root/drivers/usb/host/ohci-spear.c
// SPDX-License-Identifier: GPL-2.0
/*
* OHCI HCD (Host Controller Driver) for USB.
*
* Copyright (C) 2010 ST Microelectronics.
* Deepak Sikri<deepak.sikri@st.com>
*
* Based on various ohci-*.c drivers
*/

#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/signal.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>

#include "ohci.h"

#define DRIVER_DESC "OHCI SPEAr driver"

struct spear_ohci {
        struct clk *clk;
};

#define to_spear_ohci(hcd)     (struct spear_ohci *)(hcd_to_ohci(hcd)->priv)

static struct hc_driver __read_mostly ohci_spear_hc_driver;

static int spear_ohci_hcd_drv_probe(struct platform_device *pdev)
{
        const struct hc_driver *driver = &ohci_spear_hc_driver;
        struct usb_hcd *hcd = NULL;
        struct clk *usbh_clk;
        struct spear_ohci *sohci_p;
        struct resource *res;
        int retval, irq;

        irq = platform_get_irq(pdev, 0);
        if (irq < 0) {
                retval = irq;
                goto fail;
        }

        /*
         * Right now device-tree probed devices don't get dma_mask set.
         * Since shared usb code relies on it, set it here for now.
         * Once we have dma capability bindings this can go away.
         */
        retval = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
        if (retval)
                goto fail;

        usbh_clk = devm_clk_get(&pdev->dev, NULL);
        if (IS_ERR(usbh_clk)) {
                dev_err(&pdev->dev, "Error getting interface clock\n");
                retval = PTR_ERR(usbh_clk);
                goto fail;
        }

        hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
        if (!hcd) {
                retval = -ENOMEM;
                goto fail;
        }

        hcd->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
        if (IS_ERR(hcd->regs)) {
                retval = PTR_ERR(hcd->regs);
                goto err_put_hcd;
        }

        hcd->rsrc_start = res->start;
        hcd->rsrc_len = resource_size(res);

        sohci_p = to_spear_ohci(hcd);
        sohci_p->clk = usbh_clk;

        clk_prepare_enable(sohci_p->clk);

        retval = usb_add_hcd(hcd, irq, 0);
        if (retval == 0) {
                device_wakeup_enable(hcd->self.controller);
                return retval;
        }

        clk_disable_unprepare(sohci_p->clk);
err_put_hcd:
        usb_put_hcd(hcd);
fail:
        dev_err(&pdev->dev, "init fail, %d\n", retval);

        return retval;
}

static void spear_ohci_hcd_drv_remove(struct platform_device *pdev)
{
        struct usb_hcd *hcd = platform_get_drvdata(pdev);
        struct spear_ohci *sohci_p = to_spear_ohci(hcd);

        usb_remove_hcd(hcd);
        clk_disable_unprepare(sohci_p->clk);

        usb_put_hcd(hcd);
}

#if defined(CONFIG_PM)
static int spear_ohci_hcd_drv_suspend(struct platform_device *pdev,
                pm_message_t message)
{
        struct usb_hcd *hcd = platform_get_drvdata(pdev);
        struct ohci_hcd *ohci = hcd_to_ohci(hcd);
        struct spear_ohci *sohci_p = to_spear_ohci(hcd);
        bool do_wakeup = device_may_wakeup(&pdev->dev);
        int ret;

        if (time_before(jiffies, ohci->next_statechange))
                msleep(5);
        ohci->next_statechange = jiffies;

        ret = ohci_suspend(hcd, do_wakeup);
        if (ret)
                return ret;

        clk_disable_unprepare(sohci_p->clk);

        return ret;
}

static int spear_ohci_hcd_drv_resume(struct platform_device *dev)
{
        struct usb_hcd *hcd = platform_get_drvdata(dev);
        struct ohci_hcd *ohci = hcd_to_ohci(hcd);
        struct spear_ohci *sohci_p = to_spear_ohci(hcd);

        if (time_before(jiffies, ohci->next_statechange))
                msleep(5);
        ohci->next_statechange = jiffies;

        clk_prepare_enable(sohci_p->clk);
        ohci_resume(hcd, false);
        return 0;
}
#endif

static const struct of_device_id spear_ohci_id_table[] = {
        { .compatible = "st,spear600-ohci", },
        { },
};
MODULE_DEVICE_TABLE(of, spear_ohci_id_table);

/* Driver definition to register with the platform bus */
static struct platform_driver spear_ohci_hcd_driver = {
        .probe =        spear_ohci_hcd_drv_probe,
        .remove =       spear_ohci_hcd_drv_remove,
#ifdef CONFIG_PM
        .suspend =      spear_ohci_hcd_drv_suspend,
        .resume =       spear_ohci_hcd_drv_resume,
#endif
        .driver = {
                .name = "spear-ohci",
                .of_match_table = spear_ohci_id_table,
        },
};

static const struct ohci_driver_overrides spear_overrides __initconst = {
        .extra_priv_size = sizeof(struct spear_ohci),
};
static int __init ohci_spear_init(void)
{
        if (usb_disabled())
                return -ENODEV;

        ohci_init_driver(&ohci_spear_hc_driver, &spear_overrides);
        return platform_driver_register(&spear_ohci_hcd_driver);
}
module_init(ohci_spear_init);

static void __exit ohci_spear_cleanup(void)
{
        platform_driver_unregister(&spear_ohci_hcd_driver);
}
module_exit(ohci_spear_cleanup);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Deepak Sikri");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:spear-ohci");