// SPDX-License-Identifier: GPL-2.0+
/*
 * amd5536udc_pci.c -- AMD 5536 UDC high/full speed USB device controller
 *
 * Copyright (C) 2005-2007 AMD (https://www.amd.com)
 * Author: Thomas Dahlmann
 */

/*
 * The AMD5536 UDC is part of the x86 southbridge AMD Geode CS5536.
 * It is a USB Highspeed DMA capable USB device controller. Beside ep0 it
 * provides 4 IN and 4 OUT endpoints (bulk or interrupt type).
 *
 * Make sure that UDC is assigned to port 4 by BIOS settings (port can also
 * be used as host port) and UOC bits PAD_EN and APU are set (should be done
 * by BIOS init).
 *
 * UDC DMA requires 32-bit aligned buffers so DMA with gadget ether does not
 * work without updating NET_IP_ALIGN. Or PIO mode (module param "use_dma=0")
 * can be used with gadget ether.
 *
 * This file does pci device registration, and the core driver implementation
 * is done in amd5536udc.c
 *
 * The driver is split so as to use the core UDC driver which is based on
 * Synopsys device controller IP (different than HS OTG IP) in UDCs
 * integrated to SoC platforms.
 *
 */

/* Driver strings */
#define UDC_MOD_DESCRIPTION             "AMD 5536 UDC - USB Device Controller"

/* system */
#include <linux/device.h>
#include <linux/dmapool.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/prefetch.h>
#include <linux/pci.h>

/* udc specific */
#include "amd5536udc.h"

/* pointer to device object */
static struct udc *udc;

/* description */
static const char name[] = "amd5536udc-pci";

/* Reset all pci context */
static void udc_pci_remove(struct pci_dev *pdev)
{
        struct udc              *dev;

        dev = pci_get_drvdata(pdev);

        usb_del_gadget_udc(&udc->gadget);
        /* gadget driver must not be registered */
        if (WARN_ON(dev->driver))
                return;

        /* dma pool cleanup */
        free_dma_pools(dev);

        /* reset controller */
        writel(AMD_BIT(UDC_DEVCFG_SOFTRESET), &dev->regs->cfg);
        free_irq(pdev->irq, dev);
        iounmap(dev->virt_addr);
        release_mem_region(pci_resource_start(pdev, 0),
                           pci_resource_len(pdev, 0));
        pci_disable_device(pdev);

        udc_remove(dev);
}

/* Called by pci bus driver to init pci context */
static int udc_pci_probe(
        struct pci_dev *pdev,
        const struct pci_device_id *id
)
{
        struct udc              *dev;
        unsigned long           resource;
        unsigned long           len;
        int                     retval = 0;

        /* one udc only */
        if (udc) {
                dev_dbg(&pdev->dev, "already probed\n");
                return -EBUSY;
        }

        /* init */
        dev = kzalloc(sizeof(struct udc), GFP_KERNEL);
        if (!dev)
                return -ENOMEM;

        /* pci setup */
        if (pci_enable_device(pdev) < 0) {
                retval = -ENODEV;
                goto err_pcidev;
        }

        /* PCI resource allocation */
        resource = pci_resource_start(pdev, 0);
        len = pci_resource_len(pdev, 0);

        if (!request_mem_region(resource, len, name)) {
                dev_dbg(&pdev->dev, "pci device used already\n");
                retval = -EBUSY;
                goto err_memreg;
        }

        dev->virt_addr = ioremap(resource, len);
        if (!dev->virt_addr) {
                dev_dbg(&pdev->dev, "start address cannot be mapped\n");
                retval = -EFAULT;
                goto err_ioremap;
        }

        if (!pdev->irq) {
                dev_err(&pdev->dev, "irq not set\n");
                retval = -ENODEV;
                goto err_irq;
        }

        spin_lock_init(&dev->lock);
        /* udc csr registers base */
        dev->csr = dev->virt_addr + UDC_CSR_ADDR;
        /* dev registers base */
        dev->regs = dev->virt_addr + UDC_DEVCFG_ADDR;
        /* ep registers base */
        dev->ep_regs = dev->virt_addr + UDC_EPREGS_ADDR;
        /* fifo's base */
        dev->rxfifo = (u32 __iomem *)(dev->virt_addr + UDC_RXFIFO_ADDR);
        dev->txfifo = (u32 __iomem *)(dev->virt_addr + UDC_TXFIFO_ADDR);

        if (request_irq(pdev->irq, udc_irq, IRQF_SHARED, name, dev) != 0) {
                dev_dbg(&pdev->dev, "request_irq(%d) fail\n", pdev->irq);
                retval = -EBUSY;
                goto err_irq;
        }

        pci_set_drvdata(pdev, dev);

        /* chip revision for Hs AMD5536 */
        dev->chiprev = pdev->revision;

        pci_set_master(pdev);
        pci_try_set_mwi(pdev);

        dev->phys_addr = resource;
        dev->irq = pdev->irq;
        dev->pdev = pdev;
        dev->dev = &pdev->dev;

        /* init dma pools */
        if (use_dma) {
                retval = init_dma_pools(dev);
                if (retval != 0)
                        goto err_dma;
        }

        /* general probing */
        if (udc_probe(dev)) {
                retval = -ENODEV;
                goto err_probe;
        }
        return 0;

err_probe:
        if (use_dma)
                free_dma_pools(dev);
err_dma:
        free_irq(pdev->irq, dev);
err_irq:
        iounmap(dev->virt_addr);
err_ioremap:
        release_mem_region(resource, len);
err_memreg:
        pci_disable_device(pdev);
err_pcidev:
        kfree(dev);
        return retval;
}

/* PCI device parameters */
static const struct pci_device_id pci_id[] = {
        {
                PCI_DEVICE(PCI_VENDOR_ID_AMD, 0x2096),
                .class =        PCI_CLASS_SERIAL_USB_DEVICE,
                .class_mask =   0xffffffff,
        },
        {},
};
MODULE_DEVICE_TABLE(pci, pci_id);

/* PCI functions */
static struct pci_driver udc_pci_driver = {
        .name =         name,
        .id_table =     pci_id,
        .probe =        udc_pci_probe,
        .remove =       udc_pci_remove,
};
module_pci_driver(udc_pci_driver);

MODULE_DESCRIPTION(UDC_MOD_DESCRIPTION);
MODULE_AUTHOR("Thomas Dahlmann");
MODULE_LICENSE("GPL");