diff mbox

[1/2] ohci-platform: Add support for controllers with big-endian regs / descriptors

Message ID 1390319315-8391-1-git-send-email-hdegoede@redhat.com
State Superseded, archived
Headers show

Commit Message

Hans de Goede Jan. 21, 2014, 3:48 p.m. UTC
Note this commit uses the same devicetree booleans for this as the ones
already existing in the usb-ehci bindings.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 Documentation/devicetree/bindings/usb/usb-ohci.txt |  3 +++
 drivers/usb/host/Kconfig                           |  4 ++++
 drivers/usb/host/ohci-platform.c                   | 27 ++++++++++++++++++++++
 3 files changed, 34 insertions(+)

Comments

Alan Stern Jan. 21, 2014, 4:40 p.m. UTC | #1
On Tue, 21 Jan 2014, Hans de Goede wrote:

> Note this commit uses the same devicetree booleans for this as the ones
> already existing in the usb-ehci bindings.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>

> --- a/drivers/usb/host/Kconfig
> +++ b/drivers/usb/host/Kconfig
> @@ -512,6 +512,10 @@ config USB_CNS3XXX_OHCI
>  
>  config USB_OHCI_HCD_PLATFORM
>  	tristate "Generic OHCI driver for a platform device"
> +	# Always support LE, support BE on architectures which have readl_be
> +	select USB_OHCI_LITTLE_ENDIAN
> +	select USB_OHCI_BIG_ENDIAN_DESC if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
> +	select USB_OHCI_BIG_ENDIAN_MMIO if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
>  	default n

The comment line above is slightly misleading.  USB_OHCI_LITTLE_ENDIAN
doesn't exactly mean to include support for little-endian controllers;  
it means include mixed-endian support if either
USB_OHCI_BIG_ENDIAN_DESC or USB_OHCI_BIG_ENDIAN_MMIO is set.  That is,
the driver determines at runtime whether a particular controller is
big-endian or little-endian, rather than choosing to support one or the
other at compile time.

In any case, the style we have adopted is that these select lines go in
the arch-specific defconfig, not here.  For example, check out the
occurrences of EHCI in arch/mips/Kconfig.  Also, I'm not sure how you
came up with that list of architectures for the two selects; it's hard
to say if they are right.  For instance, why did you include AVR32?

The changes to the driver itself look fine.

Similar comments apply to the ehci-platform patch.

Alan Stern

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Hans de Goede Jan. 21, 2014, 5:01 p.m. UTC | #2
Hi,

On 01/21/2014 05:40 PM, Alan Stern wrote:
> On Tue, 21 Jan 2014, Hans de Goede wrote:
>
>> Note this commit uses the same devicetree booleans for this as the ones
>> already existing in the usb-ehci bindings.
>>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>
>> --- a/drivers/usb/host/Kconfig
>> +++ b/drivers/usb/host/Kconfig
>> @@ -512,6 +512,10 @@ config USB_CNS3XXX_OHCI
>>
>>   config USB_OHCI_HCD_PLATFORM
>>   	tristate "Generic OHCI driver for a platform device"
>> +	# Always support LE, support BE on architectures which have readl_be
>> +	select USB_OHCI_LITTLE_ENDIAN
>> +	select USB_OHCI_BIG_ENDIAN_DESC if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
>> +	select USB_OHCI_BIG_ENDIAN_MMIO if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
>>   	default n
>
> The comment line above is slightly misleading.  USB_OHCI_LITTLE_ENDIAN
> doesn't exactly mean to include support for little-endian controllers;
> it means include mixed-endian support if either
> USB_OHCI_BIG_ENDIAN_DESC or USB_OHCI_BIG_ENDIAN_MMIO is set.  That is,
> the driver determines at runtime whether a particular controller is
> big-endian or little-endian, rather than choosing to support one or the
> other at compile time.

Right I already knew that, that is what the "Always" tried to summarize.

> In any case, the style we have adopted is that these select lines go in
> the arch-specific defconfig, not here.

Ok, so I should drop the Kconfig parts of both patches ?

>  For example, check out the
> occurrences of EHCI in arch/mips/Kconfig.  Also, I'm not sure how you
> came up with that list of architectures for the two selects; it's hard
> to say if they are right.  For instance, why did you include AVR32?

I included all archs which defines readl_be in asm/io.h

Regards,

Hans

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Alan Stern Jan. 21, 2014, 6:09 p.m. UTC | #3
On Tue, 21 Jan 2014, Hans de Goede wrote:

> Hi,
> 
> On 01/21/2014 05:40 PM, Alan Stern wrote:
> > On Tue, 21 Jan 2014, Hans de Goede wrote:
> >
> >> Note this commit uses the same devicetree booleans for this as the ones
> >> already existing in the usb-ehci bindings.
> >>
> >> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> >
> >> --- a/drivers/usb/host/Kconfig
> >> +++ b/drivers/usb/host/Kconfig
> >> @@ -512,6 +512,10 @@ config USB_CNS3XXX_OHCI
> >>
> >>   config USB_OHCI_HCD_PLATFORM
> >>   	tristate "Generic OHCI driver for a platform device"
> >> +	# Always support LE, support BE on architectures which have readl_be
> >> +	select USB_OHCI_LITTLE_ENDIAN
> >> +	select USB_OHCI_BIG_ENDIAN_DESC if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
> >> +	select USB_OHCI_BIG_ENDIAN_MMIO if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
> >>   	default n

> > In any case, the style we have adopted is that these select lines go in
> > the arch-specific defconfig, not here.
> 
> Ok, so I should drop the Kconfig parts of both patches ?

