drivers: display: gc9x01: convert to MIPI DBI API

Convert galaxycore GC9X01 to MIPI DBI API. In tree boards and tests
using this display have also had their devicetrees updated to use the
new MIPI DBI SPI emulated device.

Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>

boards/shields/seeed_xiao_round_display/seeed_xiao_round_display.overlay

@@ -27,6 +27,26 @@
 	aliases {
 		rtc = &pcf8563_xiao_round_display;
 	};
+
+	xiao_round_display_mipi_dbi {
+		compatible = "zephyr,mipi-dbi-spi";
+		spi-dev = <&xiao_spi>;
+		dc-gpios = <&xiao_d 3 GPIO_ACTIVE_HIGH>;
+		write-only;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		gc9a01_xiao_round_display: gc9a01@0 {
+			status = "okay";
+			compatible = "galaxycore,gc9x01x";
+			reg = <0>;
+			mipi-max-frequency = <DT_FREQ_M(100)>;
+			pixel-format = <PANEL_PIXEL_FORMAT_RGB_565>;
+			width = <240>;
+			height = <240>;
+			display-inversion;
+		};
+	};
 };
 
 &xiao_adc {
@@ -62,18 +82,6 @@
 	status = "okay";
 	cs-gpios = <&xiao_d 1 GPIO_ACTIVE_LOW>, <&xiao_d 2 GPIO_ACTIVE_LOW>;
 
-	gc9a01_xiao_round_display: gc9a01@0 {
-		status = "okay";
-		compatible = "galaxycore,gc9x01x";
-		reg = <0>;
-		spi-max-frequency = <DT_FREQ_M(100)>;
-		cmd-data-gpios = <&xiao_d 3 GPIO_ACTIVE_HIGH>;
-		pixel-format = <PANEL_PIXEL_FORMAT_RGB_565>;
-		width = <240>;
-		height = <240>;
-		display-inversion;
-	};
-
 	sdhc_xiao_round_display: sdhc@1 {
 		compatible = "zephyr,sdhc-spi-slot";
 		reg = <1>;

boards/waveshare/esp32s3_touch_lcd_1_28/esp32s3_touch_lcd_1_28_esp32s3_procpu.dts

@@ -56,6 +56,28 @@
 			pwms = <&ledc0 0 PWM_HZ(250) PWM_POLARITY_NORMAL>;
 		};
 	};
+
+	/* MIPI DBI */
+	mipi_dbi {
+		compatible = "zephyr,mipi-dbi-spi";
+		spi-dev = <&spi2>;
+		dc-gpios = <&gpio0 8 GPIO_ACTIVE_HIGH>;
+		reset-gpios = <&gpio0 14 GPIO_ACTIVE_LOW>;
+		write-only;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		gc9a01: gc9a01@0 {
+			status = "okay";
+			compatible = "galaxycore,gc9x01x";
+			reg = <0>;
+			mipi-max-frequency = <100000000>;
+			pixel-format = <PANEL_PIXEL_FORMAT_RGB_888>;
+			display-inversion;
+			width = <240>;
+			height = <240>;
+		};
+	};
 };
 
 &flash0 {
@@ -146,19 +168,6 @@
 	pinctrl-0 = <&spim2_default>;
 	pinctrl-names = "default";
 	cs-gpios = <&gpio0 9 GPIO_ACTIVE_LOW>;
-
-	gc9a01: gc9a01@0 {
-		status = "okay";
-		compatible = "galaxycore,gc9x01x";
-		reg = <0>;
-		spi-max-frequency = <100000000>;
-		cmd-data-gpios = <&gpio0 8 GPIO_ACTIVE_HIGH>;
-		reset-gpios = <&gpio0 14 GPIO_ACTIVE_LOW>;
-		pixel-format = <PANEL_PIXEL_FORMAT_RGB_888>;
-		display-inversion;
-		width = <240>;
-		height = <240>;
-	};
 };
 
