usb: Introduce DesignWare USB3 DRD Driver

The DesignWare USB3 is a highly
configurable IP Core which can be
instantiated as Dual-Role Device (DRD),
Peripheral Only and Host Only (XHCI)
configurations.

Several other parameters can be configured
like amount of FIFO space, amount of TX and
RX endpoints, amount of Host Interrupters,
etc.

The current driver has been validated with
a virtual model of version 1.73a of that core
and with an FPGA burned with version 1.83a
of the DRD core. We have support for PCIe
bus, which is used on FPGA prototyping, and
for the OMAP5, more adaptation (or glue)
layers can be easily added and the driver
is half prepared to handle any possible
configuration the HW engineer has chosen
considering we have the information on
one of the GHWPARAMS registers to do
runtime checking of certain features.

More runtime checks can, and should, be added
in order to make this driver even more flexible
with regards to number of endpoints, FIFO sizes,
transfer types, etc.

While this supports only the device side, for
now, we will add support for Host side (xHCI -
see the updated series Sebastian has sent [1])
and OTG after we have it all stabilized.

[1] http://marc.info/?l=linux-usb&m=131341992020339&w=2

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 534 insertions, 0 deletions

diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
new file mode 100644
index 0000000..432df53
--- /dev/null
+++ b/drivers/usb/dwc3/debugfs.c
@@ -0,0 +1,534 @@
+/**
+ * debugfs.c - DesignWare USB3 DRD Controller DebugFS file
+ *
+ * Copyright (C) 2010-2011 Texas Instruments Incorporated - http://www.ti.com
+ * All rights reserved.
+ *
+ * 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/kernel.h>
+#include <linux/slab.h>
+#include <linux/ptrace.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/delay.h>
+
+#include <asm/uaccess.h>
+
+#include "core.h"
+#include "gadget.h"
+#include "io.h"
+
+struct dwc3_register {
+	const char	*name;
+	u32		offset;
+};
+
+#define dump_register(nm)				\
+{							\
+	.name	= __stringify(nm),			\
+	.offset	= DWC3_ ##nm,				\
+}
+
+static const struct dwc3_register dwc3_regs[] = {
+	dump_register(GSBUSCFG0),
+	dump_register(GSBUSCFG1),
+	dump_register(GTXTHRCFG),
+	dump_register(GRXTHRCFG),
+	dump_register(GCTL),
+	dump_register(GEVTEN),
+	dump_register(GSTS),
+	dump_register(GSNPSID),
+	dump_register(GGPIO),
+	dump_register(GUID),
+	dump_register(GUCTL),
+	dump_register(GBUSERRADDR0),
+	dump_register(GBUSERRADDR1),
+	dump_register(GPRTBIMAP0),