That's rigt.  They are likely to cause trouble, and if the selects were
needed then they should already be present somewhere else.

Alan Stern

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Florian Fainelli Jan. 21, 2014, 7:39 p.m. UTC | #4
2014/1/21 Hans de Goede <hdegoede@redhat.com>:
> This uses the already documented devicetree booleans for this.

(I would greatly appreciate if you could CC people who gave you
feedback on this before)

A more informative commit message would be welcome, along with a
reference to which Device Tree binding documentation you are referring
to.

>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/usb/host/Kconfig         |  3 +++
>  drivers/usb/host/ehci-platform.c | 33 +++++++++++++++++++++++++++++++--
>  2 files changed, 34 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
> index 237d7b1..4af41f3 100644
> --- a/drivers/usb/host/Kconfig
> +++ b/drivers/usb/host/Kconfig
> @@ -256,6 +256,9 @@ config USB_EHCI_ATH79
>  config USB_EHCI_HCD_PLATFORM
>         tristate "Generic EHCI driver for a platform device"
>         depends on !PPC_OF
> +       # Support BE on architectures which have readl_be
> +       select USB_EHCI_BIG_ENDIAN_DESC if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
> +       select USB_EHCI_BIG_ENDIAN_MMIO if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)

I do not think this is that simple nor correct for at least Microblaze
and MIPS since they can run in either BE or LE mode, and those
specific platforms should already do the proper select at the
board/SoC level. This *might* be correct for SPARC, PPC32 and PPC64,
although I believe some specific PPC64 boards can run in little-endian
mode like the P-series, SPARC might too.

It seems to me that you should not touch this and keep the existing
selects in place, if it turns out that the selects are missing the
error messages you added below are catching those misuses.

>         default n
>         ---help---
>           Adds an EHCI host driver for a generic platform device, which
> diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
> index d8aebc0..5888abb 100644
> --- a/drivers/usb/host/ehci-platform.c
> +++ b/drivers/usb/host/ehci-platform.c
> @@ -55,8 +55,10 @@ static int ehci_platform_reset(struct usb_hcd *hcd)
>
>         hcd->has_tt = pdata->has_tt;
>         ehci->has_synopsys_hc_bug = pdata->has_synopsys_hc_bug;
> -       ehci->big_endian_desc = pdata->big_endian_desc;
> -       ehci->big_endian_mmio = pdata->big_endian_mmio;
> +       if (pdata->big_endian_desc)
> +               ehci->big_endian_desc = 1;
> +       if (pdata->big_endian_mmio)
> +               ehci->big_endian_mmio = 1;
>
>         if (pdata->pre_setup) {
>                 retval = pdata->pre_setup(hcd);
> @@ -142,6 +144,7 @@ static int ehci_platform_probe(struct platform_device *dev)
>         struct resource *res_mem;
>         struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
>         struct ehci_platform_priv *priv;
> +       struct ehci_hcd *ehci;
>         int err, irq, clk = 0;
>
>         if (usb_disabled())
> @@ -177,8 +180,34 @@ static int ehci_platform_probe(struct platform_device *dev)
>         platform_set_drvdata(dev, hcd);
>         dev->dev.platform_data = pdata;
>         priv = hcd_to_ehci_priv(hcd);
> +       ehci = hcd_to_ehci(hcd);
>
>         if (pdata == &ehci_platform_defaults && dev->dev.of_node) {
> +               if (of_property_read_bool(dev->dev.of_node, "big-endian-regs"))
> +                       ehci->big_endian_mmio = 1;
> +
> +               if (of_property_read_bool(dev->dev.of_node, "big-endian-desc"))
> +                       ehci->big_endian_desc = 1;
> +
> +               if (of_property_read_bool(dev->dev.of_node, "big-endian"))
> +                       ehci->big_endian_mmio = ehci->big_endian_desc = 1;

Ok, so I am confused now, should you update
pdata->ehci_big_endian_{desc,mmio} here or is it valid to directly
modify ehci->big_endian_{desc,mmio}, is not there any risk  to undo
what is done in ehci_platform_reset(), or is ehci_platform_reset()
only called for non-DT cases?

> +
> +#ifndef CONFIG_USB_EHCI_BIG_ENDIAN_MMIO
> +               if (ehci->big_endian_mmio) {
> +                       dev_err(&dev->dev,
> +                               "Error big-endian-regs not compiled in\n");

I do not think using the Device Tree property name would be very
informative since this is supposed to guard against misconfigurations
for both DT and non-DT enabled platforms, how about something like the
following:

"support for big-endian MMIO registers not enabled".

> +                       err = -EINVAL;
> +                       goto err_put_hcd;
> +               }
> +#endif
> +#ifndef CONFIG_USB_EHCI_BIG_ENDIAN_DESC
> +               if (ehci->big_endian_desc) {
> +                       dev_err(&dev->dev,
> +                               "Error big-endian-desc not compiled in\n");
> +                       err = -EINVAL;
> +                       goto err_put_hcd;

And here "support for big-endian descriptors not enabled".

