[PATCH v3 4/4] drm/panel: ilitek-ili9806e: add Rocktech RK050HR345-CT106A SPI panel

[Dario Binacchi <dario.binacchi@amarulasolutions.com>]

Add support for the Rocktech RK050HR345-CT106A panel based on the
Ilitek ILI9806E controller using the SPI bus.

The driver is designed to be easily extensible to support other panels
with different initialization sequences and display timings by
providing a specific descriptor structure for each model.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>

---

Changes in v3:
- Add Reviewed-by tag of Rob Herring

Changes in v2:
- Introduce DRM_PANEL_ILITEK_ILI9806E_CORE hidden kconfig option.
- Split core and DSI logic.
- Restore vdd-supply as required for both DSI and SPI types in the
  dt-bindings.
- Dop useless settings in case of rocktech,rk050hr345-ct106a in the
  dt-bindings.

 MAINTAINERS                                   |   1 +
 drivers/gpu/drm/panel/Kconfig                 |  10 +
 drivers/gpu/drm/panel/Makefile                |   1 +
 .../drm/panel/panel-ilitek-ili9806e-core.c    |  31 +-
 .../gpu/drm/panel/panel-ilitek-ili9806e-spi.c | 323 ++++++++++++++++++
 5 files changed, 353 insertions(+), 13 deletions(-)
 create mode 100644 drivers/gpu/drm/panel/panel-ilitek-ili9806e-spi.c

diff --git a/MAINTAINERS b/MAINTAINERS
index b856a62666dc..6aaa32eab636 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7916,6 +7916,7 @@ F:	drivers/gpu/drm/panel/panel-ilitek-ili9805.c
 
 DRM DRIVER FOR ILITEK ILI9806E PANELS
 M:	Michael Walle <mwalle@kernel.org>
+M:	Dario Binacchi <dario.binacchi@amarulasolutions.com>
 S:	Maintained
 F:	drivers/gpu/drm/panel/panel-ilitek-ili9806e-*
 
diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index 333e981eda96..d1cb04e838c5 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -270,6 +270,16 @@ config DRM_PANEL_ILITEK_ILI9806E_DSI
 	  Say Y if you want to enable support for panels based on the
 	  Ilitek ILI9806E controller using DSI.
 
+config DRM_PANEL_ILITEK_ILI9806E_SPI
+	tristate "Ilitek ILI9806E-based RGB SPI panel"
+	depends on SPI
+	select DRM_PANEL_ILITEK_ILI9806E_CORE
+	select DRM_MIPI_DBI
+	select VIDEOMODE_HELPERS
+	help
+	  Say Y if you want to enable support for panels based on the
+	  Ilitek ILI9806E controller using SPI.
+
 config DRM_PANEL_ILITEK_ILI9881C
 	tristate "Ilitek ILI9881C-based panels"
 	depends on OF
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index 13034cadb8d8..3697687651fe 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9341) += panel-ilitek-ili9341.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9805) += panel-ilitek-ili9805.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9806E_CORE) += panel-ilitek-ili9806e-core.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9806E_DSI) += panel-ilitek-ili9806e-dsi.o
+obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9806E_SPI) += panel-ilitek-ili9806e-spi.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9881C) += panel-ilitek-ili9881c.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9882T) += panel-ilitek-ili9882t.o
 obj-$(CONFIG_DRM_PANEL_INNOLUX_EJ030NA) += panel-innolux-ej030na.o
diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9806e-core.c b/drivers/gpu/drm/panel/panel-ilitek-ili9806e-core.c
index c088685d9d85..be2cf1440155 100644
--- a/drivers/gpu/drm/panel/panel-ilitek-ili9806e-core.c
+++ b/drivers/gpu/drm/panel/panel-ilitek-ili9806e-core.c
@@ -11,6 +11,7 @@
 #include <linux/export.h>
 #include <linux/gpio/consumer.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/property.h>
 #include <linux/regulator/consumer.h>
 
@@ -20,15 +21,11 @@ struct ili9806e {
 	void *transport;
 	struct drm_panel panel;
 
+	unsigned int num_supplies;
 	struct regulator_bulk_data supplies[2];
 	struct gpio_desc *reset_gpio;
 };
 
-static const char * const regulator_names[] = {
-	"vdd",
-	"vccio",
-};
-
 void *ili9806e_get_transport(struct drm_panel *panel)
 {
 	struct ili9806e *ctx = container_of(panel, struct ili9806e, panel);
@@ -44,7 +41,7 @@ int ili9806e_power_on(struct device *dev)
 
 	gpiod_set_value(ctx->reset_gpio, 1);
 
