// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2014 Google, Inc.
 *
 * Copyright (C) 2022 Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>
 *
 * Adapted from the downstream Pixel C driver written by Sean Paul
 */

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

#define MCS_CMD_ACS_PROT			0xB0
#define MCS_CMD_ACS_PROT_OFF			(0 << 0)

#define MCS_PWR_CTRL_FUNC			0xD0
#define MCS_PWR_CTRL_PARAM1_DEFAULT		(2 << 0)
#define MCS_PWR_CTRL_PARAM1_VGH_210_DIV		(1 << 4)
#define MCS_PWR_CTRL_PARAM1_VGH_240_DIV		(2 << 4)
#define MCS_PWR_CTRL_PARAM1_VGH_280_DIV		(3 << 4)
#define MCS_PWR_CTRL_PARAM1_VGH_330_DIV		(4 << 4)
#define MCS_PWR_CTRL_PARAM1_VGH_410_DIV		(5 << 4)
#define MCS_PWR_CTRL_PARAM2_DEFAULT		(9 << 4)
#define MCS_PWR_CTRL_PARAM2_VGL_210_DIV		(1 << 0)
#define MCS_PWR_CTRL_PARAM2_VGL_240_DIV		(2 << 0)
#define MCS_PWR_CTRL_PARAM2_VGL_280_DIV		(3 << 0)
#define MCS_PWR_CTRL_PARAM2_VGL_330_DIV		(4 << 0)
#define MCS_PWR_CTRL_PARAM2_VGL_410_DIV		(5 << 0)

struct jdi_panel {
	struct drm_panel base;
	struct mipi_dsi_device *link1;
	struct mipi_dsi_device *link2;

	struct regulator *supply;
	struct regulator *ddi_supply;
	struct backlight_device *backlight;

	struct gpio_desc *enable_gpio;
	struct gpio_desc *reset_gpio;

	const struct drm_display_mode *mode;
};

static inline struct jdi_panel *to_panel_jdi(struct drm_panel *panel)
{
	return container_of(panel, struct jdi_panel, base);
}

static void jdi_wait_frames(struct jdi_panel *jdi, unsigned int frames)
{
	unsigned int refresh = drm_mode_vrefresh(jdi->mode);

	if (WARN_ON(frames > refresh))
		return;

	msleep(1000 / (refresh / frames));
}

static int jdi_panel_disable(struct drm_panel *panel)
{
	struct jdi_panel *jdi = to_panel_jdi(panel);

	backlight_disable(jdi->backlight);

	jdi_wait_frames(jdi, 2);

	return 0;
}

static int jdi_panel_unprepare(struct drm_panel *panel)
{
	struct jdi_panel *jdi = to_panel_jdi(panel);
	int ret;

	ret = mipi_dsi_dcs_set_display_off(jdi->link1);
	if (ret < 0)
		dev_err(panel->dev, "failed to set display off: %d\n", ret);

	ret = mipi_dsi_dcs_set_display_off(jdi->link2);
	if (ret < 0)
		dev_err(panel->dev, "failed to set display off: %d\n", ret);

	/* Specified by JDI @ 50ms, subject to change */
	msleep(50);

	ret = mipi_dsi_dcs_enter_sleep_mode(jdi->link1);
	if (ret < 0)
		dev_err(panel->dev, "failed to enter sleep mode: %d\n", ret);
	ret = mipi_dsi_dcs_enter_sleep_mode(jdi->link2);
	if (ret < 0)
		dev_err(panel->dev, "failed to enter sleep mode: %d\n", ret);

	/* Specified by JDI @ 150ms, subject to change */
	msleep(150);

	gpiod_set_value(jdi->reset_gpio, 1);

	/* T4 = 1ms */
	usleep_range(1000, 3000);

	gpiod_set_value(jdi->enable_gpio, 0);

	/* T5 = 2ms */
	usleep_range(2000, 4000);

	regulator_disable(jdi->ddi_supply);

	/* T6 = 2ms plus some time to discharge capacitors */
	usleep_range(7000, 9000);

	regulator_disable(jdi->supply);
	/* Specified by JDI @ 20ms, subject to change */
	msleep(20);

	return ret;
}

static int jdi_setup_symmetrical_split(struct mipi_dsi_device *left,
				       struct mipi_dsi_device *right,
				       const struct drm_display_mode *mode)
{
	int err;

	err = mipi_dsi_dcs_set_column_address(left, 0, mode->hdisplay / 2 - 1);
	if (err < 0) {
		dev_err(&left->dev, "failed to set column address: %d\n", err);
		return err;
	}

