[PATCH 2/2] drm/panel: Add Ilitek IL97680A panels for Retroid Pocket Nova and Duo

[Jacob Pyke <jacob@pyk.ee>]

From: Teguh Sobirin <teguh@sobir.in>

Add support for the Ilitek IL97680A panels in the Retroid Pocket Nova
and the bottom display of the Retroid Pocket Duo. Both are 1280x960
command-mode panels using four DSI lanes and RGB888 pixels, with fixed
60 Hz and 120 Hz modes and DCS brightness control.

Share initialization and timings, with per-panel supply configurations.
Apply the requested brightness after display-on rather than setting full
brightness during initialization, to avoid a white flash on startup.

Link: https://github.com/RetroidPocket/linux/commit/32d07e207d8c09b97b9ad5009999c32c7058d4af
Signed-off-by: Teguh Sobirin <teguh@sobir.in>
Assisted-by: LLM
Signed-off-by: Jacob Pyke <jacob@pyk.ee>
---
 MAINTAINERS                                   |   1 +
 drivers/gpu/drm/panel/Kconfig                 |  11 +
 drivers/gpu/drm/panel/Makefile                |   1 +
 drivers/gpu/drm/panel/panel-ilitek-il97680a.c | 433 ++++++++++++++++++
 4 files changed, 446 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-ilitek-il97680a.c

diff --git a/MAINTAINERS b/MAINTAINERS
index d1be1cf2b93c4fa57ffcb6a17aaf2e14dad0deed..70d04c3870022c468295ce1de2a636c05e3accee 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8240,6 +8240,7 @@ M:	Jacob Pyke <jacob@pyk.ee>
 L:	dri-devel@lists.freedesktop.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/display/panel/ilitek,il97680a.yaml
+F:	drivers/gpu/drm/panel/panel-ilitek-il97680a.c
 
 DRM DRIVER FOR ILITEK ILI9225 PANELS
 M:	David Lechner <david@lechnology.com>
diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index cbdf7b8f7f7afc7f8aa3a9cefd2258ca81ac9673..fafa658d0c42cf26842e7ebb46dbf70ad59e4b9f 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -306,6 +306,17 @@ config DRM_PANEL_ILITEK_IL9322
 	  Say Y here if you want to enable support for Ilitek IL9322
 	  QVGA (320x240) RGB, YUV and ITU-T BT.656 panels.
 
