[V2,5/6] USB: OHCI: make ohci-at91 a separate driver

Message ID 1371052442-14541-6-git-send-email-manjunath.goudar@linaro.org
State Superseded
Headers show

Commit Message

manjunath.goudar@linaro.org June 12, 2013, 3:54 p.m.
Separate the  TI OHCI Atmel host controller driver from ohci-hcd
host code so that it can be built as a separate driver module.
This work is part of enabling multi-platform kernels on ARM;
it would be nice to have in 3.11.

V2:
 -Set non-standard fields in ohci_at91_hc_driver manually, rather than
  relying on an expanded struct ohci_driver_overrides.
 -Save orig_ohci_hub_control and orig_ohci_hub_status_data rather than
  relying on ohci_hub_control and hub_status_data being exported.
 -ohci_setup() has been removed because it is called in .reset member
  of the ohci_hc_driver structure.

Signed-off-by: Manjunath Goudar <manjunath.goudar@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Greg KH <greg@kroah.com>
Cc: linux-usb@vger.kernel.org
---
 drivers/usb/host/Kconfig     |    8 +++
 drivers/usb/host/Makefile    |    1 +
 drivers/usb/host/ohci-at91.c |  148 +++++++++++++++++++-----------------------
 drivers/usb/host/ohci-hcd.c  |   18 -----
 4 files changed, 74 insertions(+), 101 deletions(-)

Comments

Alan Stern June 19, 2013, 8:16 p.m. | #1
On Wed, 12 Jun 2013, Manjunath Goudar wrote:

> Separate the  TI OHCI Atmel host controller driver from ohci-hcd
> host code so that it can be built as a separate driver module.
> This work is part of enabling multi-platform kernels on ARM;
> it would be nice to have in 3.11.
> 
> V2:
>  -Set non-standard fields in ohci_at91_hc_driver manually, rather than
>   relying on an expanded struct ohci_driver_overrides.
>  -Save orig_ohci_hub_control and orig_ohci_hub_status_data rather than
>   relying on ohci_hub_control and hub_status_data being exported.
>  -ohci_setup() has been removed because it is called in .reset member
>   of the ohci_hc_driver structure.

> @@ -111,6 +125,8 @@ static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *);
>  static int usb_hcd_at91_probe(const struct hc_driver *driver,
>  			struct platform_device *pdev)
>  {
> +	struct at91_usbh_data	*board;
> +	struct ohci_hcd	*ohci;

Variables are supposed to be not aligned at all (in which case you 
don't use tabs) or all aligned the same way.  In this case you put a 
tab before the "*board"; therefore the "*ohci" should line up with it.

No, this isn't an artifact of my email program.  They really are not
aligned.

> @@ -163,8 +179,11 @@ static int usb_hcd_at91_probe(const struct hc_driver *driver,
>  		goto err5;
>  	}
>  
> +	board = hcd->self.controller->platform_data;
> +	ohci = hcd_to_ohci(hcd);
> +	ohci->num_ports = board->ports;
>  	at91_start_hc(pdev);
> -	ohci_hcd_init(hcd_to_ohci(hcd));
> +	ohci_setup(hcd);

Didn't you say above that this version of the patch removes the call to 
ohci_setup()?

> @@ -686,7 +631,7 @@ ohci_hcd_at91_drv_suspend(struct platform_device *pdev, pm_message_t mesg)
>  	 * REVISIT: some boards will be able to turn VBUS off...
>  	 */
>  	if (at91_suspend_entering_slow_clock()) {
> -		ohci_usb_reset (ohci);
> +		ohci_restart(ohci);

Why did you change this?  Did we discuss it earlier?

