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
 24struct armada375_cluster_phy {
 25	struct phy *phy;
 26	void __iomem *reg;
 27	bool use_usb3;
 28	int phy_provided;
 29};
 30
 31static 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
 50static 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 */
 63static 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
102static 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
135static const struct of_device_id of_usb_cluster_table[] = {
136	{ .compatible = "marvell,armada-375-usb-cluster", },
137	{ /* end of list */ },
138};
139
140static 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};
147builtin_platform_driver(armada375_usb_phy_driver);