// SPDX-License-Identifier: GPL-2.0
/*
 * Elida kd35t133 5.5" MIPI-DSI panel driver
 * Copyright (C) 2020 Theobroma Systems Design und Consulting GmbH
 *
 * based on
 *
 * Rockteck jh057n00900 5.5" MIPI-DSI panel driver
 * Copyright (C) Purism SPC 2019
 */

#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/media-bus-format.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regulator/consumer.h>

#include <video/display_timing.h>
#include <video/mipi_display.h>

#include <drm/drm_mipi_dsi.h>
#include <drm/drm_modes.h>
#include <drm/drm_panel.h>

/* Manufacturer specific Commands send via DSI */
#define KD35T133_CMD_INTERFACEMODECTRL		0xb0
#define KD35T133_CMD_FRAMERATECTRL		0xb1
#define KD35T133_CMD_DISPLAYINVERSIONCTRL	0xb4
#define KD35T133_CMD_DISPLAYFUNCTIONCTRL	0xb6
#define KD35T133_CMD_POWERCONTROL1		0xc0
#define KD35T133_CMD_POWERCONTROL2		0xc1
#define KD35T133_CMD_VCOMCONTROL		0xc5
#define KD35T133_CMD_POSITIVEGAMMA		0xe0
#define KD35T133_CMD_NEGATIVEGAMMA		0xe1
#define KD35T133_CMD_SETIMAGEFUNCTION		0xe9
#define KD35T133_CMD_ADJUSTCONTROL3		0xf7

struct kd35t133 {
	struct device *dev;
	struct drm_panel panel;
	struct gpio_desc *reset_gpio;
	struct regulator *vdd;
	struct regulator *iovcc;
	bool prepared;
};

static inline struct kd35t133 *panel_to_kd35t133(struct drm_panel *panel)
{
	return container_of(panel, struct kd35t133, panel);
}

#define dsi_dcs_write_seq(dsi, cmd, seq...) do {			\
		static const u8 b[] = { cmd, seq };			\
		int ret;						\
		ret = mipi_dsi_dcs_write_buffer(dsi, b, ARRAY_SIZE(b));	\
		if (ret < 0)						\
			return ret;					\
	} while (0)

static int kd35t133_init_sequence(struct kd35t133 *ctx)
{
	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
	struct device *dev = ctx->dev;

	/*
	 * Init sequence was supplied by the panel vendor with minimal
	 * documentation.
	 */
	dsi_dcs_write_seq(dsi, KD35T133_CMD_POSITIVEGAMMA,
			  0x00, 0x13, 0x18, 0x04, 0x0f, 0x06, 0x3a, 0x56,
			  0x4d, 0x03, 0x0a, 0x06, 0x30, 0x3e, 0x0f);
	dsi_dcs_write_seq(dsi, KD35T133_CMD_NEGATIVEGAMMA,
			  0x00, 0x13, 0x18, 0x01, 0x11, 0x06, 0x38, 0x34,
			  0x4d, 0x06, 0x0d, 0x0b, 0x31, 0x37, 0x0f);
	dsi_dcs_write_seq(dsi, KD35T133_CMD_POWERCONTROL1, 0x18, 0x17);
	dsi_dcs_write_seq(dsi, KD35T133_CMD_POWERCONTROL2, 0x41);
	dsi_dcs_write_seq(dsi, KD35T133_CMD_VCOMCONTROL, 0x00, 0x1a, 0x80);
	dsi_dcs_write_seq(dsi, MIPI_DCS_SET_ADDRESS_MODE, 0x48);
	dsi_dcs_write_seq(dsi, MIPI_DCS_SET_PIXEL_FORMAT, 0x55);
	dsi_dcs_write_seq(dsi, KD35T133_CMD_INTERFACEMODECTRL, 0x00);
	dsi_dcs_write_seq(dsi, KD35T133_CMD_FRAMERATECTRL, 0xa0);
	dsi_dcs_write_seq(dsi, KD35T133_CMD_DISPLAYINVERSIONCTRL, 0x02);
	dsi_dcs_write_seq(dsi, KD35T133_CMD_DISPLAYFUNCTIONCTRL,
			  0x20, 0x02);
	dsi_dcs_write_seq(dsi, KD35T133_CMD_SETIMAGEFUNCTION, 0x00);
	dsi_dcs_write_seq(dsi, KD35T133_CMD_ADJUSTCONTROL3,
			  0xa9, 0x51, 0x2c, 0x82);
	mipi_dsi_dcs_write(dsi, MIPI_DCS_ENTER_INVERT_MODE, NULL, 0);