+	dump_register(GPRTBIMAP1),
+	dump_register(GHWPARAMS0),
+	dump_register(GHWPARAMS1),
+	dump_register(GHWPARAMS2),
+	dump_register(GHWPARAMS3),
+	dump_register(GHWPARAMS4),
+	dump_register(GHWPARAMS5),
+	dump_register(GHWPARAMS6),
+	dump_register(GHWPARAMS7),
+	dump_register(GDBGFIFOSPACE),
+	dump_register(GDBGLTSSM),
+	dump_register(GPRTBIMAP_HS0),
+	dump_register(GPRTBIMAP_HS1),
+	dump_register(GPRTBIMAP_FS0),
+	dump_register(GPRTBIMAP_FS1),
+
+	dump_register(GUSB2PHYCFG(0)),
+	dump_register(GUSB2PHYCFG(1)),
+	dump_register(GUSB2PHYCFG(2)),
+	dump_register(GUSB2PHYCFG(3)),
+	dump_register(GUSB2PHYCFG(4)),
+	dump_register(GUSB2PHYCFG(5)),
+	dump_register(GUSB2PHYCFG(6)),
+	dump_register(GUSB2PHYCFG(7)),
+	dump_register(GUSB2PHYCFG(8)),
+	dump_register(GUSB2PHYCFG(9)),
+	dump_register(GUSB2PHYCFG(10)),
+	dump_register(GUSB2PHYCFG(11)),
+	dump_register(GUSB2PHYCFG(12)),
+	dump_register(GUSB2PHYCFG(13)),
+	dump_register(GUSB2PHYCFG(14)),
+	dump_register(GUSB2PHYCFG(15)),
+
+	dump_register(GUSB2I2CCTL(0)),
+	dump_register(GUSB2I2CCTL(1)),
+	dump_register(GUSB2I2CCTL(2)),
+	dump_register(GUSB2I2CCTL(3)),
+	dump_register(GUSB2I2CCTL(4)),
+	dump_register(GUSB2I2CCTL(5)),
+	dump_register(GUSB2I2CCTL(6)),
+	dump_register(GUSB2I2CCTL(7)),
+	dump_register(GUSB2I2CCTL(8)),
+	dump_register(GUSB2I2CCTL(9)),
+	dump_register(GUSB2I2CCTL(10)),
+	dump_register(GUSB2I2CCTL(11)),
+	dump_register(GUSB2I2CCTL(12)),
+	dump_register(GUSB2I2CCTL(13)),
+	dump_register(GUSB2I2CCTL(14)),
+	dump_register(GUSB2I2CCTL(15)),
+
+	dump_register(GUSB2PHYACC(0)),
+	dump_register(GUSB2PHYACC(1)),
+	dump_register(GUSB2PHYACC(2)),
+	dump_register(GUSB2PHYACC(3)),
+	dump_register(GUSB2PHYACC(4)),
+	dump_register(GUSB2PHYACC(5)),
+	dump_register(GUSB2PHYACC(6)),
+	dump_register(GUSB2PHYACC(7)),
+	dump_register(GUSB2PHYACC(8)),
+	dump_register(GUSB2PHYACC(9)),
+	dump_register(GUSB2PHYACC(10)),
+	dump_register(GUSB2PHYACC(11)),
+	dump_register(GUSB2PHYACC(12)),
+	dump_register(GUSB2PHYACC(13)),
+	dump_register(GUSB2PHYACC(14)),
+	dump_register(GUSB2PHYACC(15)),
+
+	dump_register(GUSB3PIPECTL(0)),
+	dump_register(GUSB3PIPECTL(1)),
+	dump_register(GUSB3PIPECTL(2)),
+	dump_register(GUSB3PIPECTL(3)),
+	dump_register(GUSB3PIPECTL(4)),
+	dump_register(GUSB3PIPECTL(5)),
+	dump_register(GUSB3PIPECTL(6)),
+	dump_register(GUSB3PIPECTL(7)),
+	dump_register(GUSB3PIPECTL(8)),
+	dump_register(GUSB3PIPECTL(9)),
+	dump_register(GUSB3PIPECTL(10)),
+	dump_register(GUSB3PIPECTL(11)),
+	dump_register(GUSB3PIPECTL(12)),
+	dump_register(GUSB3PIPECTL(13)),
