1// SPDX-License-Identifier: GPL-2.0
2/*
3 * dwc3-keystone.c - Keystone Specific Glue layer
4 *
5 * Copyright (C) 2010-2013 Texas Instruments Incorporated - https://www.ti.com
6 *
7 * Author: WingMan Kwok <w-kwok2@ti.com>
8 */
9
10#include <linux/module.h>
11#include <linux/kernel.h>
12#include <linux/interrupt.h>
13#include <linux/platform_device.h>
14#include <linux/dma-mapping.h>
15#include <linux/io.h>
16#include <linux/of.h>
17#include <linux/of_platform.h>
18#include <linux/phy/phy.h>
19#include <linux/pm_runtime.h>
20
21/* USBSS register offsets */
22#define USBSS_REVISION		0x0000
23#define USBSS_SYSCONFIG		0x0010
24#define USBSS_IRQ_EOI		0x0018
25#define USBSS_IRQSTATUS_RAW_0	0x0020
26#define USBSS_IRQSTATUS_0	0x0024
27#define USBSS_IRQENABLE_SET_0	0x0028
28#define USBSS_IRQENABLE_CLR_0	0x002c
29
30/* IRQ register bits */
31#define USBSS_IRQ_EOI_LINE(n)	BIT(n)
32#define USBSS_IRQ_EVENT_ST	BIT(0)
33#define USBSS_IRQ_COREIRQ_EN	BIT(0)
34#define USBSS_IRQ_COREIRQ_CLR	BIT(0)
35
36struct dwc3_keystone {
37	struct device			*dev;
38	void __iomem			*usbss;
39	struct phy			*usb3_phy;
40};
41
42static inline u32 kdwc3_readl(void __iomem *base, u32 offset)
43{
44	return readl(base + offset);
45}
46
47static inline void kdwc3_writel(void __iomem *base, u32 offset, u32 value)
48{
49	writel(value, base + offset);
50}
51
52static void kdwc3_enable_irqs(struct dwc3_keystone *kdwc)
53{
54	u32 val;
55
56	val = kdwc3_readl(kdwc->usbss, USBSS_IRQENABLE_SET_0);
57	val |= USBSS_IRQ_COREIRQ_EN;
58	kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, val);
59}
60
61static void kdwc3_disable_irqs(struct dwc3_keystone *kdwc)
62{
63	u32 val;
64
65	val = kdwc3_readl(kdwc->usbss, USBSS_IRQENABLE_SET_0);
66	val &= ~USBSS_IRQ_COREIRQ_EN;
67	kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, val);
68}
69
70static irqreturn_t dwc3_keystone_interrupt(int irq, void *_kdwc)
71{
72	struct dwc3_keystone	*kdwc = _kdwc;
73
74	kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_CLR_0, USBSS_IRQ_COREIRQ_CLR);
75	kdwc3_writel(kdwc->usbss, USBSS_IRQSTATUS_0, USBSS_IRQ_EVENT_ST);
76	kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, USBSS_IRQ_COREIRQ_EN);
77	kdwc3_writel(kdwc->usbss, USBSS_IRQ_EOI, USBSS_IRQ_EOI_LINE(0));
78
79	return IRQ_HANDLED;
80}
81
82static int kdwc3_probe(struct platform_device *pdev)
83{
84	struct device		*dev = &pdev->dev;
85	struct device_node	*node = pdev->dev.of_node;
86	struct dwc3_keystone	*kdwc;
87	int			error, irq;
88
89	kdwc = devm_kzalloc(dev, sizeof(*kdwc), GFP_KERNEL);
90	if (!kdwc)
91		return -ENOMEM;
92
93	platform_set_drvdata(pdev, kdwc);
94
95	kdwc->dev = dev;
96
97	kdwc->usbss = devm_platform_ioremap_resource(pdev, 0);
98	if (IS_ERR(kdwc->usbss))
99		return PTR_ERR(kdwc->usbss);
100
101	/* PSC dependency on AM65 needs SERDES0 to be powered before USB0 */
102	kdwc->usb3_phy = devm_phy_optional_get(dev, "usb3-phy");
103	if (IS_ERR(kdwc->usb3_phy))
104		return dev_err_probe(dev, PTR_ERR(kdwc->usb3_phy), "couldn't get usb3 phy\n");
105
106	phy_pm_runtime_get_sync(kdwc->usb3_phy);
