drm/panel: add Ilitek ILI7807S panel driver

Add a DRM panel driver for the DLC DLC0697 1080x1920@60Hz MIPI DSI
panel based on the Ilitek ILI7807S display controller.

The panel operates in video burst mode with four data lanes using
RGB888 pixel format.

Signed-off-by: Arpit Saini <arpit.saini@oss.qualcomm.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260701-ili7807s-v4-2-c7d76d4780a5@oss.qualcomm.com

drivers/gpu/drm/panel/Kconfig

@@ -285,6 +285,18 @@ config DRM_PANEL_HYDIS_HV101HD1
 
 	  If M is selected the module will be called panel-hydis-hv101hd1
 
+config DRM_PANEL_ILITEK_ILI7807S
+	tristate "Ilitek ILI7807S-based panels"
+	depends on OF
+	depends on DRM_MIPI_DSI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y if you want to enable support for panels based on the
+	  Ilitek ILI7807S display controller, such as the DLC DLC0697
+	  1080x1920 MIPI DSI panel.
+
+	  If M is selected the module will be called panel-ilitek-ili7807s.
+
 config DRM_PANEL_ILITEK_IL9322
 	tristate "Ilitek ILI9322 320x240 QVGA panels"
 	depends on OF && SPI

drivers/gpu/drm/panel/Makefile

@@ -28,6 +28,7 @@ obj-$(CONFIG_DRM_PANEL_HIMAX_HX83112B) += panel-himax-hx83112b.o
 obj-$(CONFIG_DRM_PANEL_HIMAX_HX83121A) += panel-himax-hx83121a.o
 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-$(CONFIG_DRM_PANEL_ILITEK_ILI9341) += panel-ilitek-ili9341.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9488) += panel-ilitek-ili9488.o