> +               }
> +#endif
>                 priv->phy = devm_phy_get(&dev->dev, "usb");
>                 if (IS_ERR(priv->phy)) {
>                         err = PTR_ERR(priv->phy);
> --
> 1.8.5.3
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Florian Fainelli Jan. 21, 2014, 7:48 p.m. UTC | #5
2014/1/21 Alan Stern <stern@rowland.harvard.edu>:
> On Tue, 21 Jan 2014, Hans de Goede wrote:
>
>> Hi,
>>
>> On 01/21/2014 05:40 PM, Alan Stern wrote:
>> > On Tue, 21 Jan 2014, Hans de Goede wrote:
>> >
>> >> Note this commit uses the same devicetree booleans for this as the ones
>> >> already existing in the usb-ehci bindings.
>> >>
>> >> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> >
>> >> --- a/drivers/usb/host/Kconfig
>> >> +++ b/drivers/usb/host/Kconfig
>> >> @@ -512,6 +512,10 @@ config USB_CNS3XXX_OHCI
>> >>
>> >>   config USB_OHCI_HCD_PLATFORM
>> >>    tristate "Generic OHCI driver for a platform device"
>> >> +  # Always support LE, support BE on architectures which have readl_be
>> >> +  select USB_OHCI_LITTLE_ENDIAN
>> >> +  select USB_OHCI_BIG_ENDIAN_DESC if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
>> >> +  select USB_OHCI_BIG_ENDIAN_MMIO if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
>> >>    default n
>
>> > In any case, the style we have adopted is that these select lines go in
>> > the arch-specific defconfig, not here.
>>
>> Ok, so I should drop the Kconfig parts of both patches ?
>
> That's rigt.  They are likely to cause trouble, and if the selects were
> needed then they should already be present somewhere else.

Absolutely, they will actually break platforms. Since you added some
guards for when these properties are set, but proper support in the
kernel is not enabled, this is already catching misuses, and as such
is already an improvement.
Hans de Goede Jan. 22, 2014, 7:28 p.m. UTC | #6
Hi,

On 01/21/2014 08:39 PM, Florian Fainelli wrote:
> 2014/1/21 Hans de Goede <hdegoede@redhat.com>:
>> This uses the already documented devicetree booleans for this.
>
> (I would greatly appreciate if you could CC people who gave you
> feedback on this before)

Will do.

> A more informative commit message would be welcome, along with a
> reference to which Device Tree binding documentation you are referring
> to.

I've added a reference to the bindings doc in the commit msg for my next version.

>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>>   drivers/usb/host/Kconfig         |  3 +++
>>   drivers/usb/host/ehci-platform.c | 33 +++++++++++++++++++++++++++++++--
>>   2 files changed, 34 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
>> index 237d7b1..4af41f3 100644
>> --- a/drivers/usb/host/Kconfig
>> +++ b/drivers/usb/host/Kconfig
>> @@ -256,6 +256,9 @@ config USB_EHCI_ATH79
>>   config USB_EHCI_HCD_PLATFORM
>>          tristate "Generic EHCI driver for a platform device"
>>          depends on !PPC_OF
>> +       # Support BE on architectures which have readl_be
>> +       select USB_EHCI_BIG_ENDIAN_DESC if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
>> +       select USB_EHCI_BIG_ENDIAN_MMIO if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
>
> I do not think this is that simple nor correct for at least Microblaze
> and MIPS since they can run in either BE or LE mode, and those
> specific platforms should already do the proper select at the
> board/SoC level. This *might* be correct for SPARC, PPC32 and PPC64,
> although I believe some specific PPC64 boards can run in little-endian
> mode like the P-series, SPARC might too.
>
> It seems to me that you should not touch this and keep the existing
> selects in place, if it turns out that the selects are missing the
> error messages you added below are catching those misuses.

As discussed with Alan, I will drop these lines from my next version.

>>          default n
>>          ---help---
>>            Adds an EHCI host driver for a generic platform device, which
>> diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
>> index d8aebc0..5888abb 100644
>> --- a/drivers/usb/host/ehci-platform.c
>> +++ b/drivers/usb/host/ehci-platform.c
>> @@ -55,8 +55,10 @@ static int ehci_platform_reset(struct usb_hcd *hcd)
>>
>>          hcd->has_tt = pdata->has_tt;
>>          ehci->has_synopsys_hc_bug = pdata->has_synopsys_hc_bug;
>> -       ehci->big_endian_desc = pdata->big_endian_desc;
>> -       ehci->big_endian_mmio = pdata->big_endian_mmio;
>> +       if (pdata->big_endian_desc)
>> +               ehci->big_endian_desc = 1;
>> +       if (pdata->big_endian_mmio)
>> +               ehci->big_endian_mmio = 1;
>>
>>          if (pdata->pre_setup) {
>>                  retval = pdata->pre_setup(hcd);
>> @@ -142,6 +144,7 @@ static int ehci_platform_probe(struct platform_device *dev)
>>          struct resource *res_mem;
>>          struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
>>          struct ehci_platform_priv *priv;
>> +       struct ehci_hcd *ehci;
>>          int err, irq, clk = 0;
>>
>>          if (usb_disabled())
>> @@ -177,8 +180,34 @@ static int ehci_platform_probe(struct platform_device *dev)
>>          platform_set_drvdata(dev, hcd);
>>          dev->dev.platform_data = pdata;
>>          priv = hcd_to_ehci_priv(hcd);
>> +       ehci = hcd_to_ehci(hcd);
>>
>>          if (pdata == &ehci_platform_defaults && dev->dev.of_node) {
>> +               if (of_property_read_bool(dev->dev.of_node, "big-endian-regs"))
>> +                       ehci->big_endian_mmio = 1;
>> +
>> +               if (of_property_read_bool(dev->dev.of_node, "big-endian-desc"))
>> +                       ehci->big_endian_desc = 1;
>> +
>> +               if (of_property_read_bool(dev->dev.of_node, "big-endian"))
>> +                       ehci->big_endian_mmio = ehci->big_endian_desc = 1;
>
> Ok, so I am confused now, should you update
> pdata->ehci_big_endian_{desc,mmio} here or is it valid to directly
> modify ehci->big_endian_{desc,mmio}, is not there any risk  to undo
> what is done in ehci_platform_reset(), or is ehci_platform_reset()
> only called for non-DT cases?