	dev_dbg(dev, "Panel init sequence done\n");
	return 0;
}

static int kd35t133_unprepare(struct drm_panel *panel)
{
	struct kd35t133 *ctx = panel_to_kd35t133(panel);
	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
	int ret;

	if (!ctx->prepared)
		return 0;

	ret = mipi_dsi_dcs_set_display_off(dsi);
	if (ret < 0)
		dev_err(ctx->dev, "failed to set display off: %d\n", ret);

	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
	if (ret < 0) {
		dev_err(ctx->dev, "failed to enter sleep mode: %d\n", ret);
		return ret;
	}

	regulator_disable(ctx->iovcc);
	regulator_disable(ctx->vdd);

	ctx->prepared = false;

	return 0;
}

static int kd35t133_prepare(struct drm_panel *panel)
{
	struct kd35t133 *ctx = panel_to_kd35t133(panel);
	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
	int ret;

	if (ctx->prepared)
		return 0;

	dev_dbg(ctx->dev, "Resetting the panel\n");
	ret = regulator_enable(ctx->vdd);
	if (ret < 0) {
		dev_err(ctx->dev, "Failed to enable vdd supply: %d\n", ret);
		return ret;
	}

	ret = regulator_enable(ctx->iovcc);
	if (ret < 0) {
		dev_err(ctx->dev, "Failed to enable iovcc supply: %d\n", ret);
		goto disable_vdd;
	}

	msleep(20);

	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
	usleep_range(10, 20);
	gpiod_set_value_cansleep(ctx->reset_gpio, 0);

	msleep(20);

	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
	if (ret < 0) {
		dev_err(ctx->dev, "Failed to exit sleep mode: %d\n", ret);
		goto disable_iovcc;
	}

	msleep(250);

	ret = kd35t133_init_sequence(ctx);
	if (ret < 0) {
		dev_err(ctx->dev, "Panel init sequence failed: %d\n", ret);
		goto disable_iovcc;
	}

	ret = mipi_dsi_dcs_set_display_on(dsi);
	if (ret < 0) {
		dev_err(ctx->dev, "Failed to set display on: %d\n", ret);
		goto disable_iovcc;
	}

	msleep(50);

	ctx->prepared = true;

	return 0;

disable_iovcc:
	regulator_disable(ctx->iovcc);
disable_vdd:
	regulator_disable(ctx->vdd);
	return ret;
}

static const struct drm_display_mode default_mode = {
	.hdisplay	= 320,
	.hsync_start	= 320 + 130,
	.hsync_end	= 320 + 130 + 4,
	.htotal		= 320 + 130 + 4 + 130,
	.vdisplay	= 480,
	.vsync_start	= 480 + 2,
	.vsync_end	= 480 + 2 + 1,
	.vtotal		= 480 + 2 + 1 + 2,
	.clock		= 17000,
	.width_mm	= 42,
	.height_mm	= 82,
};

static int kd35t133_get_modes(struct drm_panel *panel,
				struct drm_connector *connector)
{
	struct kd35t133 *ctx = panel_to_kd35t133(panel);
	struct drm_display_mode *mode;

	mode = drm_mode_duplicate(connector->dev, &default_mode);
	if (!mode) {
		dev_err(ctx->dev, "Failed to add mode %ux%u@%u\n",
			default_mode.hdisplay, default_mode.vdisplay,
			drm_mode_vrefresh(&default_mode));
		return -ENOMEM;
	}

	drm_mode_set_name(mode);

