XX_GEN1_CTRL2_TO_PATTERN,
 	.ctrl2_partial = SSD16XX_GEN1_CTRL2_TO_PATTERN,
+	.x_addr_in_bytes = true,
 };
 #endif
 
@@ -986,6 +1049,19 @@ static struct ssd16xx_quirks quirks_solomon_ssd1675a = {
 	.pp_height_bits = 16,
 	.ctrl2_full = SSD16XX_GEN1_CTRL2_TO_PATTERN,
 	.ctrl2_partial = SSD16XX_GEN1_CTRL2_TO_PATTERN,
+	.x_addr_in_bytes = true,
+};
+#endif
+
+#if DT_HAS_COMPAT_STATUS_OKAY(solomon_ssd1677)
+static const struct ssd16xx_quirks quirks_solomon_ssd1677 = {
+	.max_width = 680,
+	.max_height = 960,
+	.pp_width_bits = 16,
+	.pp_height_bits = 16,
+	.ctrl2_full = SSD16XX_GEN2_CTRL2_DISPLAY,
+	.ctrl2_partial = SSD16XX_GEN2_CTRL2_DISPLAY | SSD16XX_GEN2_CTRL2_MODE2,
+	.x_addr_in_bytes = false,
 };
 #endif
 
@@ -997,6 +1073,7 @@ static const struct ssd16xx_quirks quirks_solomon_ssd1680 = {
 	.pp_height_bits = 16,
 	.ctrl2_full = SSD16XX_GEN2_CTRL2_DISPLAY,
 	.ctrl2_partial = SSD16XX_GEN2_CTRL2_DISPLAY | SSD16XX_GEN2_CTRL2_MODE2,
+	.x_addr_in_bytes = true,
 };
 #endif
 
@@ -1008,6 +1085,7 @@ static struct ssd16xx_quirks quirks_solomon_ssd1681 = {
 	.pp_height_bits = 16,
 	.ctrl2_full = SSD16XX_GEN2_CTRL2_DISPLAY,
 	.ctrl2_partial = SSD16XX_GEN2_CTRL2_DISPLAY | SSD16XX_GEN2_CTRL2_MODE2,
+	.x_addr_in_bytes = true,
 };
 #endif
 
@@ -1072,7 +1150,9 @@ static struct ssd16xx_quirks quirks_solomon_ssd1681 = {
 		.height = DT_PROP(n, height),				\
 		.width = DT_PROP(n, width),				\
 		.rotation = DT_PROP(n, rotation),			\
+		.scan_y_reverse = DT_PROP(n, scan_y_reverse),		\
 		.tssv = DT_PROP_OR(n, tssv, 0),				\
+		.gdo_flags = DT_PROP_OR(n, gdo_flags, 0),		\
 		.softstart = SSD16XX_ASSIGN_ARRAY(n, softstart),	\
 		.profiles = {						\
 			[SSD16XX_PROFILE_FULL] =			\
@@ -1098,6 +1178,8 @@ DT_FOREACH_STATUS_OKAY_VARGS(solomon_ssd1673, SSD16XX_DEFINE,
 			     &quirks_solomon_ssd1673);
 DT_FOREACH_STATUS_OKAY_VARGS(solomon_ssd1675a, SSD16XX_DEFINE,
 			     &quirks_solomon_ssd1675a);
+DT_FOREACH_STATUS_OKAY_VARGS(solomon_ssd1677, SSD16XX_DEFINE,
+			     &quirks_solomon_ssd1677);
 DT_FOREACH_STATUS_OKAY_VARGS(solomon_ssd1680, SSD16XX_DEFINE,
 			     &quirks_solomon_ssd1680);
 DT_FOREACH_STATUS_OKAY_VARGS(solomon_ssd1681, SSD16XX_DEFINE,
diff --git a/dts/bindings/display/solomon,ssd1677.yaml b/dts/bindings/display/solomon,ssd1677.yaml
@@ -0,0 +1,8 @@
+# Copyright (c) 2022 Andreas Sandberg
+# SPDX-License-Identifier: Apache-2.0
+
+description: Solomon Systech SSD1677 960x680 EPD display controller
+
+compatible: "solomon,ssd1677"
+
+include: solomon,ssd16xx-common.yaml
diff --git a/dts/bindings/display/solomon,ssd16xx-common.yaml b/dts/bindings/display/solomon,ssd16xx-common.yaml
@@ -43,6 +43,20 @@ properties:
       Display rotation (CW) in degrees.
       If not defined, rotation is off by default.
 
+  scan-y-reverse:
+    type: boolean
+    description: Reverse the scan direction along Y axis for the display.
+
+      Some displays have the scan direction reversed along the Y axis.
+
+  gdo-flags:
+    type: int
+    description: Gate scanning sequence and direction
+
+      Additional flags passed into Driver Output control command to
+      determine the how the output pin layout for the panel is and
+      what should be scanning sequence and the direction.
+
 child-binding:
   description: |
     Child nodes describe refresh profiles. Each refresh profile
