root/drivers/usb/host/ohci-st.c
// SPDX-License-Identifier: GPL-2.0
/*
 * ST OHCI driver
 *
 * Copyright (C) 2014 STMicroelectronics – All Rights Reserved
 *
 * Author: Peter Griffin <peter.griffin@linaro.org>
 *
 * Derived from ohci-platform.c
 */

#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/hrtimer.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/usb/ohci_pdriver.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>

#include "ohci.h"

#define USB_MAX_CLKS 3

struct st_ohci_platform_priv {
        struct clk *clks[USB_MAX_CLKS];
        struct clk *clk48;
        struct reset_control *rst;
        struct reset_control *pwr;
        struct phy *phy;
};

#define DRIVER_DESC "OHCI STMicroelectronics driver"

#define hcd_to_ohci_priv(h) \
        ((struct st_ohci_platform_priv *)hcd_to_ohci(h)->priv)

static int st_ohci_platform_power_on(struct platform_device *dev)
{
        struct usb_hcd *hcd = platform_get_drvdata(dev);
        struct st_ohci_platform_priv *priv = hcd_to_ohci_priv(hcd);
        int clk, ret;

        ret = reset_control_deassert(priv->pwr);
        if (ret)
                return ret;

        ret = reset_control_deassert(priv->rst);
        if (ret)
                goto err_assert_power;

        /* some SoCs don't have a dedicated 48Mhz clock, but those that do
           need the rate to be explicitly set */
        if (priv->clk48) {
                ret = clk_set_rate(priv->clk48, 48000000);
                if (ret)
                        goto err_assert_reset;
        }

        for (clk = 0; clk < USB_MAX_CLKS && priv->clks[clk]; clk++) {
                ret = clk_prepare_enable(priv->clks[clk]);
                if (ret)
                        goto err_disable_clks;
        }

        ret = phy_init(priv->phy);
        if (ret)
                goto err_disable_clks;

        ret = phy_power_on(priv->phy);
        if (ret)
                goto err_exit_phy;

        return 0;

err_exit_phy:
        phy_exit(priv->phy);
err_disable_clks:
        while (--clk >= 0)
                clk_disable_unprepare(priv->clks[clk]);
err_assert_reset:
        reset_control_assert(priv->rst);
err_assert_power:
        reset_control_assert(priv->pwr);

        return ret;
}

static void st_ohci_platform_power_off(struct platform_device *dev)
{
        struct usb_hcd *hcd = platform_get_drvdata(dev);
        struct st_ohci_platform_priv *priv = hcd_to_ohci_priv(hcd);

        int clk;

        reset_control_assert(priv->pwr);

        reset_control_assert(priv->rst);

        phy_power_off(priv->phy);

        phy_exit(priv->phy);

        for (clk = USB_MAX_CLKS - 1; clk >= 0; clk--)
                if (priv->clks[clk])
                        clk_disable_unprepare(priv->clks[clk]);
}

static struct hc_driver __read_mostly ohci_platform_hc_driver;

static const struct ohci_driver_overrides platform_overrides __initconst = {
        .product_desc =         "ST OHCI controller",
        .extra_priv_size =      sizeof(struct st_ohci_platform_priv),
};

static struct usb_ohci_pdata ohci_platform_defaults = {
        .power_on =             st_ohci_platform_power_on,
        .power_suspend =        st_ohci_platform_power_off,
        .power_off =            st_ohci_platform_power_off,
};

static int st_ohci_platform_probe(struct platform_device *dev)
{
        struct usb_hcd *hcd;
        struct resource *res_mem;
        struct usb_ohci_pdata *pdata = &ohci_platform_defaults;
        struct st_ohci_platform_priv *priv;
        int err, irq, clk = 0;

        if (usb_disabled())
                return -ENODEV;

        irq = platform_get_irq(dev, 0);
        if (irq < 0)
                return irq;

        hcd = usb_create_hcd(&ohci_platform_hc_driver, &dev->dev,
                        dev_name(&dev->dev));
        if (!hcd)
                return -ENOMEM;

        platform_set_drvdata(dev, hcd);
        dev->dev.platform_data = pdata;
        priv = hcd_to_ohci_priv(hcd);

        priv->phy = devm_phy_get(&dev->dev, "usb");
        if (IS_ERR(priv->phy)) {
                err = PTR_ERR(priv->phy);
                goto err_put_hcd;
        }

        for (clk = 0; clk < USB_MAX_CLKS; clk++) {
                priv->clks[clk] = of_clk_get(dev->dev.of_node, clk);
                if (IS_ERR(priv->clks[clk])) {
                        err = PTR_ERR(priv->clks[clk]);
                        if (err == -EPROBE_DEFER)
                                goto err_put_clks;
                        priv->clks[clk] = NULL;
                        break;
                }
        }

