drm: panel: Add Samsung S6E8FC0 DSI controller for M1906F9 panel

Add driver for Samsung S6E8FC0 DSI controller for M1906F9 video mode panel,
found in Xiaomi Mi A3 mobile phone.

Co-developed-by: Kamil Gołda <kamil.golda@protonmail.com>
Signed-off-by: Kamil Gołda <kamil.golda@protonmail.com>
Reviewed-by: David Heidelberg <david@ixit.cz>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Yedaya Katsman <yedaya.ka@gmail.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260320-panel-patches-v7-2-3eaefc4b3878@gmail.com

MAINTAINERS

@@ -8302,6 +8302,11 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/display/panel/samsung,s6e3ha8.yaml
 F:	drivers/gpu/drm/panel/panel-samsung-s6e3ha8.c
 
+DRM DRIVER FOR SAMSUNG S6E8FC0 PANELS
+M:	Yedaya Katsman <yedaya.ka@gmail.com>
+S:	Maintained
+F:	drivers/gpu/drm/panel/panel-samsung-s6e8fc0-m1906f9.c
+
 DRM DRIVER FOR SAMSUNG SOFEF00 DDIC
 M:	David Heidelberg <david@ixit.cz>
 M:	Casey Connolly <casey.connolly@linaro.org>

drivers/gpu/drm/panel/Kconfig

@@ -966,6 +966,19 @@ config DRM_PANEL_SAMSUNG_S6E8AA5X01_AMS561RA01
 	  ~5.6 inch AMOLED display, and the controller is driven by the MIPI
 	  DSI protocol with 4 lanes.
 
+config DRM_PANEL_SAMSUNG_S6E8FC0
+	tristate "Samsung S6E8FC0 DSI controller"
+	depends on OF
+	depends on BACKLIGHT_CLASS_DEVICE
+	select DRM_MIPI_DSI
+	help
+	  Say Y or M here if you want to enable support for the Samsung
+	  S6E8FC0 DSI controller and connected panel.
+	  Currently supported panels:
+
+	    M1906F9 (M1906F9SH or M1906F9SI), 6.09 inch 720x1560, found
+	    in the Xiaomi Mi A3 smartphone (xiaomi-laurel).
+
 config DRM_PANEL_SAMSUNG_SOFEF00
 	tristate "Samsung SOFEF00 DSI panel controller"
 	depends on OF

drivers/gpu/drm/panel/Makefile

@@ -98,6 +98,7 @@ obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E88A0_AMS427AP24) += panel-samsung-s6e88a0-ams4
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E88A0_AMS452EF01) += panel-samsung-s6e88a0-ams452ef01.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0) += panel-samsung-s6e8aa0.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8AA5X01_AMS561RA01) += panel-samsung-s6e8aa5x01-ams561ra01.o
+obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8FC0) += panel-samsung-s6e8fc0-m1906f9.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_SOFEF00) += panel-samsung-sofef00.o
 obj-$(CONFIG_DRM_PANEL_SEIKO_43WVF1G) += panel-seiko-43wvf1g.o
 obj-$(CONFIG_DRM_PANEL_SHARP_LQ079L1SX01) += panel-sharp-lq079l1sx01.o

