drivers/usb/dwc3/core.c - kernel/msm - Gitiles

 /**
  * core.c - DesignWare USB3 DRD Controller Core file
  *
  * Copyright (C) 2010-2011 Texas Instruments Incorporated - http://www.ti.com
  *
  * Authors: Felipe Balbi <balbi@ti.com>,
  *	    Sebastian Andrzej Siewior <bigeasy@linutronix.de>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions, and the following disclaimer,
  *    without modification.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. The names of the above-listed copyright holders may not be used
  *    to endorse or promote products derived from this software without
  *    specific prior written permission.
  *
  * ALTERNATIVELY, this software may be distributed under the terms of the
  * GNU General Public License ("GPL") version 2, as published by the Free
  * Software Foundation.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/interrupt.h>
 #include <linux/ioport.h>
 #include <linux/io.h>
 #include <linux/list.h>
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>

 #include <linux/usb/ch9.h>
 #include <linux/usb/gadget.h>

 #include "core.h"
 #include "gadget.h"
 #include "io.h"

 #include "debug.h"

 /**
  * dwc3_core_soft_reset - Issues core soft reset and PHY reset
  * @dwc: pointer to our context structure
  */
 static void dwc3_core_soft_reset(struct dwc3 *dwc)
 {
 	u32		reg;

 	/* Before Resetting PHY, put Core in Reset */
 	reg = dwc3_readl(dwc->regs, DWC3_GCTL);
 	reg |= DWC3_GCTL_CORESOFTRESET;
 	dwc3_writel(dwc->regs, DWC3_GCTL, reg);

 	/* Assert USB3 PHY reset */
 	reg = dwc3_readl(dwc->regs, DWC3_GUSB3PIPECTL(0));
 	reg |= DWC3_GUSB3PIPECTL_PHYSOFTRST;
 	dwc3_writel(dwc->regs, DWC3_GUSB3PIPECTL(0), reg);

 	/* Assert USB2 PHY reset */
 	reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
 	reg |= DWC3_GUSB2PHYCFG_PHYSOFTRST;
 	dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);

 	mdelay(100);

 	/* Clear USB3 PHY reset */
 	reg = dwc3_readl(dwc->regs, DWC3_GUSB3PIPECTL(0));
 	reg &= ~DWC3_GUSB3PIPECTL_PHYSOFTRST;
 	dwc3_writel(dwc->regs, DWC3_GUSB3PIPECTL(0), reg);

 	/* Clear USB2 PHY reset */
 	reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
 	reg &= ~DWC3_GUSB2PHYCFG_PHYSOFTRST;
 	dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);

 	/* After PHYs are stable we can take Core out of reset state */
 	reg = dwc3_readl(dwc->regs, DWC3_GCTL);
 	reg &= ~DWC3_GCTL_CORESOFTRESET;
 	dwc3_writel(dwc->regs, DWC3_GCTL, reg);
 }

 /**
  * dwc3_free_one_event_buffer - Frees one event buffer
  * @dwc: Pointer to our controller context structure
  * @evt: Pointer to event buffer to be freed
  */
 static void dwc3_free_one_event_buffer(struct dwc3 *dwc,
 		struct dwc3_event_buffer *evt)
 {
 	dma_free_coherent(dwc->dev, evt->length, evt->buf, evt->dma);
 	kfree(evt);
 }

 /**
  * dwc3_alloc_one_event_buffer - Allocated one event buffer structure
  * @dwc: Pointer to our controller context structure
  * @length: size of the event buffer
  *
  * Returns a pointer to the allocated event buffer structure on succes
  * otherwise ERR_PTR(errno).
  */
 static struct dwc3_event_buffer *__devinit
 dwc3_alloc_one_event_buffer(struct dwc3 *dwc, unsigned length)
 {
 	struct dwc3_event_buffer	*evt;

 	evt = kzalloc(sizeof(*evt), GFP_KERNEL);
 	if (!evt)
 		return ERR_PTR(-ENOMEM);

