drivers/phy/phy-armada375-usb2.c

   1 /*
   2  * USB cluster support for Armada 375 platform.
   3  *
   4  * Copyright (C) 2014 Marvell
   5  *
   6  * Gregory CLEMENT <gregory.clement@free-electrons.com>
   7  *
   8  * This file is licensed under the terms of the GNU General Public
   9  * License version 2 or later. This program is licensed "as is"
  10  * without any warranty of any kind, whether express or implied.
  11  *
  12  * Armada 375 comes with an USB2 host and device controller and an
  13  * USB3 controller. The USB cluster control register allows to manage
  14  * common features of both USB controllers.
  15  */
  16
  17 #include <dt-bindings/phy/phy.h>
  18 #include <linux/init.h>
  19 #include <linux/io.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/of_address.h>
  23 #include <linux/phy/phy.h>
  24 #include <linux/platform_device.h>
  25
  26 #define USB2_PHY_CONFIG_DISABLE BIT(0)
  27
  28 struct armada375_cluster_phy {
  29         struct phy *phy;
  30         void __iomem *reg;
  31         bool use_usb3;
  32         int phy_provided;
  33 };
  34
  35 static int armada375_usb_phy_init(struct phy *phy)
  36 {
  37         struct armada375_cluster_phy *cluster_phy;
  38         u32 reg;
  39
  40         cluster_phy = phy_get_drvdata(phy);
  41         if (!cluster_phy)
  42                 return -ENODEV;
  43
  44         reg = readl(cluster_phy->reg);
  45         if (cluster_phy->use_usb3)
  46                 reg |= USB2_PHY_CONFIG_DISABLE;
  47         else
  48                 reg &= ~USB2_PHY_CONFIG_DISABLE;
  49         writel(reg, cluster_phy->reg);
  50
  51         return 0;
  52 }
  53
  54 static const struct phy_ops armada375_usb_phy_ops = {
  55         .init = armada375_usb_phy_init,
  56         .owner = THIS_MODULE,
  57 };
  58
  59 /*
  60  * Only one controller can use this PHY. We shouldn't have the case
  61  * when two controllers want to use this PHY. But if this case occurs
  62  * then we provide a phy to the first one and return an error for the
  63  * next one. This error has also to be an error returned by
  64  * devm_phy_optional_get() so different from ENODEV for USB2. In the
  65  * USB3 case it still optional and we use ENODEV.
  66  */
  67 static struct phy *armada375_usb_phy_xlate(struct device *dev,
  68                                         struct of_phandle_args *args)
  69 {
  70         struct armada375_cluster_phy *cluster_phy = dev_get_drvdata(dev);
  71
  72         if (!cluster_phy)
  73                 return  ERR_PTR(-ENODEV);
  74
  75         /*
  76          * Either the phy had never been requested and then the first
  77          * usb claiming it can get it, or it had already been
  78          * requested in this case, we only allow to use it with the
  79          * same configuration.
  80          */
  81         if (WARN_ON((cluster_phy->phy_provided != PHY_NONE) &&
  82                         (cluster_phy->phy_provided != args->args[0]))) {
  83                 dev_err(dev, "This PHY has already been provided!\n");
  84                 dev_err(dev, "Check your device tree, only one controller can use it\n.");
  85                 if (args->args[0] == PHY_TYPE_USB2)
  86                         return ERR_PTR(-EBUSY);
  87                 else
  88                         return ERR_PTR(-ENODEV);
  89         }
  90
  91         if (args->args[0] == PHY_TYPE_USB2)
  92                 cluster_phy->use_usb3 = false;
  93         else if (args->args[0] == PHY_TYPE_USB3)
  94                 cluster_phy->use_usb3 = true;
  95         else {
  96                 dev_err(dev, "Invalid PHY mode\n");
  97                 return ERR_PTR(-ENODEV);
  98         }
  99
 100         /* Store which phy mode is used for next test */
 101         cluster_phy->phy_provided = args->args[0];
 102
 103         return cluster_phy->phy;
 104 }
 105
 106 static int armada375_usb_phy_probe(struct platform_device *pdev)
 107 {
 108         struct device *dev = &pdev->dev;
 109         struct phy *phy;
 110         struct phy_provider *phy_provider;
 111         void __iomem *usb_cluster_base;
 112         struct resource *res;
 113         struct armada375_cluster_phy *cluster_phy;
 114
 115         cluster_phy = devm_kzalloc(dev, sizeof(*cluster_phy), GFP_KERNEL);
 116         if (!cluster_phy)
 117                 return  -ENOMEM;
 118
 119         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 120         usb_cluster_base = devm_ioremap_resource(&pdev->dev, res);
 121         if (IS_ERR(usb_cluster_base))
 122                 return PTR_ERR(usb_cluster_base);
 123
 124         phy = devm_phy_create(dev, NULL, &armada375_usb_phy_ops);
 125         if (IS_ERR(phy)) {
 126                 dev_err(dev, "failed to create PHY\n");
 127                 return PTR_ERR(phy);
 128         }
 129
 130         cluster_phy->phy = phy;
 131         cluster_phy->reg = usb_cluster_base;
 132
 133         dev_set_drvdata(dev, cluster_phy);
 134         phy_set_drvdata(phy, cluster_phy);
 135
 136         phy_provider = devm_of_phy_provider_register(&pdev->dev,
 137                                                      armada375_usb_phy_xlate);
 138         return PTR_ERR_OR_ZERO(phy_provider);
 139 }
 140
 141 static const struct of_device_id of_usb_cluster_table[] = {
 142         { .compatible = "marvell,armada-375-usb-cluster", },
 143         { /* end of list */ },
 144 };
 145 MODULE_DEVICE_TABLE(of, of_usb_cluster_table);
 146
 147 static struct platform_driver armada375_usb_phy_driver = {
 148         .probe  = armada375_usb_phy_probe,
 149         .driver = {
 150                 .of_match_table = of_usb_cluster_table,
 151                 .name  = "armada-375-usb-cluster",
 152         }
 153 };
 154 module_platform_driver(armada375_usb_phy_driver);
 155
 156 MODULE_DESCRIPTION("Armada 375 USB cluster driver");
 157 MODULE_AUTHOR("Gregory CLEMENT <gregory.clement@free-electrons.com>");
 158 MODULE_LICENSE("GPL");