// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2019 Renesas Electronics Corporation
 * Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 */

#include <linux/gpio/consumer.h>
#include <linux/media-bus-format.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_graph.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>

#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_of.h>
#include <drm/drm_panel.h>

struct lvds_codec {
        struct device *dev;
        struct drm_bridge bridge;
        struct drm_bridge *panel_bridge;
        struct drm_bridge_timings timings;
        struct regulator *vcc;
        struct gpio_desc *powerdown_gpio;
        u32 connector_type;
        unsigned int bus_format;
};

static inline struct lvds_codec *to_lvds_codec(struct drm_bridge *bridge)
{
        return container_of(bridge, struct lvds_codec, bridge);
}

static int lvds_codec_attach(struct drm_bridge *bridge,
                             struct drm_encoder *encoder,
                             enum drm_bridge_attach_flags flags)
{
        struct lvds_codec *lvds_codec = to_lvds_codec(bridge);

        return drm_bridge_attach(encoder, lvds_codec->panel_bridge,
                                 bridge, flags);
}

static void lvds_codec_enable(struct drm_bridge *bridge)
{
        struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
        int ret;

        ret = regulator_enable(lvds_codec->vcc);
        if (ret) {
                dev_err(lvds_codec->dev,
                        "Failed to enable regulator \"vcc\": %d\n", ret);
                return;
        }

        if (lvds_codec->powerdown_gpio)
                gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 0);
}

static void lvds_codec_disable(struct drm_bridge *bridge)
{
        struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
        int ret;

        if (lvds_codec->powerdown_gpio)
                gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 1);

        ret = regulator_disable(lvds_codec->vcc);
        if (ret)
                dev_err(lvds_codec->dev,
                        "Failed to disable regulator \"vcc\": %d\n", ret);
}

#define MAX_INPUT_SEL_FORMATS 1
static u32 *
lvds_codec_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
                                     struct drm_bridge_state *bridge_state,
                                     struct drm_crtc_state *crtc_state,
                                     struct drm_connector_state *conn_state,
                                     u32 output_fmt,
                                     unsigned int *num_input_fmts)
{
        struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
        u32 *input_fmts;

        *num_input_fmts = 0;

        input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
                             GFP_KERNEL);
        if (!input_fmts)
                return NULL;

        input_fmts[0] = lvds_codec->bus_format;
        *num_input_fmts = MAX_INPUT_SEL_FORMATS;

        return input_fmts;
}

static const struct drm_bridge_funcs funcs = {
        .attach = lvds_codec_attach,
        .enable = lvds_codec_enable,
        .disable = lvds_codec_disable,
        .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
        .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
        .atomic_reset = drm_atomic_helper_bridge_reset,
        .atomic_get_input_bus_fmts = lvds_codec_atomic_get_input_bus_fmts,
};

static int lvds_codec_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct device_node *panel_node;
        struct device_node *bus_node;
        struct drm_panel *panel;
        struct lvds_codec *lvds_codec;
        u32 val;
        int ret;

        lvds_codec = devm_drm_bridge_alloc(dev, struct lvds_codec, bridge,
                                           &funcs);
        if (IS_ERR(lvds_codec))
                return PTR_ERR(lvds_codec);

        lvds_codec->dev = &pdev->dev;
        lvds_codec->connector_type = (uintptr_t)of_device_get_match_data(dev);

        lvds_codec->vcc = devm_regulator_get(lvds_codec->dev, "power");
        if (IS_ERR(lvds_codec->vcc))
                return dev_err_probe(dev, PTR_ERR(lvds_codec->vcc),
                                     "Unable to get \"vcc\" supply\n");

        lvds_codec->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown",
                                                             GPIOD_OUT_HIGH);
        if (IS_ERR(lvds_codec->powerdown_gpio))
                return dev_err_probe(dev, PTR_ERR(lvds_codec->powerdown_gpio),
                                     "powerdown GPIO failure\n");

        /* Locate the panel DT node. */
        panel_node = of_graph_get_remote_node(dev->of_node, 1, 0);
        if (!panel_node) {
                dev_dbg(dev, "panel DT node not found\n");
                return -ENXIO;
        }

        panel = of_drm_find_panel(panel_node);
        of_node_put(panel_node);
        if (IS_ERR(panel)) {
                dev_dbg(dev, "panel not found, deferring probe\n");
                return PTR_ERR(panel);
        }

        lvds_codec->panel_bridge =
                devm_drm_panel_bridge_add_typed(dev, panel,
                                                lvds_codec->connector_type);
        if (IS_ERR(lvds_codec->panel_bridge))
                return PTR_ERR(lvds_codec->panel_bridge);

        /*
         * Decoder input LVDS format is a property of the decoder chip or even
         * its strapping. Handle data-mapping the same way lvds-panel does. In
         * case data-mapping is not present, do nothing, since there are still
         * legacy bindings which do not specify this property.
         */
        if (lvds_codec->connector_type != DRM_MODE_CONNECTOR_LVDS) {
                bus_node = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
                if (!bus_node) {
                        dev_dbg(dev, "bus DT node not found\n");
                        return -ENXIO;
                }

                ret = drm_of_lvds_get_data_mapping(bus_node);
                of_node_put(bus_node);
                if (ret == -ENODEV) {
                        dev_warn(dev, "missing 'data-mapping' DT property\n");
                } else if (ret < 0) {
                        dev_err(dev, "invalid 'data-mapping' DT property\n");
                        return ret;
                } else {
                        lvds_codec->bus_format = ret;
                }
        } else {
                lvds_codec->bus_format = MEDIA_BUS_FMT_RGB888_1X24;
        }

        /*
         * Encoder might sample data on different clock edge than the display,
         * for example OnSemi FIN3385 has a dedicated strapping pin to select
         * the sampling edge.
         */
        if (lvds_codec->connector_type == DRM_MODE_CONNECTOR_LVDS &&
            !of_property_read_u32(dev->of_node, "pclk-sample", &val)) {
                lvds_codec->timings.input_bus_flags = val ?
                        DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE :
                        DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
        }

        /*
         * The panel_bridge bridge is attached to the panel's of_node,
         * but we need a bridge attached to our of_node for our user
         * to look up.
         */
        lvds_codec->bridge.of_node = dev->of_node;
        lvds_codec->bridge.timings = &lvds_codec->timings;
        drm_bridge_add(&lvds_codec->bridge);

        platform_set_drvdata(pdev, lvds_codec);

        return 0;
}

static void lvds_codec_remove(struct platform_device *pdev)
{
        struct lvds_codec *lvds_codec = platform_get_drvdata(pdev);

        drm_bridge_remove(&lvds_codec->bridge);
}

static const struct of_device_id lvds_codec_match[] = {
        {
                .compatible = "lvds-decoder",
                .data = (void *)DRM_MODE_CONNECTOR_DPI,
        },
        {
                .compatible = "lvds-encoder",
                .data = (void *)DRM_MODE_CONNECTOR_LVDS,
        },
        {
                .compatible = "thine,thc63lvdm83d",
                .data = (void *)DRM_MODE_CONNECTOR_LVDS,
        },
        {},
};
MODULE_DEVICE_TABLE(of, lvds_codec_match);

static struct platform_driver lvds_codec_driver = {
        .probe  = lvds_codec_probe,
        .remove = lvds_codec_remove,
        .driver         = {
                .name           = "lvds-codec",
                .of_match_table = lvds_codec_match,
        },
};
module_platform_driver(lvds_codec_driver);

MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
MODULE_DESCRIPTION("LVDS encoders and decoders");
MODULE_LICENSE("GPL");