 	evt->dwc	= dwc;
 	evt->length	= length;
 	evt->buf	= dma_alloc_coherent(dwc->dev, length,
 			&evt->dma, GFP_KERNEL);
 	if (!evt->buf) {
 		kfree(evt);
 		return ERR_PTR(-ENOMEM);
 	}

 	return evt;
 }

 /**
  * dwc3_free_event_buffers - frees all allocated event buffers
  * @dwc: Pointer to our controller context structure
  */
 static void dwc3_free_event_buffers(struct dwc3 *dwc)
 {
 	struct dwc3_event_buffer	*evt;
 	int i;

 	for (i = 0; i < DWC3_EVENT_BUFFERS_NUM; i++) {
 		evt = dwc->ev_buffs[i];
 		if (evt) {
 			dwc3_free_one_event_buffer(dwc, evt);
 			dwc->ev_buffs[i] = NULL;
 		}
 	}
 }

 /**
  * dwc3_alloc_event_buffers - Allocates @num event buffers of size @length
  * @dwc: Pointer to out controller context structure
  * @num: number of event buffers to allocate
  * @length: size of event buffer
  *
  * Returns 0 on success otherwise negative errno. In error the case, dwc
  * may contain some buffers allocated but not all which were requested.
  */
 static int __devinit dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned num,
 		unsigned length)
 {
 	int			i;

 	for (i = 0; i < num; i++) {
 		struct dwc3_event_buffer	*evt;

 		evt = dwc3_alloc_one_event_buffer(dwc, length);
 		if (IS_ERR(evt)) {
 			dev_err(dwc->dev, "can't allocate event buffer\n");
 			return PTR_ERR(evt);
 		}
 		dwc->ev_buffs[i] = evt;
 	}

 	return 0;
 }

 /**
  * dwc3_event_buffers_setup - setup our allocated event buffers
  * @dwc: Pointer to out controller context structure
  *
  * Returns 0 on success otherwise negative errno.
  */
 static int __devinit dwc3_event_buffers_setup(struct dwc3 *dwc)
 {
 	struct dwc3_event_buffer	*evt;
 	int				n;

 	for (n = 0; n < DWC3_EVENT_BUFFERS_NUM; n++) {
 		evt = dwc->ev_buffs[n];
 		dev_dbg(dwc->dev, "Event buf %p dma %08llx length %d\n",
 				evt->buf, (unsigned long long) evt->dma,
 				evt->length);

 		dwc3_writel(dwc->regs, DWC3_GEVNTADRLO(n),
 				lower_32_bits(evt->dma));
 		dwc3_writel(dwc->regs, DWC3_GEVNTADRHI(n),
 				upper_32_bits(evt->dma));
 		dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(n),
 				evt->length & 0xffff);
 		dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(n), 0);
 	}

 	return 0;
 }

 static void dwc3_event_buffers_cleanup(struct dwc3 *dwc)
 {
 	struct dwc3_event_buffer	*evt;
 	int				n;

 	for (n = 0; n < DWC3_EVENT_BUFFERS_NUM; n++) {
 		evt = dwc->ev_buffs[n];
 		dwc3_writel(dwc->regs, DWC3_GEVNTADRLO(n), 0);
 		dwc3_writel(dwc->regs, DWC3_GEVNTADRHI(n), 0);
 		dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(n), 0);
 		dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(n), 0);
 	}
 }

 /**
  * dwc3_core_init - Low-level initialization of DWC3 Core
  * @dwc: Pointer to our controller context structure
  *
  * Returns 0 on success otherwise negative errno.
  */
 static int __devinit dwc3_core_init(struct dwc3 *dwc)
 {
 	unsigned long		timeout;
 	u32			reg;
 	int			ret;

 	reg = dwc3_readl(dwc->regs, DWC3_GSNPSID);
 	/* This should read as U3 followed by revision number */
 	if ((reg & DWC3_GSNPSID_MASK) != 0x55330000) {
 		dev_err(dwc->dev, "this is not a DesignWare USB3 DRD Core\n");
 		ret = -ENODEV;
 		goto err0;
 	}
 	dwc->revision = reg & DWC3_GSNPSREV_MASK;

 	dwc3_core_soft_reset(dwc);