+	dump_register(GUSB3PIPECTL(14)),
+	dump_register(GUSB3PIPECTL(15)),
+
+	dump_register(GTXFIFOSIZ(0)),
+	dump_register(GTXFIFOSIZ(1)),
+	dump_register(GTXFIFOSIZ(2)),
+	dump_register(GTXFIFOSIZ(3)),
+	dump_register(GTXFIFOSIZ(4)),
+	dump_register(GTXFIFOSIZ(5)),
+	dump_register(GTXFIFOSIZ(6)),
+	dump_register(GTXFIFOSIZ(7)),
+	dump_register(GTXFIFOSIZ(8)),
+	dump_register(GTXFIFOSIZ(9)),
+	dump_register(GTXFIFOSIZ(10)),
+	dump_register(GTXFIFOSIZ(11)),
+	dump_register(GTXFIFOSIZ(12)),
+	dump_register(GTXFIFOSIZ(13)),
+	dump_register(GTXFIFOSIZ(14)),
+	dump_register(GTXFIFOSIZ(15)),
+	dump_register(GTXFIFOSIZ(16)),
+	dump_register(GTXFIFOSIZ(17)),
+	dump_register(GTXFIFOSIZ(18)),
+	dump_register(GTXFIFOSIZ(19)),
+	dump_register(GTXFIFOSIZ(20)),
+	dump_register(GTXFIFOSIZ(21)),
+	dump_register(GTXFIFOSIZ(22)),
+	dump_register(GTXFIFOSIZ(23)),
+	dump_register(GTXFIFOSIZ(24)),
+	dump_register(GTXFIFOSIZ(25)),
+	dump_register(GTXFIFOSIZ(26)),
+	dump_register(GTXFIFOSIZ(27)),
+	dump_register(GTXFIFOSIZ(28)),
+	dump_register(GTXFIFOSIZ(29)),
+	dump_register(GTXFIFOSIZ(30)),
+	dump_register(GTXFIFOSIZ(31)),
+
+	dump_register(GRXFIFOSIZ(0)),
+	dump_register(GRXFIFOSIZ(1)),
+	dump_register(GRXFIFOSIZ(2)),
+	dump_register(GRXFIFOSIZ(3)),
+	dump_register(GRXFIFOSIZ(4)),
+	dump_register(GRXFIFOSIZ(5)),
+	dump_register(GRXFIFOSIZ(6)),
+	dump_register(GRXFIFOSIZ(7)),
+	dump_register(GRXFIFOSIZ(8)),
+	dump_register(GRXFIFOSIZ(9)),
+	dump_register(GRXFIFOSIZ(10)),
+	dump_register(GRXFIFOSIZ(11)),
+	dump_register(GRXFIFOSIZ(12)),
+	dump_register(GRXFIFOSIZ(13)),
+	dump_register(GRXFIFOSIZ(14)),
+	dump_register(GRXFIFOSIZ(15)),
+	dump_register(GRXFIFOSIZ(16)),
+	dump_register(GRXFIFOSIZ(17)),
+	dump_register(GRXFIFOSIZ(18)),
+	dump_register(GRXFIFOSIZ(19)),
+	dump_register(GRXFIFOSIZ(20)),
+	dump_register(GRXFIFOSIZ(21)),
+	dump_register(GRXFIFOSIZ(22)),
+	dump_register(GRXFIFOSIZ(23)),
+	dump_register(GRXFIFOSIZ(24)),
+	dump_register(GRXFIFOSIZ(25)),
+	dump_register(GRXFIFOSIZ(26)),
+	dump_register(GRXFIFOSIZ(27)),
+	dump_register(GRXFIFOSIZ(28)),
+	dump_register(GRXFIFOSIZ(29)),
+	dump_register(GRXFIFOSIZ(30)),
+	dump_register(GRXFIFOSIZ(31)),
+
+	dump_register(GEVNTADRLO(0)),
+	dump_register(GEVNTADRHI(0)),
+	dump_register(GEVNTSIZ(0)),
+	dump_register(GEVNTCOUNT(0)),
+
+	dump_register(GHWPARAMS8),
+	dump_register(DCFG),
+	dump_register(DCTL),
+	dump_register(DEVTEN),
+	dump_register(DSTS),
+	dump_register(DGCMDPAR),
+	dump_register(DGCMD),
+	dump_register(DALEPENA),
+
+	dump_register(DEPCMDPAR2(0)),
+	dump_register(DEPCMDPAR2(1)),
