drivers/usb/phy/phy-rcar-gen2-usb.c

   1 /*
   2  * Renesas R-Car Gen2 USB phy driver
   3  *
   4  * Copyright (C) 2013 Renesas Solutions Corp.
   5  * Copyright (C) 2013 Cogent Embedded, Inc.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/clk.h>
  13 #include <linux/delay.h>
  14 #include <linux/io.h>
  15 #include <linux/module.h>
  16 #include <linux/platform_data/usb-rcar-gen2-phy.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/usb/otg.h>
  20
  21 struct rcar_gen2_usb_phy_priv {
  22         struct usb_phy phy;
  23         void __iomem *base;
  24         struct clk *clk;
  25         spinlock_t lock;
  26         int usecount;
  27         u32 ugctrl2;
  28 };
  29
  30 #define usb_phy_to_priv(p) container_of(p, struct rcar_gen2_usb_phy_priv, phy)
  31
  32 /* Low Power Status register */
  33 #define USBHS_LPSTS_REG                 0x02
  34 #define USBHS_LPSTS_SUSPM               (1 << 14)
  35
  36 /* USB General control register */
  37 #define USBHS_UGCTRL_REG                0x80
  38 #define USBHS_UGCTRL_CONNECT            (1 << 2)
  39 #define USBHS_UGCTRL_PLLRESET           (1 << 0)
  40
  41 /* USB General control register 2 */
  42 #define USBHS_UGCTRL2_REG               0x84
  43 #define USBHS_UGCTRL2_USB0_PCI          (1 << 4)
  44 #define USBHS_UGCTRL2_USB0_HS           (3 << 4)
  45 #define USBHS_UGCTRL2_USB2_PCI          (0 << 31)
  46 #define USBHS_UGCTRL2_USB2_SS           (1 << 31)
  47
  48 /* USB General status register */
  49 #define USBHS_UGSTS_REG                 0x88
  50 #define USBHS_UGSTS_LOCK                (3 << 8)
  51
  52 /* Enable USBHS internal phy */
  53 static int __rcar_gen2_usbhs_phy_enable(void __iomem *base)
  54 {
  55         u32 val;
  56         int i;
  57
  58         /* USBHS PHY power on */
  59         val = ioread32(base + USBHS_UGCTRL_REG);
  60         val &= ~USBHS_UGCTRL_PLLRESET;
  61         iowrite32(val, base + USBHS_UGCTRL_REG);
  62
  63         val = ioread16(base + USBHS_LPSTS_REG);
  64         val |= USBHS_LPSTS_SUSPM;
  65         iowrite16(val, base + USBHS_LPSTS_REG);
  66
  67         for (i = 0; i < 20; i++) {
  68                 val = ioread32(base + USBHS_UGSTS_REG);
  69                 if ((val & USBHS_UGSTS_LOCK) == USBHS_UGSTS_LOCK) {
  70                         val = ioread32(base + USBHS_UGCTRL_REG);
  71                         val |= USBHS_UGCTRL_CONNECT;
  72                         iowrite32(val, base + USBHS_UGCTRL_REG);
  73                         return 0;
  74                 }
  75                 udelay(1);
  76         }
  77
  78         /* Timed out waiting for the PLL lock */
  79         return -ETIMEDOUT;
  80 }
  81
  82 /* Disable USBHS internal phy */
  83 static int __rcar_gen2_usbhs_phy_disable(void __iomem *base)
  84 {
  85         u32 val;
  86
  87         /* USBHS PHY power off */
  88         val = ioread32(base + USBHS_UGCTRL_REG);
  89         val &= ~USBHS_UGCTRL_CONNECT;
  90         iowrite32(val, base + USBHS_UGCTRL_REG);
  91
  92         val = ioread16(base + USBHS_LPSTS_REG);
  93         val &= ~USBHS_LPSTS_SUSPM;
  94         iowrite16(val, base + USBHS_LPSTS_REG);
  95
  96         val = ioread32(base + USBHS_UGCTRL_REG);
  97         val |= USBHS_UGCTRL_PLLRESET;
  98         iowrite32(val, base + USBHS_UGCTRL_REG);
  99         return 0;
 100 }
 101
 102 /* Setup USB channels */
 103 static void __rcar_gen2_usb_phy_init(struct rcar_gen2_usb_phy_priv *priv)
 104 {
 105         u32 val;
 106
 107         clk_prepare_enable(priv->clk);
 108
 109         /* Set USB channels in the USBHS UGCTRL2 register */
 110         val = ioread32(priv->base);
 111         val &= ~(USBHS_UGCTRL2_USB0_HS | USBHS_UGCTRL2_USB2_SS);
 112         val |= priv->ugctrl2;
 113         iowrite32(val, priv->base);
 114 }
 115
 116 /* Shutdown USB channels */
 117 static void __rcar_gen2_usb_phy_shutdown(struct rcar_gen2_usb_phy_priv *priv)
 118 {
 119         __rcar_gen2_usbhs_phy_disable(priv->base);
 120         clk_disable_unprepare(priv->clk);
 121 }
 122
 123 static int rcar_gen2_usb_phy_set_suspend(struct usb_phy *phy, int suspend)
 124 {
 125         struct rcar_gen2_usb_phy_priv *priv = usb_phy_to_priv(phy);
 126         unsigned long flags;
 127         int retval;
 128