 &trng0 {

drivers/display/Kconfig.gc9x01x

@@ -5,6 +5,6 @@ config GC9X01X
 	bool "GC9X01X display driver"
 	default y
 	depends on DT_HAS_GALAXYCORE_GC9X01X_ENABLED
-	select SPI
+	select MIPI_DBI
 	help
 	  Enable driver for GC9X01X display driver.

drivers/display/display_gc9x01x.c

@@ -10,8 +10,7 @@
 
 #include <zephyr/dt-bindings/display/panel.h>
 #include <zephyr/drivers/display.h>
-#include <zephyr/drivers/gpio.h>
-#include <zephyr/drivers/spi.h>
+#include <zephyr/drivers/mipi_dbi.h>
 #include <zephyr/pm/device.h>
 #include <zephyr/sys/util.h>
 #include <zephyr/sys/byteorder.h>
@@ -19,12 +18,6 @@
 #include <zephyr/logging/log.h>
 LOG_MODULE_REGISTER(display_gc9x01x, CONFIG_DISPLAY_LOG_LEVEL);
 
-/* Command/data GPIO level for commands. */
-#define GC9X01X_GPIO_LEVEL_CMD 0U
-
-/* Command/data GPIO level for data. */
-#define GC9X01X_GPIO_LEVEL_DATA 1U
-
 /* Maximum number of default init registers  */
 #define GC9X01X_NUM_DEFAULT_INIT_REGS 12U
 
@@ -37,9 +30,8 @@ struct gc9x01x_data {
 
 /* Configuration data struct.*/
 struct gc9x01x_config {
-	struct spi_dt_spec spi;
-	struct gpio_dt_spec cmd_data;
-	struct gpio_dt_spec reset;
+	const struct device *mipi_dev;
+	struct mipi_dbi_config dbi_config;
 	uint8_t pixel_format;
 	uint16_t orientation;
 	uint16_t x_resolution;
@@ -229,35 +221,9 @@ static int gc9x01x_transmit(const struct device *dev, uint8_t cmd, const void *t
 			    size_t tx_len)
 {
 	const struct gc9x01x_config *config = dev->config;
-	int ret;
-	struct spi_buf tx_buf = {.buf = &cmd, .len = 1U};
-	struct spi_buf_set tx_bufs = {.buffers = &tx_buf, .count = 1U};
-
-	ret = gpio_pin_set_dt(&config->cmd_data, GC9X01X_GPIO_LEVEL_CMD);
-	if (ret < 0) {
-		return ret;
-	}
-	ret = spi_write_dt(&config->spi, &tx_bufs);
-	if (ret < 0) {
-		return ret;
-	}
-
-	/* send data (if any) */
-	if (tx_data != NULL) {
-		tx_buf.buf = (void *)tx_data;
-		tx_buf.len = tx_len;
-
-		ret = gpio_pin_set_dt(&config->cmd_data, GC9X01X_GPIO_LEVEL_DATA);
-		if (ret < 0) {
-			return ret;
-		}
-		ret = spi_write_dt(&config->spi, &tx_bufs);
-		if (ret < 0) {
-			return ret;
-		}
-	}
 
-	return 0;
+	return mipi_dbi_command_write(config->mipi_dev, &config->dbi_config,
+				      cmd, tx_data, tx_len);
 }
 
 static int gc9x01x_regs_init(const struct device *dev)
@@ -266,6 +232,10 @@ static int gc9x01x_regs_init(const struct device *dev)
 	const struct gc9x01x_regs *regs = config->regs;
 	int ret;
 
+	if (!device_is_ready(config->mipi_dev)) {
+		return -ENODEV;
+	}
+
 	/* Enable inter-command mode */
 	ret = gc9x01x_transmit(dev, GC9X01X_CMD_INREGEN1, NULL, 0);
 	if (ret < 0) {
@@ -371,17 +341,15 @@ static int gc9x01x_enter_sleep(const struct device *dev)
 static int gc9x01x_hw_reset(const struct device *dev)
 {
 	const struct gc9x01x_config *config = dev->config;
+	int ret;
 
