// SPDX-License-Identifier: GPL-2.0
/*
 * ZynqMP DisplayPort Subsystem Driver
 *
 * Copyright (C) 2017 - 2020 Xilinx, Inc.
 *
 * Authors:
 * - Hyun Woo Kwon <hyun.kwon@xilinx.com>
 * - Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 */

#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/of_graph.h>
#include <linux/of_reserved_mem.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>

#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_modeset_helper.h>
#include <drm/drm_module.h>

#include "zynqmp_disp.h"
#include "zynqmp_dp.h"
#include "zynqmp_dpsub.h"
#include "zynqmp_kms.h"

/* -----------------------------------------------------------------------------
 * Power Management
 */

static int __maybe_unused zynqmp_dpsub_suspend(struct device *dev)
{
        struct zynqmp_dpsub *dpsub = dev_get_drvdata(dev);

        if (!dpsub->drm)
                return 0;

        return drm_mode_config_helper_suspend(&dpsub->drm->dev);
}

static int __maybe_unused zynqmp_dpsub_resume(struct device *dev)
{
        struct zynqmp_dpsub *dpsub = dev_get_drvdata(dev);

        if (!dpsub->drm)
                return 0;

        return drm_mode_config_helper_resume(&dpsub->drm->dev);
}

static const struct dev_pm_ops zynqmp_dpsub_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(zynqmp_dpsub_suspend, zynqmp_dpsub_resume)
};

/* -----------------------------------------------------------------------------
 * Probe & Remove
 */

static int zynqmp_dpsub_init_clocks(struct zynqmp_dpsub *dpsub)
{
        int ret;

        dpsub->apb_clk = devm_clk_get(dpsub->dev, "dp_apb_clk");
        if (IS_ERR(dpsub->apb_clk))
                return PTR_ERR(dpsub->apb_clk);

        ret = clk_prepare_enable(dpsub->apb_clk);
        if (ret) {
                dev_err(dpsub->dev, "failed to enable the APB clock\n");
                return ret;
        }

        /*
         * Try the live PL video clock, and fall back to the PS clock if the
         * live PL video clock isn't valid.
         */
        dpsub->vid_clk = devm_clk_get(dpsub->dev, "dp_live_video_in_clk");
        if (!IS_ERR(dpsub->vid_clk))
                dpsub->vid_clk_from_ps = false;
        else if (PTR_ERR(dpsub->vid_clk) == -EPROBE_DEFER)
                return PTR_ERR(dpsub->vid_clk);

        if (IS_ERR_OR_NULL(dpsub->vid_clk)) {
                dpsub->vid_clk = devm_clk_get(dpsub->dev, "dp_vtc_pixel_clk_in");
                if (IS_ERR(dpsub->vid_clk)) {
                        dev_err(dpsub->dev, "failed to init any video clock\n");
                        return PTR_ERR(dpsub->vid_clk);
                }
                dpsub->vid_clk_from_ps = true;
        }

        /*
         * Try the live PL audio clock, and fall back to the PS clock if the
         * live PL audio clock isn't valid. Missing audio clock disables audio
         * but isn't an error.
         */
        dpsub->aud_clk = devm_clk_get(dpsub->dev, "dp_live_audio_aclk");
        if (!IS_ERR(dpsub->aud_clk)) {
                dpsub->aud_clk_from_ps = false;
                return 0;
        }

        dpsub->aud_clk = devm_clk_get(dpsub->dev, "dp_aud_clk");
        if (!IS_ERR(dpsub->aud_clk)) {
                dpsub->aud_clk_from_ps = true;
                return 0;
        }

        dev_info(dpsub->dev, "audio disabled due to missing clock\n");
        return 0;
}

static int zynqmp_dpsub_parse_dt(struct zynqmp_dpsub *dpsub)
{
        struct device_node *np;
        unsigned int i;

        /*
         * For backward compatibility with old device trees that don't contain
         * ports, consider that only the DP output port is connected if no
         * ports child no exists.
         */
        np = of_get_child_by_name(dpsub->dev->of_node, "ports");
        of_node_put(np);
        if (!np) {
                dev_warn(dpsub->dev, "missing ports, update DT bindings\n");
                dpsub->connected_ports = BIT(ZYNQMP_DPSUB_PORT_OUT_DP);
                dpsub->dma_enabled = true;
                return 0;
        }

        /* Check which ports are connected. */
        for (i = 0; i < ZYNQMP_DPSUB_NUM_PORTS; ++i) {
                struct device_node *np;

                np = of_graph_get_remote_node(dpsub->dev->of_node, i, -1);
                if (np) {
                        dpsub->connected_ports |= BIT(i);
                        of_node_put(np);
                }
        }

