// SPDX-License-Identifier: GPL-2.0+
/*
 * Generic LVDS panel driver
 *
 * Copyright (C) 2016 Laurent Pinchart
 * Copyright (C) 2016 Renesas Electronics Corporation
 *
 * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
 */

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

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

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

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

        const char *label;
        struct drm_display_mode dmode;
        u32 bus_flags;
        unsigned int bus_format;

        struct regulator *supply;

        struct gpio_desc *enable_gpio;
        struct gpio_desc *reset_gpio;

        enum drm_panel_orientation orientation;
};

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

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);

        if (lvds->supply)
                regulator_disable(lvds->supply);

        return 0;
}

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

        if (lvds->supply) {
                int err;

                err = regulator_enable(lvds->supply);
                if (err < 0) {
                        dev_err(lvds->dev, "failed to enable supply: %d\n",
                                err);
                        return err;
                }
        }

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

        return 0;
}

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

        mode = drm_mode_duplicate(connector->dev, &lvds->dmode);
        if (!mode)
                return 0;

        mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
        drm_mode_probed_add(connector, mode);

        connector->display_info.width_mm = lvds->dmode.width_mm;
        connector->display_info.height_mm = lvds->dmode.height_mm;
        drm_display_info_set_bus_formats(&connector->display_info,
                                         &lvds->bus_format, 1);
        connector->display_info.bus_flags = lvds->bus_flags;

        /*
         * TODO: Remove once all drm drivers call
         * drm_connector_set_orientation_from_panel()
         */
        drm_connector_set_panel_orientation(connector, lvds->orientation);

        return 1;
}

static enum drm_panel_orientation panel_lvds_get_orientation(struct drm_panel *panel)
{
        struct panel_lvds *lvds = to_panel_lvds(panel);

        return lvds->orientation;
}

static const struct drm_panel_funcs panel_lvds_funcs = {
        .unprepare = panel_lvds_unprepare,
        .prepare = panel_lvds_prepare,
        .get_modes = panel_lvds_get_modes,
        .get_orientation = panel_lvds_get_orientation,
};

static int panel_lvds_parse_dt(struct panel_lvds *lvds)
{
        struct device_node *np = lvds->dev->of_node;
        int ret;

        ret = of_drm_get_panel_orientation(np, &lvds->orientation);
        if (ret < 0) {
                dev_err(lvds->dev, "%pOF: failed to get orientation %d\n", np, ret);
                return ret;
        }

        ret = of_get_drm_panel_display_mode(np, &lvds->dmode, &lvds->bus_flags);
        if (ret < 0) {
                dev_err(lvds->dev, "%pOF: problems parsing panel-timing (%d)\n",
                        np, ret);
                return ret;
        }

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

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

        lvds->bus_format = ret;

        lvds->bus_flags |= of_property_read_bool(np, "data-mirror") ?
                           DRM_BUS_FLAG_DATA_LSB_TO_MSB :
                           DRM_BUS_FLAG_DATA_MSB_TO_LSB;

        return 0;
}

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

        lvds = devm_drm_panel_alloc(&pdev->dev, struct panel_lvds, panel,
                                    &panel_lvds_funcs,
                                    DRM_MODE_CONNECTOR_LVDS);
        if (IS_ERR(lvds))
                return PTR_ERR(lvds);

        lvds->dev = &pdev->dev;

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

        lvds->supply = devm_regulator_get_optional(lvds->dev, "power");
        if (IS_ERR(lvds->supply)) {
                ret = PTR_ERR(lvds->supply);

                if (ret != -ENODEV) {
                        if (ret != -EPROBE_DEFER)
                                dev_err(lvds->dev, "failed to request regulator: %d\n",
                                        ret);
                        return ret;
                }

                lvds->supply = NULL;
        }

        /* 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;
        }

        /*
         * 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.
         */

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

        drm_panel_add(&lvds->panel);

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

static void panel_lvds_remove(struct platform_device *pdev)
{
        struct panel_lvds *lvds = platform_get_drvdata(pdev);

        drm_panel_remove(&lvds->panel);

        drm_panel_disable(&lvds->panel);
}

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");