-	if (config->reset.port == NULL) {
-		return -ENODEV;
+	ret = mipi_dbi_reset(config->mipi_dev, 100);
+	if (ret < 0) {
+		return ret;
 	}
-
-	gpio_pin_set_dt(&config->reset, 1U);
-	k_msleep(100);
-	gpio_pin_set_dt(&config->reset, 0U);
 	k_msleep(10);
 
-	return 0;
+	return ret;
 }
 
 static int gc9x01x_display_blanking_off(const struct device *dev)
@@ -492,38 +460,8 @@ static int gc9x01x_configure(const struct device *dev)
 
 static int gc9x01x_init(const struct device *dev)
 {
-	const struct gc9x01x_config *config = dev->config;
 	int ret;
 
-	if (!spi_is_ready_dt(&config->spi)) {
-		LOG_ERR("SPI device is not ready");
-		return -ENODEV;
-	}
-
-	if (!gpio_is_ready_dt(&config->cmd_data)) {
-		LOG_ERR("Command/Data GPIO device not ready");
-		return -ENODEV;
-	}
-
-	ret = gpio_pin_configure_dt(&config->cmd_data, GPIO_OUTPUT);
-	if (ret < 0) {
-		LOG_ERR("Could not configure command/data GPIO (%d)", ret);
-		return ret;
-	}
-
-	if (config->reset.port != NULL) {
-		if (!device_is_ready(config->reset.port)) {
-			LOG_ERR("Reset GPIO device not ready");
-			return -ENODEV;
-		}
-
-		ret = gpio_pin_configure_dt(&config->reset, GPIO_OUTPUT_INACTIVE);
-		if (ret < 0) {
-			LOG_ERR("Could not configure reset GPIO (%d)", ret);
-			return ret;
-		}
-	}
-
 	gc9x01x_hw_reset(dev);
 
 	gc9x01x_display_blanking_on(dev);
@@ -573,8 +511,7 @@ static int gc9x01x_write(const struct device *dev, const uint16_t x, const uint1
 	struct gc9x01x_data *data = dev->data;
 	int ret;
 	const uint8_t *write_data_start = (const uint8_t *)buf;
-	struct spi_buf tx_buf;
-	struct spi_buf_set tx_bufs;
+	struct display_buffer_descriptor mipi_desc;
 	uint16_t write_cnt;
 	uint16_t nbr_of_writes;
 	uint16_t write_h;
@@ -592,26 +529,30 @@ static int gc9x01x_write(const struct device *dev, const uint16_t x, const uint1
 	if (desc->pitch > desc->width) {
 		write_h = 1U;
 		nbr_of_writes = desc->height;
+		mipi_desc.height = 1;
+		mipi_desc.buf_size = desc->pitch * data->bytes_per_pixel;
 	} else {
 		write_h = desc->height;
+		mipi_desc.height = desc->height;
+		mipi_desc.buf_size = desc->width * data->bytes_per_pixel * write_h;
 		nbr_of_writes = 1U;
 	}
 
-	ret = gc9x01x_transmit(dev, GC9X01X_CMD_MEMWR, write_data_start,
-				  desc->width * data->bytes_per_pixel * write_h);
+	mipi_desc.width = desc->width;
+	/* Per MIPI API, pitch must always match width */
+	mipi_desc.pitch = desc->width;
+
+	ret = gc9x01x_transmit(dev, GC9X01X_CMD_MEMWR, NULL, 0);
 	if (ret < 0) {
 		return ret;
 	}
 
