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_platform.h>
 17#include <linux/phy/phy.h>
 18#include <linux/pm_runtime.h>
 19
 20/* USBSS register offsets */
 21#define USBSS_REVISION		0x0000
 22#define USBSS_SYSCONFIG		0x0010
 23#define USBSS_IRQ_EOI		0x0018
 24#define USBSS_IRQSTATUS_RAW_0	0x0020
 25#define USBSS_IRQSTATUS_0	0x0024
 26#define USBSS_IRQENABLE_SET_0	0x0028
 27#define USBSS_IRQENABLE_CLR_0	0x002c
 28
 29/* IRQ register bits */
 30#define USBSS_IRQ_EOI_LINE(n)	BIT(n)
 31#define USBSS_IRQ_EVENT_ST	BIT(0)
 32#define USBSS_IRQ_COREIRQ_EN	BIT(0)
 33#define USBSS_IRQ_COREIRQ_CLR	BIT(0)
 34
 35struct dwc3_keystone {
 36	struct device			*dev;
 37	void __iomem			*usbss;
 38	struct phy			*usb3_phy;
 39};
 40
 41static inline u32 kdwc3_readl(void __iomem *base, u32 offset)
 42{
 43	return readl(base + offset);
 44}
 45
 46static inline void kdwc3_writel(void __iomem *base, u32 offset, u32 value)
 47{
 48	writel(value, base + offset);
 49}
 50
 51static void kdwc3_enable_irqs(struct dwc3_keystone *kdwc)
 52{
 53	u32 val;
 54
 55	val = kdwc3_readl(kdwc->usbss, USBSS_IRQENABLE_SET_0);
 56	val |= USBSS_IRQ_COREIRQ_EN;
 57	kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, val);
 58}
 59
 60static void kdwc3_disable_irqs(struct dwc3_keystone *kdwc)
 61{
 62	u32 val;
 63
 64	val = kdwc3_readl(kdwc->usbss, USBSS_IRQENABLE_SET_0);
 65	val &= ~USBSS_IRQ_COREIRQ_EN;
 66	kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, val);
 67}
 68
 69static irqreturn_t dwc3_keystone_interrupt(int irq, void *_kdwc)
 70{
 71	struct dwc3_keystone	*kdwc = _kdwc;
 72
 73	kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_CLR_0, USBSS_IRQ_COREIRQ_CLR);
 74	kdwc3_writel(kdwc->usbss, USBSS_IRQSTATUS_0, USBSS_IRQ_EVENT_ST);
 75	kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, USBSS_IRQ_COREIRQ_EN);
 76	kdwc3_writel(kdwc->usbss, USBSS_IRQ_EOI, USBSS_IRQ_EOI_LINE(0));
 77
 78	return IRQ_HANDLED;
 79}
 80
 81static int kdwc3_probe(struct platform_device *pdev)
 82{
 83	struct device		*dev = &pdev->dev;
 84	struct device_node	*node = pdev->dev.of_node;
 85	struct dwc3_keystone	*kdwc;
 86	int			error, irq;
 87
 88	kdwc = devm_kzalloc(dev, sizeof(*kdwc), GFP_KERNEL);
 89	if (!kdwc)
 90		return -ENOMEM;
 91
 92	platform_set_drvdata(pdev, kdwc);
 93
 94	kdwc->dev = dev;
 95
 96	kdwc->usbss = devm_platform_ioremap_resource(pdev, 0);
 97	if (IS_ERR(kdwc->usbss))
 98		return PTR_ERR(kdwc->usbss);
 99
100	/* PSC dependency on AM65 needs SERDES0 to be powered before USB0 */
101	kdwc->usb3_phy = devm_phy_optional_get(dev, "usb3-phy");
102	if (IS_ERR(kdwc->usb3_phy)) {
103		error = PTR_ERR(kdwc->usb3_phy);
104		if (error != -EPROBE_DEFER)
105			dev_err(dev, "couldn't get usb3 phy: %d\n", error);
106
107		return error;
108	}
109
110	phy_pm_runtime_get_sync(kdwc->usb3_phy);
111
112	error = phy_reset(kdwc->usb3_phy);
113	if (error < 0) {
114		dev_err(dev, "usb3 phy reset failed: %d\n", error);
