drivers/phy/phy-bcm-kona-usb2.c

   1 /*
   2  * phy-bcm-kona-usb2.c - Broadcom Kona USB2 Phy Driver
   3  *
   4  * Copyright (C) 2013 Linaro Limited
   5  * Matt Porter <mporter@linaro.org>
   6  *
   7  * This software is licensed under the terms of the GNU General Public
   8  * License version 2, as published by the Free Software Foundation, and
   9  * may be copied, distributed, and modified under those terms.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/clk.h>
  18 #include <linux/delay.h>
  19 #include <linux/err.h>
  20 #include <linux/io.h>
  21 #include <linux/module.h>
  22 #include <linux/of.h>
  23 #include <linux/phy/phy.h>
  24 #include <linux/platform_device.h>
  25
  26 #define OTGCTL                  (0)
  27 #define OTGCTL_OTGSTAT2         BIT(31)
  28 #define OTGCTL_OTGSTAT1         BIT(30)
  29 #define OTGCTL_PRST_N_SW        BIT(11)
  30 #define OTGCTL_HRESET_N         BIT(10)
  31 #define OTGCTL_UTMI_LINE_STATE1 BIT(9)
  32 #define OTGCTL_UTMI_LINE_STATE0 BIT(8)
  33
  34 #define P1CTL                   (8)
  35 #define P1CTL_SOFT_RESET        BIT(1)
  36 #define P1CTL_NON_DRIVING       BIT(0)
  37
  38 struct bcm_kona_usb {
  39         void __iomem *regs;
  40 };
  41
  42 static void bcm_kona_usb_phy_power(struct bcm_kona_usb *phy, int on)
  43 {
  44         u32 val;
  45
  46         val = readl(phy->regs + OTGCTL);
  47         if (on) {
  48                 /* Configure and power PHY */
  49                 val &= ~(OTGCTL_OTGSTAT2 | OTGCTL_OTGSTAT1 |
  50                          OTGCTL_UTMI_LINE_STATE1 | OTGCTL_UTMI_LINE_STATE0);
  51                 val |= OTGCTL_PRST_N_SW | OTGCTL_HRESET_N;
  52         } else {
  53                 val &= ~(OTGCTL_PRST_N_SW | OTGCTL_HRESET_N);
  54         }
  55         writel(val, phy->regs + OTGCTL);
  56 }
  57
  58 static int bcm_kona_usb_phy_init(struct phy *gphy)
  59 {
  60         struct bcm_kona_usb *phy = phy_get_drvdata(gphy);
  61         u32 val;
  62
  63         /* Soft reset PHY */
  64         val = readl(phy->regs + P1CTL);
  65         val &= ~P1CTL_NON_DRIVING;
  66         val |= P1CTL_SOFT_RESET;
  67         writel(val, phy->regs + P1CTL);
  68         writel(val & ~P1CTL_SOFT_RESET, phy->regs + P1CTL);
  69         /* Reset needs to be asserted for 2ms */
  70         mdelay(2);
  71         writel(val | P1CTL_SOFT_RESET, phy->regs + P1CTL);
  72
  73         return 0;
  74 }
  75
  76 static int bcm_kona_usb_phy_power_on(struct phy *gphy)
  77 {
  78         struct bcm_kona_usb *phy = phy_get_drvdata(gphy);
  79
  80         bcm_kona_usb_phy_power(phy, 1);
  81
  82         return 0;
  83 }
  84
  85 static int bcm_kona_usb_phy_power_off(struct phy *gphy)
  86 {
  87         struct bcm_kona_usb *phy = phy_get_drvdata(gphy);
  88
  89         bcm_kona_usb_phy_power(phy, 0);
  90
  91         return 0;
  92 }
  93
  94 static const struct phy_ops ops = {
  95         .init           = bcm_kona_usb_phy_init,
  96         .power_on       = bcm_kona_usb_phy_power_on,
  97         .power_off      = bcm_kona_usb_phy_power_off,
  98         .owner          = THIS_MODULE,
  99 };
 100
 101 static int bcm_kona_usb2_probe(struct platform_device *pdev)
 102 {
 103         struct device *dev = &pdev->dev;
 104         struct bcm_kona_usb *phy;
 105         struct resource *res;
 106         struct phy *gphy;
 107         struct phy_provider *phy_provider;
 108
 109         phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
 110         if (!phy)
 111                 return -ENOMEM;
 112
 113         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 114         phy->regs = devm_ioremap_resource(&pdev->dev, res);
 115         if (IS_ERR(phy->regs))
 116                 return PTR_ERR(phy->regs);
 117
 118         platform_set_drvdata(pdev, phy);
 119
 120         gphy = devm_phy_create(dev, NULL, &ops);
 121         if (IS_ERR(gphy))
 122                 return PTR_ERR(gphy);
 123
 124         /* The Kona PHY supports an 8-bit wide UTMI interface */
 125         phy_set_bus_width(gphy, 8);
 126
 127         phy_set_drvdata(gphy, phy);
 128
 129         phy_provider = devm_of_phy_provider_register(dev,
 130                         of_phy_simple_xlate);
 131
 132         return PTR_ERR_OR_ZERO(phy_provider);
 133 }
 134
 135 static const struct of_device_id bcm_kona_usb2_dt_ids[] = {
 136         { .compatible = "brcm,kona-usb2-phy" },
 137         { /* sentinel */ }
 138 };
 139
 140 MODULE_DEVICE_TABLE(of, bcm_kona_usb2_dt_ids);
 141
 142 static struct platform_driver bcm_kona_usb2_driver = {
 143         .probe          = bcm_kona_usb2_probe,
 144         .driver         = {
 145                 .name   = "bcm-kona-usb2",
 146                 .of_match_table = bcm_kona_usb2_dt_ids,
 147         },
 148 };
 149
 150 module_platform_driver(bcm_kona_usb2_driver);
 151
 152 MODULE_ALIAS("platform:bcm-kona-usb2");
 153 MODULE_AUTHOR("Matt Porter <mporter@linaro.org>");
 154 MODULE_DESCRIPTION("BCM Kona USB 2.0 PHY driver");
 155 MODULE_LICENSE("GPL v2");