drivers/usb/phy/phy-keystone.c

   1 /*
   2  * phy-keystone - USB PHY, talking to dwc3 controller in Keystone.
   3  *
   4  * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * Author: WingMan Kwok <w-kwok2@ti.com>
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/usb/usb_phy_generic.h>
  22 #include <linux/io.h>
  23 #include <linux/of.h>
  24
  25 #include "phy-generic.h"
  26
  27 /* USB PHY control register offsets */
  28 #define USB_PHY_CTL_UTMI                0x0000
  29 #define USB_PHY_CTL_PIPE                0x0004
  30 #define USB_PHY_CTL_PARAM_1             0x0008
  31 #define USB_PHY_CTL_PARAM_2             0x000c
  32 #define USB_PHY_CTL_CLOCK               0x0010
  33 #define USB_PHY_CTL_PLL                 0x0014
  34
  35 #define PHY_REF_SSP_EN                  BIT(29)
  36
  37 struct keystone_usbphy {
  38         struct usb_phy_generic  usb_phy_gen;
  39         void __iomem                    *phy_ctrl;
  40 };
  41
  42 static inline u32 keystone_usbphy_readl(void __iomem *base, u32 offset)
  43 {
  44         return readl(base + offset);
  45 }
  46
  47 static inline void keystone_usbphy_writel(void __iomem *base,
  48                                           u32 offset, u32 value)
  49 {
  50         writel(value, base + offset);
  51 }
  52
  53 static int keystone_usbphy_init(struct usb_phy *phy)
  54 {
  55         struct keystone_usbphy *k_phy = dev_get_drvdata(phy->dev);
  56         u32 val;
  57
  58         val  = keystone_usbphy_readl(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK);
  59         keystone_usbphy_writel(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK,
  60                                 val | PHY_REF_SSP_EN);
  61         return 0;
  62 }
  63
  64 static void keystone_usbphy_shutdown(struct usb_phy *phy)
  65 {
  66         struct keystone_usbphy *k_phy = dev_get_drvdata(phy->dev);
  67         u32 val;
  68
  69         val  = keystone_usbphy_readl(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK);
  70         keystone_usbphy_writel(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK,
  71                                 val &= ~PHY_REF_SSP_EN);
  72 }
  73
  74 static int keystone_usbphy_probe(struct platform_device *pdev)
  75 {
  76         struct device           *dev = &pdev->dev;
  77         struct keystone_usbphy  *k_phy;
  78         struct resource         *res;
  79         int ret;
  80
  81         k_phy = devm_kzalloc(dev, sizeof(*k_phy), GFP_KERNEL);
  82         if (!k_phy)
  83                 return -ENOMEM;
  84
  85         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  86         k_phy->phy_ctrl = devm_ioremap_resource(dev, res);
  87         if (IS_ERR(k_phy->phy_ctrl))
  88                 return PTR_ERR(k_phy->phy_ctrl);
  89
  90         ret = usb_phy_gen_create_phy(dev, &k_phy->usb_phy_gen, NULL);
  91         if (ret)
  92                 return ret;
  93
  94         k_phy->usb_phy_gen.phy.init = keystone_usbphy_init;
  95         k_phy->usb_phy_gen.phy.shutdown = keystone_usbphy_shutdown;
  96
  97         platform_set_drvdata(pdev, k_phy);
  98
  99         ret = usb_add_phy_dev(&k_phy->usb_phy_gen.phy);
 100         if (ret)
 101                 return ret;
 102
 103         return 0;
 104 }
 105
 106 static int keystone_usbphy_remove(struct platform_device *pdev)
 107 {
 108         struct keystone_usbphy *k_phy = platform_get_drvdata(pdev);
 109
 110         usb_remove_phy(&k_phy->usb_phy_gen.phy);
 111
 112         return 0;
 113 }
 114
 115 static const struct of_device_id keystone_usbphy_ids[] = {
 116         { .compatible = "ti,keystone-usbphy" },
 117         { }
 118 };
 119 MODULE_DEVICE_TABLE(of, keystone_usbphy_ids);
 120
 121 static struct platform_driver keystone_usbphy_driver = {
 122         .probe          = keystone_usbphy_probe,
 123         .remove         = keystone_usbphy_remove,
 124         .driver         = {
 125                 .name   = "keystone-usbphy",
 126                 .of_match_table = keystone_usbphy_ids,
 127         },
 128 };
 129
 130 module_platform_driver(keystone_usbphy_driver);
 131
 132 MODULE_ALIAS("platform:keystone-usbphy");
 133 MODULE_AUTHOR("Texas Instruments Inc.");
 134 MODULE_DESCRIPTION("Keystone USB phy driver");
 135 MODULE_LICENSE("GPL v2");