        /* Sanity checks. */
        if ((dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_VIDEO)) &&
            (dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_GFX))) {
                dev_err(dpsub->dev, "only one live video input is supported\n");
                return -EINVAL;
        }

        if ((dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_VIDEO)) ||
            (dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_GFX))) {
                if (dpsub->vid_clk_from_ps) {
                        dev_err(dpsub->dev,
                                "live video input requires PL clock\n");
                        return -EINVAL;
                }
        } else {
                dpsub->dma_enabled = true;
        }

        if (dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_AUDIO))
                dev_warn(dpsub->dev, "live audio unsupported, ignoring\n");

        if ((dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_OUT_VIDEO)) ||
            (dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_OUT_AUDIO)))
                dev_warn(dpsub->dev, "output to PL unsupported, ignoring\n");

        if (!(dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_OUT_DP))) {
                dev_err(dpsub->dev, "DP output port not connected\n");
                return -EINVAL;
        }

        return 0;
}

void zynqmp_dpsub_release(struct zynqmp_dpsub *dpsub)
{
        kfree(dpsub->disp);
        kfree(dpsub);
}

static int zynqmp_dpsub_probe(struct platform_device *pdev)
{
        struct zynqmp_dpsub *dpsub;
        int ret;

        /* Allocate private data. */
        dpsub = kzalloc_obj(*dpsub);
        if (!dpsub)
                return -ENOMEM;

        dpsub->dev = &pdev->dev;
        platform_set_drvdata(pdev, dpsub);

        ret = dma_set_mask(dpsub->dev, DMA_BIT_MASK(ZYNQMP_DISP_MAX_DMA_BIT));
        if (ret)
                return ret;

        dma_set_max_seg_size(&pdev->dev, DMA_BIT_MASK(32));

        /* Try the reserved memory. Proceed if there's none. */
        of_reserved_mem_device_init(&pdev->dev);

        ret = zynqmp_dpsub_init_clocks(dpsub);
        if (ret < 0)
                goto err_mem;

        ret = zynqmp_dpsub_parse_dt(dpsub);
        if (ret < 0)
                goto err_mem;

        pm_runtime_enable(&pdev->dev);

        /*
         * DP should be probed first so that the zynqmp_disp can set the output
         * format accordingly.
         */
        ret = zynqmp_dp_probe(dpsub);
        if (ret)
                goto err_pm;

        ret = zynqmp_disp_probe(dpsub);
        if (ret)
                goto err_dp;

        drm_bridge_add(dpsub->bridge);

        if (dpsub->dma_enabled) {
                ret = zynqmp_dpsub_drm_init(dpsub);
                if (ret)
                        goto err_disp;
        }

        ret = zynqmp_audio_init(dpsub);
        if (ret)
                goto err_drm_cleanup;

        dev_info(&pdev->dev, "ZynqMP DisplayPort Subsystem driver probed");

        return 0;

err_drm_cleanup:
        if (dpsub->drm)
                zynqmp_dpsub_drm_cleanup(dpsub);
err_disp:
        drm_bridge_remove(dpsub->bridge);
        zynqmp_disp_remove(dpsub);
err_dp:
        zynqmp_dp_remove(dpsub);
err_pm:
        pm_runtime_disable(&pdev->dev);
        clk_disable_unprepare(dpsub->apb_clk);
err_mem:
        of_reserved_mem_device_release(&pdev->dev);
        if (!dpsub->drm)
                zynqmp_dpsub_release(dpsub);
        return ret;
}

static void zynqmp_dpsub_remove(struct platform_device *pdev)
{
        struct zynqmp_dpsub *dpsub = platform_get_drvdata(pdev);

        zynqmp_audio_uninit(dpsub);

        if (dpsub->drm)
                zynqmp_dpsub_drm_cleanup(dpsub);

        drm_bridge_remove(dpsub->bridge);
        zynqmp_disp_remove(dpsub);
        zynqmp_dp_remove(dpsub);

        pm_runtime_disable(&pdev->dev);
        clk_disable_unprepare(dpsub->apb_clk);
        of_reserved_mem_device_release(&pdev->dev);

        if (!dpsub->drm)
                zynqmp_dpsub_release(dpsub);
}

static void zynqmp_dpsub_shutdown(struct platform_device *pdev)
{
        struct zynqmp_dpsub *dpsub = platform_get_drvdata(pdev);

        if (!dpsub->drm)
                return;

        drm_atomic_helper_shutdown(&dpsub->drm->dev);
}

static const struct of_device_id zynqmp_dpsub_of_match[] = {
        { .compatible = "xlnx,zynqmp-dpsub-1.7", },
        { /* end of table */ },
};
MODULE_DEVICE_TABLE(of, zynqmp_dpsub_of_match);

static struct platform_driver zynqmp_dpsub_driver = {
        .probe                  = zynqmp_dpsub_probe,
        .remove                 = zynqmp_dpsub_remove,
        .shutdown               = zynqmp_dpsub_shutdown,
        .driver                 = {
                .name           = "zynqmp-dpsub",
                .pm             = &zynqmp_dpsub_pm_ops,
                .of_match_table = zynqmp_dpsub_of_match,
        },
};

drm_module_platform_driver(zynqmp_dpsub_driver);

MODULE_AUTHOR("Xilinx, Inc.");
MODULE_DESCRIPTION("ZynqMP DP Subsystem Driver");
MODULE_LICENSE("GPL v2");