+config DRM_PANEL_ILITEK_IL97680A
+	tristate "Ilitek IL97680A-based panels"
+	depends on OF
+	depends on DRM_MIPI_DSI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here to enable the 1280x960 Ilitek IL97680A panels in the
+	  Retroid Pocket Nova and the bottom display of the Retroid Pocket Duo.
+	  These panels use four-lane MIPI DSI command mode and support fixed
+	  60 Hz and 120 Hz refresh rates with brightness controlled over DCS.
+
 config DRM_PANEL_ILITEK_ILI9341
 	tristate "Ilitek ILI9341 240x320 QVGA panels"
 	depends on SPI
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index 3b523cf37833067c3b0b02ffd90694c3558f0741..ca03c07a1d255c1a8e0bd34dc0f3ba4fe2b65098 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_DRM_PANEL_HIMAX_HX8394) += panel-himax-hx8394.o
 obj-$(CONFIG_DRM_PANEL_HYDIS_HV101HD1) += panel-hydis-hv101hd1.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI7807S) += panel-ilitek-ili7807s.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_IL9322) += panel-ilitek-ili9322.o
+obj-$(CONFIG_DRM_PANEL_ILITEK_IL97680A) += panel-ilitek-il97680a.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9341) += panel-ilitek-ili9341.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9488) += panel-ilitek-ili9488.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9805) += panel-ilitek-ili9805.o
diff --git a/drivers/gpu/drm/panel/panel-ilitek-il97680a.c b/drivers/gpu/drm/panel/panel-ilitek-il97680a.c
new file mode 100644
index 0000000000000000000000000000000000000000..8edc9ee9ea3f685179765027bd2864c9c592e4de
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-ilitek-il97680a.c
@@ -0,0 +1,433 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Ilitek IL97680A panels driver
+ *
+ * Copyright (c) 2026 Teguh Sobirin <teguh@sobir.in>
+ * Copyright (c) 2026 Jacob Pyke <jacob@pyk.ee>
+ */
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+
+#include <video/mipi_display.h>
+
+#include <drm/drm_connector.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_of.h>
+#include <drm/drm_panel.h>
+
+struct il97680a {
+	struct drm_panel panel;
+	struct drm_connector *connector;
+	struct mipi_dsi_device *dsi;
+	const struct il97680a_desc *desc;
+	enum drm_panel_orientation orientation;
+
+	struct gpio_desc *reset_gpio;
+	struct regulator_bulk_data *supplies;
+	/* Protects panel power state and serializes DSI transfers. */
+	struct mutex lock;
+	bool powered;
+	bool prepared;
+	bool enabled;
+};
+
+struct il97680a_desc {
+	const struct regulator_bulk_data *supplies;
+	unsigned int num_supplies;
+};
+
+static const struct regulator_bulk_data il97680a_rpnova_supplies[] = {
+	{ .supply = "vdd" },
+	{ .supply = "vddio" },
+	{ .supply = "vci" },
+	{ .supply = "vdd18" },
+	{ .supply = "vdd28" },
+};
+
+static const struct regulator_bulk_data il97680a_rpduo_supplies[] = {
+	{ .supply = "vdd" },
+	{ .supply = "vddio" },
+	{ .supply = "vci" },
+};
+
+static inline struct il97680a *to_il97680a(struct drm_panel *panel)
+{
+	return container_of(panel, struct il97680a, panel);
+}
+
+static const struct drm_display_mode il97680a_retroid_modes[] = {
+	{
+		/* 120Hz */
+		.clock = (1280 + 12 + 2 + 8) * (960 + 12 + 2 + 24) * 120 / 1000,
+		.hdisplay = 1280,
+		.hsync_start = 1280 + 12,
+		.hsync_end = 1280 + 12 + 2,
+		.htotal = 1280 + 12 + 2 + 8,
+		.vdisplay = 960,
+		.vsync_start = 960 + 12,
+		.vsync_end = 960 + 12 + 2,
+		.vtotal = 960 + 12 + 2 + 24,
+	},
+	{
+		/* 60Hz */
+		.clock = (1280 + 12 + 2 + 8) * (960 + 12 + 2 + 24) * 60 / 1000,
+		.hdisplay = 1280,
+		.hsync_start = 1280 + 12,
+		.hsync_end = 1280 + 12 + 2,
+		.htotal = 1280 + 12 + 2 + 8,
+		.vdisplay = 960,
+		.vsync_start = 960 + 12,
+		.vsync_end = 960 + 12 + 2,
+		.vtotal = 960 + 12 + 2 + 24,
+	}
+};
+
+static int il97680a_get_current_mode(struct il97680a *pinfo)
+{
+	struct drm_connector *connector = pinfo->connector;
+	struct drm_crtc_state *crtc_state;
+	unsigned int i;
+
+	if (!connector || !connector->state || !connector->state->crtc)
+		return 0;
+
+	crtc_state = connector->state->crtc->state;
+	if (!crtc_state)
+		return -EINVAL;
+
+	for (i = 0; i < ARRAY_SIZE(il97680a_retroid_modes); i++) {
+		if (drm_mode_match(&crtc_state->mode,
+				   &il97680a_retroid_modes[i],
+				   DRM_MODE_MATCH_TIMINGS | DRM_MODE_MATCH_CLOCK))
+			return i;
+	}
+
+	return -EINVAL;
+}
+