        /* some SoCs don't have a dedicated 48Mhz clock, but those that
           do need the rate to be explicitly set */
        priv->clk48 = devm_clk_get(&dev->dev, "clk48");
        if (IS_ERR(priv->clk48)) {
                dev_info(&dev->dev, "48MHz clk not found\n");
                priv->clk48 = NULL;
        }

        priv->pwr =
                devm_reset_control_get_optional_shared(&dev->dev, "power");
        if (IS_ERR(priv->pwr)) {
                err = PTR_ERR(priv->pwr);
                goto err_put_clks;
        }

        priv->rst =
                devm_reset_control_get_optional_shared(&dev->dev, "softreset");
        if (IS_ERR(priv->rst)) {
                err = PTR_ERR(priv->rst);
                goto err_put_clks;
        }

        if (pdata->power_on) {
                err = pdata->power_on(dev);
                if (err < 0)
                        goto err_power;
        }

        hcd->regs = devm_platform_get_and_ioremap_resource(dev, 0, &res_mem);
        if (IS_ERR(hcd->regs)) {
                err = PTR_ERR(hcd->regs);
                goto err_power;
        }
        hcd->rsrc_start = res_mem->start;
        hcd->rsrc_len = resource_size(res_mem);

        err = usb_add_hcd(hcd, irq, IRQF_SHARED);
        if (err)
                goto err_power;

        device_wakeup_enable(hcd->self.controller);

        platform_set_drvdata(dev, hcd);

        return err;

err_power:
        if (pdata->power_off)
                pdata->power_off(dev);

err_put_clks:
        while (--clk >= 0)
                clk_put(priv->clks[clk]);
err_put_hcd:
        if (pdata == &ohci_platform_defaults)
                dev->dev.platform_data = NULL;

        usb_put_hcd(hcd);

        return err;
}

static void st_ohci_platform_remove(struct platform_device *dev)
{
        struct usb_hcd *hcd = platform_get_drvdata(dev);
        struct usb_ohci_pdata *pdata = dev_get_platdata(&dev->dev);
        struct st_ohci_platform_priv *priv = hcd_to_ohci_priv(hcd);
        int clk;

        usb_remove_hcd(hcd);

        if (pdata->power_off)
                pdata->power_off(dev);


        for (clk = 0; clk < USB_MAX_CLKS && priv->clks[clk]; clk++)
                clk_put(priv->clks[clk]);

        usb_put_hcd(hcd);

        if (pdata == &ohci_platform_defaults)
                dev->dev.platform_data = NULL;
}

#ifdef CONFIG_PM_SLEEP

static int st_ohci_suspend(struct device *dev)
{
        struct usb_hcd *hcd = dev_get_drvdata(dev);
        struct usb_ohci_pdata *pdata = dev->platform_data;
        struct platform_device *pdev = to_platform_device(dev);
        bool do_wakeup = device_may_wakeup(dev);
        int ret;

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

        if (pdata->power_suspend)
                pdata->power_suspend(pdev);

        return ret;
}

static int st_ohci_resume(struct device *dev)
{
        struct usb_hcd *hcd = dev_get_drvdata(dev);
        struct usb_ohci_pdata *pdata = dev_get_platdata(dev);
        struct platform_device *pdev = to_platform_device(dev);
        int err;

        if (pdata->power_on) {
                err = pdata->power_on(pdev);
                if (err < 0)
                        return err;
        }

        ohci_resume(hcd, false);
        return 0;
}

static SIMPLE_DEV_PM_OPS(st_ohci_pm_ops, st_ohci_suspend, st_ohci_resume);

#endif /* CONFIG_PM_SLEEP */

static const struct of_device_id st_ohci_platform_ids[] = {
        { .compatible = "st,st-ohci-300x", },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, st_ohci_platform_ids);

static struct platform_driver ohci_platform_driver = {
        .probe          = st_ohci_platform_probe,
        .remove         = st_ohci_platform_remove,
        .shutdown       = usb_hcd_platform_shutdown,
        .driver         = {
                .name   = "st-ohci",
#ifdef CONFIG_PM_SLEEP
                .pm     = &st_ohci_pm_ops,
#endif
                .of_match_table = st_ohci_platform_ids,
        }
};

static int __init ohci_platform_init(void)
{
        if (usb_disabled())
                return -ENODEV;

        ohci_init_driver(&ohci_platform_hc_driver, &platform_overrides);
        return platform_driver_register(&ohci_platform_driver);
}
module_init(ohci_platform_init);

static void __exit ohci_platform_cleanup(void)
{
        platform_driver_unregister(&ohci_platform_driver);
}
module_exit(ohci_platform_cleanup);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Peter Griffin <peter.griffin@linaro.org>");
MODULE_LICENSE("GPL");