	err = mipi_dsi_dcs_set_column_address(right, 0, mode->hdisplay / 2 - 1);
	if (err < 0) {
		dev_err(&right->dev, "failed to set column address: %d\n", err);
		return err;
	}

	err = mipi_dsi_dcs_set_page_address(left, 0, mode->vdisplay - 1);
	if (err < 0) {
		dev_err(&left->dev, "failed to set page address: %d\n", err);
		return err;
	}

	err = mipi_dsi_dcs_set_page_address(right, 0, mode->vdisplay - 1);
	if (err < 0) {
		dev_err(&right->dev, "failed to set page address: %d\n", err);
		return err;
	}

	return 0;
}

static int jdi_write_dcdc_registers(struct jdi_panel *jdi)
{
	/* Clear the manufacturer command access protection */
	mipi_dsi_generic_write_seq(jdi->link1, MCS_CMD_ACS_PROT,
				   MCS_CMD_ACS_PROT_OFF);
	mipi_dsi_generic_write_seq(jdi->link2, MCS_CMD_ACS_PROT,
				   MCS_CMD_ACS_PROT_OFF);
	/*
	 * Change the VGH/VGL divide rations to move the noise generated by the
	 * TCONN. This should hopefully avoid interaction with the backlight
	 * controller.
	 */
	mipi_dsi_generic_write_seq(jdi->link1, MCS_PWR_CTRL_FUNC,
				   MCS_PWR_CTRL_PARAM1_VGH_330_DIV |
				   MCS_PWR_CTRL_PARAM1_DEFAULT,
				   MCS_PWR_CTRL_PARAM2_VGL_410_DIV |
				   MCS_PWR_CTRL_PARAM2_DEFAULT);

	mipi_dsi_generic_write_seq(jdi->link2, MCS_PWR_CTRL_FUNC,
				   MCS_PWR_CTRL_PARAM1_VGH_330_DIV |
				   MCS_PWR_CTRL_PARAM1_DEFAULT,
				   MCS_PWR_CTRL_PARAM2_VGL_410_DIV |
				   MCS_PWR_CTRL_PARAM2_DEFAULT);

	return 0;
}

static int jdi_panel_prepare(struct drm_panel *panel)
{
	struct jdi_panel *jdi = to_panel_jdi(panel);
	int err;

	/* Disable backlight to avoid showing random pixels
	 * with a conservative delay for it to take effect.
	 */
	backlight_disable(jdi->backlight);
	jdi_wait_frames(jdi, 3);

	jdi->link1->mode_flags |= MIPI_DSI_MODE_LPM;
	jdi->link2->mode_flags |= MIPI_DSI_MODE_LPM;

	err = regulator_enable(jdi->supply);
	if (err < 0) {
		dev_err(panel->dev, "failed to enable supply: %d\n", err);
		return err;
	}
	/* T1 = 2ms */
	usleep_range(2000, 4000);

	err = regulator_enable(jdi->ddi_supply);
	if (err < 0) {
		dev_err(panel->dev, "failed to enable ddi_supply: %d\n", err);
		goto supply_off;
	}
	/* T2 = 1ms */
	usleep_range(1000, 3000);

	gpiod_set_value(jdi->enable_gpio, 1);
	/* T3 = 10ms */
	usleep_range(10000, 15000);

	gpiod_set_value(jdi->reset_gpio, 0);
	/* Specified by JDI @ 3ms, subject to change */
	usleep_range(3000, 5000);

	/*
	 * TODO: The device supports both left-right and even-odd split
	 * configurations, but this driver currently supports only the left-
	 * right split. To support a different mode a mechanism needs to be
	 * put in place to communicate the configuration back to the DSI host
	 * controller.
	 */
	err = jdi_setup_symmetrical_split(jdi->link1, jdi->link2,
					  jdi->mode);
	if (err < 0) {
		dev_err(panel->dev, "failed to set up symmetrical split: %d\n",
			err);
		goto poweroff;
	}

	err = mipi_dsi_dcs_set_tear_scanline(jdi->link1,
					     jdi->mode->vdisplay - 16);
	if (err < 0) {
		dev_err(panel->dev, "failed to set tear scanline: %d\n", err);
		goto poweroff;
	}

	err = mipi_dsi_dcs_set_tear_scanline(jdi->link2,
					     jdi->mode->vdisplay - 16);
	if (err < 0) {
		dev_err(panel->dev, "failed to set tear scanline: %d\n", err);
		goto poweroff;
	}

	err = mipi_dsi_dcs_set_tear_on(jdi->link1,
				       MIPI_DSI_DCS_TEAR_MODE_VBLANK);
	if (err < 0) {
		dev_err(panel->dev, "failed to set tear on: %d\n", err);
		goto poweroff;
	}