 129         spin_lock_irqsave(&priv->lock, flags);
 130         retval = suspend ? __rcar_gen2_usbhs_phy_disable(priv->base) :
 131                            __rcar_gen2_usbhs_phy_enable(priv->base);
 132         spin_unlock_irqrestore(&priv->lock, flags);
 133         return retval;
 134 }
 135
 136 static int rcar_gen2_usb_phy_init(struct usb_phy *phy)
 137 {
 138         struct rcar_gen2_usb_phy_priv *priv = usb_phy_to_priv(phy);
 139         unsigned long flags;
 140
 141         spin_lock_irqsave(&priv->lock, flags);
 142         /*
 143          * Enable the clock and setup USB channels
 144          * if it's the first user
 145          */
 146         if (!priv->usecount++)
 147                 __rcar_gen2_usb_phy_init(priv);
 148         spin_unlock_irqrestore(&priv->lock, flags);
 149         return 0;
 150 }
 151
 152 static void rcar_gen2_usb_phy_shutdown(struct usb_phy *phy)
 153 {
 154         struct rcar_gen2_usb_phy_priv *priv = usb_phy_to_priv(phy);
 155         unsigned long flags;
 156
 157         spin_lock_irqsave(&priv->lock, flags);
 158         if (!priv->usecount) {
 159                 dev_warn(phy->dev, "Trying to disable phy with 0 usecount\n");
 160                 goto out;
 161         }
 162
 163         /* Disable everything if it's the last user */
 164         if (!--priv->usecount)
 165                 __rcar_gen2_usb_phy_shutdown(priv);
 166 out:
 167         spin_unlock_irqrestore(&priv->lock, flags);
 168 }
 169
 170 static int rcar_gen2_usb_phy_probe(struct platform_device *pdev)
 171 {
 172         struct device *dev = &pdev->dev;
 173         struct rcar_gen2_phy_platform_data *pdata;
 174         struct rcar_gen2_usb_phy_priv *priv;
 175         struct resource *res;
 176         void __iomem *base;
 177         struct clk *clk;
 178         int retval;
 179
 180         pdata = dev_get_platdata(&pdev->dev);
 181         if (!pdata) {
 182                 dev_err(dev, "No platform data\n");
 183                 return -EINVAL;
 184         }
 185
 186         clk = devm_clk_get(&pdev->dev, "usbhs");
 187         if (IS_ERR(clk)) {
 188                 dev_err(&pdev->dev, "Can't get the clock\n");
 189                 return PTR_ERR(clk);
 190         }
 191
 192         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 193         base = devm_ioremap_resource(dev, res);
 194         if (IS_ERR(base))
 195                 return PTR_ERR(base);
 196
 197         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 198         if (!priv) {
 199                 dev_err(dev, "Memory allocation failed\n");
 200                 return -ENOMEM;
 201         }
 202
 203         spin_lock_init(&priv->lock);
 204         priv->clk = clk;
 205         priv->base = base;
 206         priv->ugctrl2 = pdata->chan0_pci ?
 207                         USBHS_UGCTRL2_USB0_PCI : USBHS_UGCTRL2_USB0_HS;
 208         priv->ugctrl2 |= pdata->chan2_pci ?
 209                         USBHS_UGCTRL2_USB2_PCI : USBHS_UGCTRL2_USB2_SS;
 210         priv->phy.dev = dev;
 211         priv->phy.label = dev_name(dev);
 212         priv->phy.init = rcar_gen2_usb_phy_init;
 213         priv->phy.shutdown = rcar_gen2_usb_phy_shutdown;
 214         priv->phy.set_suspend = rcar_gen2_usb_phy_set_suspend;
 215
 216         retval = usb_add_phy(&priv->phy, USB_PHY_TYPE_USB2);
 217         if (retval < 0) {
 218                 dev_err(dev, "Failed to add USB phy\n");
 219                 return retval;
 220         }
 221
 222         platform_set_drvdata(pdev, priv);
 223
 224         return retval;
 225 }
 226
 227 static int rcar_gen2_usb_phy_remove(struct platform_device *pdev)
 228 {
 229         struct rcar_gen2_usb_phy_priv *priv = platform_get_drvdata(pdev);
 230
 231         usb_remove_phy(&priv->phy);
 232
 233         return 0;
 234 }
 235
 236 static struct platform_driver rcar_gen2_usb_phy_driver = {
 237         .driver = {
 238                 .name = "usb_phy_rcar_gen2",
 239         },
 240         .probe = rcar_gen2_usb_phy_probe,
 241         .remove = rcar_gen2_usb_phy_remove,
 242 };
 243
 244 module_platform_driver(rcar_gen2_usb_phy_driver);
 245
 246 MODULE_LICENSE("GPL v2");
 247 MODULE_DESCRIPTION("Renesas R-Car Gen2 USB phy");
 248 MODULE_AUTHOR("Valentine Barshak <valentine.barshak@cogentembedded.com>");