drm/panel: Support for startek-kd070fhfid015 MIPI-DSI panel

This driver support the Startek KD070FHFID015, which is a 7-inch TFT LCD
display using MIPI DSI interface.

Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Alexandre Mergnat <amergnat@baylibre.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230711-startek_display-v4-2-fb1d53bfdef6@baylibre.com

drivers/gpu/drm/panel/Kconfig

@@ -734,6 +734,17 @@ config DRM_PANEL_SONY_TULIP_TRULY_NT35521
 	  NT35521 1280x720 video mode panel as found on Sony Xperia M4
 	  Aqua phone.
 
+config DRM_PANEL_STARTEK_KD070FHFID015
+	tristate "STARTEK KD070FHFID015 panel"
+	depends on OF
+	depends on DRM_MIPI_DSI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here if you want to enable support for STARTEK KD070FHFID015 DSI panel
+	  based on RENESAS-R69429 controller. The pannel is a 7-inch TFT LCD display
+	  with a resolution of 1024 x 600 pixels. It provides a MIPI DSI interface to
+	  the host, a built-in LED backlight and touch controller.
+
 config DRM_PANEL_TDO_TL070WSH30
 	tristate "TDO TL070WSH30 DSI panel"
 	depends on OF

drivers/gpu/drm/panel/Makefile

@@ -74,6 +74,7 @@ obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7789V) += panel-sitronix-st7789v.o
 obj-$(CONFIG_DRM_PANEL_SONY_ACX565AKM) += panel-sony-acx565akm.o
 obj-$(CONFIG_DRM_PANEL_SONY_TD4353_JDI) += panel-sony-td4353-jdi.o
 obj-$(CONFIG_DRM_PANEL_SONY_TULIP_TRULY_NT35521) += panel-sony-tulip-truly-nt35521.o
+obj-$(CONFIG_DRM_PANEL_STARTEK_KD070FHFID015) += panel-startek-kd070fhfid015.o
 obj-$(CONFIG_DRM_PANEL_TDO_TL070WSH30) += panel-tdo-tl070wsh30.o
 obj-$(CONFIG_DRM_PANEL_TPO_TD028TTEC1) += panel-tpo-td028ttec1.o
 obj-$(CONFIG_DRM_PANEL_TPO_TD043MTEA1) += panel-tpo-td043mtea1.o