+	dump_register(DEPCMDPAR2(2)),
+	dump_register(DEPCMDPAR2(3)),
+	dump_register(DEPCMDPAR2(4)),
+	dump_register(DEPCMDPAR2(5)),
+	dump_register(DEPCMDPAR2(6)),
+	dump_register(DEPCMDPAR2(7)),
+	dump_register(DEPCMDPAR2(8)),
+	dump_register(DEPCMDPAR2(9)),
+	dump_register(DEPCMDPAR2(10)),
+	dump_register(DEPCMDPAR2(11)),
+	dump_register(DEPCMDPAR2(12)),
+	dump_register(DEPCMDPAR2(13)),
+	dump_register(DEPCMDPAR2(14)),
+	dump_register(DEPCMDPAR2(15)),
+	dump_register(DEPCMDPAR2(16)),
+	dump_register(DEPCMDPAR2(17)),
+	dump_register(DEPCMDPAR2(18)),
+	dump_register(DEPCMDPAR2(19)),
+	dump_register(DEPCMDPAR2(20)),
+	dump_register(DEPCMDPAR2(21)),
+	dump_register(DEPCMDPAR2(22)),
+	dump_register(DEPCMDPAR2(23)),
+	dump_register(DEPCMDPAR2(24)),
+	dump_register(DEPCMDPAR2(25)),
+	dump_register(DEPCMDPAR2(26)),
+	dump_register(DEPCMDPAR2(27)),
+	dump_register(DEPCMDPAR2(28)),
+	dump_register(DEPCMDPAR2(29)),
+	dump_register(DEPCMDPAR2(30)),
+	dump_register(DEPCMDPAR2(31)),
+
+	dump_register(DEPCMDPAR1(0)),
+	dump_register(DEPCMDPAR1(1)),
+	dump_register(DEPCMDPAR1(2)),
+	dump_register(DEPCMDPAR1(3)),
+	dump_register(DEPCMDPAR1(4)),
+	dump_register(DEPCMDPAR1(5)),
+	dump_register(DEPCMDPAR1(6)),
+	dump_register(DEPCMDPAR1(7)),
+	dump_register(DEPCMDPAR1(8)),
+	dump_register(DEPCMDPAR1(9)),
+	dump_register(DEPCMDPAR1(10)),
+	dump_register(DEPCMDPAR1(11)),
+	dump_register(DEPCMDPAR1(12)),
+	dump_register(DEPCMDPAR1(13)),
+	dump_register(DEPCMDPAR1(14)),
+	dump_register(DEPCMDPAR1(15)),
+	dump_register(DEPCMDPAR1(16)),
+	dump_register(DEPCMDPAR1(17)),
+	dump_register(DEPCMDPAR1(18)),
+	dump_register(DEPCMDPAR1(19)),
+	dump_register(DEPCMDPAR1(20)),
+	dump_register(DEPCMDPAR1(21)),
+	dump_register(DEPCMDPAR1(22)),
+	dump_register(DEPCMDPAR1(23)),
+	dump_register(DEPCMDPAR1(24)),
+	dump_register(DEPCMDPAR1(25)),
+	dump_register(DEPCMDPAR1(26)),
+	dump_register(DEPCMDPAR1(27)),
+	dump_register(DEPCMDPAR1(28)),
+	dump_register(DEPCMDPAR1(29)),
+	dump_register(DEPCMDPAR1(30)),
+	dump_register(DEPCMDPAR1(31)),
+
+	dump_register(DEPCMDPAR0(0)),
+	dump_register(DEPCMDPAR0(1)),
+	dump_register(DEPCMDPAR0(2)),
+	dump_register(DEPCMDPAR0(3)),
+	dump_register(DEPCMDPAR0(4)),
+	dump_register(DEPCMDPAR0(5)),
+	dump_register(DEPCMDPAR0(6)),
+	dump_register(DEPCMDPAR0(7)),
+	dump_register(DEPCMDPAR0(8)),
+	dump_register(DEPCMDPAR0(9)),
+	dump_register(DEPCMDPAR0(10)),
+	dump_register(DEPCMDPAR0(11)),
+	dump_register(DEPCMDPAR0(12)),
+	dump_register(DEPCMDPAR0(13)),
+	dump_register(DEPCMDPAR0(14)),
