// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2017 NXP Semiconductors.
 * Author: Marco Franchi <marco.franchi@nxp.com>
 *
 * Based on Panel Simple driver by Thierry Reding <treding@nvidia.com>
 */

#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/platform_device.h>
#include <linux/regulator/consumer.h>

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

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

struct seiko_panel_desc {
        const struct drm_display_mode *modes;
        unsigned int num_modes;
        const struct display_timing *timings;
        unsigned int num_timings;

        unsigned int bpc;

        /**
         * @width: width (in millimeters) of the panel's active display area
         * @height: height (in millimeters) of the panel's active display area
         */
        struct {
                unsigned int width;
                unsigned int height;
        } size;

        u32 bus_format;
        u32 bus_flags;
};

struct seiko_panel {
        struct drm_panel base;
        const struct seiko_panel_desc *desc;
        struct regulator *dvdd;
        struct regulator *avdd;
        struct gpio_desc *enable_gpio;
};

static inline struct seiko_panel *to_seiko_panel(struct drm_panel *panel)
{
        return container_of(panel, struct seiko_panel, base);
}

static int seiko_panel_get_fixed_modes(struct seiko_panel *panel,
                                       struct drm_connector *connector)
{
        struct drm_display_mode *mode;
        unsigned int i, num = 0;

        if (!panel->desc)
                return 0;

        for (i = 0; i < panel->desc->num_timings; i++) {
                const struct display_timing *dt = &panel->desc->timings[i];
                struct videomode vm;

                videomode_from_timing(dt, &vm);
                mode = drm_mode_create(connector->dev);
                if (!mode) {
                        dev_err(panel->base.dev, "failed to add mode %ux%u\n",
                                dt->hactive.typ, dt->vactive.typ);
                        continue;
                }

                drm_display_mode_from_videomode(&vm, mode);

                mode->type |= DRM_MODE_TYPE_DRIVER;

                if (panel->desc->num_timings == 1)
                        mode->type |= DRM_MODE_TYPE_PREFERRED;

                drm_mode_probed_add(connector, mode);
                num++;
        }

        for (i = 0; i < panel->desc->num_modes; i++) {
                const struct drm_display_mode *m = &panel->desc->modes[i];

                mode = drm_mode_duplicate(connector->dev, m);
                if (!mode) {
                        dev_err(panel->base.dev, "failed to add mode %ux%u@%u\n",
                                m->hdisplay, m->vdisplay,
                                drm_mode_vrefresh(m));
                        continue;
                }

                mode->type |= DRM_MODE_TYPE_DRIVER;

                if (panel->desc->num_modes == 1)
                        mode->type |= DRM_MODE_TYPE_PREFERRED;

                drm_mode_set_name(mode);

                drm_mode_probed_add(connector, mode);
                num++;
        }

        connector->display_info.bpc = panel->desc->bpc;
        connector->display_info.width_mm = panel->desc->size.width;
        connector->display_info.height_mm = panel->desc->size.height;
        if (panel->desc->bus_format)
                drm_display_info_set_bus_formats(&connector->display_info,
                                                 &panel->desc->bus_format, 1);
        connector->display_info.bus_flags = panel->desc->bus_flags;

        return num;
}

static int seiko_panel_unprepare(struct drm_panel *panel)
{
        struct seiko_panel *p = to_seiko_panel(panel);

        gpiod_set_value_cansleep(p->enable_gpio, 0);

        regulator_disable(p->avdd);

        /* Add a 100ms delay as per the panel datasheet */
        msleep(100);

        regulator_disable(p->dvdd);

        return 0;
}

static int seiko_panel_prepare(struct drm_panel *panel)
{
        struct seiko_panel *p = to_seiko_panel(panel);
        int err;

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

        /* Add a 100ms delay as per the panel datasheet */
        msleep(100);

        err = regulator_enable(p->avdd);
        if (err < 0) {
                dev_err(panel->dev, "failed to enable avdd: %d\n", err);
                goto disable_dvdd;
        }

        gpiod_set_value_cansleep(p->enable_gpio, 1);

        return 0;

disable_dvdd:
        regulator_disable(p->dvdd);
        return err;
}

static int seiko_panel_get_modes(struct drm_panel *panel,
                                 struct drm_connector *connector)
{
        struct seiko_panel *p = to_seiko_panel(panel);