	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
	connector->display_info.width_mm = mode->width_mm;
	connector->display_info.height_mm = mode->height_mm;
	drm_mode_probed_add(connector, mode);

	return 1;
}

static const struct drm_panel_funcs kd35t133_funcs = {
	.unprepare	= kd35t133_unprepare,
	.prepare	= kd35t133_prepare,
	.get_modes	= kd35t133_get_modes,
};

static int kd35t133_probe(struct mipi_dsi_device *dsi)
{
	struct device *dev = &dsi->dev;
	struct kd35t133 *ctx;
	int ret;

	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
	if (!ctx)
		return -ENOMEM;

	ctx->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
	if (IS_ERR(ctx->reset_gpio)) {
		dev_err(dev, "cannot get reset gpio\n");
		return PTR_ERR(ctx->reset_gpio);
	}

	ctx->vdd = devm_regulator_get(dev, "vdd");
	if (IS_ERR(ctx->vdd)) {
		ret = PTR_ERR(ctx->vdd);
		if (ret != -EPROBE_DEFER)
			dev_err(dev, "Failed to request vdd regulator: %d\n", ret);
		return ret;
	}

	ctx->iovcc = devm_regulator_get(dev, "iovcc");
	if (IS_ERR(ctx->iovcc)) {
		ret = PTR_ERR(ctx->iovcc);
		if (ret != -EPROBE_DEFER)
			dev_err(dev, "Failed to request iovcc regulator: %d\n", ret);
		return ret;
	}

	mipi_dsi_set_drvdata(dsi, ctx);

	ctx->dev = dev;

	dsi->lanes = 1;
	dsi->format = MIPI_DSI_FMT_RGB888;
	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
			  MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_EOT_PACKET;

	drm_panel_init(&ctx->panel, &dsi->dev, &kd35t133_funcs,
		       DRM_MODE_CONNECTOR_DSI);

	ret = drm_panel_of_backlight(&ctx->panel);
	if (ret)
		return ret;

	drm_panel_add(&ctx->panel);

	ret = mipi_dsi_attach(dsi);
	if (ret < 0) {
		dev_err(dev, "mipi_dsi_attach failed: %d\n", ret);
		drm_panel_remove(&ctx->panel);
		return ret;
	}

	return 0;
}

static void kd35t133_shutdown(struct mipi_dsi_device *dsi)
{
	struct kd35t133 *ctx = mipi_dsi_get_drvdata(dsi);
	int ret;

	ret = drm_panel_unprepare(&ctx->panel);
	if (ret < 0)
		dev_err(&dsi->dev, "Failed to unprepare panel: %d\n", ret);

	ret = drm_panel_disable(&ctx->panel);
	if (ret < 0)
		dev_err(&dsi->dev, "Failed to disable panel: %d\n", ret);
}

static int kd35t133_remove(struct mipi_dsi_device *dsi)
{
	struct kd35t133 *ctx = mipi_dsi_get_drvdata(dsi);
	int ret;

	kd35t133_shutdown(dsi);

	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);

	return 0;
}

static const struct of_device_id kd35t133_of_match[] = {
	{ .compatible = "elida,kd35t133" },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, kd35t133_of_match);

static struct mipi_dsi_driver kd35t133_driver = {
	.driver = {
		.name = "panel-elida-kd35t133",
		.of_match_table = kd35t133_of_match,
	},
	.probe	= kd35t133_probe,
	.remove = kd35t133_remove,
	.shutdown = kd35t133_shutdown,
};
module_mipi_dsi_driver(kd35t133_driver);

MODULE_AUTHOR("Heiko Stuebner <heiko.stuebner@theobroma-systems.com>");
MODULE_DESCRIPTION("DRM driver for Elida kd35t133 MIPI DSI panel");
MODULE_LICENSE("GPL v2");