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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * phy-bcm-kona-usb2.c - Broadcom Kona USB2 Phy Driver
   4  *
   5  * Copyright (C) 2013 Linaro Limited
   6  * Matt Porter <mporter@linaro.org>
   7  */
   8
   9 #include <linux/clk.h>
  10 #include <linux/delay.h>
  11 #include <linux/err.h>
  12 #include <linux/io.h>
  13 #include <linux/module.h>
  14 #include <linux/of.h>
  15 #include <linux/phy/phy.h>
  16 #include <linux/platform_device.h>
  17
  18 #define OTGCTL                  (0)
  19 #define OTGCTL_OTGSTAT2         BIT(31)
  20 #define OTGCTL_OTGSTAT1         BIT(30)
  21 #define OTGCTL_PRST_N_SW        BIT(11)
  22 #define OTGCTL_HRESET_N         BIT(10)
  23 #define OTGCTL_UTMI_LINE_STATE1 BIT(9)
  24 #define OTGCTL_UTMI_LINE_STATE0 BIT(8)
  25
  26 #define P1CTL                   (8)
  27 #define P1CTL_SOFT_RESET        BIT(1)
  28 #define P1CTL_NON_DRIVING       BIT(0)
  29
  30 struct bcm_kona_usb {
  31         void __iomem *regs;
  32 };
  33
  34 static void bcm_kona_usb_phy_power(struct bcm_kona_usb *phy, int on)
  35 {
  36         u32 val;
  37
  38         val = readl(phy->regs + OTGCTL);
  39         if (on) {
  40                 /* Configure and power PHY */
  41                 val &= ~(OTGCTL_OTGSTAT2 | OTGCTL_OTGSTAT1 |
  42                          OTGCTL_UTMI_LINE_STATE1 | OTGCTL_UTMI_LINE_STATE0);
  43                 val |= OTGCTL_PRST_N_SW | OTGCTL_HRESET_N;
  44         } else {
  45                 val &= ~(OTGCTL_PRST_N_SW | OTGCTL_HRESET_N);
  46         }
  47         writel(val, phy->regs + OTGCTL);
  48 }
  49
  50 static int bcm_kona_usb_phy_init(struct phy *gphy)
  51 {
  52         struct bcm_kona_usb *phy = phy_get_drvdata(gphy);
  53         u32 val;
  54
  55         /* Soft reset PHY */
  56         val = readl(phy->regs + P1CTL);
  57         val &= ~P1CTL_NON_DRIVING;
  58         val |= P1CTL_SOFT_RESET;
  59         writel(val, phy->regs + P1CTL);
  60         writel(val & ~P1CTL_SOFT_RESET, phy->regs + P1CTL);
  61         /* Reset needs to be asserted for 2ms */
  62         mdelay(2);
  63         writel(val | P1CTL_SOFT_RESET, phy->regs + P1CTL);
  64
  65         return 0;
  66 }
  67
  68 static int bcm_kona_usb_phy_power_on(struct phy *gphy)
  69 {
  70         struct bcm_kona_usb *phy = phy_get_drvdata(gphy);
  71
  72         bcm_kona_usb_phy_power(phy, 1);
  73
  74         return 0;
  75 }
  76
  77 static int bcm_kona_usb_phy_power_off(struct phy *gphy)
  78 {
  79         struct bcm_kona_usb *phy = phy_get_drvdata(gphy);
  80
  81         bcm_kona_usb_phy_power(phy, 0);
  82
  83         return 0;
  84 }
  85
  86 static const struct phy_ops ops = {
  87         .init           = bcm_kona_usb_phy_init,
  88         .power_on       = bcm_kona_usb_phy_power_on,
  89         .power_off      = bcm_kona_usb_phy_power_off,
  90         .owner          = THIS_MODULE,
  91 };
  92
  93 static int bcm_kona_usb2_probe(struct platform_device *pdev)
  94 {
  95         struct device *dev = &pdev->dev;
  96         struct bcm_kona_usb *phy;
  97         struct phy *gphy;
  98         struct phy_provider *phy_provider;
  99
 100         phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
 101         if (!phy)
 102                 return -ENOMEM;
 103
 104         phy->regs = devm_platform_ioremap_resource(pdev, 0);
 105         if (IS_ERR(phy->regs))
 106                 return PTR_ERR(phy->regs);
 107
 108         platform_set_drvdata(pdev, phy);
 109
 110         gphy = devm_phy_create(dev, NULL, &ops);
 111         if (IS_ERR(gphy))
 112                 return PTR_ERR(gphy);
 113
 114         /* The Kona PHY supports an 8-bit wide UTMI interface */
 115         phy_set_bus_width(gphy, 8);
 116
 117         phy_set_drvdata(gphy, phy);
 118
 119         phy_provider = devm_of_phy_provider_register(dev,
 120                         of_phy_simple_xlate);
 121
 122         return PTR_ERR_OR_ZERO(phy_provider);
 123 }
 124
 125 static const struct of_device_id bcm_kona_usb2_dt_ids[] = {
 126         { .compatible = "brcm,kona-usb2-phy" },
 127         { /* sentinel */ }
 128 };
 129
 130 MODULE_DEVICE_TABLE(of, bcm_kona_usb2_dt_ids);
 131
 132 static struct platform_driver bcm_kona_usb2_driver = {
 133         .probe          = bcm_kona_usb2_probe,
 134         .driver         = {
 135                 .name   = "bcm-kona-usb2",
 136                 .of_match_table = bcm_kona_usb2_dt_ids,
 137         },
 138 };
 139
 140 module_platform_driver(bcm_kona_usb2_driver);
 141
 142 MODULE_ALIAS("platform:bcm-kona-usb2");
 143 MODULE_AUTHOR("Matt Porter <mporter@linaro.org>");
 144 MODULE_DESCRIPTION("BCM Kona USB 2.0 PHY driver");
 145 MODULE_LICENSE("GPL v2");