diff mbox series

[V4,26/28] PCI: Add DT binding for "reset-gpios" property

Message ID 20190516055307.25737-27-mmaddireddy@nvidia.com
State Changes Requested
Headers show
Series Enable Tegra PCIe root port features | expand

Commit Message

Manikanta Maddireddy May 16, 2019, 5:53 a.m. UTC
Add DT binding for "reset-gpios" property which supports GPIO based PERST#
signal.

Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Thierry Reding <treding@nvidia.com>
---
V4: No change

V3: Moved to common pci binding doc

V2: Using standard "reset-gpio" property

 Documentation/devicetree/bindings/pci/pci.txt | 3 +++
 1 file changed, 3 insertions(+)

Comments

Thierry Reding June 17, 2019, 11:30 a.m. UTC | #1
On Thu, May 16, 2019 at 11:23:05AM +0530, Manikanta Maddireddy wrote:
> Add DT binding for "reset-gpios" property which supports GPIO based PERST#
> signal.
> 
> Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
> Reviewed-by: Rob Herring <robh@kernel.org>
> Acked-by: Thierry Reding <treding@nvidia.com>
> ---
> V4: No change
> 
> V3: Moved to common pci binding doc
> 
> V2: Using standard "reset-gpio" property
> 
>  Documentation/devicetree/bindings/pci/pci.txt | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/pci/pci.txt b/Documentation/devicetree/bindings/pci/pci.txt
> index c77981c5dd18..79124898aa5b 100644
> --- a/Documentation/devicetree/bindings/pci/pci.txt
> +++ b/Documentation/devicetree/bindings/pci/pci.txt
> @@ -24,3 +24,6 @@ driver implementation may support the following properties:
>     unsupported link speed, for instance, trying to do training for
>     unsupported link speed, etc.  Must be '4' for gen4, '3' for gen3, '2'
>     for gen2, and '1' for gen1. Any other values are invalid.
> +- reset-gpios:
> +   If present this property specifies PERST# GPIO. Host drivers can parse the
> +   GPIO and apply fundamental reset to endpoints.

As mentioned in patch 27/28, maybe mention here that this is only a
workaround for bad board designs and that it shouldn't be necessary in
the majority of cases.

Thierry
Manikanta Maddireddy June 17, 2019, 11:38 a.m. UTC | #2
On 17-Jun-19 5:00 PM, Thierry Reding wrote:
> On Thu, May 16, 2019 at 11:23:05AM +0530, Manikanta Maddireddy wrote:
>> Add DT binding for "reset-gpios" property which supports GPIO based PERST#
>> signal.
>>
>> Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
>> Reviewed-by: Rob Herring <robh@kernel.org>
>> Acked-by: Thierry Reding <treding@nvidia.com>
>> ---
>> V4: No change
>>
>> V3: Moved to common pci binding doc
>>
>> V2: Using standard "reset-gpio" property
>>
>>  Documentation/devicetree/bindings/pci/pci.txt | 3 +++
>>  1 file changed, 3 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/pci/pci.txt b/Documentation/devicetree/bindings/pci/pci.txt
>> index c77981c5dd18..79124898aa5b 100644
>> --- a/Documentation/devicetree/bindings/pci/pci.txt
>> +++ b/Documentation/devicetree/bindings/pci/pci.txt
>> @@ -24,3 +24,6 @@ driver implementation may support the following properties:
>>     unsupported link speed, for instance, trying to do training for
>>     unsupported link speed, etc.  Must be '4' for gen4, '3' for gen3, '2'
>>     for gen2, and '1' for gen1. Any other values are invalid.
>> +- reset-gpios:
>> +   If present this property specifies PERST# GPIO. Host drivers can parse the
>> +   GPIO and apply fundamental reset to endpoints.
> As mentioned in patch 27/28, maybe mention here that this is only a
> workaround for bad board designs and that it shouldn't be necessary in
> the majority of cases.
>
> Thierry

This is common DT binding doc, I cannot add Tegra specific here.
reset-gpios is common DT prop, so Rob asked me to add it in common file.

Manikanta
Thierry Reding June 17, 2019, 11:48 a.m. UTC | #3
On Mon, Jun 17, 2019 at 05:08:45PM +0530, Manikanta Maddireddy wrote:
> 
> 
> On 17-Jun-19 5:00 PM, Thierry Reding wrote:
> > On Thu, May 16, 2019 at 11:23:05AM +0530, Manikanta Maddireddy wrote:
> >> Add DT binding for "reset-gpios" property which supports GPIO based PERST#
> >> signal.
> >>
> >> Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
> >> Reviewed-by: Rob Herring <robh@kernel.org>
> >> Acked-by: Thierry Reding <treding@nvidia.com>
> >> ---
> >> V4: No change
> >>
> >> V3: Moved to common pci binding doc
> >>
> >> V2: Using standard "reset-gpio" property
> >>
> >>  Documentation/devicetree/bindings/pci/pci.txt | 3 +++
> >>  1 file changed, 3 insertions(+)
> >>
> >> diff --git a/Documentation/devicetree/bindings/pci/pci.txt b/Documentation/devicetree/bindings/pci/pci.txt
> >> index c77981c5dd18..79124898aa5b 100644
> >> --- a/Documentation/devicetree/bindings/pci/pci.txt
> >> +++ b/Documentation/devicetree/bindings/pci/pci.txt
> >> @@ -24,3 +24,6 @@ driver implementation may support the following properties:
> >>     unsupported link speed, for instance, trying to do training for
> >>     unsupported link speed, etc.  Must be '4' for gen4, '3' for gen3, '2'
> >>     for gen2, and '1' for gen1. Any other values are invalid.
> >> +- reset-gpios:
> >> +   If present this property specifies PERST# GPIO. Host drivers can parse the
> >> +   GPIO and apply fundamental reset to endpoints.
> > As mentioned in patch 27/28, maybe mention here that this is only a
> > workaround for bad board designs and that it shouldn't be necessary in
> > the majority of cases.
> >
> > Thierry
> 
> This is common DT binding doc, I cannot add Tegra specific here.
> reset-gpios is common DT prop, so Rob asked me to add it in common file.

Ah, indeed. Alright, let's document it in the Tegra driver patch, then.

Thierry
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/pci/pci.txt b/Documentation/devicetree/bindings/pci/pci.txt
index c77981c5dd18..79124898aa5b 100644
--- a/Documentation/devicetree/bindings/pci/pci.txt
+++ b/Documentation/devicetree/bindings/pci/pci.txt
@@ -24,3 +24,6 @@  driver implementation may support the following properties:
    unsupported link speed, for instance, trying to do training for
    unsupported link speed, etc.  Must be '4' for gen4, '3' for gen3, '2'
    for gen2, and '1' for gen1. Any other values are invalid.
+- reset-gpios:
+   If present this property specifies PERST# GPIO. Host drivers can parse the
+   GPIO and apply fundamental reset to endpoints.