drivers/phy/marvell/phy-armada375-usb2.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * USB cluster support for Armada 375 platform.
   4  *
   5  * Copyright (C) 2014 Marvell
   6  *
   7  * Gregory CLEMENT <gregory.clement@free-electrons.com>
   8  *
   9  * Armada 375 comes with an USB2 host and device controller and an
  10  * USB3 controller. The USB cluster control register allows to manage
  11  * common features of both USB controllers.
  12  */
  13
  14 #include <dt-bindings/phy/phy.h>
  15 #include <linux/init.h>
  16 #include <linux/io.h>
  17 #include <linux/kernel.h>
  18 #include <linux/of_address.h>
  19 #include <linux/phy/phy.h>
  20 #include <linux/platform_device.h>
  21
  22 #define USB2_PHY_CONFIG_DISABLE BIT(0)
  23
  24 struct armada375_cluster_phy {
  25         struct phy *phy;
  26         void __iomem *reg;
  27         bool use_usb3;
  28         int phy_provided;
  29 };
  30
  31 static int armada375_usb_phy_init(struct phy *phy)
  32 {
  33         struct armada375_cluster_phy *cluster_phy;
  34         u32 reg;
  35
  36         cluster_phy = phy_get_drvdata(phy);
  37         if (!cluster_phy)
  38                 return -ENODEV;
  39
  40         reg = readl(cluster_phy->reg);
  41         if (cluster_phy->use_usb3)
  42                 reg |= USB2_PHY_CONFIG_DISABLE;
  43         else
  44                 reg &= ~USB2_PHY_CONFIG_DISABLE;
  45         writel(reg, cluster_phy->reg);
  46
  47         return 0;
  48 }
  49
  50 static const struct phy_ops armada375_usb_phy_ops = {
  51         .init = armada375_usb_phy_init,
  52         .owner = THIS_MODULE,
  53 };
  54
  55 /*
  56  * Only one controller can use this PHY. We shouldn't have the case
  57  * when two controllers want to use this PHY. But if this case occurs
  58  * then we provide a phy to the first one and return an error for the
  59  * next one. This error has also to be an error returned by
  60  * devm_phy_optional_get() so different from ENODEV for USB2. In the
  61  * USB3 case it still optional and we use ENODEV.
  62  */
  63 static struct phy *armada375_usb_phy_xlate(struct device *dev,
  64                                         struct of_phandle_args *args)
  65 {
  66         struct armada375_cluster_phy *cluster_phy = dev_get_drvdata(dev);
  67
  68         if (!cluster_phy)
  69                 return  ERR_PTR(-ENODEV);
  70
  71         /*
  72          * Either the phy had never been requested and then the first
  73          * usb claiming it can get it, or it had already been
  74          * requested in this case, we only allow to use it with the
  75          * same configuration.
  76          */
  77         if (WARN_ON((cluster_phy->phy_provided != PHY_NONE) &&
  78                         (cluster_phy->phy_provided != args->args[0]))) {
  79                 dev_err(dev, "This PHY has already been provided!\n");
  80                 dev_err(dev, "Check your device tree, only one controller can use it\n.");
  81                 if (args->args[0] == PHY_TYPE_USB2)
  82                         return ERR_PTR(-EBUSY);
  83                 else
  84                         return ERR_PTR(-ENODEV);
  85         }
  86
  87         if (args->args[0] == PHY_TYPE_USB2)
  88                 cluster_phy->use_usb3 = false;
  89         else if (args->args[0] == PHY_TYPE_USB3)
  90                 cluster_phy->use_usb3 = true;
  91         else {
  92                 dev_err(dev, "Invalid PHY mode\n");
  93                 return ERR_PTR(-ENODEV);
  94         }
  95
  96         /* Store which phy mode is used for next test */
  97         cluster_phy->phy_provided = args->args[0];
  98
  99         return cluster_phy->phy;
 100 }
 101
 102 static int armada375_usb_phy_probe(struct platform_device *pdev)
 103 {
 104         struct device *dev = &pdev->dev;
 105         struct phy *phy;
 106         struct phy_provider *phy_provider;
 107         void __iomem *usb_cluster_base;
 108         struct armada375_cluster_phy *cluster_phy;
 109
 110         cluster_phy = devm_kzalloc(dev, sizeof(*cluster_phy), GFP_KERNEL);
 111         if (!cluster_phy)
 112                 return  -ENOMEM;
 113
 114         usb_cluster_base = devm_platform_ioremap_resource(pdev, 0);
 115         if (IS_ERR(usb_cluster_base))
 116                 return PTR_ERR(usb_cluster_base);
 117
 118         phy = devm_phy_create(dev, NULL, &armada375_usb_phy_ops);
 119         if (IS_ERR(phy)) {
 120                 dev_err(dev, "failed to create PHY\n");
 121                 return PTR_ERR(phy);
 122         }
 123
 124         cluster_phy->phy = phy;
 125         cluster_phy->reg = usb_cluster_base;
 126
 127         dev_set_drvdata(dev, cluster_phy);
 128         phy_set_drvdata(phy, cluster_phy);
 129
 130         phy_provider = devm_of_phy_provider_register(&pdev->dev,
 131                                                      armada375_usb_phy_xlate);
 132         return PTR_ERR_OR_ZERO(phy_provider);
 133 }
 134
 135 static const struct of_device_id of_usb_cluster_table[] = {
 136         { .compatible = "marvell,armada-375-usb-cluster", },
 137         { /* end of list */ },
 138 };
 139
 140 static struct platform_driver armada375_usb_phy_driver = {
 141         .probe  = armada375_usb_phy_probe,
 142         .driver = {
 143                 .of_match_table = of_usb_cluster_table,
 144                 .name  = "armada-375-usb-cluster",
 145         }
 146 };
 147 builtin_platform_driver(armada375_usb_phy_driver);