Both the pdata checks in ehci_platform_reset() and the dt checks here only
ever set these flags, neither code path clears them. And in the dt case pdata
will be NULL and vice versa.

>
>> +
>> +#ifndef CONFIG_USB_EHCI_BIG_ENDIAN_MMIO
>> +               if (ehci->big_endian_mmio) {
>> +                       dev_err(&dev->dev,
>> +                               "Error big-endian-regs not compiled in\n");
>
> I do not think using the Device Tree property name would be very
> informative since this is supposed to guard against misconfigurations
> for both DT and non-DT enabled platforms

Nope this is in a dt only code path.

>> +                       err = -EINVAL;
>> +                       goto err_put_hcd;
>> +               }
>> +#endif
>> +#ifndef CONFIG_USB_EHCI_BIG_ENDIAN_DESC
>> +               if (ehci->big_endian_desc) {
>> +                       dev_err(&dev->dev,
>> +                               "Error big-endian-desc not compiled in\n");
>> +                       err = -EINVAL;
>> +                       goto err_put_hcd;
>
> And here "support for big-endian descriptors not enabled".
>
>> +               }
>> +#endif
>>                  priv->phy = devm_phy_get(&dev->dev, "usb");
>>                  if (IS_ERR(priv->phy)) {
>>                          err = PTR_ERR(priv->phy);

Regards,

Hans

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Jonas Gorski Jan. 22, 2014, 8:34 p.m. UTC | #7
Hi,

On Wed, 22 Jan 2014 20:28:26 +0100
Hans de Goede <hdegoede@redhat.com> wrote:
> Hi,
> 
> On 01/21/2014 08:39 PM, Florian Fainelli wrote:
> > 2014/1/21 Hans de Goede <hdegoede@redhat.com>:
> >> This uses the already documented devicetree booleans for this.
> >
> > (I would greatly appreciate if you could CC people who gave you
> > feedback on this before)
> 
> Will do.
> 
> > A more informative commit message would be welcome, along with a
> > reference to which Device Tree binding documentation you are referring
> > to.
> 
> I've added a reference to the bindings doc in the commit msg for my next version.
> 
> >> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> >> ---
> >>   drivers/usb/host/Kconfig         |  3 +++
> >>   drivers/usb/host/ehci-platform.c | 33 +++++++++++++++++++++++++++++++--
> >>   2 files changed, 34 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
> >> index 237d7b1..4af41f3 100644
> >> --- a/drivers/usb/host/Kconfig
> >> +++ b/drivers/usb/host/Kconfig
> >> @@ -256,6 +256,9 @@ config USB_EHCI_ATH79
> >>   config USB_EHCI_HCD_PLATFORM
> >>          tristate "Generic EHCI driver for a platform device"
> >>          depends on !PPC_OF
> >> +       # Support BE on architectures which have readl_be
> >> +       select USB_EHCI_BIG_ENDIAN_DESC if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
> >> +       select USB_EHCI_BIG_ENDIAN_MMIO if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
> >
> > I do not think this is that simple nor correct for at least Microblaze
> > and MIPS since they can run in either BE or LE mode, and those
> > specific platforms should already do the proper select at the
> > board/SoC level. This *might* be correct for SPARC, PPC32 and PPC64,
> > although I believe some specific PPC64 boards can run in little-endian
> > mode like the P-series, SPARC might too.
> >
> > It seems to me that you should not touch this and keep the existing
> > selects in place, if it turns out that the selects are missing the
> > error messages you added below are catching those misuses.
> 
> As discussed with Alan, I will drop these lines from my next version.
> 
> >>          default n
> >>          ---help---
> >>            Adds an EHCI host driver for a generic platform device, which
> >> diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
> >> index d8aebc0..5888abb 100644
> >> --- a/drivers/usb/host/ehci-platform.c
> >> +++ b/drivers/usb/host/ehci-platform.c
> >> @@ -55,8 +55,10 @@ static int ehci_platform_reset(struct usb_hcd *hcd)
> >>
> >>          hcd->has_tt = pdata->has_tt;
> >>          ehci->has_synopsys_hc_bug = pdata->has_synopsys_hc_bug;
> >> -       ehci->big_endian_desc = pdata->big_endian_desc;
> >> -       ehci->big_endian_mmio = pdata->big_endian_mmio;
> >> +       if (pdata->big_endian_desc)
> >> +               ehci->big_endian_desc = 1;
> >> +       if (pdata->big_endian_mmio)
> >> +               ehci->big_endian_mmio = 1;
> >>
> >>          if (pdata->pre_setup) {
> >>                  retval = pdata->pre_setup(hcd);
> >> @@ -142,6 +144,7 @@ static int ehci_platform_probe(struct platform_device *dev)
> >>          struct resource *res_mem;
> >>          struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
> >>          struct ehci_platform_priv *priv;
> >> +       struct ehci_hcd *ehci;
> >>          int err, irq, clk = 0;
> >>
> >>          if (usb_disabled())
> >> @@ -177,8 +180,34 @@ static int ehci_platform_probe(struct platform_device *dev)
> >>          platform_set_drvdata(dev, hcd);
> >>          dev->dev.platform_data = pdata;
> >>          priv = hcd_to_ehci_priv(hcd);
> >> +       ehci = hcd_to_ehci(hcd);
> >>
> >>          if (pdata == &ehci_platform_defaults && dev->dev.of_node) {
> >> +               if (of_property_read_bool(dev->dev.of_node, "big-endian-regs"))
> >> +                       ehci->big_endian_mmio = 1;
> >> +
> >> +               if (of_property_read_bool(dev->dev.of_node, "big-endian-desc"))
> >> +                       ehci->big_endian_desc = 1;
> >> +
> >> +               if (of_property_read_bool(dev->dev.of_node, "big-endian"))
> >> +                       ehci->big_endian_mmio = ehci->big_endian_desc = 1;
> >
> > Ok, so I am confused now, should you update
> > pdata->ehci_big_endian_{desc,mmio} here or is it valid to directly
> > modify ehci->big_endian_{desc,mmio}, is not there any risk  to undo
> > what is done in ehci_platform_reset(), or is ehci_platform_reset()
> > only called for non-DT cases?
> 
> Both the pdata checks in ehci_platform_reset() and the dt checks here only
> ever set these flags, neither code path clears them. And in the dt case pdata
> will be NULL and vice versa.