drivers/gpu/drm/panel/panel-samsung-s6e8fc0-m1906f9.c

@@ -0,0 +1,301 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) Kamil Gołda <kamil.golda@protonmail.com>
+// Copyright (c) Yedaya Katsman <yedaya.ka@gmail.com>
+// Generated with linux-mdss-dsi-panel-driver-generator from vendor device tree:
+//   Copyright (c) The Linux Foundation. All rights reserved.
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.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 s6e8fc0_ctx {
+	struct drm_panel panel;
+	struct mipi_dsi_device *dsi;
+	struct regulator_bulk_data *supplies;
+	struct gpio_desc *reset_gpio;
+};
+
+static const struct regulator_bulk_data s6e8fc0_supplies[] = {
+	{ .supply = "vdd" },
+	{ .supply = "vci" },
+};
+
+static inline
+struct s6e8fc0_ctx *to_s6e8fc0_ctx(struct drm_panel *panel)
+{
+	return container_of_const(panel, struct s6e8fc0_ctx, panel);
+}
+
+static void s6e8fc0_m1906f9_reset(struct s6e8fc0_ctx *ctx)
+{
+	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+	usleep_range(12000, 13000);
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+	usleep_range(2000, 3000);
+	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+	usleep_range(10000, 11000);
+}
+
+#define s6e8fc0_test_key_on_lvl2(ctx) \
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xf0, 0x5a, 0x5a)
+#define s6e8fc0_test_key_off_lvl2(ctx) \
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xf0, 0xa5, 0xa5)
+#define s6e8fc0_test_key_on_lvl3(ctx) \
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xfc, 0x5a, 0x5a)
+#define s6e8fc0_test_key_off_lvl3(ctx) \
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xfc, 0xa5, 0xa5)
+
+static int s6e8fc0_m1906f9_on(struct s6e8fc0_ctx *ctx)
+{
+	struct mipi_dsi_multi_context dsi_ctx = { .dsi = ctx->dsi };
+
+	s6e8fc0_test_key_on_lvl3(&dsi_ctx);
+
+	mipi_dsi_dcs_set_display_brightness_multi(&dsi_ctx, 0x0000);
+	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, 50);
+	mipi_dsi_dcs_set_display_on_multi(&dsi_ctx);
+
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xb0, 0x04, 0xed);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xed,
+				     0xe4, 0x08, 0x96, 0xa4, 0x2a, 0x72, 0xe2,
+				     0xca, 0x00);
+	s6e8fc0_test_key_off_lvl3(&dsi_ctx);
+	s6e8fc0_test_key_on_lvl2(&dsi_ctx);
+	s6e8fc0_test_key_on_lvl3(&dsi_ctx);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xe1, 0x93);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xb0, 0x05, 0xf4);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf4, 0x03);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xed, 0x01, 0x81, 0x04);
+	s6e8fc0_test_key_off_lvl2(&dsi_ctx);
+	s6e8fc0_test_key_off_lvl3(&dsi_ctx);
+
+	return dsi_ctx.accum_err;
+}
+
+static int s6e8fc0_m1906f9_off(struct s6e8fc0_ctx *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 s6e8fc0_m1906f9_prepare(struct drm_panel *panel)
+{
+	struct s6e8fc0_ctx *ctx = to_s6e8fc0_ctx(panel);
+	struct device *dev = &ctx->dsi->dev;
+	int ret;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(s6e8fc0_supplies), ctx->supplies);
+	if (ret < 0) {
+		dev_err(dev, "Failed to enable regulators: %d\n", ret);
+		return ret;
+	}
+
+	s6e8fc0_m1906f9_reset(ctx);
+
+	ret = s6e8fc0_m1906f9_on(ctx);
+	if (ret < 0) {
+		dev_err(dev, "Failed to initialize panel: %d\n", ret);
+		gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+		regulator_bulk_disable(ARRAY_SIZE(s6e8fc0_supplies), ctx->supplies);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int s6e8fc0_m1906f9_unprepare(struct drm_panel *panel)
+{
+	struct s6e8fc0_ctx *ctx = to_s6e8fc0_ctx(panel);
+	struct device *dev = &ctx->dsi->dev;
+	int ret;
+
+	ret = s6e8fc0_m1906f9_off(ctx);
+	if (ret < 0)
+		dev_err(dev, "Failed to un-initialize panel: %d\n", ret);
+
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+	regulator_bulk_disable(ARRAY_SIZE(s6e8fc0_supplies), ctx->supplies);
+
+	return 0;
+}
+
+static const struct drm_display_mode s6e8fc0_m1906f9_samsungp_mode = {