drivers/gpu/drm/panel/panel-ilitek-ili7807s.c

@@ -0,0 +1,285 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
+ */
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+
+#include <video/mipi_display.h>
+
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_probe_helper.h>
+
+struct panel_desc {
+	const struct drm_display_mode *mode;
+	unsigned int lanes;
+	enum mipi_dsi_pixel_format format;
+	unsigned long mode_flags;
+	void (*init)(struct mipi_dsi_multi_context *dsi_ctx);
+};
+
+struct ili7807s {
+	struct drm_panel panel;
+	struct mipi_dsi_device *dsi;
+	const struct panel_desc *desc;
+
+	struct regulator_bulk_data *supplies;
+	struct gpio_desc *reset_gpio;
+};
+
+static const struct regulator_bulk_data ili7807s_supplies[] = {
+	{ .supply = "vddi" },
+	{ .supply = "avdd" },
+	{ .supply = "avee" },
+};
+
+static inline struct ili7807s *to_ili7807s(struct drm_panel *panel)
+{
+	return container_of(panel, struct ili7807s, panel);
+}
+
+static void ili7807s_reset(struct ili7807s *ctx)
+{
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+	usleep_range(10000, 11000);
+	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+	usleep_range(10000, 11000);
+}
+
+static void dlc0697_init_sequence(struct mipi_dsi_multi_context *dsi_ctx)
+{
+	mipi_dsi_dcs_soft_reset_multi(dsi_ctx);
+	mipi_dsi_msleep(dsi_ctx, 120);
+
+	mipi_dsi_dcs_write_seq_multi(dsi_ctx, 0xff, 0x78, 0x07, 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_SET_CABC_MIN_BRIGHTNESS, 0x09, 0x99);
+	mipi_dsi_dcs_write_seq_multi(dsi_ctx, MIPI_DCS_WRITE_CONTROL_DISPLAY, 0x24);
+	mipi_dsi_dcs_write_seq_multi(dsi_ctx, MIPI_DCS_WRITE_POWER_SAVE, 0x01);
+	mipi_dsi_dcs_set_display_brightness_multi(dsi_ctx, 0x1fff);
+
+	mipi_dsi_dcs_exit_sleep_mode_multi(dsi_ctx);
+	mipi_dsi_msleep(dsi_ctx, 120);
+
+	mipi_dsi_dcs_set_display_on_multi(dsi_ctx);
+	mipi_dsi_msleep(dsi_ctx, 20);
+}
+
+static int ili7807s_on(struct ili7807s *ctx)
+{
+	struct mipi_dsi_multi_context dsi_ctx = { .dsi = ctx->dsi };
+
+	ctx->desc->init(&dsi_ctx);
+
+	return dsi_ctx.accum_err;
+}
+
+static int ili7807s_off(struct ili7807s *ctx)
+{
+	struct mipi_dsi_multi_context dsi_ctx = { .dsi = ctx->dsi };
+
+	mipi_dsi_dcs_set_display_off_multi(&dsi_ctx);
+	mipi_dsi_msleep(&dsi_ctx, 20);
+
+	mipi_dsi_dcs_enter_sleep_mode_multi(&dsi_ctx);
+	mipi_dsi_msleep(&dsi_ctx, 120);
+
+	return dsi_ctx.accum_err;
+}
+
+static int ili7807s_prepare(struct drm_panel *panel)
+{
+	struct ili7807s *ctx = to_ili7807s(panel);
+	int ret;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(ili7807s_supplies), ctx->supplies);
+	if (ret < 0) {
+		dev_err(ctx->panel.dev, "failed to enable regulators: %d\n", ret);
+		return ret;
+	}
+
+	msleep(20);
+
+	ili7807s_reset(ctx);
+
+	ret = ili7807s_on(ctx);
+	if (ret < 0) {
+		dev_err(ctx->panel.dev, "failed to initialise panel: %d\n", ret);
+		goto err;
+	}
+
+	return 0;
+
+err:
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+
+	regulator_bulk_disable(ARRAY_SIZE(ili7807s_supplies), ctx->supplies);
+	return ret;
+}
+
+static int ili7807s_unprepare(struct drm_panel *panel)
+{
+	struct ili7807s *ctx = to_ili7807s(panel);
+	int ret;
+
+	ret = ili7807s_off(ctx);
+	if (ret < 0)
+		dev_err(ctx->panel.dev, "failed to disable panel: %d\n", ret);
+
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+
+	regulator_bulk_disable(ARRAY_SIZE(ili7807s_supplies), ctx->supplies);
+
+	return 0;
+}
+
+static int ili7807s_get_modes(struct drm_panel *panel,
+			      struct drm_connector *connector)
+{
+	struct ili7807s *ctx = to_ili7807s(panel);
+
+	return drm_connector_helper_get_modes_fixed(connector, ctx->desc->mode);
+}
+
+static const struct drm_panel_funcs ili7807s_panel_funcs = {
+	.prepare = ili7807s_prepare,
+	.unprepare = ili7807s_unprepare,
+	.get_modes = ili7807s_get_modes,
+};
+
+static int ili7807s_bl_update_status(struct backlight_device *bl)
+{
+	struct mipi_dsi_device *dsi = bl_get_data(bl);
+	u16 brightness = backlight_get_brightness(bl);
+	int ret;
+
+	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+	ret = mipi_dsi_dcs_set_display_brightness_large(dsi, brightness);
+
+	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+	return ret;
+}
+
+static const struct backlight_ops ili7807s_bl_ops = {
+	.update_status = ili7807s_bl_update_status,
+};
+
+static struct backlight_device *ili7807s_create_backlight(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	const struct backlight_properties props = {
+		.type           = BACKLIGHT_RAW,
+		.brightness     = 0x3fff,
+		.max_brightness = 0x3fff,
+	};
+
+	return devm_backlight_device_register(dev, dev_name(dev), dev, dsi,
+					      &ili7807s_bl_ops, &props);
+}
+
+static const struct drm_display_mode dlc0697_mode = {
+	.clock = (1080 + 18 + 2 + 16) * (1920 + 26 + 4 + 20) * 60 / 1000,
+
+	.hdisplay    = 1080,
+	.hsync_start = 1080 + 18,
+	.hsync_end   = 1080 + 18 + 2,
+	.htotal      = 1080 + 18 + 2 + 16,
+
+	.vdisplay    = 1920,
+	.vsync_start = 1920 + 26,
+	.vsync_end   = 1920 + 26 + 4,
+	.vtotal      = 1920 + 26 + 4 + 20,
+
+	.width_mm  = 87,
+	.height_mm = 154,
+	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
+};
+
+static const struct panel_desc dlc0697_desc = {
+	.mode       = &dlc0697_mode,
+	.lanes      = 4,
+	.format     = MIPI_DSI_FMT_RGB888,
+	.mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST,
+	.init       = dlc0697_init_sequence,
+};
+
+static int ili7807s_probe(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	const struct panel_desc *desc;
+	struct ili7807s *ctx;
+	int ret;
+
+	ctx = devm_drm_panel_alloc(dev, struct ili7807s, panel,
+				   &ili7807s_panel_funcs,
+				   DRM_MODE_CONNECTOR_DSI);
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
+
+	desc = of_device_get_match_data(dev);
+	ctx->desc = desc;
+
+	ret = devm_regulator_bulk_get_const(dev, ARRAY_SIZE(ili7807s_supplies),
+					    ili7807s_supplies, &ctx->supplies);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "failed to get regulators\n");
+
+	ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(ctx->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(ctx->reset_gpio),
+				     "failed to get reset gpio\n");
+
+	ctx->dsi = dsi;
+	mipi_dsi_set_drvdata(dsi, ctx);
+
+	dsi->lanes      = desc->lanes;
+	dsi->format     = desc->format;
+	dsi->mode_flags = desc->mode_flags | MIPI_DSI_MODE_LPM;
+
+	ctx->panel.prepare_prev_first = true;
+
+	ret = drm_panel_of_backlight(&ctx->panel);
+	if (ret)
+		return ret;
+
+	if (!ctx->panel.backlight) {
+		ctx->panel.backlight = ili7807s_create_backlight(dsi);
+		if (IS_ERR(ctx->panel.backlight))
+			return dev_err_probe(dev, PTR_ERR(ctx->panel.backlight),
+					     "failed to create backlight\n");
+	}
+
+	ret = devm_drm_panel_add(dev, &ctx->panel);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "failed to add panel\n");
+
+	return devm_mipi_dsi_attach(dev, dsi);
+}
+
+static const struct of_device_id ili7807s_of_match[] = {
+	{ .compatible = "dlc,dlc0697", .data = &dlc0697_desc },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ili7807s_of_match);
+
+static struct mipi_dsi_driver ili7807s_dsi_driver = {
+	.probe  = ili7807s_probe,
+	.driver = {
+		.name           = "panel-ilitek-ili7807s",
+		.of_match_table = ili7807s_of_match,
+	},
+};
+module_mipi_dsi_driver(ili7807s_dsi_driver);
+
+MODULE_AUTHOR("Arpit Saini <arpit.saini@oss.qualcomm.com>");
+MODULE_DESCRIPTION("Panel driver for Ilitek ILI7807S LCD DSI panel");
+MODULE_LICENSE("GPL");