drivers/gpu/drm/panel/panel-startek-kd070fhfid015.c

@@ -0,0 +1,406 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2016 InforceComputing
+ * Copyright (C) 2016 Linaro Ltd
+ * Copyright (C) 2023 BayLibre, SAS
+ *
+ * Authors:
+ * - Vinay Simha BN <simhavcs@gmail.com>
+ * - Sumit Semwal <sumit.semwal@linaro.org>
+ * - Guillaume La Roque <glaroque@baylibre.com>
+ *
+ */
+
+#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>
+
+#define DSI_REG_MCAP	0xB0
+#define DSI_REG_IS	0xB3 /* Interface Setting */
+#define DSI_REG_IIS	0xB4 /* Interface ID Setting */
+#define DSI_REG_CTRL	0xB6
+
+enum {
+	IOVCC = 0,
+	POWER = 1
+};
+
+struct stk_panel {
+	bool prepared;
+	const struct drm_display_mode *mode;
+	struct backlight_device *backlight;
+	struct drm_panel base;
+	struct gpio_desc *enable_gpio; /* Power IC supply enable */
+	struct gpio_desc *reset_gpio; /* External reset */
+	struct mipi_dsi_device *dsi;
+	struct regulator_bulk_data supplies[2];
+};
+
+static inline struct stk_panel *to_stk_panel(struct drm_panel *panel)
+{
+	return container_of(panel, struct stk_panel, base);
+}
+
+static int stk_panel_init(struct stk_panel *stk)
+{
+	struct mipi_dsi_device *dsi = stk->dsi;
+	struct device *dev = &stk->dsi->dev;
+	int ret;
+
+	ret = mipi_dsi_dcs_soft_reset(dsi);
+	if (ret < 0) {
+		dev_err(dev, "failed to mipi_dsi_dcs_soft_reset: %d\n", ret);
+		return ret;
+	}
+	mdelay(5);
+
+	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
+	if (ret < 0) {
+		dev_err(dev, "failed to set exit sleep mode: %d\n", ret);
+		return ret;
+	}
+	msleep(120);
+
+	mipi_dsi_generic_write_seq(dsi, DSI_REG_MCAP, 0x04);
+
+	/* Interface setting, video mode */
+	mipi_dsi_generic_write_seq(dsi, DSI_REG_IS, 0x14, 0x08, 0x00, 0x22, 0x00);
+	mipi_dsi_generic_write_seq(dsi, DSI_REG_IIS, 0x0C, 0x00);
+	mipi_dsi_generic_write_seq(dsi, DSI_REG_CTRL, 0x3A, 0xD3);
+
+	ret = mipi_dsi_dcs_set_display_brightness(dsi, 0x77);
+	if (ret < 0) {
+		dev_err(dev, "failed to write display brightness: %d\n", ret);
+		return ret;
+	}
+
+	mipi_dsi_dcs_write_seq(dsi, MIPI_DCS_WRITE_CONTROL_DISPLAY,
+			       MIPI_DCS_WRITE_MEMORY_START);
+
+	ret = mipi_dsi_dcs_set_pixel_format(dsi, 0x77);
+	if (ret < 0) {
+		dev_err(dev, "failed to set pixel format: %d\n", ret);
+		return ret;
+	}
+
+	ret = mipi_dsi_dcs_set_column_address(dsi, 0, stk->mode->hdisplay - 1);
+	if (ret < 0) {
+		dev_err(dev, "failed to set column address: %d\n", ret);
+		return ret;
+	}
+
+	ret = mipi_dsi_dcs_set_page_address(dsi, 0, stk->mode->vdisplay - 1);
+	if (ret < 0) {
+		dev_err(dev, "failed to set page address: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int stk_panel_on(struct stk_panel *stk)
+{
+	struct mipi_dsi_device *dsi = stk->dsi;
+	struct device *dev = &stk->dsi->dev;
+	int ret;
+
+	ret = mipi_dsi_dcs_set_display_on(dsi);
+	if (ret < 0)
+		dev_err(dev, "failed to set display on: %d\n", ret);
+
+	mdelay(20);
+
+	return ret;
+}
+
+static void stk_panel_off(struct stk_panel *stk)
+{
+	struct mipi_dsi_device *dsi = stk->dsi;
+	struct device *dev = &stk->dsi->dev;
+	int ret;
+
+	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+	ret = mipi_dsi_dcs_set_display_off(dsi);
+	if (ret < 0)
+		dev_err(dev, "failed to set display off: %d\n", ret);
+
+	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
+	if (ret < 0)
+		dev_err(dev, "failed to enter sleep mode: %d\n", ret);
+
+	msleep(100);
+}
+
+static int stk_panel_unprepare(struct drm_panel *panel)
+{
+	struct stk_panel *stk = to_stk_panel(panel);
+
+	if (!stk->prepared)
+		return 0;
+
+	stk_panel_off(stk);
+	regulator_bulk_disable(ARRAY_SIZE(stk->supplies), stk->supplies);
+	gpiod_set_value(stk->reset_gpio, 0);
+	gpiod_set_value(stk->enable_gpio, 1);
+
+	stk->prepared = false;
+
+	return 0;
+}
+
+static int stk_panel_prepare(struct drm_panel *panel)
+{
+	struct stk_panel *stk = to_stk_panel(panel);
+	struct device *dev = &stk->dsi->dev;
+	int ret;
+
+	if (stk->prepared)
+		return 0;
+
+	gpiod_set_value(stk->reset_gpio, 0);
+	gpiod_set_value(stk->enable_gpio, 0);
+	ret = regulator_enable(stk->supplies[IOVCC].consumer);
+	if (ret < 0)
+		return ret;
+
+	mdelay(8);
+	ret = regulator_enable(stk->supplies[POWER].consumer);
+	if (ret < 0)
+		goto iovccoff;
+
+	mdelay(20);
+	gpiod_set_value(stk->enable_gpio, 1);
+	mdelay(20);
+	gpiod_set_value(stk->reset_gpio, 1);
+	mdelay(10);
+	ret = stk_panel_init(stk);
+	if (ret < 0) {
+		dev_err(dev, "failed to init panel: %d\n", ret);
+		goto poweroff;
+	}
+
+	ret = stk_panel_on(stk);
+	if (ret < 0) {
+		dev_err(dev, "failed to set panel on: %d\n", ret);
+		goto poweroff;
+	}
+
+	stk->prepared = true;
+
+	return 0;
+
+poweroff:
+	regulator_disable(stk->supplies[POWER].consumer);
+iovccoff:
+	regulator_disable(stk->supplies[IOVCC].consumer);
+	gpiod_set_value(stk->reset_gpio, 0);
+	gpiod_set_value(stk->enable_gpio, 0);
+
+	return ret;
+}
+
+static const struct drm_display_mode default_mode = {