+	.clock = (720 + 350 + 40 + 294) * (1560 + 17 + 2 + 5) * 60 / 1000,
+	.hdisplay = 720,
+	.hsync_start = 720 + 350,
+	.hsync_end = 720 + 350 + 40,
+	.htotal = 720 + 350 + 40 + 294,
+	.vdisplay = 1560,
+	.vsync_start = 1560 + 17,
+	.vsync_end = 1560 + 17 + 2,
+	.vtotal = 1560 + 17 + 2 + 5,
+	.width_mm = 65,
+	.height_mm = 140,
+	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
+};
+
+static int s6e8fc0_m1906f9_get_modes(struct drm_panel *panel,
+				      struct drm_connector *connector)
+{
+	return drm_connector_helper_get_modes_fixed(connector, &s6e8fc0_m1906f9_samsungp_mode);
+}
+
+static const struct drm_panel_funcs s6e8fc0_m1906f9_panel_funcs = {
+	.prepare = s6e8fc0_m1906f9_prepare,
+	.unprepare = s6e8fc0_m1906f9_unprepare,
+	.get_modes = s6e8fc0_m1906f9_get_modes,
+};
+
+static int s6e8fc0_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);
+	if (ret < 0)
+		return ret;
+
+	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+	return 0;
+}
+
+static int s6e8fc0_bl_get_brightness(struct backlight_device *bl)
+{
+	struct mipi_dsi_device *dsi = bl_get_data(bl);
+	u16 brightness;
+	int ret;
+
+	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+	ret = mipi_dsi_dcs_get_display_brightness_large(dsi, &brightness);
+	if (ret < 0)
+		return ret;
+
+	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+	return brightness;
+}
+
+static const struct backlight_ops s6e8fc0_bl_ops = {
+	.update_status = s6e8fc0_bl_update_status,
+	.get_brightness = s6e8fc0_bl_get_brightness,
+};
+
+static struct backlight_device *
+s6e8fc0_m1906f9_create_backlight(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	const struct backlight_properties props = {
+		.type = BACKLIGHT_RAW,
+		.brightness = 512,
+		.max_brightness = 1023,
+	};
+
+	return devm_backlight_device_register(dev, dev_name(dev), dev, dsi,
+					      &s6e8fc0_bl_ops, &props);
+}
+
+static int s6e8fc0_m1906f9_probe(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	struct s6e8fc0_ctx *ctx;
+	int ret;
+
+	ctx = devm_drm_panel_alloc(dev, struct s6e8fc0_ctx, panel,
+				   &s6e8fc0_m1906f9_panel_funcs,
+				   DRM_MODE_CONNECTOR_DSI);
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
+
+	ret = devm_regulator_bulk_get_const(dev,
+					    ARRAY_SIZE(s6e8fc0_supplies),
+					    s6e8fc0_supplies,
+					    &ctx->supplies);
+	if (ret < 0)
+		return ret;
+
+	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-gpios\n");
+
+	ctx->dsi = dsi;
+	mipi_dsi_set_drvdata(dsi, ctx);
+
+	dsi->lanes = 4;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
+			  MIPI_DSI_CLOCK_NON_CONTINUOUS;
+
+	ctx->panel.prepare_prev_first = true;
+
+	ctx->panel.backlight = s6e8fc0_m1906f9_create_backlight(dsi);
+	if (IS_ERR(ctx->panel.backlight))
+		return dev_err_probe(dev, PTR_ERR(ctx->panel.backlight),
+				     "Failed to create backlight\n");
+
+	drm_panel_add(&ctx->panel);
+
+	ret = mipi_dsi_attach(dsi);
+	if (ret < 0) {
+		drm_panel_remove(&ctx->panel);
+		return dev_err_probe(dev, ret, "Failed to attach to DSI host\n");
+	}
+
+	return 0;
+}
+
+static void s6e8fc0_remove(struct mipi_dsi_device *dsi)
+{
+	struct s6e8fc0_ctx *ctx = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	ret = mipi_dsi_detach(dsi);
+	if (ret < 0)
+		dev_err(&dsi->dev, "Failed to detach from DSI host: %d\n", ret);
+
+	drm_panel_remove(&ctx->panel);
+}
+
+static const struct of_device_id samsung_s6e8fc0_of_match[] = {
+	{ .compatible = "samsung,s6e8fc0-m1906f9" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, samsung_s6e8fc0_of_match);
+
+static struct mipi_dsi_driver s6e8fc0_driver = {
+	.probe = s6e8fc0_m1906f9_probe,
+	.remove = s6e8fc0_remove,
+	.driver = {
+		.name = "panel-samsung-s6e8fc0-m1906f9",
+		.of_match_table = samsung_s6e8fc0_of_match,
+	},
+};
+module_mipi_dsi_driver(s6e8fc0_driver);
+
+MODULE_AUTHOR("Kamil Gołda <kamil.golda@protonmail.com>");
+MODULE_DESCRIPTION("DRM driver for Samsung s6e8fc0 DSI controller");
+MODULE_LICENSE("GPL");