	err = mipi_dsi_dcs_set_tear_on(jdi->link2,
				       MIPI_DSI_DCS_TEAR_MODE_VBLANK);
	if (err < 0) {
		dev_err(panel->dev, "failed to set tear on: %d\n", err);
		goto poweroff;
	}

	err = mipi_dsi_dcs_set_pixel_format(jdi->link1, MIPI_DCS_PIXEL_FMT_24BIT);
	if (err < 0) {
		dev_err(panel->dev, "failed to set pixel format: %d\n", err);
		goto poweroff;
	}

	err = mipi_dsi_dcs_set_pixel_format(jdi->link2, MIPI_DCS_PIXEL_FMT_24BIT);
	if (err < 0) {
		dev_err(panel->dev, "failed to set pixel format: %d\n", err);
		goto poweroff;
	}

	err = mipi_dsi_dcs_exit_sleep_mode(jdi->link1);
	if (err < 0) {
		dev_err(panel->dev, "failed to exit sleep mode: %d\n", err);
		goto poweroff;
	}

	err = mipi_dsi_dcs_exit_sleep_mode(jdi->link2);
	if (err < 0) {
		dev_err(panel->dev, "failed to exit sleep mode: %d\n", err);
		goto poweroff;
	}

	err = jdi_write_dcdc_registers(jdi);
	if (err < 0) {
		dev_err(panel->dev, "failed to write dcdc registers: %d\n", err);
		goto poweroff;
	}
	/*
	 * We need to wait 150ms between mipi_dsi_dcs_exit_sleep_mode() and
	 * mipi_dsi_dcs_set_display_on().
	 */
	msleep(150);

	err = mipi_dsi_dcs_set_display_on(jdi->link1);
	if (err < 0) {
		dev_err(panel->dev, "failed to set display on: %d\n", err);
		goto poweroff;
	}

	err = mipi_dsi_dcs_set_display_on(jdi->link2);
	if (err < 0) {
		dev_err(panel->dev, "failed to set display on: %d\n", err);
		goto poweroff;
	}

	jdi->link1->mode_flags &= ~MIPI_DSI_MODE_LPM;
	jdi->link2->mode_flags &= ~MIPI_DSI_MODE_LPM;

	return 0;

poweroff:
	regulator_disable(jdi->ddi_supply);

	/* T6 = 2ms plus some time to discharge capacitors */
	usleep_range(7000, 9000);
supply_off:
	regulator_disable(jdi->supply);
	/* Specified by JDI @ 20ms, subject to change */
	msleep(20);

	return err;
}

static int jdi_panel_enable(struct drm_panel *panel)
{
	struct jdi_panel *jdi = to_panel_jdi(panel);

	/*
	 * Ensure we send image data before turning the backlight
	 * on, to avoid the display showing random pixels.
	 */
	jdi_wait_frames(jdi, 3);

	backlight_enable(jdi->backlight);

	return 0;
}

static const struct drm_display_mode default_mode = {
	.clock = (2560 + 80 + 80 + 80) * (1800 + 4 + 4 + 4) * 60 / 1000,
	.hdisplay = 2560,
	.hsync_start = 2560 + 80,
	.hsync_end = 2560 + 80 + 80,
	.htotal = 2560 + 80 + 80 + 80,
	.vdisplay = 1800,
	.vsync_start = 1800 + 4,
	.vsync_end = 1800 + 4 + 4,
	.vtotal = 1800 + 4 + 4 + 4,
	.flags = 0,
};

static int jdi_panel_get_modes(struct drm_panel *panel,
			       struct drm_connector *connector)
{
	struct drm_display_mode *mode;
	struct jdi_panel *jdi = to_panel_jdi(panel);
	struct device *dev = &jdi->link1->dev;

	mode = drm_mode_duplicate(connector->dev, &default_mode);
	if (!mode) {
		dev_err(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 = 211;
	connector->display_info.height_mm = 148;
	connector->display_info.bpc = 8;

	return 1;
}

static const struct drm_panel_funcs jdi_panel_funcs = {
	.prepare = jdi_panel_prepare,
	.enable = jdi_panel_enable,
	.disable = jdi_panel_disable,
	.unprepare = jdi_panel_unprepare,
	.get_modes = jdi_panel_get_modes,
};

static const struct of_device_id jdi_of_match[] = {
	{ .compatible = "jdi,lpm102a188a", },
	{ }
};
MODULE_DEVICE_TABLE(of, jdi_of_match);

static int jdi_panel_add(struct jdi_panel *jdi)
{
	struct device *dev = &jdi->link1->dev;

