/*
 * Copyright (c) 2017, Fuzhou Rockchip Electronics Co., Ltd
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/backlight.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regulator/consumer.h>

#include <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_panel.h>

#include <video/mipi_display.h>

struct innolux_panel {
	struct drm_panel base;
	struct mipi_dsi_device *link;

	struct backlight_device *backlight;
	struct regulator *supply;
	struct gpio_desc *enable_gpio;

	bool prepared;
	bool enabled;
};

static inline struct innolux_panel *to_innolux_panel(struct drm_panel *panel)
{
	return container_of(panel, struct innolux_panel, base);
}

static int innolux_panel_disable(struct drm_panel *panel)
{
	struct innolux_panel *innolux = to_innolux_panel(panel);
	int err;

	if (!innolux->enabled)
		return 0;

	backlight_disable(innolux->backlight);

	err = mipi_dsi_dcs_set_display_off(innolux->link);
	if (err < 0)
		DRM_DEV_ERROR(panel->dev, "failed to set display off: %d\n",
			      err);

	innolux->enabled = false;

	return 0;
}

static int innolux_panel_unprepare(struct drm_panel *panel)
{
	struct innolux_panel *innolux = to_innolux_panel(panel);
	int err;

	if (!innolux->prepared)
		return 0;

	err = mipi_dsi_dcs_enter_sleep_mode(innolux->link);
	if (err < 0) {
		DRM_DEV_ERROR(panel->dev, "failed to enter sleep mode: %d\n",
			      err);
		return err;
	}

	gpiod_set_value_cansleep(innolux->enable_gpio, 0);

	/* T8: 80ms - 1000ms */
	msleep(80);

	err = regulator_disable(innolux->supply);
	if (err < 0)
		return err;

	innolux->prepared = false;

	return 0;
}

static int innolux_panel_prepare(struct drm_panel *panel)
{
	struct innolux_panel *innolux = to_innolux_panel(panel);
	int err, regulator_err;

	if (innolux->prepared)
		return 0;

	gpiod_set_value_cansleep(innolux->enable_gpio, 0);

	err = regulator_enable(innolux->supply);
	if (err < 0)
		return err;

	/* T2: 15ms - 1000ms */
	usleep_range(15000, 16000);

	gpiod_set_value_cansleep(innolux->enable_gpio, 1);

	/* T4: 15ms - 1000ms */
	usleep_range(15000, 16000);

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

	/* T6: 120ms - 1000ms*/
	msleep(120);

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

	/* T7: 5ms */
	usleep_range(5000, 6000);

	innolux->prepared = true;

	return 0;

poweroff:
	regulator_err = regulator_disable(innolux->supply);
	if (regulator_err)
		DRM_DEV_ERROR(panel->dev, "failed to disable regulator: %d\n",
			      regulator_err);

	gpiod_set_value_cansleep(innolux->enable_gpio, 0);
	return err;
}

static int innolux_panel_enable(struct drm_panel *panel)
{
	struct innolux_panel *innolux = to_innolux_panel(panel);
	int ret;

	if (innolux->enabled)
		return 0;

	ret = backlight_enable(innolux->backlight);
	if (ret) {
		DRM_DEV_ERROR(panel->drm->dev,
			      "Failed to enable backlight %d\n", ret);
		return ret;
	}

	innolux->enabled = true;

	return 0;
}

static const struct drm_display_mode default_mode = {
	.clock = 56900,
	.hdisplay = 768,
	.hsync_start = 768 + 40,
	.hsync_end = 768 + 40 + 40,
	.htotal = 768 + 40 + 40 + 40,
	.vdisplay = 1024,
	.vsync_start = 1024 + 20,
	.vsync_end = 1024 + 20 + 4,
	.vtotal = 1024 + 20 + 4 + 20,
	.vrefresh = 60,
};

static int innolux_panel_get_modes(struct drm_panel *panel)
{
	struct drm_display_mode *mode;

