Quelle  phy-keystone.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0+
/*
 * phy-keystone - USB PHY, talking to dwc3 controller in Keystone.
 *
 * Copyright (C) 2013 Texas Instruments Incorporated - https://www.ti.com
 *
 * Author: WingMan Kwok <w-kwok2@ti.com>
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/usb/usb_phy_generic.h>
#include <linux/io.h>
#include <linux/of.h>

#include "phy-generic.h"

/* USB PHY control register offsets */
#define USB_PHY_CTL_UTMI  0x0000
#define USB_PHY_CTL_PIPE  0x0004
#define USB_PHY_CTL_PARAM_1  0x0008
#define USB_PHY_CTL_PARAM_2  0x000c
#define USB_PHY_CTL_CLOCK  0x0010
#define USB_PHY_CTL_PLL   0x0014

#define PHY_REF_SSP_EN   BIT(29)

struct keystone_usbphy {
 struct usb_phy_generic usb_phy_gen;
 void __iomem   *phy_ctrl;
};

static inline u32 keystone_usbphy_readl(void __iomem *base, u32 offset)
{
 return readl(base + offset);
}

static inline void keystone_usbphy_writel(void __iomem *base,
       u32 offset, u32 value)
{
 writel(value, base + offset);
}

static int keystone_usbphy_init(struct usb_phy *phy)
{
 struct keystone_usbphy *k_phy = dev_get_drvdata(phy->dev);
 u32 val;

 val  = keystone_usbphy_readl(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK);
 keystone_usbphy_writel(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK,
    val | PHY_REF_SSP_EN);
 return 0;
}

static void keystone_usbphy_shutdown(struct usb_phy *phy)
{
 struct keystone_usbphy *k_phy = dev_get_drvdata(phy->dev);
 u32 val;

 val  = keystone_usbphy_readl(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK);
 keystone_usbphy_writel(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK,
    val & ~PHY_REF_SSP_EN);
}

static int keystone_usbphy_probe(struct platform_device *pdev)
{
 struct device  *dev = &pdev->dev;
 struct keystone_usbphy *k_phy;
 int ret;

 k_phy = devm_kzalloc(dev, sizeof(*k_phy), GFP_KERNEL);
 if (!k_phy)
  return -ENOMEM;

 k_phy->phy_ctrl = devm_platform_ioremap_resource(pdev, 0);
 if (IS_ERR(k_phy->phy_ctrl))
  return PTR_ERR(k_phy->phy_ctrl);

 ret = usb_phy_gen_create_phy(dev, &k_phy->usb_phy_gen);
 if (ret)
  return ret;

 k_phy->usb_phy_gen.phy.init = keystone_usbphy_init;
 k_phy->usb_phy_gen.phy.shutdown = keystone_usbphy_shutdown;

 platform_set_drvdata(pdev, k_phy);

 return usb_add_phy_dev(&k_phy->usb_phy_gen.phy);
}

static void keystone_usbphy_remove(struct platform_device *pdev)
{
 struct keystone_usbphy *k_phy = platform_get_drvdata(pdev);

 usb_remove_phy(&k_phy->usb_phy_gen.phy);
}

static const struct of_device_id keystone_usbphy_ids[] = {
 { .compatible = "ti,keystone-usbphy" },
 { }
};
MODULE_DEVICE_TABLE(of, keystone_usbphy_ids);

static struct platform_driver keystone_usbphy_driver = {
 .probe          = keystone_usbphy_probe,
 .remove         = keystone_usbphy_remove,
 .driver         = {
  .name   = "keystone-usbphy",
  .of_match_table = keystone_usbphy_ids,
 },
};

module_platform_driver(keystone_usbphy_driver);

MODULE_ALIAS("platform:keystone-usbphy");
MODULE_AUTHOR("Texas Instruments Inc.");
MODULE_DESCRIPTION("Keystone USB phy driver");
MODULE_LICENSE("GPL v2");