Alan Stern
manjunath.goudar@linaro.org June 20, 2013, 2:58 p.m. | #2
On 20 June 2013 01:46, Alan Stern <stern@rowland.harvard.edu> wrote:

> On Wed, 12 Jun 2013, Manjunath Goudar wrote:
>
> > Separate the  TI OHCI Atmel host controller driver from ohci-hcd
> > host code so that it can be built as a separate driver module.
> > This work is part of enabling multi-platform kernels on ARM;
> > it would be nice to have in 3.11.
> >
> > V2:
> >  -Set non-standard fields in ohci_at91_hc_driver manually, rather than
> >   relying on an expanded struct ohci_driver_overrides.
> >  -Save orig_ohci_hub_control and orig_ohci_hub_status_data rather than
> >   relying on ohci_hub_control and hub_status_data being exported.
> >  -ohci_setup() has been removed because it is called in .reset member
> >   of the ohci_hc_driver structure.
>
> > @@ -111,6 +125,8 @@ static void usb_hcd_at91_remove (struct usb_hcd *,
> struct platform_device *);
> >  static int usb_hcd_at91_probe(const struct hc_driver *driver,
> >                       struct platform_device *pdev)
> >  {
> > +     struct at91_usbh_data   *board;
> > +     struct ohci_hcd *ohci;
>
> Variables are supposed to be not aligned at all (in which case you
> don't use tabs) or all aligned the same way.  In this case you put a
> tab before the "*board"; therefore the "*ohci" should line up with it.
>
> No, this isn't an artifact of my email program.  They really are not
> aligned.
>
> > @@ -163,8 +179,11 @@ static int usb_hcd_at91_probe(const struct
> hc_driver *driver,
> >               goto err5;
> >       }
> >
> > +     board = hcd->self.controller->platform_data;
> > +     ohci = hcd_to_ohci(hcd);
> > +     ohci->num_ports = board->ports;
> >       at91_start_hc(pdev);
> > -     ohci_hcd_init(hcd_to_ohci(hcd));
> > +     ohci_setup(hcd);
>
> Didn't you say above that this version of the patch removes the call to
> ohci_setup()?


> > @@ -686,7 +631,7 @@ ohci_hcd_at91_drv_suspend(struct platform_device
> *pdev, pm_message_t mesg)
> >        * REVISIT: some boards will be able to turn VBUS off...
> >        */
> >       if (at91_suspend_entering_slow_clock()) {
> > -             ohci_usb_reset (ohci);
> > +             ohci_restart(ohci);
>
> Why did you change this?  Did we discuss it earlier?
>

We are not discussed  regarding this,I think we need to call
use ohci_resume() instead of ohci_restart().

Manjunath Goudar

>
> Alan Stern
>
>
Alan Stern June 20, 2013, 4:53 p.m. | #3
On Thu, 20 Jun 2013, Manjunath Goudar wrote:

> > > @@ -686,7 +631,7 @@ ohci_hcd_at91_drv_suspend(struct platform_device
> > *pdev, pm_message_t mesg)
> > >        * REVISIT: some boards will be able to turn VBUS off...
> > >        */
> > >       if (at91_suspend_entering_slow_clock()) {
> > > -             ohci_usb_reset (ohci);
> > > +             ohci_restart(ohci);
> >
> > Why did you change this?  Did we discuss it earlier?
> >
> 
> We are not discussed  regarding this,I think we need to call
> use ohci_resume() instead of ohci_restart().

Why?  Don't you think the current code has a good reason for calling 
ohci_usb_reset()?

Alan Stern
manjunath.goudar@linaro.org June 21, 2013, 6:56 a.m. | #4
On 20 June 2013 22:23, Alan Stern <stern@rowland.harvard.edu> wrote:

> On Thu, 20 Jun 2013, Manjunath Goudar wrote:
>
> > > > @@ -686,7 +631,7 @@ ohci_hcd_at91_drv_suspend(struct platform_device
> > > *pdev, pm_message_t mesg)
> > > >        * REVISIT: some boards will be able to turn VBUS off...
> > > >        */
> > > >       if (at91_suspend_entering_slow_clock()) {
> > > > -             ohci_usb_reset (ohci);
> > > > +             ohci_restart(ohci);
> > >
> > > Why did you change this?  Did we discuss it earlier?
> > >
> >
> > We are not discussed  regarding this,I think we need to call
> > use ohci_resume() instead of ohci_restart().
>
> Why?  Don't you think the current code has a good reason for calling
> ohci_usb_reset()?
>
>
Here ohci_usb_reset() is static function,that is what I am planing to call
ohci_setup() or ohci_restart() because it is calling  ohci_usb_reset(),
If not calling, we can make ohci_usb_reset() function as non-static
function
or use directly  ohci_usb_reset() function code here.