 	/* issue device SoftReset too */
 	timeout = jiffies + msecs_to_jiffies(500);
 	dwc3_writel(dwc->regs, DWC3_DCTL, DWC3_DCTL_CSFTRST);
 	do {
 		reg = dwc3_readl(dwc->regs, DWC3_DCTL);
 		if (!(reg & DWC3_DCTL_CSFTRST))
 			break;

 		if (time_after(jiffies, timeout)) {
 			dev_err(dwc->dev, "Reset Timed Out\n");
 			ret = -ETIMEDOUT;
 			goto err0;
 		}

 		cpu_relax();
 	} while (true);

 	ret = dwc3_alloc_event_buffers(dwc, DWC3_EVENT_BUFFERS_NUM,
 			DWC3_EVENT_BUFFERS_SIZE);
 	if (ret) {
 		dev_err(dwc->dev, "failed to allocate event buffers\n");
 		ret = -ENOMEM;
 		goto err1;
 	}

 	ret = dwc3_event_buffers_setup(dwc);
 	if (ret) {
 		dev_err(dwc->dev, "failed to setup event buffers\n");
 		goto err1;
 	}

 	return 0;

 err1:
 	dwc3_free_event_buffers(dwc);

 err0:
 	return ret;
 }

 static void dwc3_core_exit(struct dwc3 *dwc)
 {
 	dwc3_event_buffers_cleanup(dwc);
 	dwc3_free_event_buffers(dwc);
 }

 #define DWC3_ALIGN_MASK		(16 - 1)

 static int __devinit dwc3_probe(struct platform_device *pdev)
 {
 	const struct platform_device_id *id = platform_get_device_id(pdev);
 	struct resource		*res;
 	struct dwc3		*dwc;
 	void __iomem		*regs;
 	unsigned int		features = id->driver_data;
 	int			ret = -ENOMEM;
 	int			irq;
 	void			*mem;

 	mem = kzalloc(sizeof(*dwc) + DWC3_ALIGN_MASK, GFP_KERNEL);
 	if (!mem) {
 		dev_err(&pdev->dev, "not enough memory\n");
 		goto err0;
 	}
 	dwc = PTR_ALIGN(mem, DWC3_ALIGN_MASK + 1);
 	dwc->mem = mem;

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
 		dev_err(&pdev->dev, "missing resource\n");
 		goto err1;
 	}

 	res = request_mem_region(res->start, resource_size(res),
 			dev_name(&pdev->dev));
 	if (!res) {
 		dev_err(&pdev->dev, "can't request mem region\n");
 		goto err1;
 	}

 	regs = ioremap(res->start, resource_size(res));
 	if (!regs) {
 		dev_err(&pdev->dev, "ioremap failed\n");
 		goto err2;
 	}

 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {
 		dev_err(&pdev->dev, "missing IRQ\n");
 		goto err3;
 	}

 	spin_lock_init(&dwc->lock);
 	platform_set_drvdata(pdev, dwc);

 	dwc->regs	= regs;
 	dwc->regs_size	= resource_size(res);
 	dwc->dev	= &pdev->dev;
 	dwc->irq	= irq;

 	pm_runtime_enable(&pdev->dev);
 	pm_runtime_get_sync(&pdev->dev);
 	pm_runtime_forbid(&pdev->dev);

 	ret = dwc3_core_init(dwc);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to initialize core\n");
 		goto err3;
 	}

 	if (features & DWC3_HAS_PERIPHERAL) {
 		ret = dwc3_gadget_init(dwc);
 		if (ret) {
 			dev_err(&pdev->dev, "failed to initialized gadget\n");
 			goto err4;
 		}
 	}

 	ret = dwc3_debugfs_init(dwc);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to initialize debugfs\n");
 		goto err5;
 	}

 	pm_runtime_allow(&pdev->dev);

 	return 0;

 err5:
 	if (features & DWC3_HAS_PERIPHERAL)
 		dwc3_gadget_exit(dwc);

 err4:
 	dwc3_core_exit(dwc);

 err3:
 	iounmap(regs);

 err2:
 	release_mem_region(res->start, resource_size(res));

 err1:
 	kfree(dwc->mem);

 err0:
 	return ret;
 }

 static int __devexit dwc3_remove(struct platform_device *pdev)
 {
 	const struct platform_device_id *id = platform_get_device_id(pdev);
 	struct dwc3	*dwc = platform_get_drvdata(pdev);
 	struct resource	*res;
 	unsigned int	features = id->driver_data;

