drivers/usb/phy/phy-keystone.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * phy-keystone - USB PHY, talking to dwc3 controller in Keystone.
   4  *
   5  * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
   6  *
   7  * Author: WingMan Kwok <w-kwok2@ti.com>
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/usb/usb_phy_generic.h>
  13 #include <linux/io.h>
  14 #include <linux/of.h>
  15
  16 #include "phy-generic.h"
  17
  18 /* USB PHY control register offsets */
  19 #define USB_PHY_CTL_UTMI                0x0000
  20 #define USB_PHY_CTL_PIPE                0x0004
  21 #define USB_PHY_CTL_PARAM_1             0x0008
  22 #define USB_PHY_CTL_PARAM_2             0x000c
  23 #define USB_PHY_CTL_CLOCK               0x0010
  24 #define USB_PHY_CTL_PLL                 0x0014
  25
  26 #define PHY_REF_SSP_EN                  BIT(29)
  27
  28 struct keystone_usbphy {
  29         struct usb_phy_generic  usb_phy_gen;
  30         void __iomem                    *phy_ctrl;
  31 };
  32
  33 static inline u32 keystone_usbphy_readl(void __iomem *base, u32 offset)
  34 {
  35         return readl(base + offset);
  36 }
  37
  38 static inline void keystone_usbphy_writel(void __iomem *base,
  39                                           u32 offset, u32 value)
  40 {
  41         writel(value, base + offset);
  42 }
  43
  44 static int keystone_usbphy_init(struct usb_phy *phy)
  45 {
  46         struct keystone_usbphy *k_phy = dev_get_drvdata(phy->dev);
  47         u32 val;
  48
  49         val  = keystone_usbphy_readl(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK);
  50         keystone_usbphy_writel(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK,
  51                                 val | PHY_REF_SSP_EN);
  52         return 0;
  53 }
  54
  55 static void keystone_usbphy_shutdown(struct usb_phy *phy)
  56 {
  57         struct keystone_usbphy *k_phy = dev_get_drvdata(phy->dev);
  58         u32 val;
  59
  60         val  = keystone_usbphy_readl(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK);
  61         keystone_usbphy_writel(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK,
  62                                 val &= ~PHY_REF_SSP_EN);
  63 }
  64
  65 static int keystone_usbphy_probe(struct platform_device *pdev)
  66 {
  67         struct device           *dev = &pdev->dev;
  68         struct keystone_usbphy  *k_phy;
  69         struct resource         *res;
  70         int ret;
  71
  72         k_phy = devm_kzalloc(dev, sizeof(*k_phy), GFP_KERNEL);
  73         if (!k_phy)
  74                 return -ENOMEM;
  75
  76         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  77         k_phy->phy_ctrl = devm_ioremap_resource(dev, res);
  78         if (IS_ERR(k_phy->phy_ctrl))
  79                 return PTR_ERR(k_phy->phy_ctrl);
  80
  81         ret = usb_phy_gen_create_phy(dev, &k_phy->usb_phy_gen, NULL);
  82         if (ret)
  83                 return ret;
  84
  85         k_phy->usb_phy_gen.phy.init = keystone_usbphy_init;
  86         k_phy->usb_phy_gen.phy.shutdown = keystone_usbphy_shutdown;
  87
  88         platform_set_drvdata(pdev, k_phy);
  89
  90         return usb_add_phy_dev(&k_phy->usb_phy_gen.phy);
  91 }
  92
  93 static int keystone_usbphy_remove(struct platform_device *pdev)
  94 {
  95         struct keystone_usbphy *k_phy = platform_get_drvdata(pdev);
  96
  97         usb_remove_phy(&k_phy->usb_phy_gen.phy);
  98
  99         return 0;
 100 }
 101
 102 static const struct of_device_id keystone_usbphy_ids[] = {
 103         { .compatible = "ti,keystone-usbphy" },
 104         { }
 105 };
 106 MODULE_DEVICE_TABLE(of, keystone_usbphy_ids);
 107
 108 static struct platform_driver keystone_usbphy_driver = {
 109         .probe          = keystone_usbphy_probe,
 110         .remove         = keystone_usbphy_remove,
 111         .driver         = {
 112                 .name   = "keystone-usbphy",
 113                 .of_match_table = keystone_usbphy_ids,
 114         },
 115 };
 116
 117 module_platform_driver(keystone_usbphy_driver);
 118
 119 MODULE_ALIAS("platform:keystone-usbphy");
 120 MODULE_AUTHOR("Texas Instruments Inc.");
 121 MODULE_DESCRIPTION("Keystone USB phy driver");
 122 MODULE_LICENSE("GPL v2");