/*
 * rcar_du_crtc.c  --  R-Car Display Unit CRTCs
 *
 * Copyright (C) 2016 Laurent Pinchart
 * Copyright (C) 2016 Renesas Electronics Corporation
 *
 * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
 *
 * 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_platform.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

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

#include <video/display_timing.h>
#include <video/of_display_timing.h>
#include <video/videomode.h>

struct panel_lvds {
        struct drm_panel panel;
        struct device *dev;

        const char *label;
        unsigned int width;
        unsigned int height;
        struct videomode video_mode;
        unsigned int bus_format;
        bool data_mirror;

        struct backlight_device *backlight;

        struct gpio_desc *enable_gpio;
        struct gpio_desc *reset_gpio;
};

static inline struct panel_lvds *to_panel_lvds(struct drm_panel *panel)
{
        return container_of(panel, struct panel_lvds, panel);
}

static int panel_lvds_disable(struct drm_panel *panel)
{
        struct panel_lvds *lvds = to_panel_lvds(panel);

        if (lvds->backlight) {
                lvds->backlight->props.power = FB_BLANK_POWERDOWN;
                lvds->backlight->props.state |= BL_CORE_FBBLANK;
                backlight_update_status(lvds->backlight);
        }

        return 0;
}

static int panel_lvds_unprepare(struct drm_panel *panel)
{
        struct panel_lvds *lvds = to_panel_lvds(panel);

        if (lvds->enable_gpio)
                gpiod_set_value_cansleep(lvds->enable_gpio, 0);

        return 0;
}

static int panel_lvds_prepare(struct drm_panel *panel)
{
        struct panel_lvds *lvds = to_panel_lvds(panel);

        if (lvds->enable_gpio)
                gpiod_set_value_cansleep(lvds->enable_gpio, 1);

        return 0;
}

static int panel_lvds_enable(struct drm_panel *panel)
{
        struct panel_lvds *lvds = to_panel_lvds(panel);

        if (lvds->backlight) {
                lvds->backlight->props.state &= ~BL_CORE_FBBLANK;
                lvds->backlight->props.power = FB_BLANK_UNBLANK;
                backlight_update_status(lvds->backlight);
        }

        return 0;
}

static int panel_lvds_get_modes(struct drm_panel *panel)
{
        struct panel_lvds *lvds = to_panel_lvds(panel);
        struct drm_connector *connector = lvds->panel.connector;
        struct drm_display_mode *mode;

        mode = drm_mode_create(lvds->panel.drm);
        if (!mode)
                return 0;

        drm_display_mode_from_videomode(&lvds->video_mode, mode);
        mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
        drm_mode_probed_add(connector, mode);

        connector->display_info.width_mm = lvds->width;
        connector->display_info.height_mm = lvds->height;
        drm_display_info_set_bus_formats(&connector->display_info,
                                         &lvds->bus_format, 1);
        connector->display_info.bus_flags = lvds->data_mirror
                                          ? DRM_BUS_FLAG_DATA_LSB_TO_MSB
                                          : DRM_BUS_FLAG_DATA_MSB_TO_LSB;

        return 1;
}

static const struct drm_panel_funcs panel_lvds_funcs = {
        .disable = panel_lvds_disable,
        .unprepare = panel_lvds_unprepare,
        .prepare = panel_lvds_prepare,
        .enable = panel_lvds_enable,
        .get_modes = panel_lvds_get_modes,
};

static int panel_lvds_parse_dt(struct panel_lvds *lvds)
{
        struct device_node *np = lvds->dev->of_node;
        struct display_timing timing;
        const char *mapping;
        int ret;

        ret = of_get_display_timing(np, "panel-timing", &timing);
        if (ret < 0)
                return ret;

        videomode_from_timing(&timing, &lvds->video_mode);

        ret = of_property_read_u32(np, "width-mm", &lvds->width);
        if (ret < 0) {
                dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
                        np, "width-mm");
                return -ENODEV;
        }
        ret = of_property_read_u32(np, "height-mm", &lvds->height);
        if (ret < 0) {
                dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
                        np, "height-mm");
                return -ENODEV;
        }

        of_property_read_string(np, "label", &lvds->label);

        ret = of_property_read_string(np, "data-mapping", &mapping);
        if (ret < 0) {
                dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
                        np, "data-mapping");
                return -ENODEV;
        }

        if (!strcmp(mapping, "jeida-18")) {
                lvds->bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG;
        } else if (!strcmp(mapping, "jeida-24")) {
                lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA;
        } else if (!strcmp(mapping, "vesa-24")) {
                lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_SPWG;
        } else {
                dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
                        np, "data-mapping");
                return -EINVAL;
        }

        lvds->data_mirror = of_property_read_bool(np, "data-mirror");

        return 0;
}

static int panel_lvds_probe(struct platform_device *pdev)
{
        struct panel_lvds *lvds;
        struct device_node *np;
        int ret;

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

        lvds->dev = &pdev->dev;

        ret = panel_lvds_parse_dt(lvds);
        if (ret < 0)
                return ret;

        /* Get GPIOs and backlight controller. */
        lvds->enable_gpio = devm_gpiod_get_optional(lvds->dev, "enable",
                                                     GPIOD_OUT_LOW);
        if (IS_ERR(lvds->enable_gpio)) {
                ret = PTR_ERR(lvds->enable_gpio);
                dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
                        "enable", ret);
                return ret;
        }

        lvds->reset_gpio = devm_gpiod_get_optional(lvds->dev, "reset",
                                                     GPIOD_OUT_HIGH);
        if (IS_ERR(lvds->reset_gpio)) {
                ret = PTR_ERR(lvds->reset_gpio);
                dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
                        "reset", ret);
                return ret;
        }

        np = of_parse_phandle(lvds->dev->of_node, "backlight", 0);
        if (np) {
                lvds->backlight = of_find_backlight_by_node(np);
                of_node_put(np);

                if (!lvds->backlight)
                        return -EPROBE_DEFER;
        }

        /*
         * TODO: Handle all power supplies specified in the DT node in a generic
         * way for panels that don't care about power supply ordering. LVDS
         * panels that require a specific power sequence will need a dedicated
         * driver.
         */

        /* Register the panel. */
        drm_panel_init(&lvds->panel);
        lvds->panel.dev = lvds->dev;
        lvds->panel.funcs = &panel_lvds_funcs;

        ret = drm_panel_add(&lvds->panel);
        if (ret < 0)
                goto error;

        dev_set_drvdata(lvds->dev, lvds);
        return 0;

error:
        put_device(&lvds->backlight->dev);
        return ret;
}

static int panel_lvds_remove(struct platform_device *pdev)
{
        struct panel_lvds *lvds = dev_get_drvdata(&pdev->dev);

        drm_panel_detach(&lvds->panel);
        drm_panel_remove(&lvds->panel);

        panel_lvds_disable(&lvds->panel);

        if (lvds->backlight)
                put_device(&lvds->backlight->dev);

        return 0;
}

static const struct of_device_id panel_lvds_of_table[] = {
        { .compatible = "panel-lvds", },
        { /* Sentinel */ },
};

MODULE_DEVICE_TABLE(of, panel_lvds_of_table);

static struct platform_driver panel_lvds_driver = {
        .probe          = panel_lvds_probe,
        .remove         = panel_lvds_remove,
        .driver         = {
                .name   = "panel-lvds",
                .of_match_table = panel_lvds_of_table,
        },
};

module_platform_driver(panel_lvds_driver);

MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
MODULE_DESCRIPTION("LVDS Panel Driver");
MODULE_LICENSE("GPL");