LXR linux/drivers/phy/marvell/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
  28struct armada375_cluster_phy {
  29        struct phy *phy;
  30        void __iomem *reg;
  31        bool use_usb3;
  32        int phy_provided;
  33};
  34
  35static 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
  54static 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 */
  67static 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
 106static 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
 141static const struct of_device_id of_usb_cluster_table[] = {
 142        { .compatible = "marvell,armada-375-usb-cluster", },
 143        { /* end of list */ },
 144};
 145MODULE_DEVICE_TABLE(of, of_usb_cluster_table);
 146
 147static 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};
 154module_platform_driver(armada375_usb_phy_driver);
 155
 156MODULE_DESCRIPTION("Armada 375 USB cluster driver");
 157MODULE_AUTHOR("Gregory CLEMENT <gregory.clement@free-electrons.com>");
 158MODULE_LICENSE("GPL");
 159