	mode = drm_mode_duplicate(panel->drm, &default_mode);
	if (!mode) {
		DRM_DEV_ERROR(panel->drm->dev, "failed to add mode %ux%ux@%u\n",
			      default_mode.hdisplay, default_mode.vdisplay,
			      default_mode.vrefresh);
		return -ENOMEM;
	}

	drm_mode_set_name(mode);

	drm_mode_probed_add(panel->connector, mode);

	panel->connector->display_info.width_mm = 120;
	panel->connector->display_info.height_mm = 160;
	panel->connector->display_info.bpc = 8;

	return 1;
}

static const struct drm_panel_funcs innolux_panel_funcs = {
	.disable = innolux_panel_disable,
	.unprepare = innolux_panel_unprepare,
	.prepare = innolux_panel_prepare,
	.enable = innolux_panel_enable,
	.get_modes = innolux_panel_get_modes,
};

static const struct of_device_id innolux_of_match[] = {
	{ .compatible = "innolux,p079zca", },
	{ }
};
MODULE_DEVICE_TABLE(of, innolux_of_match);

static int innolux_panel_add(struct innolux_panel *innolux)
{
	struct device *dev = &innolux->link->dev;
	int err;

	innolux->supply = devm_regulator_get(dev, "power");
	if (IS_ERR(innolux->supply))
		return PTR_ERR(innolux->supply);

	innolux->enable_gpio = devm_gpiod_get_optional(dev, "enable",
						       GPIOD_OUT_HIGH);
	if (IS_ERR(innolux->enable_gpio)) {
		err = PTR_ERR(innolux->enable_gpio);
		dev_dbg(dev, "failed to get enable gpio: %d\n", err);
		innolux->enable_gpio = NULL;
	}

	innolux->backlight = devm_of_find_backlight(dev);

	if (IS_ERR(innolux->backlight))
		return PTR_ERR(innolux->backlight);

	drm_panel_init(&innolux->base);
	innolux->base.funcs = &innolux_panel_funcs;
	innolux->base.dev = &innolux->link->dev;

	return drm_panel_add(&innolux->base);
}

static void innolux_panel_del(struct innolux_panel *innolux)
{
	if (innolux->base.dev)
		drm_panel_remove(&innolux->base);
}

static int innolux_panel_probe(struct mipi_dsi_device *dsi)
{
	struct innolux_panel *innolux;
	int err;

	dsi->lanes = 4;
	dsi->format = MIPI_DSI_FMT_RGB888;
	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
			  MIPI_DSI_MODE_LPM;

	innolux = devm_kzalloc(&dsi->dev, sizeof(*innolux), GFP_KERNEL);
	if (!innolux)
		return -ENOMEM;

	mipi_dsi_set_drvdata(dsi, innolux);

	innolux->link = dsi;

	err = innolux_panel_add(innolux);
	if (err < 0)
		return err;

	err = mipi_dsi_attach(dsi);
	return err;
}

static int innolux_panel_remove(struct mipi_dsi_device *dsi)
{
	struct innolux_panel *innolux = mipi_dsi_get_drvdata(dsi);
	int err;

	err = innolux_panel_unprepare(&innolux->base);
	if (err < 0)
		DRM_DEV_ERROR(&dsi->dev, "failed to unprepare panel: %d\n",
			      err);

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

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

	drm_panel_detach(&innolux->base);
	innolux_panel_del(innolux);

	return 0;
}

static void innolux_panel_shutdown(struct mipi_dsi_device *dsi)
{
	struct innolux_panel *innolux = mipi_dsi_get_drvdata(dsi);

	innolux_panel_unprepare(&innolux->base);
	innolux_panel_disable(&innolux->base);
}

static struct mipi_dsi_driver innolux_panel_driver = {
	.driver = {
		.name = "panel-innolux-p079zca",
		.of_match_table = innolux_of_match,
	},
	.probe = innolux_panel_probe,
	.remove = innolux_panel_remove,
	.shutdown = innolux_panel_shutdown,
};
module_mipi_dsi_driver(innolux_panel_driver);

MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
MODULE_DESCRIPTION("Innolux P079ZCA panel driver");
MODULE_LICENSE("GPL v2");