        /* add hard-coded panel modes */
        return seiko_panel_get_fixed_modes(p, connector);
}

static int seiko_panel_get_timings(struct drm_panel *panel,
                                    unsigned int num_timings,
                                    struct display_timing *timings)
{
        struct seiko_panel *p = to_seiko_panel(panel);
        unsigned int i;

        if (p->desc->num_timings < num_timings)
                num_timings = p->desc->num_timings;

        if (timings)
                for (i = 0; i < num_timings; i++)
                        timings[i] = p->desc->timings[i];

        return p->desc->num_timings;
}

static const struct drm_panel_funcs seiko_panel_funcs = {
        .unprepare = seiko_panel_unprepare,
        .prepare = seiko_panel_prepare,
        .get_modes = seiko_panel_get_modes,
        .get_timings = seiko_panel_get_timings,
};

static int seiko_panel_probe(struct device *dev,
                                        const struct seiko_panel_desc *desc)
{
        struct seiko_panel *panel;
        int err;

        panel = devm_drm_panel_alloc(dev, struct seiko_panel, base,
                                     &seiko_panel_funcs,
                                     DRM_MODE_CONNECTOR_DPI);
        if (IS_ERR(panel))
                return PTR_ERR(panel);

        panel->desc = desc;

        panel->dvdd = devm_regulator_get(dev, "dvdd");
        if (IS_ERR(panel->dvdd))
                return PTR_ERR(panel->dvdd);

        panel->avdd = devm_regulator_get(dev, "avdd");
        if (IS_ERR(panel->avdd))
                return PTR_ERR(panel->avdd);

        panel->enable_gpio = devm_gpiod_get_optional(dev, "enable",
                                                     GPIOD_OUT_LOW);
        if (IS_ERR(panel->enable_gpio))
                return dev_err_probe(dev, PTR_ERR(panel->enable_gpio),
                                     "failed to request GPIO\n");

        err = drm_panel_of_backlight(&panel->base);
        if (err)
                return err;

        drm_panel_add(&panel->base);

        dev_set_drvdata(dev, panel);

        return 0;
}

static void seiko_panel_remove(struct platform_device *pdev)
{
        struct seiko_panel *panel = platform_get_drvdata(pdev);

        drm_panel_remove(&panel->base);
}

static const struct display_timing seiko_43wvf1g_timing = {
        .pixelclock = { 33500000, 33500000, 33500000 },
        .hactive = { 800, 800, 800 },
        .hfront_porch = {  164, 164, 164 },
        .hback_porch = { 89, 89, 89 },
        .hsync_len = { 10, 10, 10 },
        .vactive = { 480, 480, 480 },
        .vfront_porch = { 10, 10, 10 },
        .vback_porch = { 23, 23, 23 },
        .vsync_len = { 10, 10, 10 },
        .flags = DISPLAY_FLAGS_DE_LOW,
};

static const struct seiko_panel_desc seiko_43wvf1g = {
        .timings = &seiko_43wvf1g_timing,
        .num_timings = 1,
        .bpc = 8,
        .size = {
                .width = 93,
                .height = 57,
        },
        .bus_format = MEDIA_BUS_FMT_RGB888_1X24,
        .bus_flags = DRM_BUS_FLAG_DE_HIGH | DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
};

static const struct of_device_id platform_of_match[] = {
        {
                .compatible = "sii,43wvf1g",
                .data = &seiko_43wvf1g,
        }, {
                /* sentinel */
        }
};
MODULE_DEVICE_TABLE(of, platform_of_match);

static int seiko_panel_platform_probe(struct platform_device *pdev)
{
        const struct of_device_id *id;

        id = of_match_node(platform_of_match, pdev->dev.of_node);
        if (!id)
                return -ENODEV;

        return seiko_panel_probe(&pdev->dev, id->data);
}

static struct platform_driver seiko_panel_platform_driver = {
        .driver = {
                .name = "seiko_panel",
                .of_match_table = platform_of_match,
        },
        .probe = seiko_panel_platform_probe,
        .remove = seiko_panel_remove,
};
module_platform_driver(seiko_panel_platform_driver);

MODULE_AUTHOR("Marco Franchi <marco.franchi@nxp.com>");
MODULE_DESCRIPTION("Seiko 43WVF1G panel driver");
MODULE_LICENSE("GPL v2");