tjh.dev
Linux kernel mirror (for testing)
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linux
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");