Let me know which one is good approach.


Alan Stern
>
>
Alan Stern June 21, 2013, 4:33 p.m. | #5
On Fri, 21 Jun 2013, Manjunath Goudar wrote:

> On 20 June 2013 22:23, Alan Stern <stern@rowland.harvard.edu> wrote:
> 
> > On Thu, 20 Jun 2013, Manjunath Goudar wrote:
> >
> > > > > @@ -686,7 +631,7 @@ ohci_hcd_at91_drv_suspend(struct platform_device
> > > > *pdev, pm_message_t mesg)
> > > > >        * REVISIT: some boards will be able to turn VBUS off...
> > > > >        */
> > > > >       if (at91_suspend_entering_slow_clock()) {
> > > > > -             ohci_usb_reset (ohci);
> > > > > +             ohci_restart(ohci);
> > > >
> > > > Why did you change this?  Did we discuss it earlier?
> > > >
> > >
> > > We are not discussed  regarding this,I think we need to call
> > > use ohci_resume() instead of ohci_restart().
> >
> > Why?  Don't you think the current code has a good reason for calling
> > ohci_usb_reset()?
> >
> >
> Here ohci_usb_reset() is static function,that is what I am planing to call
> ohci_setup() or ohci_restart() because it is calling  ohci_usb_reset(),
> If not calling, we can make ohci_usb_reset() function as non-static
> function
> or use directly  ohci_usb_reset() function code here.
> 
> Let me know which one is good approach.

As a general rule, you should never change code that you don't 
understand.  Do you _know_ that it will be safe to call ohci_setup() or 
ohci_restart() at this point?

It might be a good idea to get in touch with the person who wrote that
routine originally and ask why they used ohci_usb_reset().

Alan Stern
manjunath.goudar@linaro.org June 22, 2013, 6:39 p.m. | #6
On 21 June 2013 22:03, Alan Stern <stern@rowland.harvard.edu> wrote:

> On Fri, 21 Jun 2013, Manjunath Goudar wrote:
>
> > On 20 June 2013 22:23, Alan Stern <stern@rowland.harvard.edu> wrote:
> >
> > > On Thu, 20 Jun 2013, Manjunath Goudar wrote:
> > >
> > > > > > @@ -686,7 +631,7 @@ ohci_hcd_at91_drv_suspend(struct
> platform_device
> > > > > *pdev, pm_message_t mesg)
> > > > > >        * REVISIT: some boards will be able to turn VBUS off...
> > > > > >        */
> > > > > >       if (at91_suspend_entering_slow_clock()) {
> > > > > > -             ohci_usb_reset (ohci);
> > > > > > +             ohci_restart(ohci);
> > > > >
> > > > > Why did you change this?  Did we discuss it earlier?
> > > > >
> > > >
> > > > We are not discussed  regarding this,I think we need to call
> > > > use ohci_resume() instead of ohci_restart().
> > >
> > > Why?  Don't you think the current code has a good reason for calling
> > > ohci_usb_reset()?
> > >
> > >
> > Here ohci_usb_reset() is static function,that is what I am planing to
> call
> > ohci_setup() or ohci_restart() because it is calling  ohci_usb_reset(),
> > If not calling, we can make ohci_usb_reset() function as non-static
> > function
> > or use directly  ohci_usb_reset() function code here.
> >
> > Let me know which one is good approach.
>
> As a general rule, you should never change code that you don't
> understand.  Do you _know_ that it will be safe to call ohci_setup() or
> ohci_restart() at this point?
>
>
From David Brownell comment I am understanding,instead of calling
ohci_setup()
or ohci_restart(),we can use directly below code.

        ohci->hc_control &= OHCI_CTRL_RWC;
        ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
        ohci->rh_state = OHCI_RH_HALTED;

the 3rd line code is written by you,I want to know what exactly it is doing.
Is it required here?




