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");