	jdi->mode = &default_mode;

	jdi->supply = devm_regulator_get(dev, "power");
	if (IS_ERR(jdi->supply))
		return dev_err_probe(dev, PTR_ERR(jdi->supply),
				     "failed to get power regulator\n");

	jdi->ddi_supply = devm_regulator_get(dev, "ddi");
	if (IS_ERR(jdi->ddi_supply))
		return dev_err_probe(dev, PTR_ERR(jdi->ddi_supply),
				     "failed to get ddi regulator\n");

	jdi->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
	if (IS_ERR(jdi->reset_gpio))
		return dev_err_probe(dev, PTR_ERR(jdi->reset_gpio),
				     "failed to get reset gpio\n");
	/* T4 = 1ms */
	usleep_range(1000, 3000);

	jdi->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
	if (IS_ERR(jdi->enable_gpio))
		return dev_err_probe(dev, PTR_ERR(jdi->enable_gpio),
				     "failed to get enable gpio\n");
	/* T5 = 2ms */
	usleep_range(2000, 4000);

	jdi->backlight = devm_of_find_backlight(dev);
	if (IS_ERR(jdi->backlight))
		return dev_err_probe(dev, PTR_ERR(jdi->backlight),
				     "failed to create backlight\n");

	drm_panel_init(&jdi->base, &jdi->link1->dev, &jdi_panel_funcs,
		       DRM_MODE_CONNECTOR_DSI);

	drm_panel_add(&jdi->base);

	return 0;
}

static void jdi_panel_del(struct jdi_panel *jdi)
{
	if (jdi->base.dev)
		drm_panel_remove(&jdi->base);

	if (jdi->link2)
		put_device(&jdi->link2->dev);
}

static int jdi_panel_dsi_probe(struct mipi_dsi_device *dsi)
{
	struct mipi_dsi_device *secondary = NULL;
	struct jdi_panel *jdi;
	struct device_node *np;
	int err;

	dsi->lanes = 4;
	dsi->format = MIPI_DSI_FMT_RGB888;
	dsi->mode_flags = 0;

	/* Find DSI-LINK1 */
	np = of_parse_phandle(dsi->dev.of_node, "link2", 0);
	if (np) {
		secondary = of_find_mipi_dsi_device_by_node(np);
		of_node_put(np);

		if (!secondary)
			return -EPROBE_DEFER;
	}

	/* register a panel for only the DSI-LINK1 interface */
	if (secondary) {
		jdi = devm_kzalloc(&dsi->dev, sizeof(*jdi), GFP_KERNEL);
		if (!jdi) {
			put_device(&secondary->dev);
			return -ENOMEM;
		}

		mipi_dsi_set_drvdata(dsi, jdi);

		jdi->link1 = dsi;
		jdi->link2 = secondary;

		err = jdi_panel_add(jdi);
		if (err < 0) {
			put_device(&secondary->dev);
			return err;
		}
	}

	err = mipi_dsi_attach(dsi);
	if (err < 0) {
		if (secondary)
			jdi_panel_del(jdi);

		return err;
	}

	return 0;
}

static void jdi_panel_dsi_remove(struct mipi_dsi_device *dsi)
{
	struct jdi_panel *jdi = mipi_dsi_get_drvdata(dsi);
	int err;

	/* only detach from host for the DSI-LINK2 interface */
	if (!jdi)
		mipi_dsi_detach(dsi);

	err = jdi_panel_disable(&jdi->base);
	if (err < 0)
		dev_err(&dsi->dev, "failed to disable panel: %d\n", err);

	err = mipi_dsi_detach(dsi);
	if (err < 0)
		dev_err(&dsi->dev, "failed to detach from DSI host: %d\n", err);

	jdi_panel_del(jdi);
}

static void jdi_panel_dsi_shutdown(struct mipi_dsi_device *dsi)
{
	struct jdi_panel *jdi = mipi_dsi_get_drvdata(dsi);

	if (!jdi)
		return;

	jdi_panel_disable(&jdi->base);
}

static struct mipi_dsi_driver jdi_panel_dsi_driver = {
	.driver = {
		.name = "panel-jdi-lpm102a188a",
		.of_match_table = jdi_of_match,
	},
	.probe = jdi_panel_dsi_probe,
	.remove = jdi_panel_dsi_remove,
	.shutdown = jdi_panel_dsi_shutdown,
};
module_mipi_dsi_driver(jdi_panel_dsi_driver);

MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>");
MODULE_AUTHOR("Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>");
MODULE_DESCRIPTION("DRM Driver for JDI LPM102A188A DSI panel, command mode");
MODULE_LICENSE("GPL");