> It might be a good idea to get in touch with the person who wrote that
> routine originally and ask why they used ohci_usb_reset().
>
> yes I will.

Hi David,

As I understood ohci_usb_reset() is calling for to notice
disconnect,reconnect,
or wakeup without the 48 MHz clock active.
After fix power management hanging(869aa98c) issue by Patrice Vilchez,I
think
ohci_usb_reset() is not required to call. what is your opinion about this.

Manjunath Goudar



> Alan Stern
>
>
Alan Stern June 22, 2013, 7:08 p.m. | #7
On Sun, 23 Jun 2013, Manjunath Goudar wrote:

> > As a general rule, you should never change code that you don't
> > understand.  Do you _know_ that it will be safe to call ohci_setup() or
> > ohci_restart() at this point?
> >
> >
> From David Brownell comment I am understanding,instead of calling
> ohci_setup()
> or ohci_restart(),we can use directly below code.
> 
>         ohci->hc_control &= OHCI_CTRL_RWC;
>         ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
>         ohci->rh_state = OHCI_RH_HALTED;

Of course you can use that code; that's exactly what ohci_usb_reset() 
does now.

> the 3rd line code is written by you,I want to know what exactly it is doing.
> Is it required here?

Yes, it is required.  ohci->rh_state stores the current state of the
root hub.  When the controller is reset, the root hub goes into the 
HALTED state; this line records that fact.

> > It might be a good idea to get in touch with the person who wrote that
> > routine originally and ask why they used ohci_usb_reset().
> >
> > yes I will.
> 
> Hi David,
> 
> As I understood ohci_usb_reset() is calling for to notice
> disconnect,reconnect,
> or wakeup without the 48 MHz clock active.
> After fix power management hanging(869aa98c) issue by Patrice Vilchez,I
> think
> ohci_usb_reset() is not required to call. what is your opinion about this.

Sadly, David Brownell died in 2011.  I can tell you, though, that
commit 869aa98c does not eliminate the need to call ohci_usb_reset().

Alan Stern
manjunath.goudar@linaro.org June 22, 2013, 7:54 p.m. | #8
On 23 June 2013 00:38, Alan Stern <stern@rowland.harvard.edu> wrote:

> On Sun, 23 Jun 2013, Manjunath Goudar wrote:
>
> > > As a general rule, you should never change code that you don't
> > > understand.  Do you _know_ that it will be safe to call ohci_setup() or
> > > ohci_restart() at this point?
> > >
> > >
> > From David Brownell comment I am understanding,instead of calling
> > ohci_setup()
> > or ohci_restart(),we can use directly below code.
> >
> >         ohci->hc_control &= OHCI_CTRL_RWC;
> >         ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
> >         ohci->rh_state = OHCI_RH_HALTED;
>
> Of course you can use that code; that's exactly what ohci_usb_reset()
> does now.
>
>
OK then I will use above three line code for ohci_usb_reset() alternative.


> the 3rd line code is written by you,I want to know what exactly it is
> doing.
> > Is it required here?
>
> Yes, it is required.  ohci->rh_state stores the current state of the
> root hub.  When the controller is reset, the root hub goes into the
> HALTED state; this line records that fact.
>
>
Thank you for spending your valuable time, answering my doubt.


> > > It might be a good idea to get in touch with the person who wrote that
> > > routine originally and ask why they used ohci_usb_reset().
> > >
> > > yes I will.
> >
> > Hi David,
> >
> > As I understood ohci_usb_reset() is calling for to notice
> > disconnect,reconnect,
> > or wakeup without the 48 MHz clock active.
> > After fix power management hanging(869aa98c) issue by Patrice Vilchez,I
> > think
> > ohci_usb_reset() is not required to call. what is your opinion about
> this.
>
> Sadly, David Brownell died in 2011.  I can tell you, though, that
> commit 869aa98c does not eliminate the need to call ohci_usb_reset().
>
>
So sad :( :(


> Alan Stern
>
>

Patch

diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index 46c2f42..e4dc9ab 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -390,6 +390,14 @@  config USB_OHCI_HCD_SPEAR
           Enables support for the on-chip OHCI controller on
           ST SPEAr chips.
 