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

 	pm_runtime_put(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);

 	dwc3_debugfs_exit(dwc);

 	if (features & DWC3_HAS_PERIPHERAL)
 		dwc3_gadget_exit(dwc);

 	dwc3_core_exit(dwc);
 	release_mem_region(res->start, resource_size(res));
 	iounmap(dwc->regs);
 	kfree(dwc->mem);

 	return 0;
 }

 static const struct platform_device_id dwc3_id_table[] __devinitconst = {
 	{
 		.name	= "dwc3-omap",
 		.driver_data = (DWC3_HAS_PERIPHERAL
 			| DWC3_HAS_XHCI
 			| DWC3_HAS_OTG),
 	},
 	{
 		.name	= "dwc3-pci",
 		.driver_data = DWC3_HAS_PERIPHERAL,
 	},
 	{  },	/* Terminating Entry */
 };
 MODULE_DEVICE_TABLE(platform, dwc3_id_table);

 static struct platform_driver dwc3_driver = {
 	.probe		= dwc3_probe,
 	.remove		= __devexit_p(dwc3_remove),
 	.driver		= {
 		.name	= "dwc3",
 	},
 	.id_table	= dwc3_id_table,
 };

 MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
 MODULE_LICENSE("Dual BSD/GPL");
 MODULE_DESCRIPTION("DesignWare USB3 DRD Controller Driver");

 static int __devinit dwc3_init(void)
 {
 	return platform_driver_register(&dwc3_driver);
 }
 module_init(dwc3_init);

 static void __exit dwc3_exit(void)
 {
 	platform_driver_unregister(&dwc3_driver);
 }
 module_exit(dwc3_exit);
	/**
	* core.c - DesignWare USB3 DRD Controller Core file
	*
	* Copyright (C) 2010-2011 Texas Instruments Incorporated - http://www.ti.com
	*
	* Authors: Felipe Balbi <balbi@ti.com>,
	* Sebastian Andrzej Siewior <bigeasy@linutronix.de>
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions, and the following disclaimer,
	* without modification.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* 3. The names of the above-listed copyright holders may not be used
	* to endorse or promote products derived from this software without
	* specific prior written permission.
	*
	* ALTERNATIVELY, this software may be distributed under the terms of the
	* GNU General Public License ("GPL") version 2, as published by the Free
	* Software Foundation.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
	* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
	* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
	* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
	* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
	* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/spinlock.h>
	#include <linux/platform_device.h>
	#include <linux/pm_runtime.h>
	#include <linux/interrupt.h>
	#include <linux/ioport.h>
	#include <linux/io.h>
	#include <linux/list.h>
	#include <linux/delay.h>
	#include <linux/dma-mapping.h>

	#include <linux/usb/ch9.h>
	#include <linux/usb/gadget.h>

	#include "core.h"
	#include "gadget.h"
	#include "io.h"

	#include "debug.h"

	/**
	* dwc3_core_soft_reset - Issues core soft reset and PHY reset
	* @dwc: pointer to our context structure
	*/
	static void dwc3_core_soft_reset(struct dwc3 *dwc)
	{
	u32 reg;

	/* Before Resetting PHY, put Core in Reset */
	reg = dwc3_readl(dwc->regs, DWC3_GCTL);
	reg \|= DWC3_GCTL_CORESOFTRESET;
	dwc3_writel(dwc->regs, DWC3_GCTL, reg);