-	ret = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
+	ret = regulator_bulk_enable(ctx->num_supplies, ctx->supplies);
 	if (ret) {
 		dev_err(dev, "regulator bulk enable failed: %d\n", ret);
 		return ret;
@@ -65,7 +62,7 @@ int ili9806e_power_off(struct device *dev)
 
 	gpiod_set_value(ctx->reset_gpio, 1);
 
-	ret = regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
+	ret = regulator_bulk_disable(ctx->num_supplies, ctx->supplies);
 	if (ret)
 		dev_err(dev, "regulator bulk disable failed: %d\n", ret);
 
@@ -78,7 +75,8 @@ int ili9806e_probe(struct device *dev, void *transport,
 		  int connector_type)
 {
 	struct ili9806e *ctx;
-	int i, ret;
+	bool set_prepare_prev_first = false;
+	int ret;
 
 	ctx = devm_kzalloc(dev, sizeof(struct ili9806e), GFP_KERNEL);
 	if (!ctx)
@@ -87,11 +85,16 @@ int ili9806e_probe(struct device *dev, void *transport,
 	dev_set_drvdata(dev, ctx);
 	ctx->transport = transport;
 
-	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++)
-		ctx->supplies[i].supply = regulator_names[i];
+	ctx->supplies[ctx->num_supplies++].supply = "vdd";
+	if (of_device_is_compatible(dev->of_node,
+				    "densitron,dmt028vghmcmi-1d") ||
+	    of_device_is_compatible(dev->of_node,
+				    "ortustech,com35h3p70ulc")) {
+		ctx->supplies[ctx->num_supplies++].supply = "vccio";
+		set_prepare_prev_first = true;
+	}
 
-	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ctx->supplies),
-				      ctx->supplies);
+	ret = devm_regulator_bulk_get(dev, ctx->num_supplies, ctx->supplies);
 	if (ret)
 		return dev_err_probe(dev, ret, "failed to get regulators\n");
 
@@ -106,7 +109,9 @@ int ili9806e_probe(struct device *dev, void *transport,
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to get backlight\n");
 
-	ctx->panel.prepare_prev_first = true;
+	if (set_prepare_prev_first)
+		ctx->panel.prepare_prev_first = true;
+
 	drm_panel_add(&ctx->panel);
 