-	tx_bufs.buffers = &tx_buf;
-	tx_bufs.count = 1U;
-
-	write_data_start += desc->pitch * data->bytes_per_pixel;
-	for (write_cnt = 1U; write_cnt < nbr_of_writes; ++write_cnt) {
-		tx_buf.buf = (void *)write_data_start;
-		tx_buf.len = desc->width * data->bytes_per_pixel * write_h;
-
-		ret = spi_write_dt(&config->spi, &tx_bufs);
+	for (write_cnt = 0U; write_cnt < nbr_of_writes; ++write_cnt) {
+		ret = mipi_dbi_write_display(config->mipi_dev,
+					     &config->dbi_config,
+					     write_data_start,
+					     &mipi_desc,
+					     data->pixel_format);
 		if (ret < 0) {
 			return ret;
 		}
@@ -679,9 +620,13 @@ static const struct display_driver_api gc9x01x_api = {
 #define GC9X01X_INIT(inst)                                                                         \
 	GC9X01X_REGS_INIT(inst);                                                                   \
 	static const struct gc9x01x_config gc9x01x_config_##inst = {                               \
-		.spi = SPI_DT_SPEC_INST_GET(inst, SPI_OP_MODE_MASTER | SPI_WORD_SET(8), 0),        \
-		.cmd_data = GPIO_DT_SPEC_INST_GET(inst, cmd_data_gpios),                           \
-		.reset = GPIO_DT_SPEC_INST_GET_OR(inst, reset_gpios, {0}),                         \
+		.mipi_dev = DEVICE_DT_GET(DT_INST_PARENT(inst)),                                   \
+		.dbi_config = {                                                                    \
+			.mode = MIPI_DBI_MODE_SPI_4WIRE,                                           \
+			.config = MIPI_DBI_SPI_CONFIG_DT_INST(inst,                                \
+							      SPI_OP_MODE_MASTER |                 \
+							      SPI_WORD_SET(8), 0),                 \
+		},                                                                                 \
 		.pixel_format = DT_INST_PROP(inst, pixel_format),                                  \
 		.orientation = DT_INST_ENUM_IDX(inst, orientation),                                \
 		.x_resolution = DT_INST_PROP(inst, width),                                         \

dts/bindings/display/galaxycore,gc9x01x.yaml

@@ -29,23 +29,9 @@ description: |
 
 compatible: "galaxycore,gc9x01x"
 
-include: [spi-device.yaml, display-controller.yaml, lcd-controller.yaml]
+include: [mipi-dbi-spi-device.yaml, display-controller.yaml, lcd-controller.yaml]
 
 properties:
-  reset-gpios:
-    type: phandle-array
-    description: |
-      RESET pin of the GC9X01X.
-      If connected directly the MCU pin should be configured
-      as active low.
-
-  cmd-data-gpios:
-    type: phandle-array
-    required: true
-    description: |
-      Data/Command pin of the GC9X01X is to be configured
-      high(1) for data, low(0) for command.
-
   orientation:
     type: string
     default: "normal"

tests/drivers/build_all/display/app.overlay

@@ -125,6 +125,16 @@
 					tcon = <0x22>;
 				};
 			};
+
+			test_spi_gc9x01x: gc9x01x@6 {
+				compatible = "galaxycore,gc9x01x";
+				reg = <6>;
+				mipi-max-frequency = <100000000>;
+				pixel-format = <16>;
+
+				width = <240>;
+				height = <240>;
+			};
 		};
 
 
@@ -136,21 +146,12 @@
 			status = "okay";
 			clock-frequency = <2000000>;
 
-			/* one entry for every devices at spi.dtsi */
+			/* one entry for every device. Note that this must
+			 * include MIPI DBI devices as well.
+			 */
 			cs-gpios = <&test_gpio 0 0 &test_gpio 0 1 &test_gpio 0 2
-				&test_gpio 0 3 &test_gpio 0 4 &test_gpio 0 5>;
-
-			test_spi_gc9x01x: gc9x01x@1 {
-				compatible = "galaxycore,gc9x01x";
-				reg = <1>;
-				spi-max-frequency = <100000000>;
-				cmd-data-gpios = <&test_gpio 1 0>;
-				reset-gpios = <&test_gpio 2 0>;
-				pixel-format = <16>;
-
-				width = <240>;
-				height = <240>;
-			};
+				&test_gpio 0 3 &test_gpio 0 4 &test_gpio 0 5
+				&test_gpio 0 6>;
 
 			test_led_strip_0: lpd8806@2 {
 				compatible = "greeled,lpd8806";