	/* Assert USB3 PHY reset */
	reg = dwc3_readl(dwc->regs, DWC3_GUSB3PIPECTL(0));
	reg \|= DWC3_GUSB3PIPECTL_PHYSOFTRST;
	dwc3_writel(dwc->regs, DWC3_GUSB3PIPECTL(0), reg);

	/* Assert USB2 PHY reset */
	reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
	reg \|= DWC3_GUSB2PHYCFG_PHYSOFTRST;
	dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);

	mdelay(100);

	/* Clear USB3 PHY reset */
	reg = dwc3_readl(dwc->regs, DWC3_GUSB3PIPECTL(0));
	reg &= ~DWC3_GUSB3PIPECTL_PHYSOFTRST;
	dwc3_writel(dwc->regs, DWC3_GUSB3PIPECTL(0), reg);

	/* Clear USB2 PHY reset */
	reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
	reg &= ~DWC3_GUSB2PHYCFG_PHYSOFTRST;
	dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);

	/* After PHYs are stable we can take Core out of reset state */
	reg = dwc3_readl(dwc->regs, DWC3_GCTL);
	reg &= ~DWC3_GCTL_CORESOFTRESET;
	dwc3_writel(dwc->regs, DWC3_GCTL, reg);
	}

	/**
	* dwc3_free_one_event_buffer - Frees one event buffer
	* @dwc: Pointer to our controller context structure
	* @evt: Pointer to event buffer to be freed
	*/
	static void dwc3_free_one_event_buffer(struct dwc3 *dwc,
	struct dwc3_event_buffer *evt)
	{
	dma_free_coherent(dwc->dev, evt->length, evt->buf, evt->dma);
	kfree(evt);
	}

	/**
	* dwc3_alloc_one_event_buffer - Allocated one event buffer structure
	* @dwc: Pointer to our controller context structure
	* @length: size of the event buffer
	*
	* Returns a pointer to the allocated event buffer structure on succes
	* otherwise ERR_PTR(errno).
	*/
	static struct dwc3_event_buffer *__devinit
	dwc3_alloc_one_event_buffer(struct dwc3 *dwc, unsigned length)
	{
	struct dwc3_event_buffer *evt;

	evt = kzalloc(sizeof(*evt), GFP_KERNEL);
	if (!evt)
	return ERR_PTR(-ENOMEM);

	evt->dwc = dwc;
	evt->length = length;
	evt->buf = dma_alloc_coherent(dwc->dev, length,
	&evt->dma, GFP_KERNEL);
	if (!evt->buf) {
	kfree(evt);
	return ERR_PTR(-ENOMEM);
	}

	return evt;
	}

	/**
	* dwc3_free_event_buffers - frees all allocated event buffers
	* @dwc: Pointer to our controller context structure
	*/
	static void dwc3_free_event_buffers(struct dwc3 *dwc)
	{
	struct dwc3_event_buffer *evt;
	int i;

	for (i = 0; i < DWC3_EVENT_BUFFERS_NUM; i++) {
	evt = dwc->ev_buffs[i];
	if (evt) {
	dwc3_free_one_event_buffer(dwc, evt);
	dwc->ev_buffs[i] = NULL;
	}
	}
	}

	/**
	* dwc3_alloc_event_buffers - Allocates @num event buffers of size @length
	* @dwc: Pointer to out controller context structure
	* @num: number of event buffers to allocate
	* @length: size of event buffer
	*
	* Returns 0 on success otherwise negative errno. In error the case, dwc
	* may contain some buffers allocated but not all which were requested.
	*/
	static int __devinit dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned num,
	unsigned length)
	{
	int i;

	for (i = 0; i < num; i++) {
	struct dwc3_event_buffer *evt;

	evt = dwc3_alloc_one_event_buffer(dwc, length);
	if (IS_ERR(evt)) {
	dev_err(dwc->dev, "can't allocate event buffer\n");
	return PTR_ERR(evt);
	}
	dwc->ev_buffs[i] = evt;
	}