+config USB_OHCI_HCD_AT91
+        tristate  "Support for Atmel on-chip OHCI USB controller"
+        depends on USB_OHCI_HCD && ARCH_AT91
+        default y
+        ---help---
+          Enables support for the on-chip OHCI controller on
+          Atmel chips.
+
 config USB_OHCI_HCD_OMAP3
 	tristate "OHCI support for OMAP3 and later chips"
 	depends on (ARCH_OMAP3 || ARCH_OMAP4)
diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
index 26cb6b3..f3e02c0 100644
--- a/drivers/usb/host/Makefile
+++ b/drivers/usb/host/Makefile
@@ -49,6 +49,7 @@  obj-$(CONFIG_USB_OHCI_EXYNOS)	+= ohci-exynos.o
 obj-$(CONFIG_USB_OHCI_HCD_OMAP1)	+= ohci-omap.o
 obj-$(CONFIG_USB_OHCI_HCD_OMAP3)	+= ohci-omap3.o
 obj-$(CONFIG_USB_OHCI_HCD_SPEAR)	+= ohci-spear.o
+obj-$(CONFIG_USB_OHCI_HCD_AT91)	+= ohci-at91.o
 
 obj-$(CONFIG_USB_UHCI_HCD)	+= uhci-hcd.o
 obj-$(CONFIG_USB_FHCI_HCD)	+= fhci.o
diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c
index 2ee1496..fb2f127 100644
--- a/drivers/usb/host/ohci-at91.c
+++ b/drivers/usb/host/ohci-at91.c
@@ -13,27 +13,41 @@ 
  */
 
 #include <linux/clk.h>
-#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
 #include <linux/of_platform.h>
 #include <linux/of_gpio.h>
+#include <linux/platform_device.h>
 #include <linux/platform_data/atmel.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
 
 #include <mach/hardware.h>
 #include <asm/gpio.h>
 
 #include <mach/cpu.h>
 
-#ifndef CONFIG_ARCH_AT91
-#error "CONFIG_ARCH_AT91 must be defined."
-#endif
+
+#include "ohci.h"
 
 #define valid_port(index)	((index) >= 0 && (index) < AT91_MAX_USBH_PORTS)
 #define at91_for_each_port(index)	\
 		for ((index) = 0; (index) < AT91_MAX_USBH_PORTS; (index)++)
 
 /* interface and function clocks; sometimes also an AHB clock */
+
+#define DRIVER_DESC "OHCI Atmel driver"
+
+static const char hcd_name[] = "ohci-atmel";
+
+static struct hc_driver __read_mostly ohci_at91_hc_driver;
 static struct clk *iclk, *fclk, *hclk;
 static int clocked;
+static int (*orig_ohci_hub_control)(struct usb_hcd  *hcd, u16 typeReq, u16 wValue,
+			u16 wIndex, char *buf, u16 wLength);
+static int (*orig_ohci_hub_status_data)(struct usb_hcd *hcd, char *buf);
 
 extern int usb_disabled(void);
 
@@ -111,6 +125,8 @@  static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *);
 static int usb_hcd_at91_probe(const struct hc_driver *driver,
 			struct platform_device *pdev)
 {
+	struct at91_usbh_data	*board;
+	struct ohci_hcd	*ohci;
 	int retval;
 	struct usb_hcd *hcd = NULL;
 
@@ -163,8 +179,11 @@  static int usb_hcd_at91_probe(const struct hc_driver *driver,
 		goto err5;
 	}
 
