1/**
2 * dwc3-keystone.c - Keystone Specific Glue layer
3 *
4 * Copyright (C) 2010-2013 Texas Instruments Incorporated - http://www.ti.com
5 *
6 * Author: WingMan Kwok <w-kwok2@ti.com>
7 *
8 * This program is free software: you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2  of
10 * the License as published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 */
17
18#include <linux/clk.h>
19#include <linux/module.h>
20#include <linux/kernel.h>
21#include <linux/interrupt.h>
22#include <linux/platform_device.h>
23#include <linux/dma-mapping.h>
24#include <linux/io.h>
25#include <linux/of_platform.h>
26
27/* USBSS register offsets */
28#define USBSS_REVISION		0x0000
29#define USBSS_SYSCONFIG		0x0010
30#define USBSS_IRQ_EOI		0x0018
31#define USBSS_IRQSTATUS_RAW_0	0x0020
32#define USBSS_IRQSTATUS_0	0x0024
33#define USBSS_IRQENABLE_SET_0	0x0028
34#define USBSS_IRQENABLE_CLR_0	0x002c
35
36/* IRQ register bits */
37#define USBSS_IRQ_EOI_LINE(n)	BIT(n)
38#define USBSS_IRQ_EVENT_ST	BIT(0)
39#define USBSS_IRQ_COREIRQ_EN	BIT(0)
40#define USBSS_IRQ_COREIRQ_CLR	BIT(0)
41
42static u64 kdwc3_dma_mask;
43
44struct dwc3_keystone {
45	struct device			*dev;
46	struct clk			*clk;
47	void __iomem			*usbss;
48};
49
50static inline u32 kdwc3_readl(void __iomem *base, u32 offset)
51{
52	return readl(base + offset);
53}
54
55static inline void kdwc3_writel(void __iomem *base, u32 offset, u32 value)
56{
57	writel(value, base + offset);
58}
59
60static void kdwc3_enable_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 void kdwc3_disable_irqs(struct dwc3_keystone *kdwc)
70{
71	u32 val;
72
73	val = kdwc3_readl(kdwc->usbss, USBSS_IRQENABLE_SET_0);
74	val &= ~USBSS_IRQ_COREIRQ_EN;
75	kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, val);
76}
77
78static irqreturn_t dwc3_keystone_interrupt(int irq, void *_kdwc)
79{
80	struct dwc3_keystone	*kdwc = _kdwc;
81
82	kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_CLR_0, USBSS_IRQ_COREIRQ_CLR);
83	kdwc3_writel(kdwc->usbss, USBSS_IRQSTATUS_0, USBSS_IRQ_EVENT_ST);
84	kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, USBSS_IRQ_COREIRQ_EN);
85	kdwc3_writel(kdwc->usbss, USBSS_IRQ_EOI, USBSS_IRQ_EOI_LINE(0));
86
87	return IRQ_HANDLED;
88}
89
90static int kdwc3_probe(struct platform_device *pdev)
91{
92	struct device		*dev = &pdev->dev;
93	struct device_node	*node = pdev->dev.of_node;
94	struct dwc3_keystone	*kdwc;
95	struct resource		*res;
96	int			error, irq;
97
98	kdwc = devm_kzalloc(dev, sizeof(*kdwc), GFP_KERNEL);
99	if (!kdwc)
100		return -ENOMEM;
101
102	platform_set_drvdata(pdev, kdwc);
103
104	kdwc->dev = dev;
105
106	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
107	kdwc->usbss = devm_ioremap_resource(dev, res);
108	if (IS_ERR(kdwc->usbss))
109		return PTR_ERR(kdwc->usbss);
110
111	kdwc3_dma_mask = dma_get_mask(dev);
112	dev->dma_mask = &kdwc3_dma_mask;
113
114	kdwc->clk = devm_clk_get(kdwc->dev, "usb");
115
116	error = clk_prepare_enable(kdwc->clk);
117	if (error < 0) {
118		dev_dbg(kdwc->dev, "unable to enable usb clock, err %d\n",
119			error);
120		return error;
121	}
122
123	irq = platform_get_irq(pdev, 0);
124	if (irq < 0) {
125		dev_err(&pdev->dev, "missing irq\n");
126		error = irq;
127		goto err_irq;
128	}
129
130	error = devm_request_irq(dev, irq, dwc3_keystone_interrupt, IRQF_SHARED,
131			dev_name(dev), kdwc);
132	if (error) {
133		dev_err(dev, "failed to request IRQ #%d --> %d\n",
134				irq, error);
135		goto err_irq;
136	}
137
138	kdwc3_enable_irqs(kdwc);
139
140	error = of_platform_populate(node, NULL, NULL, dev);
141	if (error) {
142		dev_err(&pdev->dev, "failed to create dwc3 core\n");
143		goto err_core;
144	}
145
146	return 0;
147
148err_core:
149	kdwc3_disable_irqs(kdwc);
150err_irq:
151	clk_disable_unprepare(kdwc->clk);
152
153	return error;
154}
155
156static int kdwc3_remove_core(struct device *dev, void *c)
157{
158	struct platform_device *pdev = to_platform_device(dev);
159
160	platform_device_unregister(pdev);
161
162	return 0;
163}
164
165static int kdwc3_remove(struct platform_device *pdev)
166{
167	struct dwc3_keystone *kdwc = platform_get_drvdata(pdev);
168
169	kdwc3_disable_irqs(kdwc);
170	device_for_each_child(&pdev->dev, NULL, kdwc3_remove_core);
171	clk_disable_unprepare(kdwc->clk);
172	platform_set_drvdata(pdev, NULL);
173
174	return 0;
175}
176
177static const struct of_device_id kdwc3_of_match[] = {
178	{ .compatible = "ti,keystone-dwc3", },
179	{},
180};
181MODULE_DEVICE_TABLE(of, kdwc3_of_match);
182
183static struct platform_driver kdwc3_driver = {
184	.probe		= kdwc3_probe,
185	.remove		= kdwc3_remove,
186	.driver		= {
187		.name	= "keystone-dwc3",
188		.of_match_table	= kdwc3_of_match,
189	},
190};
191
192module_platform_driver(kdwc3_driver);
193
194MODULE_ALIAS("platform:keystone-dwc3");
195MODULE_AUTHOR("WingMan Kwok <w-kwok2@ti.com>");
196MODULE_LICENSE("GPL v2");
197MODULE_DESCRIPTION("DesignWare USB3 KEYSTONE Glue Layer");
198