+	dump_register(DEPCMDPAR0(15)),
+	dump_register(DEPCMDPAR0(16)),
+	dump_register(DEPCMDPAR0(17)),
+	dump_register(DEPCMDPAR0(18)),
+	dump_register(DEPCMDPAR0(19)),
+	dump_register(DEPCMDPAR0(20)),
+	dump_register(DEPCMDPAR0(21)),
+	dump_register(DEPCMDPAR0(22)),
+	dump_register(DEPCMDPAR0(23)),
+	dump_register(DEPCMDPAR0(24)),
+	dump_register(DEPCMDPAR0(25)),
+	dump_register(DEPCMDPAR0(26)),
+	dump_register(DEPCMDPAR0(27)),
+	dump_register(DEPCMDPAR0(28)),
+	dump_register(DEPCMDPAR0(29)),
+	dump_register(DEPCMDPAR0(30)),
+	dump_register(DEPCMDPAR0(31)),
+
+	dump_register(DEPCMD(0)),
+	dump_register(DEPCMD(1)),
+	dump_register(DEPCMD(2)),
+	dump_register(DEPCMD(3)),
+	dump_register(DEPCMD(4)),
+	dump_register(DEPCMD(5)),
+	dump_register(DEPCMD(6)),
+	dump_register(DEPCMD(7)),
+	dump_register(DEPCMD(8)),
+	dump_register(DEPCMD(9)),
+	dump_register(DEPCMD(10)),
+	dump_register(DEPCMD(11)),
+	dump_register(DEPCMD(12)),
+	dump_register(DEPCMD(13)),
+	dump_register(DEPCMD(14)),
+	dump_register(DEPCMD(15)),
+	dump_register(DEPCMD(16)),
+	dump_register(DEPCMD(17)),
+	dump_register(DEPCMD(18)),
+	dump_register(DEPCMD(19)),
+	dump_register(DEPCMD(20)),
+	dump_register(DEPCMD(21)),
+	dump_register(DEPCMD(22)),
+	dump_register(DEPCMD(23)),
+	dump_register(DEPCMD(24)),
+	dump_register(DEPCMD(25)),
+	dump_register(DEPCMD(26)),
+	dump_register(DEPCMD(27)),
+	dump_register(DEPCMD(28)),
+	dump_register(DEPCMD(29)),
+	dump_register(DEPCMD(30)),
+	dump_register(DEPCMD(31)),
+
+	dump_register(OCFG),
+	dump_register(OCTL),
+	dump_register(OEVTEN),
+	dump_register(OSTS),
+};
+
+static int dwc3_regdump_show(struct seq_file *s, void *unused)
+{
+	struct dwc3		*dwc = s->private;
+	int			i;
+
+	seq_printf(s, "DesignWare USB3 Core Register Dump\n");
+
+	for (i = 0; i < ARRAY_SIZE(dwc3_regs); i++) {
+		seq_printf(s, "%-20s :    %08x\n", dwc3_regs[i].name,
+				dwc3_readl(dwc->regs, dwc3_regs[i].offset));
+	}
+
+	return 0;
+}
+
+static int dwc3_regdump_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, dwc3_regdump_show, inode->i_private);
+}
+
+static const struct file_operations dwc3_regdump_fops = {
+	.open			= dwc3_regdump_open,
+	.read			= seq_read,
+	.release		= single_release,
+};
+
+
+static int dwc3_send_testmode_cmd(struct dwc3 *dwc, int mode)
+{
+	u32 timeout = 250;
+
+	dwc3_writel(dwc->regs, DWC3_DGCMDPAR, mode);
+	dwc3_writel(dwc->regs, DWC3_DGCMD, DWC3_DGCMD_RUN_SOC_BUS_LOOPBACK |
+			DWC3_DEPCMD_CMDACT);
+	do {
+		u32 reg;
+
+		reg = dwc3_readl(dwc->regs, DWC3_DGCMD);
+		if (!(reg & DWC3_DEPCMD_CMDACT))
+			return 0;
