blob: a49217ae35333846bb76912666f0efa12bca6813 [file] [log] [blame]
/**
* 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>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 of
* the License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#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/of.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/usb/of.h>
#include <linux/usb/otg.h>
#include "platform_data.h"
#include "core.h"
#include "gadget.h"
#include "io.h"
#include "debug.h"
/* -------------------------------------------------------------------------- */
void dwc3_set_mode(struct dwc3 *dwc, u32 mode)
{
u32 reg;
reg = dwc3_readl(dwc->regs, DWC3_GCTL);
reg &= ~(DWC3_GCTL_PRTCAPDIR(DWC3_GCTL_PRTCAP_OTG));
reg |= DWC3_GCTL_PRTCAPDIR(mode);
dwc3_writel(dwc->regs, DWC3_GCTL, reg);
}
/**
* 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);
usb_phy_init(dwc->usb2_phy);
usb_phy_init(dwc->usb3_phy);
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);
mdelay(100);
/* 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);
}
/**
* dwc3_alloc_one_event_buffer - Allocates 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 success
* otherwise ERR_PTR(errno).
*/
static struct dwc3_event_buffer *dwc3_alloc_one_event_buffer(struct dwc3 *dwc,
unsigned length)
{
struct dwc3_event_buffer *evt;
evt = devm_kzalloc(dwc->dev, 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)
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 < dwc->num_event_buffers; i++) {
evt = dwc->ev_buffs[i];
if (evt)
dwc3_free_one_event_buffer(dwc, evt);
}
}
/**
* dwc3_alloc_event_buffers - Allocates @num event buffers of size @length
* @dwc: pointer to our controller context structure
* @length: size of event buffer
*
* Returns 0 on success otherwise negative errno. In the error case, dwc
* may contain some buffers allocated but not all which were requested.
*/
static int dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned length)
{
int num;
int i;
num = DWC3_NUM_INT(dwc->hwparams.hwparams1);
dwc->num_event_buffers = num;
dwc->ev_buffs = devm_kzalloc(dwc->dev, sizeof(*dwc->ev_buffs) * num,
GFP_KERNEL);
if (!dwc->ev_buffs) {
dev_err(dwc->dev, "can't allocate event buffers array\n");
return -ENOMEM;
}
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 our controller context structure
*
* Returns 0 on success otherwise negative errno.
*/
static int dwc3_event_buffers_setup(struct dwc3 *dwc)
{
struct dwc3_event_buffer *evt;
int n;
for (n = 0; n < dwc->num_event_buffers; 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);
evt->lpos = 0;
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),
DWC3_GEVNTSIZ_SIZE(evt->length));
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 < dwc->num_event_buffers; n++) {
evt = dwc->ev_buffs[n];
evt->lpos = 0;
dwc3_writel(dwc->regs, DWC3_GEVNTADRLO(n), 0);
dwc3_writel(dwc->regs, DWC3_GEVNTADRHI(n), 0);
dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(n), DWC3_GEVNTSIZ_INTMASK
| DWC3_GEVNTSIZ_SIZE(0));
dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(n), 0);
}
}
static void dwc3_core_num_eps(struct dwc3 *dwc)
{
struct dwc3_hwparams *parms = &dwc->hwparams;
dwc->num_in_eps = DWC3_NUM_IN_EPS(parms);
dwc->num_out_eps = DWC3_NUM_EPS(parms) - dwc->num_in_eps;
dev_vdbg(dwc->dev, "found %d IN and %d OUT endpoints\n",
dwc->num_in_eps, dwc->num_out_eps);
}
static void dwc3_cache_hwparams(struct dwc3 *dwc)
{
struct dwc3_hwparams *parms = &dwc->hwparams;
parms->hwparams0 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS0);
parms->hwparams1 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS1);
parms->hwparams2 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS2);
parms->hwparams3 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS3);
parms->hwparams4 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS4);
parms->hwparams5 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS5);