If it's safe to set ehci->big_endian_{desc,mmio} from the _probe()
routine, then maybe the pdata sets in _reset() should be moved into here
instead of adding extra cludges/checks into _reset().

> 
> >
> >> +
> >> +#ifndef CONFIG_USB_EHCI_BIG_ENDIAN_MMIO
> >> +               if (ehci->big_endian_mmio) {
> >> +                       dev_err(&dev->dev,
> >> +                               "Error big-endian-regs not compiled in\n");
> >
> > I do not think using the Device Tree property name would be very
> > informative since this is supposed to guard against misconfigurations
> > for both DT and non-DT enabled platforms
> 
> Nope this is in a dt only code path.

Then these built-in checks could be done for both paths, as !DT also
has the issue, just doesn't warn/error out with it.

I also agree with Florian that the error message could be better
worded, or should be at least have a ":" after "Error". When seeing
the error message the fist time, I would wonder what "error
big-endian-regs" are, and why I would want to have them ;)

Finally, IS_ENABLED()* allows you to drop those ugly #ifndefs:

	if (ehci->big_endian_mmio &&
	    !IS_ENABLED(CONFIG_USB_EHCI_BIG_ENDIAN_MMIO)) {
                       dev_err(&dev->dev,
                               "Error big-endian-regs not compiled in\n");

looks much nicer IMHO ;)



Regards
Jonas


*Yes, I know IS_BUILTIN() would be more formal correct, but IS_ENABLED()
reads IMHO nicer, and I doubt these config symbols will ever go
tristate ;)
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Hans de Goede Jan. 22, 2014, 8:52 p.m. UTC | #8
Hi,