+static int il97680a_init_sequence(struct il97680a *pinfo, unsigned int mode)
+{
+	struct mipi_dsi_multi_context dsi_ctx = { .dsi = pinfo->dsi };
+	int vrefresh = drm_mode_vrefresh(&il97680a_retroid_modes[mode]);
+
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xff, 0x5a, 0xa5, 0x08);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xc8, 0x62);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xff, 0x5a, 0xa5, 0x21);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xa4, 0x38);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xff, 0x5a, 0xa5, 0x23);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x85, 0x15);
+
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xff, 0x5a, 0xa5, 0x00);
+
+	if (vrefresh == 120)
+		mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x60, 0x00);
+	else
+		mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x60, 0x01);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6d, 0x00);
+
+	mipi_dsi_dcs_set_tear_on_multi(&dsi_ctx, MIPI_DSI_DCS_TEAR_MODE_VBLANK);
+
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, MIPI_DCS_WRITE_CONTROL_DISPLAY,
+				     0x20);
+
+	mipi_dsi_dcs_exit_sleep_mode_multi(&dsi_ctx);
+	mipi_dsi_msleep(&dsi_ctx, 120);
+
+	return dsi_ctx.accum_err;
+}
+
+static const struct il97680a_desc il97680a_rpnova_desc = {
+	.supplies = il97680a_rpnova_supplies,
+	.num_supplies = ARRAY_SIZE(il97680a_rpnova_supplies),
+};
+
+static const struct il97680a_desc il97680a_rpduo_desc = {
+	.supplies = il97680a_rpduo_supplies,
+	.num_supplies = ARRAY_SIZE(il97680a_rpduo_supplies),
+};
+
+static void il97680a_reset(struct il97680a *pinfo)
+{
+	gpiod_set_value_cansleep(pinfo->reset_gpio, 0);
+	usleep_range(20000, 21000);
+	gpiod_set_value_cansleep(pinfo->reset_gpio, 1);
+	usleep_range(20000, 21000);
+	gpiod_set_value_cansleep(pinfo->reset_gpio, 0);
+	usleep_range(20000, 21000);
+}
+
+static void il97680a_power_off(struct il97680a *pinfo)
+{
+	int ret;
+
+	pinfo->enabled = false;
+	pinfo->prepared = false;
+	gpiod_set_value_cansleep(pinfo->reset_gpio, 1);
+
+	if (!pinfo->powered)
+		return;
+
+	ret = regulator_bulk_disable(pinfo->desc->num_supplies, pinfo->supplies);
+	if (ret)
+		dev_err(pinfo->panel.dev, "Failed to disable supplies: %d\n", ret);
+	else
+		pinfo->powered = false;
+}
+
+static int il97680a_prepare(struct drm_panel *panel)
+{
+	struct il97680a *pinfo = to_il97680a(panel);
+	int mode, ret;
+
+	guard(mutex)(&pinfo->lock);
+
+	mode = il97680a_get_current_mode(pinfo);
+	if (mode < 0) {
+		dev_err(panel->dev, "Invalid display mode\n");
+		return mode;
+	}
+
+	if (!pinfo->powered) {
+		ret = regulator_bulk_enable(pinfo->desc->num_supplies, pinfo->supplies);
+		if (ret)
+			return ret;
+		pinfo->powered = true;
+	}
+
+	il97680a_reset(pinfo);
+
+	ret = il97680a_init_sequence(pinfo, mode);
+	if (ret) {
+		il97680a_power_off(pinfo);
+		return ret;
+	}
+
+	pinfo->prepared = true;
+
+	return 0;
+}
+
+static int il97680a_enable(struct drm_panel *panel)
+{
+	struct il97680a *pinfo = to_il97680a(panel);
+	struct mipi_dsi_multi_context dsi_ctx = { .dsi = pinfo->dsi };
+
+	guard(mutex)(&pinfo->lock);
+
+	if (!pinfo->prepared)
+		return -EPERM;
+
+	mipi_dsi_dcs_set_display_on_multi(&dsi_ctx);
+	mipi_dsi_msleep(&dsi_ctx, 50);
+
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xff, 0x5a, 0xa5, 0x22);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xe1, 0x01);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xff, 0x5a, 0xa5, 0x00);
+
+	if (!dsi_ctx.accum_err)
+		pinfo->enabled = true;
+
+	return dsi_ctx.accum_err;
+}
+
+static int il97680a_disable(struct drm_panel *panel)
+{
+	struct il97680a *pinfo = to_il97680a(panel);
+	struct mipi_dsi_multi_context dsi_ctx = { .dsi = pinfo->dsi };
+
+	guard(mutex)(&pinfo->lock);
+
+	pinfo->enabled = false;
+	if (!pinfo->prepared)
+		return 0;
+
+	mipi_dsi_dcs_set_display_off_multi(&dsi_ctx);
+	msleep(20);
+
+	return 0;
+}
+
+static int il97680a_unprepare(struct drm_panel *panel)
+{
+	struct il97680a *pinfo = to_il97680a(panel);
+	struct mipi_dsi_multi_context dsi_ctx = { .dsi = pinfo->dsi };
+
+	guard(mutex)(&pinfo->lock);
+
+	pinfo->enabled = false;
+	if (pinfo->prepared) {
+		mipi_dsi_dcs_enter_sleep_mode_multi(&dsi_ctx);
+		msleep(120);
+	}
+
+	il97680a_power_off(pinfo);
+
+	return 0;
+}
+
+static int il97680a_get_modes(struct drm_panel *panel,
+			      struct drm_connector *connector)
+{