parms->hwparams6 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS6);
parms->hwparams7 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS7);
parms->hwparams8 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS8);
}
/**
* 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 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;
/* 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);
dwc3_core_soft_reset(dwc);
reg = dwc3_readl(dwc->regs, DWC3_GCTL);
reg &= ~DWC3_GCTL_SCALEDOWN_MASK;
reg &= ~DWC3_GCTL_DISSCRAMBLE;
switch (DWC3_GHWPARAMS1_EN_PWROPT(dwc->hwparams.hwparams1)) {
case DWC3_GHWPARAMS1_EN_PWROPT_CLK:
reg &= ~DWC3_GCTL_DSBLCLKGTNG;
break;
default:
dev_dbg(dwc->dev, "No power optimization available\n");
}
/*
* WORKAROUND: DWC3 revisions <1.90a have a bug
* where the device can fail to connect at SuperSpeed
* and falls back to high-speed mode which causes
* the device to enter a Connect/Disconnect loop
*/
if (dwc->revision < DWC3_REVISION_190A)
reg |= DWC3_GCTL_U2RSTECN;
dwc3_core_num_eps(dwc);
dwc3_writel(dwc->regs, DWC3_GCTL, reg);
return 0;
err0:
return ret;
}
static void dwc3_core_exit(struct dwc3 *dwc)
{
usb_phy_shutdown(dwc->usb2_phy);
usb_phy_shutdown(dwc->usb3_phy);
}
#define DWC3_ALIGN_MASK (16 - 1)
static int dwc3_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct dwc3_platform_data *pdata = dev_get_platdata(dev);
struct device_node *node = dev->of_node;
struct resource *res;
struct dwc3 *dwc;
int ret = -ENOMEM;
void __iomem *regs;
void *mem;
mem = devm_kzalloc(dev, sizeof(*dwc) + DWC3_ALIGN_MASK, GFP_KERNEL);
if (!mem) {
dev_err(dev, "not enough memory\n");
return -ENOMEM;
}
dwc = PTR_ALIGN(mem, DWC3_ALIGN_MASK + 1);
dwc->mem = mem;
res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!res) {
dev_err(dev, "missing IRQ\n");
return -ENODEV;
}
dwc->xhci_resources[1].start = res->start;
dwc->xhci_resources[1].end = res->end;
dwc->xhci_resources[1].flags = res->flags;
dwc->xhci_resources[1].name = res->name;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(dev, "missing memory resource\n");
return -ENODEV;
}
if (node) {
dwc->maximum_speed = of_usb_get_maximum_speed(node);
dwc->usb2_phy = devm_usb_get_phy_by_phandle(dev, "usb-phy", 0);
dwc->usb3_phy = devm_usb_get_phy_by_phandle(dev, "usb-phy", 1);
dwc->needs_fifo_resize = of_property_read_bool(node, "tx-fifo-resize");
dwc->dr_mode = of_usb_get_dr_mode(node);
} else if (pdata) {
dwc->maximum_speed = pdata->maximum_speed;
dwc->usb2_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2);
dwc->usb3_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB3);
dwc->needs_fifo_resize = pdata->tx_fifo_resize;
dwc->dr_mode = pdata->dr_mode;
} else {
dwc->usb2_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2);
dwc->usb3_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB3);
}
/* default to superspeed if no maximum_speed passed */
if (dwc->maximum_speed == USB_SPEED_UNKNOWN)
dwc->maximum_speed = USB_SPEED_SUPER;
if (IS_ERR(dwc->usb2_phy)) {
ret = PTR_ERR(dwc->usb2_phy);
/*
* if -ENXIO is returned, it means PHY layer wasn't
* enabled, so it makes no sense to return -EPROBE_DEFER
* in that case, since no PHY driver will ever probe.
*/
if (ret == -ENXIO)
return ret;
dev_err(dev, "no usb2 phy configured\n");
return -EPROBE_DEFER;
}
if (IS_ERR(dwc->usb3_phy)) {
ret = PTR_ERR(dwc->usb3_phy);
/*
* if -ENXIO is returned, it means PHY layer wasn't
* enabled, so it makes no sense to return -EPROBE_DEFER
* in that case, since no PHY driver will ever probe.
*/
if (ret == -ENXIO)
return ret;
dev_err(dev, "no usb3 phy configured\n");
return -EPROBE_DEFER;
}
dwc->xhci_resources[0].start = res->start;
dwc->xhci_resources[0].end = dwc->xhci_resources[0].start +
DWC3_XHCI_REGS_END;
dwc->xhci_resources[0].flags = res->flags;
dwc->xhci_resources[0].name = res->name;
res->start += DWC3_GLOBALS_REGS_START;
/*
* Request memory region but exclude xHCI regs,
* since it will be requested by the xhci-plat driver.