+		timeout--;
+		if (!timeout)
+			return -ETIMEDOUT;
+		mdelay(1);
+	} while (1);
+}
+
+static struct dwc3_trb_hw trb_0 __aligned(16);
+static struct dwc3_trb_hw trb_1 __aligned(16);
+
+#define BUF_SIZE	4096
+static int dwc3_testmode_open(struct inode *inode, struct file *file)
+{
+	struct dwc3 *dwc = inode->i_private;
+	struct dwc3_gadget_ep_cmd_params par0;
+	struct dwc3_gadget_ep_cmd_params par1;
+	struct dwc3_trb         trb;
+	int ret;
+	u8 *buf0;
+	u8 *buf1;
+
+	buf0 = kmalloc(BUF_SIZE, GFP_KERNEL);
+	if (!buf0)
+		return -ENOMEM;
+	buf1 = kmalloc(BUF_SIZE, GFP_KERNEL);
+	if (!buf1)
+		return -ENOMEM;
+
+	memset(buf0, 0xaa, BUF_SIZE);
+	memset(buf1, 0x33, BUF_SIZE);
+
+	memset(&trb, 0, sizeof(trb));
+	memset(&par0, 0, sizeof(par0));
+	memset(&par1, 0, sizeof(par1));
+
+	trb.lst = 1;
+	trb.trbctl = DWC3_TRBCTL_NORMAL;
+	trb.length = BUF_SIZE;
+	trb.hwo = 1;
+
+	trb.bplh = virt_to_phys(buf0);
+	dwc3_trb_to_hw(&trb, &trb_0);
+
+	trb.bplh = virt_to_phys(buf1);
+	dwc3_trb_to_hw(&trb, &trb_1);
+
+	par0.param0.depstrtxfer.transfer_desc_addr_high =
+		upper_32_bits(virt_to_phys(&trb_0));
+	par0.param1.depstrtxfer.transfer_desc_addr_low =
+		lower_32_bits(virt_to_phys(&trb_0));
+
+	par1.param0.depstrtxfer.transfer_desc_addr_high =
+		upper_32_bits(virt_to_phys(&trb_1));
+	par1.param1.depstrtxfer.transfer_desc_addr_low =
+		lower_32_bits(virt_to_phys(&trb_1));
+
+	dwc3_send_testmode_cmd(dwc, 1);
+
+	ret = dwc3_send_gadget_ep_cmd(dwc, 0, DWC3_DEPCMD_STARTTRANSFER, &par0);
+	ret = dwc3_send_gadget_ep_cmd(dwc, 1, DWC3_DEPCMD_STARTTRANSFER, &par1);
+
+	dwc3_send_testmode_cmd(dwc, 0);
+	return -EBUSY;
+}
+
+static const struct file_operations dwc3_testmode_fops = {
+	.open			= dwc3_testmode_open,
+	.read			= seq_read,
+	.release		= single_release,
+};
+
+int __devinit dwc3_debugfs_init(struct dwc3 *dwc)
+{
+	struct dentry		*root;
+	struct dentry		*file;
+	int			ret;
+
+	root = debugfs_create_dir(dev_name(dwc->dev), NULL);
+	if (IS_ERR(root)){
+		ret = PTR_ERR(root);
+		goto err0;
+	}
+
+	dwc->root = root;
+
+	file = debugfs_create_file("regdump", S_IRUGO, root, dwc,
+			&dwc3_regdump_fops);
+	if (IS_ERR(file)) {
+		ret = PTR_ERR(file);
+		goto err1;
+	}
+	file = debugfs_create_file("testmode", S_IRUGO, root, dwc,
+			&dwc3_testmode_fops);
+	if (IS_ERR(file)) {
+		ret = PTR_ERR(file);
+		goto err1;
+	}
+
+	return 0;
+
+err1:
+	debugfs_remove_recursive(root);
+
+err0:
+	return ret;
+}
+
+void __devexit dwc3_debugfs_exit(struct dwc3 *dwc)
+{
+	debugfs_remove_recursive(dwc->root);
+	dwc->root = NULL;
+}