On 01/22/2014 09:34 PM, Jonas Gorski wrote:
> Hi,
>
> On Wed, 22 Jan 2014 20:28:26 +0100
> Hans de Goede <hdegoede@redhat.com> wrote:
>> Hi,
>>
>> On 01/21/2014 08:39 PM, Florian Fainelli wrote:
>>> 2014/1/21 Hans de Goede <hdegoede@redhat.com>:
>>>> This uses the already documented devicetree booleans for this.
>>>
>>> (I would greatly appreciate if you could CC people who gave you
>>> feedback on this before)
>>
>> Will do.
>>
>>> A more informative commit message would be welcome, along with a
>>> reference to which Device Tree binding documentation you are referring
>>> to.
>>
>> I've added a reference to the bindings doc in the commit msg for my next version.
>>
>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>> ---
>>>>    drivers/usb/host/Kconfig         |  3 +++
>>>>    drivers/usb/host/ehci-platform.c | 33 +++++++++++++++++++++++++++++++--
>>>>    2 files changed, 34 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
>>>> index 237d7b1..4af41f3 100644
>>>> --- a/drivers/usb/host/Kconfig
>>>> +++ b/drivers/usb/host/Kconfig
>>>> @@ -256,6 +256,9 @@ config USB_EHCI_ATH79
>>>>    config USB_EHCI_HCD_PLATFORM
>>>>           tristate "Generic EHCI driver for a platform device"
>>>>           depends on !PPC_OF
>>>> +       # Support BE on architectures which have readl_be
>>>> +       select USB_EHCI_BIG_ENDIAN_DESC if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
>>>> +       select USB_EHCI_BIG_ENDIAN_MMIO if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
>>>
>>> I do not think this is that simple nor correct for at least Microblaze
>>> and MIPS since they can run in either BE or LE mode, and those
>>> specific platforms should already do the proper select at the
>>> board/SoC level. This *might* be correct for SPARC, PPC32 and PPC64,
>>> although I believe some specific PPC64 boards can run in little-endian
>>> mode like the P-series, SPARC might too.
>>>
>>> It seems to me that you should not touch this and keep the existing
>>> selects in place, if it turns out that the selects are missing the
>>> error messages you added below are catching those misuses.
>>
>> As discussed with Alan, I will drop these lines from my next version.
>>
>>>>           default n
>>>>           ---help---
>>>>             Adds an EHCI host driver for a generic platform device, which
>>>> diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
>>>> index d8aebc0..5888abb 100644
>>>> --- a/drivers/usb/host/ehci-platform.c
>>>> +++ b/drivers/usb/host/ehci-platform.c
>>>> @@ -55,8 +55,10 @@ static int ehci_platform_reset(struct usb_hcd *hcd)
>>>>
>>>>           hcd->has_tt = pdata->has_tt;
>>>>           ehci->has_synopsys_hc_bug = pdata->has_synopsys_hc_bug;
>>>> -       ehci->big_endian_desc = pdata->big_endian_desc;
>>>> -       ehci->big_endian_mmio = pdata->big_endian_mmio;
>>>> +       if (pdata->big_endian_desc)
>>>> +               ehci->big_endian_desc = 1;
>>>> +       if (pdata->big_endian_mmio)
>>>> +               ehci->big_endian_mmio = 1;
>>>>
>>>>           if (pdata->pre_setup) {
>>>>                   retval = pdata->pre_setup(hcd);
>>>> @@ -142,6 +144,7 @@ static int ehci_platform_probe(struct platform_device *dev)
>>>>           struct resource *res_mem;
>>>>           struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
>>>>           struct ehci_platform_priv *priv;
>>>> +       struct ehci_hcd *ehci;
>>>>           int err, irq, clk = 0;
>>>>
>>>>           if (usb_disabled())
>>>> @@ -177,8 +180,34 @@ static int ehci_platform_probe(struct platform_device *dev)
>>>>           platform_set_drvdata(dev, hcd);
>>>>           dev->dev.platform_data = pdata;
>>>>           priv = hcd_to_ehci_priv(hcd);
>>>> +       ehci = hcd_to_ehci(hcd);
>>>>
>>>>           if (pdata == &ehci_platform_defaults && dev->dev.of_node) {
>>>> +               if (of_property_read_bool(dev->dev.of_node, "big-endian-regs"))
>>>> +                       ehci->big_endian_mmio = 1;
>>>> +
>>>> +               if (of_property_read_bool(dev->dev.of_node, "big-endian-desc"))
>>>> +                       ehci->big_endian_desc = 1;
>>>> +
>>>> +               if (of_property_read_bool(dev->dev.of_node, "big-endian"))
>>>> +                       ehci->big_endian_mmio = ehci->big_endian_desc = 1;
>>>
>>> Ok, so I am confused now, should you update
>>> pdata->ehci_big_endian_{desc,mmio} here or is it valid to directly
>>> modify ehci->big_endian_{desc,mmio}, is not there any risk  to undo
>>> what is done in ehci_platform_reset(), or is ehci_platform_reset()
>>> only called for non-DT cases?
>>
>> Both the pdata checks in ehci_platform_reset() and the dt checks here only
>> ever set these flags, neither code path clears them. And in the dt case pdata
>> will be NULL and vice versa.
>
> If it's safe to set ehci->big_endian_{desc,mmio} from the _probe()
> routine, then maybe the pdata sets in _reset() should be moved into here
> instead of adding extra cludges/checks into _reset().

That seems like an entire separate patch / improvement on top of adding support
for big-endian controllers to the dt code.

If people won't to improve on thus further and / or clean things up further I'm
sure the usb-subsys maintainers would welcome patches.

<snip more suggestions best done in a separate patch written by someone else>

Regards,

Hans
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Hans de Goede Jan. 22, 2014, 9:02 p.m. UTC | #9
Hi,