+	board = hcd->self.controller->platform_data;
+	ohci = hcd_to_ohci(hcd);
+	ohci->num_ports = board->ports;
 	at91_start_hc(pdev);
-	ohci_hcd_init(hcd_to_ohci(hcd));
+	ohci_setup(hcd);
 
 	retval = usb_add_hcd(hcd, pdev->resource[1].start, IRQF_SHARED);
 	if (retval == 0)
@@ -221,36 +240,6 @@  static void usb_hcd_at91_remove(struct usb_hcd *hcd,
 }
 
 /*-------------------------------------------------------------------------*/
-
-static int
-ohci_at91_reset (struct usb_hcd *hcd)
-{
-	struct at91_usbh_data	*board = hcd->self.controller->platform_data;
-	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
-	int			ret;
-
-	if ((ret = ohci_init(ohci)) < 0)
-		return ret;
-
-	ohci->num_ports = board->ports;
-	return 0;
-}
-
-static int
-ohci_at91_start (struct usb_hcd *hcd)
-{
-	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
-	int			ret;
-
-	if ((ret = ohci_run(ohci)) < 0) {
-		dev_err(hcd->self.controller, "can't start %s\n",
-			hcd->self.bus_name);
-		ohci_stop(hcd);
-		return ret;
-	}
-	return 0;
-}
-
 static void ohci_at91_usb_set_power(struct at91_usbh_data *pdata, int port, int enable)
 {
 	if (!valid_port(port))
@@ -281,7 +270,7 @@  static int ohci_at91_usb_get_power(struct at91_usbh_data *pdata, int port)
 static int ohci_at91_hub_status_data(struct usb_hcd *hcd, char *buf)
 {
 	struct at91_usbh_data *pdata = hcd->self.controller->platform_data;
-	int length = ohci_hub_status_data(hcd, buf);
+	int length = orig_ohci_hub_status_data(hcd, buf);
 	int port;
 
 	at91_for_each_port(port) {
@@ -359,7 +348,8 @@  static int ohci_at91_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 		break;
 	}
 
-	ret = ohci_hub_control(hcd, typeReq, wValue, wIndex + 1, buf, wLength);
+	ret = orig_ohci_hub_control(hcd, typeReq, wValue, wIndex + 1,
+				buf, wLength);
 	if (ret)
 		goto out;
 
@@ -413,51 +403,6 @@  static int ohci_at91_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 
 /*-------------------------------------------------------------------------*/
 