 	return 0;
diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9806e-spi.c b/drivers/gpu/drm/panel/panel-ilitek-ili9806e-spi.c
new file mode 100644
index 000000000000..9d10b0d28f52
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-ilitek-ili9806e-spi.c
@@ -0,0 +1,323 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SPI interface to the Ilitek ILI9806E panel.
+ *
+ * Copyright (c) 2026 Amarula Solutions, Dario Binacchi <dario.binacchi@amarulasolutions.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/media-bus-format.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+
+#include <drm/drm_mipi_dbi.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_print.h>
+
+#include <video/mipi_display.h>
+
+#include "panel-ilitek-ili9806e-core.h"
+
+struct ili9806e_spi_panel {
+	struct spi_device *spi;
+	struct mipi_dbi dbi;
+	const struct ili9806e_spi_panel_desc *desc;
+};
+
+struct ili9806e_spi_panel_desc {
+	const struct drm_display_mode *display_mode;
+	u32 bus_format;
+	u32 bus_flags;
+	void (*init_sequence)(struct ili9806e_spi_panel *ctx);
+};
+
+static int ili9806e_spi_off(struct ili9806e_spi_panel *ctx)
+{
+	struct mipi_dbi *dbi = &ctx->dbi;
+
+	mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF, 0x00);
+	mipi_dbi_command(dbi, MIPI_DCS_ENTER_SLEEP_MODE, 0x00);
+
+	return 0;
+}
+
+static int ili9806e_spi_unprepare(struct drm_panel *panel)
+{
+	struct ili9806e_spi_panel *ctx = ili9806e_get_transport(panel);
+	struct device *dev = &ctx->spi->dev;
+	int ret;
+
+	ili9806e_spi_off(ctx);
+
+	ret = ili9806e_power_off(dev);
+	if (ret)
+		dev_err(dev, "power off failed: %d\n", ret);
+
+	return 0;
+}
+
+static int ili9806e_spi_prepare(struct drm_panel *panel)
+{
+	struct ili9806e_spi_panel *ctx = ili9806e_get_transport(panel);
+	struct device *dev = &ctx->spi->dev;
+	int ret;
+
+	ret = ili9806e_power_on(dev);
+	if (ret)
+		return ret;
+
+	if (ctx->desc->init_sequence)
+		ctx->desc->init_sequence(ctx);
+
+	return 0;
+}
+
+static int ili9806e_spi_get_modes(struct drm_panel *panel,
+			      struct drm_connector *connector)
+{
+	struct ili9806e_spi_panel *ctx = ili9806e_get_transport(panel);
+	const struct ili9806e_spi_panel_desc *desc = ctx->desc;
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(connector->dev, desc->display_mode);
+	if (!mode)
+		return -ENOMEM;
+
+	drm_mode_set_name(mode);
+
+	connector->display_info.width_mm = mode->width_mm;
+	connector->display_info.height_mm = mode->height_mm;
+	connector->display_info.bus_flags = desc->bus_flags;
+	drm_display_info_set_bus_formats(&connector->display_info,
+					 &desc->bus_format, 1);
+
+	drm_mode_probed_add(connector, mode);
+
+	return 1;
+}
+
+static const struct drm_panel_funcs ili9806e_spi_funcs = {
+	.unprepare = ili9806e_spi_unprepare,
+	.prepare   = ili9806e_spi_prepare,
+	.get_modes = ili9806e_spi_get_modes,
+};
+
+static int ili9806e_spi_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct ili9806e_spi_panel *ctx;
+	int err;
+
+	ctx = devm_kzalloc(dev, sizeof(struct ili9806e_spi_panel), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->spi = spi;
+	ctx->desc = device_get_match_data(dev);
+
+	err = mipi_dbi_spi_init(spi, &ctx->dbi, NULL);
+	if (err)
+		return dev_err_probe(dev, err, "MIPI DBI init failed\n");
+
+	return ili9806e_probe(dev, ctx, &ili9806e_spi_funcs,
+			      DRM_MODE_CONNECTOR_DPI);
+}