+	struct il97680a *pinfo = to_il97680a(panel);
+	struct drm_display_mode *mode;
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(il97680a_retroid_modes); i++) {
+		mode = drm_mode_duplicate(connector->dev, &il97680a_retroid_modes[i]);
+		if (!mode)
+			return -ENOMEM;
+
+		mode->type = DRM_MODE_TYPE_DRIVER;
+		if (i == 0)
+			mode->type |= DRM_MODE_TYPE_PREFERRED;
+
+		drm_mode_set_name(mode);
+		drm_mode_probed_add(connector, mode);
+	}
+
+	connector->display_info.width_mm = 91;
+	connector->display_info.height_mm = 68;
+	connector->display_info.bpc = 8;
+	pinfo->connector = connector;
+
+	return ARRAY_SIZE(il97680a_retroid_modes);
+}
+
+static enum drm_panel_orientation il97680a_get_orientation(struct drm_panel *panel)
+{
+	struct il97680a *pinfo = to_il97680a(panel);
+
+	return pinfo->orientation;
+}
+
+static const struct drm_panel_funcs il97680a_panel_funcs = {
+	.enable = il97680a_enable,
+	.disable = il97680a_disable,
+	.prepare = il97680a_prepare,
+	.unprepare = il97680a_unprepare,
+	.get_modes = il97680a_get_modes,
+	.get_orientation = il97680a_get_orientation,
+};
+
+static int il97680a_bl_update_status(struct backlight_device *bl)
+{
+	struct il97680a *pinfo = bl_get_data(bl);
+	struct mipi_dsi_device *dsi = pinfo->dsi;
+	unsigned long mode_flags;
+	int ret;
+
+	guard(mutex)(&pinfo->lock);
+
+	if (!pinfo->enabled)
+		return 0;
+
+	mode_flags = dsi->mode_flags;
+	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+	ret = mipi_dsi_dcs_set_display_brightness_large(dsi, backlight_get_brightness(bl));
+	dsi->mode_flags = mode_flags;
+
+	return ret;
+}
+
+static const struct backlight_ops il97680a_bl_ops = {
+	.update_status = il97680a_bl_update_status,
+};
+
+static struct backlight_device *
+il97680a_create_backlight(struct il97680a *pinfo)
+{
+	struct device *dev = &pinfo->dsi->dev;
+	const struct backlight_properties props = {
+		.type = BACKLIGHT_RAW,
+		.brightness = 3445,
+		.max_brightness = 3445,
+		.scale = BACKLIGHT_SCALE_NON_LINEAR,
+	};
+
+	return devm_backlight_device_register(dev, dev_name(dev), dev, pinfo,
+					      &il97680a_bl_ops, &props);
+}
+
+static int il97680a_probe(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	struct il97680a *pinfo;
+	int ret;
+
+	pinfo = devm_drm_panel_alloc(dev, struct il97680a, panel,
+				     &il97680a_panel_funcs,
+				     DRM_MODE_CONNECTOR_DSI);
+	if (IS_ERR(pinfo))
+		return PTR_ERR(pinfo);
+
+	pinfo->desc = of_device_get_match_data(dev);
+	if (!pinfo->desc)
+		return -ENODEV;
+
+	ret = devm_mutex_init(dev, &pinfo->lock);
+	if (ret)
+		return ret;
+
+	ret = devm_regulator_bulk_get_const(dev, pinfo->desc->num_supplies,
+					    pinfo->desc->supplies, &pinfo->supplies);
+	if (ret < 0)
+		return ret;
+
+	pinfo->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(pinfo->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(pinfo->reset_gpio),
+				     "Failed to get reset-gpios\n");
+
+	pinfo->dsi = dsi;
+	mipi_dsi_set_drvdata(dsi, pinfo);
+
+	ret = drm_of_get_panel_orientation(dev->of_node, &pinfo->orientation);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to get orientation\n");
+
+	dsi->lanes = 4;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags = MIPI_DSI_MODE_NO_EOT_PACKET |
+			  MIPI_DSI_CLOCK_NON_CONTINUOUS | MIPI_DSI_MODE_LPM;
+	pinfo->panel.prepare_prev_first = true;
+
+	pinfo->panel.backlight = il97680a_create_backlight(pinfo);
+	if (IS_ERR(pinfo->panel.backlight))
+		return dev_err_probe(dev, PTR_ERR(pinfo->panel.backlight),
+				     "Failed to create backlight\n");
+
+	ret = devm_drm_panel_add(dev, &pinfo->panel);
+	if (ret)
+		return ret;
+
+	return devm_mipi_dsi_attach(dev, dsi);
+}
+
+static const struct of_device_id il97680a_of_match[] = {
+	{ .compatible = "retroidpocket,rpnova-panel", .data = &il97680a_rpnova_desc },
+	{ .compatible = "retroidpocket,rpduo-panel-bottom", .data = &il97680a_rpduo_desc },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, il97680a_of_match);
+
+static struct mipi_dsi_driver il97680a_driver = {
+	.probe = il97680a_probe,
+	.driver = {
+		.name = "panel-ilitek-il97680a",
+		.of_match_table = il97680a_of_match,
+	},
+};
+module_mipi_dsi_driver(il97680a_driver);
+
+MODULE_AUTHOR("Teguh Sobirin <teguh@sobir.in>");
+MODULE_AUTHOR("Jacob Pyke <jacob@pyk.ee>");
+MODULE_DESCRIPTION("DRM driver for Ilitek IL97680A based MIPI DSI panels");
+MODULE_LICENSE("GPL");