*/
regs = devm_ioremap_resource(dev, res);
if (IS_ERR(regs))
return PTR_ERR(regs);
spin_lock_init(&dwc->lock);
platform_set_drvdata(pdev, dwc);
dwc->regs = regs;
dwc->regs_size = resource_size(res);
dwc->dev = dev;
dev->dma_mask = dev->parent->dma_mask;
dev->dma_parms = dev->parent->dma_parms;
dma_set_coherent_mask(dev, dev->parent->coherent_dma_mask);
pm_runtime_enable(dev);
pm_runtime_get_sync(dev);
pm_runtime_forbid(dev);
dwc3_cache_hwparams(dwc);
ret = dwc3_alloc_event_buffers(dwc, DWC3_EVENT_BUFFERS_SIZE);
if (ret) {
dev_err(dwc->dev, "failed to allocate event buffers\n");
ret = -ENOMEM;
goto err0;
}
ret = dwc3_core_init(dwc);
if (ret) {
dev_err(dev, "failed to initialize core\n");
goto err0;
}
usb_phy_set_suspend(dwc->usb2_phy, 0);
usb_phy_set_suspend(dwc->usb3_phy, 0);
ret = dwc3_event_buffers_setup(dwc);
if (ret) {
dev_err(dwc->dev, "failed to setup event buffers\n");
goto err1;
}
if (IS_ENABLED(CONFIG_USB_DWC3_HOST))
dwc->dr_mode = USB_DR_MODE_HOST;
else if (IS_ENABLED(CONFIG_USB_DWC3_GADGET))
dwc->dr_mode = USB_DR_MODE_PERIPHERAL;
if (dwc->dr_mode == USB_DR_MODE_UNKNOWN)
dwc->dr_mode = USB_DR_MODE_OTG;
switch (dwc->dr_mode) {
case USB_DR_MODE_PERIPHERAL:
dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_DEVICE);
ret = dwc3_gadget_init(dwc);
if (ret) {
dev_err(dev, "failed to initialize gadget\n");
goto err2;
}
break;
case USB_DR_MODE_HOST:
dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_HOST);
ret = dwc3_host_init(dwc);
if (ret) {
dev_err(dev, "failed to initialize host\n");
goto err2;
}
break;
case USB_DR_MODE_OTG:
dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
ret = dwc3_host_init(dwc);
if (ret) {
dev_err(dev, "failed to initialize host\n");
goto err2;
}
ret = dwc3_gadget_init(dwc);
if (ret) {
dev_err(dev, "failed to initialize gadget\n");
goto err2;
}
break;
default:
dev_err(dev, "Unsupported mode of operation %d\n", dwc->dr_mode);
goto err2;
}
ret = dwc3_debugfs_init(dwc);
if (ret) {
dev_err(dev, "failed to initialize debugfs\n");
goto err3;
}
pm_runtime_allow(dev);
return 0;
err3:
switch (dwc->dr_mode) {
case USB_DR_MODE_PERIPHERAL:
dwc3_gadget_exit(dwc);
break;
case USB_DR_MODE_HOST:
dwc3_host_exit(dwc);
break;
case USB_DR_MODE_OTG:
dwc3_host_exit(dwc);
dwc3_gadget_exit(dwc);
break;
default:
/* do nothing */
break;
}
err2:
dwc3_event_buffers_cleanup(dwc);
err1:
usb_phy_set_suspend(dwc->usb2_phy, 1);
usb_phy_set_suspend(dwc->usb3_phy, 1);
dwc3_core_exit(dwc);
err0:
dwc3_free_event_buffers(dwc);
return ret;
}
static int dwc3_remove(struct platform_device *pdev)
{
struct dwc3 *dwc = platform_get_drvdata(pdev);
usb_phy_set_suspend(dwc->usb2_phy, 1);
usb_phy_set_suspend(dwc->usb3_phy, 1);
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
dwc3_debugfs_exit(dwc);
switch (dwc->dr_mode) {
case USB_DR_MODE_PERIPHERAL:
dwc3_gadget_exit(dwc);
break;
case USB_DR_MODE_HOST:
dwc3_host_exit(dwc);
break;
case USB_DR_MODE_OTG:
dwc3_host_exit(dwc);
dwc3_gadget_exit(dwc);
break;
default:
/* do nothing */
break;
}
dwc3_event_buffers_cleanup(dwc);
dwc3_free_event_buffers(dwc);
dwc3_core_exit(dwc);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int dwc3_prepare(struct device *dev)
{
struct dwc3 *dwc = dev_get_drvdata(dev);
unsigned long flags;
spin_lock_irqsave(&dwc->lock, flags);
switch (dwc->dr_mode) {
case USB_DR_MODE_PERIPHERAL:
case USB_DR_MODE_OTG:
dwc3_gadget_prepare(dwc);
/* FALLTHROUGH */
case USB_DR_MODE_HOST:
default:
dwc3_event_buffers_cleanup(dwc);
break;
}
spin_unlock_irqrestore(&dwc->lock, flags);
return 0;
}
static void dwc3_complete(struct device *dev)
{
struct dwc3 *dwc = dev_get_drvdata(dev);
unsigned long flags;
spin_lock_irqsave(&dwc->lock, flags);
switch (dwc->dr_mode) {
case USB_DR_MODE_PERIPHERAL:
case USB_DR_MODE_OTG:
dwc3_gadget_complete(dwc);
/* FALLTHROUGH */
case USB_DR_MODE_HOST:
default:
dwc3_event_buffers_setup(dwc);
break;
}
spin_unlock_irqrestore(&dwc->lock, flags);
}
static int dwc3_suspend(struct device *dev)
{
struct dwc3 *dwc = dev_get_drvdata(dev);
unsigned long flags;
spin_lock_irqsave(&dwc->lock, flags);
switch (dwc->dr_mode) {
case USB_DR_MODE_PERIPHERAL:
case USB_DR_MODE_OTG:
dwc3_gadget_suspend(dwc);
/* FALLTHROUGH */
case USB_DR_MODE_HOST:
default:
/* do nothing */
break;
}
dwc->gctl = dwc3_readl(dwc->regs, DWC3_GCTL);
spin_unlock_irqrestore(&dwc->lock, flags);
usb_phy_shutdown(dwc->usb3_phy);
usb_phy_shutdown(dwc->usb2_phy);
return 0;
}
static int dwc3_resume(struct device *dev)
{
struct dwc3 *dwc = dev_get_drvdata(dev);
unsigned long flags;
usb_phy_init(dwc->usb3_phy);
usb_phy_init(dwc->usb2_phy);
spin_lock_irqsave(&dwc->lock, flags);
dwc3_writel(dwc->regs, DWC3_GCTL, dwc->gctl);
switch (dwc->dr_mode) {
case USB_DR_MODE_PERIPHERAL:
case USB_DR_MODE_OTG:
dwc3_gadget_resume(dwc);
/* FALLTHROUGH */
case USB_DR_MODE_HOST:
default:
/* do nothing */
break;
}
spin_unlock_irqrestore(&dwc->lock, flags);
pm_runtime_disable(dev);
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
return 0;
}
static const struct dev_pm_ops dwc3_dev_pm_ops = {
.prepare = dwc3_prepare,
.complete = dwc3_complete,
SET_SYSTEM_SLEEP_PM_OPS(dwc3_suspend, dwc3_resume)
};
#define DWC3_PM_OPS &(dwc3_dev_pm_ops)
#else
#define DWC3_PM_OPS NULL
#endif
#ifdef CONFIG_OF
static const struct of_device_id of_dwc3_match[] = {
{
.compatible = "snps,dwc3"
},
{
.compatible = "synopsys,dwc3"
},
{ },
};
MODULE_DEVICE_TABLE(of, of_dwc3_match);
#endif
static struct platform_driver dwc3_driver = {
.probe = dwc3_probe,
.remove = dwc3_remove,
.driver = {
.name = "dwc3",
.of_match_table = of_match_ptr(of_dwc3_match),
.pm = DWC3_PM_OPS,
},
};
module_platform_driver(dwc3_driver);
MODULE_ALIAS("platform:dwc3");
MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("DesignWare USB3 DRD Controller Driver");