	return 0;
	}

	/**
	* dwc3_event_buffers_setup - setup our allocated event buffers
	* @dwc: Pointer to out controller context structure
	*
	* Returns 0 on success otherwise negative errno.
	*/
	static int __devinit dwc3_event_buffers_setup(struct dwc3 *dwc)
	{
	struct dwc3_event_buffer *evt;
	int n;

	for (n = 0; n < DWC3_EVENT_BUFFERS_NUM; n++) {
	evt = dwc->ev_buffs[n];
	dev_dbg(dwc->dev, "Event buf %p dma %08llx length %d\n",
	evt->buf, (unsigned long long) evt->dma,
	evt->length);

	dwc3_writel(dwc->regs, DWC3_GEVNTADRLO(n),
	lower_32_bits(evt->dma));
	dwc3_writel(dwc->regs, DWC3_GEVNTADRHI(n),
	upper_32_bits(evt->dma));
	dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(n),
	evt->length & 0xffff);
	dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(n), 0);
	}

	return 0;
	}

	static void dwc3_event_buffers_cleanup(struct dwc3 *dwc)
	{
	struct dwc3_event_buffer *evt;
	int n;

	for (n = 0; n < DWC3_EVENT_BUFFERS_NUM; n++) {
	evt = dwc->ev_buffs[n];
	dwc3_writel(dwc->regs, DWC3_GEVNTADRLO(n), 0);
	dwc3_writel(dwc->regs, DWC3_GEVNTADRHI(n), 0);
	dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(n), 0);
	dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(n), 0);
	}
	}

	/**
	* dwc3_core_init - Low-level initialization of DWC3 Core
	* @dwc: Pointer to our controller context structure
	*
	* Returns 0 on success otherwise negative errno.
	*/
	static int __devinit dwc3_core_init(struct dwc3 *dwc)
	{
	unsigned long timeout;
	u32 reg;
	int ret;

	reg = dwc3_readl(dwc->regs, DWC3_GSNPSID);
	/* This should read as U3 followed by revision number */
	if ((reg & DWC3_GSNPSID_MASK) != 0x55330000) {
	dev_err(dwc->dev, "this is not a DesignWare USB3 DRD Core\n");
	ret = -ENODEV;
	goto err0;
	}
	dwc->revision = reg & DWC3_GSNPSREV_MASK;

	dwc3_core_soft_reset(dwc);

	/* issue device SoftReset too */
	timeout = jiffies + msecs_to_jiffies(500);
	dwc3_writel(dwc->regs, DWC3_DCTL, DWC3_DCTL_CSFTRST);
	do {
	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
	if (!(reg & DWC3_DCTL_CSFTRST))
	break;

	if (time_after(jiffies, timeout)) {
	dev_err(dwc->dev, "Reset Timed Out\n");
	ret = -ETIMEDOUT;
	goto err0;
	}

	cpu_relax();
	} while (true);

	ret = dwc3_alloc_event_buffers(dwc, DWC3_EVENT_BUFFERS_NUM,
	DWC3_EVENT_BUFFERS_SIZE);
	if (ret) {
	dev_err(dwc->dev, "failed to allocate event buffers\n");
	ret = -ENOMEM;
	goto err1;
	}

	ret = dwc3_event_buffers_setup(dwc);
	if (ret) {
	dev_err(dwc->dev, "failed to setup event buffers\n");
	goto err1;
	}

	return 0;

	err1:
	dwc3_free_event_buffers(dwc);

	err0:
	return ret;
	}

	static void dwc3_core_exit(struct dwc3 *dwc)
	{
	dwc3_event_buffers_cleanup(dwc);
	dwc3_free_event_buffers(dwc);
	}