+		.clock = 163204,
+		.hdisplay = 1200,
+		.hsync_start = 1200 + 144,
+		.hsync_end = 1200 + 144 + 16,
+		.htotal = 1200 + 144 + 16 + 45,
+		.vdisplay = 1920,
+		.vsync_start = 1920 + 8,
+		.vsync_end = 1920 + 8 + 4,
+		.vtotal = 1920 + 8 + 4 + 4,
+		.width_mm = 95,
+		.height_mm = 151,
+};
+
+static int stk_panel_get_modes(struct drm_panel *panel,
+			       struct drm_connector *connector)
+{
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(connector->dev, &default_mode);
+	if (!mode) {
+		dev_err(panel->dev, "failed to add mode %ux%ux@%u\n",
+			default_mode.hdisplay, default_mode.vdisplay,
+			drm_mode_vrefresh(&default_mode));
+		return -ENOMEM;
+	}
+
+	drm_mode_set_name(mode);
+	drm_mode_probed_add(connector, mode);
+	connector->display_info.width_mm = default_mode.width_mm;
+	connector->display_info.height_mm = default_mode.height_mm;
+	return 1;
+}
+
+static int dsi_dcs_bl_get_brightness(struct backlight_device *bl)
+{
+	struct mipi_dsi_device *dsi = bl_get_data(bl);
+	int ret;
+	u16 brightness;
+
+	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+	ret = mipi_dsi_dcs_get_display_brightness(dsi, &brightness);
+	if (ret < 0)
+		return ret;
+
+	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+	return brightness & 0xff;
+}
+
+static int dsi_dcs_bl_update_status(struct backlight_device *bl)
+{
+	struct mipi_dsi_device *dsi = bl_get_data(bl);
+	struct device *dev = &dsi->dev;
+	int ret;
+
+	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+	ret = mipi_dsi_dcs_set_display_brightness(dsi, bl->props.brightness);
+	if (ret < 0) {
+		dev_err(dev, "failed to set DSI control: %d\n", ret);
+		return ret;
+	}
+
+	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+	return 0;
+}
+
+static const struct backlight_ops dsi_bl_ops = {
+	.update_status = dsi_dcs_bl_update_status,
+	.get_brightness = dsi_dcs_bl_get_brightness,
+};
+
+static struct backlight_device *
+drm_panel_create_dsi_backlight(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	struct backlight_properties props = {
+		.type = BACKLIGHT_RAW,
+		.brightness = 255,
+		.max_brightness = 255,
+	};
+
+	return devm_backlight_device_register(dev, dev_name(dev), dev, dsi,
+					      &dsi_bl_ops, &props);
+}
+
+static const struct drm_panel_funcs stk_panel_funcs = {
+	.unprepare = stk_panel_unprepare,
+	.prepare = stk_panel_prepare,
+	.get_modes = stk_panel_get_modes,
+};
+
+static const struct of_device_id stk_of_match[] = {
+	{ .compatible = "startek,kd070fhfid015", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, stk_of_match);
+
+static int stk_panel_add(struct stk_panel *stk)
+{
+	struct device *dev = &stk->dsi->dev;
+	int ret;
+
+	stk->mode = &default_mode;
+
+	stk->supplies[IOVCC].supply = "iovcc";
+	stk->supplies[POWER].supply = "power";
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(stk->supplies), stk->supplies);
+	if (ret) {
+		dev_err(dev, "regulator_bulk failed\n");
+		return ret;
+	}
+
+	stk->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(stk->reset_gpio)) {
+		ret = PTR_ERR(stk->reset_gpio);
+		dev_err(dev, "cannot get reset-gpios %d\n", ret);
+		return ret;
+	}
+
+	stk->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
+	if (IS_ERR(stk->enable_gpio)) {
+		ret = PTR_ERR(stk->enable_gpio);
+		dev_err(dev, "cannot get enable-gpio %d\n", ret);
+		return ret;
+	}
+
+	stk->backlight = drm_panel_create_dsi_backlight(stk->dsi);
+	if (IS_ERR(stk->backlight)) {
+		ret = PTR_ERR(stk->backlight);
+		dev_err(dev, "failed to register backlight %d\n", ret);
+		return ret;
+	}
+
+	drm_panel_init(&stk->base, &stk->dsi->dev, &stk_panel_funcs,
+		       DRM_MODE_CONNECTOR_DSI);
+
+	drm_panel_add(&stk->base);
+
+	return 0;
+}
+
+static int stk_panel_probe(struct mipi_dsi_device *dsi)
+{
+	struct stk_panel *stk;
+	int ret;
+
+	dsi->lanes = 4;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags = (MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_LPM);
+
+	stk = devm_kzalloc(&dsi->dev, sizeof(*stk), GFP_KERNEL);
+	if (!stk)
+		return -ENOMEM;
+
+	mipi_dsi_set_drvdata(dsi, stk);
+
+	stk->dsi = dsi;
+
+	ret = stk_panel_add(stk);
+	if (ret < 0)
+		return ret;
+
+	ret = mipi_dsi_attach(dsi);
+	if (ret < 0)
+		drm_panel_remove(&stk->base);
+
+	return 0;
+}
+
+static void stk_panel_remove(struct mipi_dsi_device *dsi)
+{
+	struct stk_panel *stk = mipi_dsi_get_drvdata(dsi);
+	int err;
+
+	err = mipi_dsi_detach(dsi);
+	if (err < 0)
+		dev_err(&dsi->dev, "failed to detach from DSI host: %d\n",
+			err);
+
+	drm_panel_remove(&stk->base);
+}
+
+static struct mipi_dsi_driver stk_panel_driver = {
+	.driver = {
+		.name = "panel-startek-kd070fhfid015",
+		.of_match_table = stk_of_match,
+	},
+	.probe = stk_panel_probe,
+	.remove = stk_panel_remove,
+};
+module_mipi_dsi_driver(stk_panel_driver);
+
+MODULE_AUTHOR("Guillaume La Roque <glaroque@baylibre.com>");
+MODULE_DESCRIPTION("STARTEK KD070FHFID015");
+MODULE_LICENSE("GPL");