+
+static void ili9806e_spi_remove(struct spi_device *spi)
+{
+	ili9806e_remove(&spi->dev);
+}
+
+static void rk050hr345_ct106a_init(struct ili9806e_spi_panel *ctx)
+{
+	struct mipi_dbi *dbi = &ctx->dbi;
+
+	/* Switch to page 1 */
+	mipi_dbi_command(dbi, 0xff, 0xff, 0x98, 0x06, 0x04, 0x01);
+	/* Interface Settings */
+	mipi_dbi_command(dbi, 0x08, 0x10);
+	mipi_dbi_command(dbi, 0x21, 0x01);
+	/* Panel Settings */
+	mipi_dbi_command(dbi, 0x30, 0x01);
+	mipi_dbi_command(dbi, 0x31, 0x00);
+	/* Power Control */
+	mipi_dbi_command(dbi, 0x40, 0x15);
+	mipi_dbi_command(dbi, 0x41, 0x44);
+	mipi_dbi_command(dbi, 0x42, 0x03);
+	mipi_dbi_command(dbi, 0x43, 0x09);
+	mipi_dbi_command(dbi, 0x44, 0x09);
+	mipi_dbi_command(dbi, 0x50, 0x78);
+	mipi_dbi_command(dbi, 0x51, 0x78);
+	mipi_dbi_command(dbi, 0x52, 0x00);
+	mipi_dbi_command(dbi, 0x53, 0x3a);
+	mipi_dbi_command(dbi, 0x57, 0x50);
+	/* Timing Control */
+	mipi_dbi_command(dbi, 0x60, 0x07);
+	mipi_dbi_command(dbi, 0x61, 0x00);
+	mipi_dbi_command(dbi, 0x62, 0x08);
+	mipi_dbi_command(dbi, 0x63, 0x00);
+	/* Gamma Settings */
+	mipi_dbi_command(dbi, 0xa0, 0x00);
+	mipi_dbi_command(dbi, 0xa1, 0x03);
+	mipi_dbi_command(dbi, 0xa2, 0x0b);
+	mipi_dbi_command(dbi, 0xa3, 0x0f);
+	mipi_dbi_command(dbi, 0xa4, 0x0b);
+	mipi_dbi_command(dbi, 0xa5, 0x1b);
+	mipi_dbi_command(dbi, 0xa6, 0x0a);
+	mipi_dbi_command(dbi, 0xa7, 0x0a);
+	mipi_dbi_command(dbi, 0xa8, 0x02);
+	mipi_dbi_command(dbi, 0xa9, 0x07);
+	mipi_dbi_command(dbi, 0xaa, 0x05);
+	mipi_dbi_command(dbi, 0xab, 0x03);
+	mipi_dbi_command(dbi, 0xac, 0x0e);
+	mipi_dbi_command(dbi, 0xad, 0x32);
+	mipi_dbi_command(dbi, 0xae, 0x2d);
+	mipi_dbi_command(dbi, 0xaf, 0x00);
+	mipi_dbi_command(dbi, 0xc0, 0x00);
+	mipi_dbi_command(dbi, 0xc1, 0x03);
+	mipi_dbi_command(dbi, 0xc2, 0x0e);
+	mipi_dbi_command(dbi, 0xc3, 0x10);
+	mipi_dbi_command(dbi, 0xc4, 0x09);
+	mipi_dbi_command(dbi, 0xc5, 0x17);
+	mipi_dbi_command(dbi, 0xc6, 0x09);
+	mipi_dbi_command(dbi, 0xc7, 0x07);
+	mipi_dbi_command(dbi, 0xc8, 0x04);
+	mipi_dbi_command(dbi, 0xc9, 0x09);
+	mipi_dbi_command(dbi, 0xca, 0x06);
+	mipi_dbi_command(dbi, 0xcb, 0x06);
+	mipi_dbi_command(dbi, 0xcc, 0x0c);
+	mipi_dbi_command(dbi, 0xcd, 0x25);
+	mipi_dbi_command(dbi, 0xce, 0x20);
+	mipi_dbi_command(dbi, 0xcf, 0x00);
+
+	/* Switch to page 6 */
+	mipi_dbi_command(dbi, 0xff, 0xff, 0x98, 0x06, 0x04, 0x06);
+	/* GIP settings */
+	mipi_dbi_command(dbi, 0x00, 0x21);
+	mipi_dbi_command(dbi, 0x01, 0x09);
+	mipi_dbi_command(dbi, 0x02, 0x00);
+	mipi_dbi_command(dbi, 0x03, 0x00);
+	mipi_dbi_command(dbi, 0x04, 0x01);
+	mipi_dbi_command(dbi, 0x05, 0x01);
+	mipi_dbi_command(dbi, 0x06, 0x80);
+	mipi_dbi_command(dbi, 0x07, 0x05);
+	mipi_dbi_command(dbi, 0x08, 0x02);
+	mipi_dbi_command(dbi, 0x09, 0x80);
+	mipi_dbi_command(dbi, 0x0a, 0x00);
+	mipi_dbi_command(dbi, 0x0b, 0x00);
+	mipi_dbi_command(dbi, 0x0c, 0x0a);
+	mipi_dbi_command(dbi, 0x0d, 0x0a);
+	mipi_dbi_command(dbi, 0x0e, 0x00);
+	mipi_dbi_command(dbi, 0x0f, 0x00);
+	mipi_dbi_command(dbi, 0x10, 0xe0);
+	mipi_dbi_command(dbi, 0x11, 0xe4);
+	mipi_dbi_command(dbi, 0x12, 0x04);
+	mipi_dbi_command(dbi, 0x13, 0x00);
+	mipi_dbi_command(dbi, 0x14, 0x00);
+	mipi_dbi_command(dbi, 0x15, 0xc0);
+	mipi_dbi_command(dbi, 0x16, 0x08);
+	mipi_dbi_command(dbi, 0x17, 0x00);
+	mipi_dbi_command(dbi, 0x18, 0x00);
+	mipi_dbi_command(dbi, 0x19, 0x00);
