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