// SPDX-License-Identifier: GPL-2.0-only
/*
 * MEN Chameleon Bus.
 *
 * Copyright (C) 2014 MEN Mikroelektronik GmbH (www.men.de)
 * Author: Johannes Thumshirn <johannes.thumshirn@men.de>
 */

#include <linux/module.h>
#include <linux/pci.h>
#include <linux/mcb.h>

#include "mcb-internal.h"

struct priv {
        struct mcb_bus *bus;
        phys_addr_t mapbase;
        void __iomem *base;
};

static int mcb_pci_get_irq(struct mcb_device *mdev)
{
        struct mcb_bus *mbus = mdev->bus;
        struct device *dev = mbus->carrier;
        struct pci_dev *pdev = to_pci_dev(dev);

        return pdev->irq;
}

static int mcb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
        struct resource *res;
        struct priv *priv;
        int ret, table_size;
        unsigned long flags;

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

        ret = pci_enable_device(pdev);
        if (ret) {
                dev_err(&pdev->dev, "Failed to enable PCI device\n");
                return -ENODEV;
        }
        pci_set_master(pdev);

        flags = pci_resource_flags(pdev, 0);
        if (flags & IORESOURCE_IO) {
                ret = -ENOTSUPP;
                dev_err(&pdev->dev,
                        "IO mapped PCI devices are not supported\n");
                goto out_disable;
        }

        priv->mapbase = pci_resource_start(pdev, 0);
        if (!priv->mapbase) {
                dev_err(&pdev->dev, "No PCI resource\n");
                ret = -ENODEV;
                goto out_disable;
        }

        res = devm_request_mem_region(&pdev->dev, priv->mapbase,
                                      CHAM_HEADER_SIZE,
                                      KBUILD_MODNAME);
        if (!res) {
                dev_err(&pdev->dev, "Failed to request PCI memory\n");
                ret = -EBUSY;
                goto out_disable;
        }

        priv->base = devm_ioremap(&pdev->dev, priv->mapbase, CHAM_HEADER_SIZE);
        if (!priv->base) {
                dev_err(&pdev->dev, "Cannot ioremap\n");
                ret = -ENOMEM;
                goto out_disable;
        }

        pci_set_drvdata(pdev, priv);

        priv->bus = mcb_alloc_bus(&pdev->dev);
        if (IS_ERR(priv->bus)) {
                ret = PTR_ERR(priv->bus);
                goto out_disable;
        }

        priv->bus->get_irq = mcb_pci_get_irq;

        ret = chameleon_parse_cells(priv->bus, priv->mapbase, priv->base);
        if (ret < 0)
                goto out_mcb_bus;

        table_size = ret;

        if (table_size < CHAM_HEADER_SIZE) {
                /* Release the previous resources */
                devm_iounmap(&pdev->dev, priv->base);
                devm_release_mem_region(&pdev->dev, priv->mapbase, CHAM_HEADER_SIZE);

                /* Then, allocate it again with the actual chameleon table size */
                res = devm_request_mem_region(&pdev->dev, priv->mapbase,
                                                table_size,
                                                KBUILD_MODNAME);
                if (!res) {
                        dev_err(&pdev->dev, "Failed to request PCI memory\n");
                        ret = -EBUSY;
                        goto out_mcb_bus;
                }

                priv->base = devm_ioremap(&pdev->dev, priv->mapbase, table_size);
                if (!priv->base) {
                        dev_err(&pdev->dev, "Cannot ioremap\n");
                        ret = -ENOMEM;
                        goto out_mcb_bus;
                }
        }

        mcb_bus_add_devices(priv->bus);

        return 0;

out_mcb_bus:
        mcb_release_bus(priv->bus);
out_disable:
        pci_disable_device(pdev);
        return ret;
}

static void mcb_pci_remove(struct pci_dev *pdev)
{
        struct priv *priv = pci_get_drvdata(pdev);

        mcb_release_bus(priv->bus);

        pci_disable_device(pdev);
}

static const struct pci_device_id mcb_pci_tbl[] = {
        { PCI_DEVICE(PCI_VENDOR_ID_MEN, PCI_DEVICE_ID_MEN_CHAMELEON) },
        { PCI_DEVICE(PCI_VENDOR_ID_ALTERA, PCI_DEVICE_ID_MEN_CHAMELEON) },
        { 0 },
};
MODULE_DEVICE_TABLE(pci, mcb_pci_tbl);

static struct pci_driver mcb_pci_driver = {
        .name = "mcb-pci",
        .id_table = mcb_pci_tbl,
        .probe = mcb_pci_probe,
        .remove = mcb_pci_remove,
};

module_pci_driver(mcb_pci_driver);

MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("MCB over PCI support");
MODULE_IMPORT_NS("MCB");