+	mipi_dbi_command(dbi, 0x1a, 0x00);
+	mipi_dbi_command(dbi, 0x1b, 0x00);
+	mipi_dbi_command(dbi, 0x1c, 0x00);
+	mipi_dbi_command(dbi, 0x1d, 0x00);
+	mipi_dbi_command(dbi, 0x20, 0x01);
+	mipi_dbi_command(dbi, 0x21, 0x23);
+	mipi_dbi_command(dbi, 0x22, 0x45);
+	mipi_dbi_command(dbi, 0x23, 0x67);
+	mipi_dbi_command(dbi, 0x24, 0x01);
+	mipi_dbi_command(dbi, 0x25, 0x23);
+	mipi_dbi_command(dbi, 0x26, 0x45);
+	mipi_dbi_command(dbi, 0x27, 0x67);
+	mipi_dbi_command(dbi, 0x30, 0x01);
+	mipi_dbi_command(dbi, 0x31, 0x11);
+	mipi_dbi_command(dbi, 0x32, 0x00);
+	mipi_dbi_command(dbi, 0x33, 0xee);
+	mipi_dbi_command(dbi, 0x34, 0xff);
+	mipi_dbi_command(dbi, 0x35, 0xbb);
+	mipi_dbi_command(dbi, 0x36, 0xca);
+	mipi_dbi_command(dbi, 0x37, 0xdd);
+	mipi_dbi_command(dbi, 0x38, 0xac);
+	mipi_dbi_command(dbi, 0x39, 0x76);
+	mipi_dbi_command(dbi, 0x3a, 0x67);
+	mipi_dbi_command(dbi, 0x3b, 0x22);
+	mipi_dbi_command(dbi, 0x3c, 0x22);
+	mipi_dbi_command(dbi, 0x3d, 0x22);
+	mipi_dbi_command(dbi, 0x3e, 0x22);
+	mipi_dbi_command(dbi, 0x3f, 0x22);
+	mipi_dbi_command(dbi, 0x40, 0x22);
+	mipi_dbi_command(dbi, 0x52, 0x10);
+	mipi_dbi_command(dbi, 0x53, 0x10);
+
+	/* Switch to page 7 */
+	mipi_dbi_command(dbi, 0xff, 0xff, 0x98, 0x06, 0x04, 0x07);
+	mipi_dbi_command(dbi, 0x17, 0x22);
+	mipi_dbi_command(dbi, 0x02, 0x77);
+	mipi_dbi_command(dbi, 0xe1, 0x79);
+	mipi_dbi_command(dbi, 0xb3, 0x10);
+
+	/* Switch to page 0 */
+	mipi_dbi_command(dbi, 0xff, 0xff, 0x98, 0x06, 0x04, 0x00);
+	mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, 0x00); // 0x36
+	mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE); // 0x11
+
+	msleep(120);
+
+	mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
+
+	msleep(120);
+}
+
+static const struct drm_display_mode rk050hr345_ct106a_mode = {
+	.width_mm    = 62,
+	.height_mm   = 110,
+	.clock       = 27000,
+	.hdisplay    = 480,
+	.hsync_start = 480 + 10,
+	.hsync_end   = 480 + 10 + 10,
+	.htotal      = 480 + 10 + 10 + 10,
+	.vdisplay    = 854,
+	.vsync_start = 854 + 10,
+	.vsync_end   = 854 + 10 + 10,
+	.vtotal      = 854 + 10 + 10 + 10,
+	.flags       = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+	.type        = DRM_MODE_TYPE_PREFERRED | DRM_MODE_TYPE_DRIVER,
+};
+
+static const struct ili9806e_spi_panel_desc rk050hr345_ct106a_desc = {
+	.init_sequence = rk050hr345_ct106a_init,
+	.display_mode = &rk050hr345_ct106a_mode,
+	.bus_format = MEDIA_BUS_FMT_RGB888_1X24,
+	.bus_flags = DRM_BUS_FLAG_DE_HIGH |
+		     DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE,
+};
+
+static const struct of_device_id ili9806e_spi_of_match[] = {
+	{ .compatible = "rocktech,rk050hr345-ct106a", .data = &rk050hr345_ct106a_desc },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ili9806e_spi_of_match);
+
+static const struct spi_device_id ili9806e_spi_ids[] = {
+	{ "rk050hr345-ct106a", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(spi, ili9806e_spi_ids);
+
+static struct spi_driver ili9806e_spi_driver = {
+	.driver = {
+		.name = "ili9806e-spi",
+		.of_match_table = ili9806e_spi_of_match,
+	},
+	.probe = ili9806e_spi_probe,
+	.remove = ili9806e_spi_remove,
+	.id_table = ili9806e_spi_ids,
+};
+module_spi_driver(ili9806e_spi_driver);
+
+MODULE_AUTHOR("Dario Binacchi <dario.binacchi@amarulasolutions.com>");
+MODULE_DESCRIPTION("Ilitek ILI9806E LCD SPI Driver");
+MODULE_LICENSE("GPL");
-- 
2.43.0