115		return error;
116	}
117
118	error = phy_init(kdwc->usb3_phy);
119	if (error < 0) {
120		dev_err(dev, "usb3 phy init failed: %d\n", error);
121		return error;
122	}
123
124	error = phy_power_on(kdwc->usb3_phy);
125	if (error < 0) {
126		dev_err(dev, "usb3 phy power on failed: %d\n", error);
127		phy_exit(kdwc->usb3_phy);
128		return error;
129	}
130
131	pm_runtime_enable(kdwc->dev);
132	error = pm_runtime_get_sync(kdwc->dev);
133	if (error < 0) {
134		dev_err(kdwc->dev, "pm_runtime_get_sync failed, error %d\n",
135			error);
136		goto err_irq;
137	}
138
139	/* IRQ processing not required currently for AM65 */
140	if (of_device_is_compatible(node, "ti,am654-dwc3"))
141		goto skip_irq;
142
143	irq = platform_get_irq(pdev, 0);
144	if (irq < 0) {
145		error = irq;
146		goto err_irq;
147	}
148
149	error = devm_request_irq(dev, irq, dwc3_keystone_interrupt, IRQF_SHARED,
150			dev_name(dev), kdwc);
151	if (error) {
152		dev_err(dev, "failed to request IRQ #%d --> %d\n",
153				irq, error);
154		goto err_irq;
155	}
156
157	kdwc3_enable_irqs(kdwc);
158
159skip_irq:
160	error = of_platform_populate(node, NULL, NULL, dev);
161	if (error) {
162		dev_err(&pdev->dev, "failed to create dwc3 core\n");
163		goto err_core;
164	}
165
166	return 0;
167
168err_core:
169	kdwc3_disable_irqs(kdwc);
170err_irq:
171	pm_runtime_put_sync(kdwc->dev);
172	pm_runtime_disable(kdwc->dev);
173	phy_power_off(kdwc->usb3_phy);
174	phy_exit(kdwc->usb3_phy);
175	phy_pm_runtime_put_sync(kdwc->usb3_phy);
176
177	return error;
178}
179
180static int kdwc3_remove_core(struct device *dev, void *c)
181{
182	struct platform_device *pdev = to_platform_device(dev);
183
184	platform_device_unregister(pdev);
185
186	return 0;
187}
188
189static int kdwc3_remove(struct platform_device *pdev)
190{
191	struct dwc3_keystone *kdwc = platform_get_drvdata(pdev);
192	struct device_node *node = pdev->dev.of_node;
193
194	if (!of_device_is_compatible(node, "ti,am654-dwc3"))
195		kdwc3_disable_irqs(kdwc);
196
197	device_for_each_child(&pdev->dev, NULL, kdwc3_remove_core);
198	pm_runtime_put_sync(kdwc->dev);
199	pm_runtime_disable(kdwc->dev);
200
201	phy_power_off(kdwc->usb3_phy);
202	phy_exit(kdwc->usb3_phy);
203	phy_pm_runtime_put_sync(kdwc->usb3_phy);
204
205	platform_set_drvdata(pdev, NULL);
206
207	return 0;
208}
209
210static const struct of_device_id kdwc3_of_match[] = {
211	{ .compatible = "ti,keystone-dwc3", },
212	{ .compatible = "ti,am654-dwc3" },
213	{},
214};
215MODULE_DEVICE_TABLE(of, kdwc3_of_match);
216
217static struct platform_driver kdwc3_driver = {
218	.probe		= kdwc3_probe,
219	.remove		= kdwc3_remove,
220	.driver		= {
221		.name	= "keystone-dwc3",
222		.of_match_table	= kdwc3_of_match,
223	},
224};
225
226module_platform_driver(kdwc3_driver);
227
228MODULE_ALIAS("platform:keystone-dwc3");
229MODULE_AUTHOR("WingMan Kwok <w-kwok2@ti.com>");
230MODULE_LICENSE("GPL v2");
231MODULE_DESCRIPTION("DesignWare USB3 KEYSTONE Glue Layer");