	#define DWC3_ALIGN_MASK (16 - 1)

	static int __devinit dwc3_probe(struct platform_device *pdev)
	{
	const struct platform_device_id *id = platform_get_device_id(pdev);
	struct resource *res;
	struct dwc3 *dwc;
	void __iomem *regs;
	unsigned int features = id->driver_data;
	int ret = -ENOMEM;
	int irq;
	void *mem;

	mem = kzalloc(sizeof(*dwc) + DWC3_ALIGN_MASK, GFP_KERNEL);
	if (!mem) {
	dev_err(&pdev->dev, "not enough memory\n");
	goto err0;
	}
	dwc = PTR_ALIGN(mem, DWC3_ALIGN_MASK + 1);
	dwc->mem = mem;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
	dev_err(&pdev->dev, "missing resource\n");
	goto err1;
	}

	res = request_mem_region(res->start, resource_size(res),
	dev_name(&pdev->dev));
	if (!res) {
	dev_err(&pdev->dev, "can't request mem region\n");
	goto err1;
	}

	regs = ioremap(res->start, resource_size(res));
	if (!regs) {
	dev_err(&pdev->dev, "ioremap failed\n");
	goto err2;
	}

	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
	dev_err(&pdev->dev, "missing IRQ\n");
	goto err3;
	}

	spin_lock_init(&dwc->lock);
	platform_set_drvdata(pdev, dwc);

	dwc->regs = regs;
	dwc->regs_size = resource_size(res);
	dwc->dev = &pdev->dev;
	dwc->irq = irq;

	pm_runtime_enable(&pdev->dev);
	pm_runtime_get_sync(&pdev->dev);
	pm_runtime_forbid(&pdev->dev);

	ret = dwc3_core_init(dwc);
	if (ret) {
	dev_err(&pdev->dev, "failed to initialize core\n");
	goto err3;
	}

	if (features & DWC3_HAS_PERIPHERAL) {
	ret = dwc3_gadget_init(dwc);
	if (ret) {
	dev_err(&pdev->dev, "failed to initialized gadget\n");
	goto err4;
	}
	}

	ret = dwc3_debugfs_init(dwc);
	if (ret) {
	dev_err(&pdev->dev, "failed to initialize debugfs\n");
	goto err5;
	}

	pm_runtime_allow(&pdev->dev);

	return 0;

	err5:
	if (features & DWC3_HAS_PERIPHERAL)
	dwc3_gadget_exit(dwc);

	err4:
	dwc3_core_exit(dwc);

	err3:
	iounmap(regs);

	err2:
	release_mem_region(res->start, resource_size(res));

	err1:
	kfree(dwc->mem);

	err0:
	return ret;
	}

	static int __devexit dwc3_remove(struct platform_device *pdev)
	{
	const struct platform_device_id *id = platform_get_device_id(pdev);
	struct dwc3 *dwc = platform_get_drvdata(pdev);
	struct resource *res;
	unsigned int features = id->driver_data;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	pm_runtime_put(&pdev->dev);
	pm_runtime_disable(&pdev->dev);

	dwc3_debugfs_exit(dwc);

	if (features & DWC3_HAS_PERIPHERAL)
	dwc3_gadget_exit(dwc);

	dwc3_core_exit(dwc);
	release_mem_region(res->start, resource_size(res));
	iounmap(dwc->regs);
	kfree(dwc->mem);

	return 0;
	}

	static const struct platform_device_id dwc3_id_table[] __devinitconst = {
	{
	.name = "dwc3-omap",
	.driver_data = (DWC3_HAS_PERIPHERAL
	\| DWC3_HAS_XHCI
	\| DWC3_HAS_OTG),
	},
	{
	.name = "dwc3-pci",
	.driver_data = DWC3_HAS_PERIPHERAL,
	},
	{ }, /* Terminating Entry */
	};
	MODULE_DEVICE_TABLE(platform, dwc3_id_table);

	static struct platform_driver dwc3_driver = {
	.probe = dwc3_probe,
	.remove = __devexit_p(dwc3_remove),
	.driver = {
	.name = "dwc3",
	},
	.id_table = dwc3_id_table,
	};

	MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
	MODULE_LICENSE("Dual BSD/GPL");
	MODULE_DESCRIPTION("DesignWare USB3 DRD Controller Driver");

	static int __devinit dwc3_init(void)
	{
	return platform_driver_register(&dwc3_driver);
	}
	module_init(dwc3_init);

	static void __exit dwc3_exit(void)
	{
	platform_driver_unregister(&dwc3_driver);
	}
	module_exit(dwc3_exit);