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);
148