On 01/22/2014 09:52 PM, Hans de Goede wrote:
> Hi,
>
> On 01/22/2014 09:34 PM, Jonas Gorski wrote:
>> Hi,
>>
>> On Wed, 22 Jan 2014 20:28:26 +0100
>> Hans de Goede <hdegoede@redhat.com> wrote:
>>> Hi,
>>>
>>> On 01/21/2014 08:39 PM, Florian Fainelli wrote:
>>>> 2014/1/21 Hans de Goede <hdegoede@redhat.com>:
>>>>> This uses the already documented devicetree booleans for this.
>>>>
>>>> (I would greatly appreciate if you could CC people who gave you
>>>> feedback on this before)
>>>
>>> Will do.
>>>
>>>> A more informative commit message would be welcome, along with a
>>>> reference to which Device Tree binding documentation you are referring
>>>> to.
>>>
>>> I've added a reference to the bindings doc in the commit msg for my next version.
>>>
>>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>>> ---
>>>>>    drivers/usb/host/Kconfig         |  3 +++
>>>>>    drivers/usb/host/ehci-platform.c | 33 +++++++++++++++++++++++++++++++--
>>>>>    2 files changed, 34 insertions(+), 2 deletions(-)
>>>>>
>>>>> diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
>>>>> index 237d7b1..4af41f3 100644
>>>>> --- a/drivers/usb/host/Kconfig
>>>>> +++ b/drivers/usb/host/Kconfig
>>>>> @@ -256,6 +256,9 @@ config USB_EHCI_ATH79
>>>>>    config USB_EHCI_HCD_PLATFORM
>>>>>           tristate "Generic EHCI driver for a platform device"
>>>>>           depends on !PPC_OF
>>>>> +       # Support BE on architectures which have readl_be
>>>>> +       select USB_EHCI_BIG_ENDIAN_DESC if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
>>>>> +       select USB_EHCI_BIG_ENDIAN_MMIO if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
>>>>
>>>> I do not think this is that simple nor correct for at least Microblaze
>>>> and MIPS since they can run in either BE or LE mode, and those
>>>> specific platforms should already do the proper select at the
>>>> board/SoC level. This *might* be correct for SPARC, PPC32 and PPC64,
>>>> although I believe some specific PPC64 boards can run in little-endian
>>>> mode like the P-series, SPARC might too.
>>>>
>>>> It seems to me that you should not touch this and keep the existing
>>>> selects in place, if it turns out that the selects are missing the
>>>> error messages you added below are catching those misuses.
>>>
>>> As discussed with Alan, I will drop these lines from my next version.
>>>
>>>>>           default n
>>>>>           ---help---
>>>>>             Adds an EHCI host driver for a generic platform device, which
>>>>> diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
>>>>> index d8aebc0..5888abb 100644
>>>>> --- a/drivers/usb/host/ehci-platform.c
>>>>> +++ b/drivers/usb/host/ehci-platform.c
>>>>> @@ -55,8 +55,10 @@ static int ehci_platform_reset(struct usb_hcd *hcd)
>>>>>
>>>>>           hcd->has_tt = pdata->has_tt;
>>>>>           ehci->has_synopsys_hc_bug = pdata->has_synopsys_hc_bug;
>>>>> -       ehci->big_endian_desc = pdata->big_endian_desc;
>>>>> -       ehci->big_endian_mmio = pdata->big_endian_mmio;
>>>>> +       if (pdata->big_endian_desc)
>>>>> +               ehci->big_endian_desc = 1;
>>>>> +       if (pdata->big_endian_mmio)
>>>>> +               ehci->big_endian_mmio = 1;
>>>>>
>>>>>           if (pdata->pre_setup) {
>>>>>                   retval = pdata->pre_setup(hcd);
>>>>> @@ -142,6 +144,7 @@ static int ehci_platform_probe(struct platform_device *dev)
>>>>>           struct resource *res_mem;
>>>>>           struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
>>>>>           struct ehci_platform_priv *priv;
>>>>> +       struct ehci_hcd *ehci;
>>>>>           int err, irq, clk = 0;
>>>>>
>>>>>           if (usb_disabled())
>>>>> @@ -177,8 +180,34 @@ static int ehci_platform_probe(struct platform_device *dev)
>>>>>           platform_set_drvdata(dev, hcd);
>>>>>           dev->dev.platform_data = pdata;
>>>>>           priv = hcd_to_ehci_priv(hcd);
>>>>> +       ehci = hcd_to_ehci(hcd);
>>>>>
>>>>>           if (pdata == &ehci_platform_defaults && dev->dev.of_node) {
>>>>> +               if (of_property_read_bool(dev->dev.of_node, "big-endian-regs"))
>>>>> +                       ehci->big_endian_mmio = 1;
>>>>> +
>>>>> +               if (of_property_read_bool(dev->dev.of_node, "big-endian-desc"))
>>>>> +                       ehci->big_endian_desc = 1;
>>>>> +
>>>>> +               if (of_property_read_bool(dev->dev.of_node, "big-endian"))
>>>>> +                       ehci->big_endian_mmio = ehci->big_endian_desc = 1;
>>>>
>>>> Ok, so I am confused now, should you update
>>>> pdata->ehci_big_endian_{desc,mmio} here or is it valid to directly
>>>> modify ehci->big_endian_{desc,mmio}, is not there any risk  to undo
>>>> what is done in ehci_platform_reset(), or is ehci_platform_reset()
>>>> only called for non-DT cases?
>>>
>>> Both the pdata checks in ehci_platform_reset() and the dt checks here only
>>> ever set these flags, neither code path clears them. And in the dt case pdata
>>> will be NULL and vice versa.
>>
>> If it's safe to set ehci->big_endian_{desc,mmio} from the _probe()
>> routine, then maybe the pdata sets in _reset() should be moved into here
>> instead of adding extra cludges/checks into _reset().
>
> That seems like an entire separate patch / improvement on top of adding support
> for big-endian controllers to the dt code.
>
> If people won't to improve on thus further and / or clean things up further I'm
> sure the usb-subsys maintainers would welcome patches.

s/won't to improve on thus/want to improve this/

>
> <snip more suggestions best done in a separate patch written by someone else>
>
> Regards,
>
> Hans

Regards,

Hans
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Alan Stern Jan. 22, 2014, 9:17 p.m. UTC | #10
On Wed, 22 Jan 2014, Jonas Gorski wrote:

> If it's safe to set ehci->big_endian_{desc,mmio} from the _probe()
> routine, then maybe the pdata sets in _reset() should be moved into here
> instead of adding extra cludges/checks into _reset().

Why?  What difference would it make?

Alan Stern

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Jonas Gorski Jan. 22, 2014, 11:03 p.m. UTC | #11
On Wed, 22 Jan 2014 16:17:42 -0500 (EST)
Alan Stern <stern@rowland.harvard.edu> wrote:

> On Wed, 22 Jan 2014, Jonas Gorski wrote:
> 
> > If it's safe to set ehci->big_endian_{desc,mmio} from the _probe()
> > routine, then maybe the pdata sets in _reset() should be moved into here
> > instead of adding extra cludges/checks into _reset().
> 
> Why?  What difference would it make?