107
108	error = phy_reset(kdwc->usb3_phy);
109	if (error < 0) {
110		dev_err(dev, "usb3 phy reset failed: %d\n", error);
111		return error;
112	}
113
114	error = phy_init(kdwc->usb3_phy);
115	if (error < 0) {
116		dev_err(dev, "usb3 phy init failed: %d\n", error);
117		return error;
118	}
119
120	error = phy_power_on(kdwc->usb3_phy);
121	if (error < 0) {
122		dev_err(dev, "usb3 phy power on failed: %d\n", error);
123		phy_exit(kdwc->usb3_phy);
124		return error;
125	}
126
127	pm_runtime_enable(kdwc->dev);
128	error = pm_runtime_get_sync(kdwc->dev);
129	if (error < 0) {
130		dev_err(kdwc->dev, "pm_runtime_get_sync failed, error %d\n",
131			error);
132		goto err_irq;
133	}
134
135	/* IRQ processing not required currently for AM65 */
136	if (of_device_is_compatible(node, "ti,am654-dwc3"))
137		goto skip_irq;
138
139	irq = platform_get_irq(pdev, 0);
140	if (irq < 0) {
141		error = irq;
142		goto err_irq;
143	}
144
145	error = devm_request_irq(dev, irq, dwc3_keystone_interrupt, IRQF_SHARED,
146			dev_name(dev), kdwc);
147	if (error) {
148		dev_err(dev, "failed to request IRQ #%d --> %d\n",
149				irq, error);
150		goto err_irq;
151	}
152
153	kdwc3_enable_irqs(kdwc);
154
155skip_irq:
156	error = of_platform_populate(node, NULL, NULL, dev);
157	if (error) {
158		dev_err(&pdev->dev, "failed to create dwc3 core\n");
159		goto err_core;
160	}
161
162	return 0;
163
164err_core:
165	kdwc3_disable_irqs(kdwc);
166err_irq:
167	pm_runtime_put_sync(kdwc->dev);
168	pm_runtime_disable(kdwc->dev);
169	phy_power_off(kdwc->usb3_phy);
170	phy_exit(kdwc->usb3_phy);
171	phy_pm_runtime_put_sync(kdwc->usb3_phy);
172
173	return error;
174}
175
176static int kdwc3_remove_core(struct device *dev, void *c)
177{
178	struct platform_device *pdev = to_platform_device(dev);
179
180	platform_device_unregister(pdev);
181
182	return 0;
183}
184
185static void kdwc3_remove(struct platform_device *pdev)
186{
187	struct dwc3_keystone *kdwc = platform_get_drvdata(pdev);
188	struct device_node *node = pdev->dev.of_node;
189
190	if (!of_device_is_compatible(node, "ti,am654-dwc3"))
191		kdwc3_disable_irqs(kdwc);
192
193	device_for_each_child(&pdev->dev, NULL, kdwc3_remove_core);
194	pm_runtime_put_sync(kdwc->dev);
195	pm_runtime_disable(kdwc->dev);
196
197	phy_power_off(kdwc->usb3_phy);
198	phy_exit(kdwc->usb3_phy);
199	phy_pm_runtime_put_sync(kdwc->usb3_phy);
200}
201
202static const struct of_device_id kdwc3_of_match[] = {
203	{ .compatible = "ti,keystone-dwc3", },
204	{ .compatible = "ti,am654-dwc3" },
205	{},
206};
207MODULE_DEVICE_TABLE(of, kdwc3_of_match);
208
209static struct platform_driver kdwc3_driver = {
210	.probe		= kdwc3_probe,
211	.remove_new	= kdwc3_remove,
212	.driver		= {
213		.name	= "keystone-dwc3",
214		.of_match_table	= kdwc3_of_match,
215	},
216};
217
218module_platform_driver(kdwc3_driver);
219
220MODULE_ALIAS("platform:keystone-dwc3");
221MODULE_AUTHOR("WingMan Kwok <w-kwok2@ti.com>");
222MODULE_LICENSE("GPL v2");
223MODULE_DESCRIPTION("DesignWare USB3 KEYSTONE Glue Layer");
224