-static const struct hc_driver ohci_at91_hc_driver = {
-	.description =		hcd_name,
-	.product_desc =		"AT91 OHCI",
-	.hcd_priv_size =	sizeof(struct ohci_hcd),
-
-	/*
-	 * generic hardware linkage
-	 */
-	.irq =			ohci_irq,
-	.flags =		HCD_USB11 | HCD_MEMORY,
-
-	/*
-	 * basic lifecycle operations
-	 */
-	.reset =		ohci_at91_reset,
-	.start =		ohci_at91_start,
-	.stop =			ohci_stop,
-	.shutdown =		ohci_shutdown,
-
-	/*
-	 * managing i/o requests and associated device resources
-	 */
-	.urb_enqueue =		ohci_urb_enqueue,
-	.urb_dequeue =		ohci_urb_dequeue,
-	.endpoint_disable =	ohci_endpoint_disable,
-
-	/*
-	 * scheduling support
-	 */
-	.get_frame_number =	ohci_get_frame,
-
-	/*
-	 * root hub support
-	 */
-	.hub_status_data =	ohci_at91_hub_status_data,
-	.hub_control =		ohci_at91_hub_control,
-#ifdef CONFIG_PM
-	.bus_suspend =		ohci_bus_suspend,
-	.bus_resume =		ohci_bus_resume,
-#endif
-	.start_port_reset =	ohci_start_port_reset,
-};
-
-/*-------------------------------------------------------------------------*/
-
 static irqreturn_t ohci_hcd_at91_overcurrent_irq(int irq, void *data)
 {
 	struct platform_device *pdev = data;
@@ -686,7 +631,7 @@  ohci_hcd_at91_drv_suspend(struct platform_device *pdev, pm_message_t mesg)
 	 * REVISIT: some boards will be able to turn VBUS off...
 	 */
 	if (at91_suspend_entering_slow_clock()) {
-		ohci_usb_reset (ohci);
+		ohci_restart(ohci);
 		/* flush the writes */
 		(void) ohci_readl (ohci, &ohci->regs->control);
 		at91_stop_clock();
@@ -727,3 +672,40 @@  static struct platform_driver ohci_hcd_at91_driver = {
 		.of_match_table	= of_match_ptr(at91_ohci_dt_ids),
 	},
 };
+
+static int __init ohci_at91_init(void)
+{
+	if (usb_disabled())
+		return -ENODEV;
+
+	pr_info("%s: " DRIVER_DESC "\n", hcd_name);
+	ohci_init_driver(&ohci_at91_hc_driver, NULL);
+
+	/*
+	 * The Atmel HW has some unusual quirks, which require Atmel-specific
+	 * workarounds. We override certain hc_driver functions here to
+	 * achieve that. We explicitly do not enhance ohci_driver_overrides to
+	 * allow this more easily, since this is an unusual case, and we don't
+	 * want to encourage others to override these functions by making it
+	 * too easy.
+	 */
+
+	orig_ohci_hub_control = ohci_at91_hc_driver.hub_control;
+	orig_ohci_hub_status_data = ohci_at91_hc_driver.hub_status_data;
+
+	ohci_at91_hc_driver.hub_status_data	= ohci_at91_hub_status_data;
+	ohci_at91_hc_driver.hub_control		= ohci_at91_hub_control;
+
+	return platform_driver_register(&ohci_hcd_at91_driver);
+}
+module_init(ohci_at91_init);
+
+static void __exit ohci_at91_cleanup(void)
+{
+	platform_driver_unregister(&ohci_hcd_at91_driver);
+}
+module_exit(ohci_at91_cleanup);
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index 34ec156..b48c892 100644
--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -1192,11 +1192,6 @@  MODULE_LICENSE ("GPL");
 #define EP93XX_PLATFORM_DRIVER	ohci_hcd_ep93xx_driver
 #endif
 
-#ifdef CONFIG_ARCH_AT91
-#include "ohci-at91.c"
-#define AT91_PLATFORM_DRIVER	ohci_hcd_at91_driver
-#endif
-
 #ifdef CONFIG_ARCH_LPC32XX
 #include "ohci-nxp.c"
 #define NXP_PLATFORM_DRIVER	usb_hcd_nxp_driver
@@ -1310,12 +1305,6 @@  static int __init ohci_hcd_mod_init(void)
 		goto error_ep93xx;
 #endif
 
-#ifdef AT91_PLATFORM_DRIVER
-	retval = platform_driver_register(&AT91_PLATFORM_DRIVER);
-	if (retval < 0)
-		goto error_at91;
-#endif
-
 #ifdef NXP_PLATFORM_DRIVER
 	retval = platform_driver_register(&NXP_PLATFORM_DRIVER);
 	if (retval < 0)
@@ -1339,10 +1328,6 @@  static int __init ohci_hcd_mod_init(void)
 	platform_driver_unregister(&NXP_PLATFORM_DRIVER);
  error_nxp:
 #endif
-#ifdef AT91_PLATFORM_DRIVER
-	platform_driver_unregister(&AT91_PLATFORM_DRIVER);
- error_at91:
-#endif
 #ifdef EP93XX_PLATFORM_DRIVER
 	platform_driver_unregister(&EP93XX_PLATFORM_DRIVER);
  error_ep93xx:
@@ -1394,9 +1379,6 @@  static void __exit ohci_hcd_mod_exit(void)
 #ifdef NXP_PLATFORM_DRIVER
 	platform_driver_unregister(&NXP_PLATFORM_DRIVER);
 #endif
-#ifdef AT91_PLATFORM_DRIVER
-	platform_driver_unregister(&AT91_PLATFORM_DRIVER);
-#endif
 #ifdef EP93XX_PLATFORM_DRIVER
 	platform_driver_unregister(&EP93XX_PLATFORM_DRIVER);
 #endif