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	if (!res) {
108		dev_err(dev, "missing usbss resource\n");
109		return -EINVAL;
110	}
111
112	kdwc->usbss = devm_ioremap_resource(dev, res);
113	if (IS_ERR(kdwc->usbss))
114		return PTR_ERR(kdwc->usbss);
115
116	kdwc3_dma_mask = dma_get_mask(dev);
117	dev->dma_mask = &kdwc3_dma_mask;
118
119	kdwc->clk = devm_clk_get(kdwc->dev, "usb");
120
121	error = clk_prepare_enable(kdwc->clk);
122	if (error < 0) {
123		dev_dbg(kdwc->dev, "unable to enable usb clock, err %d\n",
124			error);
125		return error;
126	}
127
128	irq = platform_get_irq(pdev, 0);
129	if (irq < 0) {
130		dev_err(&pdev->dev, "missing irq\n");
131		goto err_irq;
132	}
133
134	error = devm_request_irq(dev, irq, dwc3_keystone_interrupt, IRQF_SHARED,
135			dev_name(dev), kdwc);
136	if (error) {
137		dev_err(dev, "failed to request IRQ #%d --> %d\n",
138				irq, error);
139		goto err_irq;
140	}
141
142	kdwc3_enable_irqs(kdwc);
143
144	error = of_platform_populate(node, NULL, NULL, dev);
145	if (error) {
146		dev_err(&pdev->dev, "failed to create dwc3 core\n");
147		goto err_core;
148	}
149
150	return 0;
151
152err_core:
153	kdwc3_disable_irqs(kdwc);
154err_irq:
155	clk_disable_unprepare(kdwc->clk);
156
157	return error;
158}
159
160static int kdwc3_remove_core(struct device *dev, void *c)
161{
162	struct platform_device *pdev = to_platform_device(dev);
163
164	platform_device_unregister(pdev);
165
166	return 0;
167}
168
169static int kdwc3_remove(struct platform_device *pdev)
170{
171	struct dwc3_keystone *kdwc = platform_get_drvdata(pdev);
172
173	kdwc3_disable_irqs(kdwc);
174	device_for_each_child(&pdev->dev, NULL, kdwc3_remove_core);
175	clk_disable_unprepare(kdwc->clk);
176	platform_set_drvdata(pdev, NULL);
177
178	return 0;
179}
180
181static const struct of_device_id kdwc3_of_match[] = {
182	{ .compatible = "ti,keystone-dwc3", },
183	{},
184};
185MODULE_DEVICE_TABLE(of, kdwc3_of_match);
186
187static struct platform_driver kdwc3_driver = {
188	.probe		= kdwc3_probe,
189	.remove		= kdwc3_remove,
190	.driver		= {
191		.name	= "keystone-dwc3",
192		.owner	        = THIS_MODULE,
193		.of_match_table	= kdwc3_of_match,
194	},
195};
196
197module_platform_driver(kdwc3_driver);
198
199MODULE_ALIAS("platform:keystone-dwc3");
200MODULE_AUTHOR("WingMan Kwok <w-kwok2@ti.com>");
201MODULE_LICENSE("GPL v2");
202MODULE_DESCRIPTION("DesignWare USB3 KEYSTONE Glue Layer");