Effectivewise none, but to me it seems to be cleaner to set them once in
probe() instead of everytime reset() is called.

I admit I don't know the code flow good enough if reset() is called
more than once in the lifetime of a hcd device.

And as I said, it would allow doing the checks the patch adds for both
DT and !DT, not just DT only.


Regards
Jonas
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Alan Stern Jan. 23, 2014, 3:46 p.m. UTC | #12
On Thu, 23 Jan 2014, Jonas Gorski wrote:

> On Wed, 22 Jan 2014 16:17:42 -0500 (EST)
> Alan Stern <stern@rowland.harvard.edu> wrote:
> 
> > On Wed, 22 Jan 2014, Jonas Gorski wrote:
> > 
> > > If it's safe to set ehci->big_endian_{desc,mmio} from the _probe()
> > > routine, then maybe the pdata sets in _reset() should be moved into here
> > > instead of adding extra cludges/checks into _reset().
> > 
> > Why?  What difference would it make?
> 
> Effectivewise none, but to me it seems to be cleaner to set them once in
> probe() instead of everytime reset() is called.
> 
> I admit I don't know the code flow good enough if reset() is called
> more than once in the lifetime of a hcd device.

Only once.

> And as I said, it would allow doing the checks the patch adds for both
> DT and !DT, not just DT only.

That's true.  Or the checks could be moved into the probe routine.

Alan Stern

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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/usb/usb-ohci.txt b/Documentation/devicetree/bindings/usb/usb-ohci.txt
index f9d6c73..aa1d765 100644
--- a/Documentation/devicetree/bindings/usb/usb-ohci.txt
+++ b/Documentation/devicetree/bindings/usb/usb-ohci.txt
@@ -6,6 +6,9 @@  Required properties:
 - interrupts : ohci controller interrupt
 
 Optional properties:
+- big-endian-regs : boolean, set this for hcds with big-endian registers
+- big-endian-desc : boolean, set this for hcds with big-endian descriptors
+- big-endian : boolean, for hcds with big-endian-regs + big-endian-desc
 - clocks : a list of phandle + clock specifier pairs
 - phys : phandle + phy specifier pair
 - phy-names : "usb"
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index e28cbe0..237d7b1 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -512,6 +512,10 @@  config USB_CNS3XXX_OHCI
 
 config USB_OHCI_HCD_PLATFORM
 	tristate "Generic OHCI driver for a platform device"
+	# Always support LE, support BE on architectures which have readl_be
+	select USB_OHCI_LITTLE_ENDIAN
+	select USB_OHCI_BIG_ENDIAN_DESC if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
+	select USB_OHCI_BIG_ENDIAN_MMIO if (AVR32 || MIPS || MICROBLAZE || SPARC || PPC32 || PPC64)
 	default n
 	---help---
 	  Adds an OHCI host driver for a generic platform device, which
diff --git a/drivers/usb/host/ohci-platform.c b/drivers/usb/host/ohci-platform.c
index b2d0e1e..71e9d8e 100644
--- a/drivers/usb/host/ohci-platform.c
+++ b/drivers/usb/host/ohci-platform.c
@@ -128,6 +128,7 @@  static int ohci_platform_probe(struct platform_device *dev)
 	struct resource *res_mem;
 	struct usb_ohci_pdata *pdata = dev_get_platdata(&dev->dev);
 	struct ohci_platform_priv *priv;
+	struct ohci_hcd *ohci;
 	int err, irq, clk = 0;
 
 	if (usb_disabled())
@@ -164,8 +165,34 @@  static int ohci_platform_probe(struct platform_device *dev)
 	platform_set_drvdata(dev, hcd);
 	dev->dev.platform_data = pdata;
 	priv = hcd_to_ohci_priv(hcd);
+	ohci = hcd_to_ohci(hcd);
 
 	if (pdata == &ohci_platform_defaults && dev->dev.of_node) {
+		if (of_property_read_bool(dev->dev.of_node, "big-endian-regs"))
+			ohci->flags |= OHCI_QUIRK_BE_MMIO;
+
+		if (of_property_read_bool(dev->dev.of_node, "big-endian-desc"))
+			ohci->flags |= OHCI_QUIRK_BE_DESC;
+
+		if (of_property_read_bool(dev->dev.of_node, "big-endian"))
+			ohci->flags |= OHCI_QUIRK_BE_MMIO | OHCI_QUIRK_BE_DESC;
+
+#ifndef CONFIG_USB_OHCI_BIG_ENDIAN_MMIO
+		if (ohci->flags & OHCI_QUIRK_BE_MMIO) {
+			dev_err(&dev->dev,
+				"Error big-endian-regs not compiled in\n");
+			err = -EINVAL;
+			goto err_put_hcd;
+		}
+#endif
+#ifndef CONFIG_USB_OHCI_BIG_ENDIAN_DESC
+		if (ohci->flags & OHCI_QUIRK_BE_DESC) {
+			dev_err(&dev->dev,
+				"Error big-endian-desc not compiled in\n");
+			err = -EINVAL;
+			goto err_put_hcd;
+		}
+#endif
 		priv->phy = devm_phy_get(&dev->dev, "usb");
 		if (IS_ERR(priv->phy)) {
 			err = PTR_ERR(priv->phy);