linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH 0/2] PCI: mediatek-gen3: Add controller support for MT8195
@ 2021-06-01  2:44 Jianjun Wang
  2021-06-01  2:44 ` [PATCH 1/2] dt-bindings: PCI: mediatek-gen3: Add " Jianjun Wang
  2021-06-01  2:44 ` [PATCH 2/2] PCI: mediatek-gen3: Add controller " Jianjun Wang
  0 siblings, 2 replies; 9+ messages in thread
From: Jianjun Wang @ 2021-06-01  2:44 UTC (permalink / raw)
  To: Ryder Lee, Bjorn Helgaas, Rob Herring, Lorenzo Pieralisi
  Cc: Matthias Brugger, linux-pci, linux-mediatek, devicetree,
	linux-kernel, linux-arm-kernel, Jianjun Wang, Randy Wu,
	youlin.pei

These series patches modify pcie-mediatek-gen3.c and dt-bindings compatible
string to support the PCIe controller for MT8195.

Jianjun Wang (2):
  dt-bindings: PCI: mediatek-gen3: Add support for MT8195
  PCI: mediatek-gen3: Add controller support for MT8195

 Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml | 4 +++-
 drivers/pci/controller/pcie-mediatek-gen3.c                   | 1 +
 2 files changed, 4 insertions(+), 1 deletion(-)

-- 
2.18.0


^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH 1/2] dt-bindings: PCI: mediatek-gen3: Add support for MT8195
  2021-06-01  2:44 [PATCH 0/2] PCI: mediatek-gen3: Add controller support for MT8195 Jianjun Wang
@ 2021-06-01  2:44 ` Jianjun Wang
  2021-06-01  3:53   ` Chen-Yu Tsai
  2021-06-01  2:44 ` [PATCH 2/2] PCI: mediatek-gen3: Add controller " Jianjun Wang
  1 sibling, 1 reply; 9+ messages in thread
From: Jianjun Wang @ 2021-06-01  2:44 UTC (permalink / raw)
  To: Ryder Lee, Bjorn Helgaas, Rob Herring, Lorenzo Pieralisi
  Cc: Matthias Brugger, linux-pci, linux-mediatek, devicetree,
	linux-kernel, linux-arm-kernel, Jianjun Wang, Randy Wu,
	youlin.pei

MT8195 is an ARM platform SoC which has the same PCIe IP with MT8192.

Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
---
 Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
index e7b1f9892da4..d5e4a3e63d97 100644
--- a/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
+++ b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
@@ -48,7 +48,9 @@ allOf:
 
 properties:
   compatible:
-    const: mediatek,mt8192-pcie
+    oneOf:
+      - const: mediatek,mt8192-pcie
+      - const: mediatek,mt8195-pcie
 
   reg:
     maxItems: 1
-- 
2.18.0


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH 2/2] PCI: mediatek-gen3: Add controller support for MT8195
  2021-06-01  2:44 [PATCH 0/2] PCI: mediatek-gen3: Add controller support for MT8195 Jianjun Wang
  2021-06-01  2:44 ` [PATCH 1/2] dt-bindings: PCI: mediatek-gen3: Add " Jianjun Wang
@ 2021-06-01  2:44 ` Jianjun Wang
  1 sibling, 0 replies; 9+ messages in thread
From: Jianjun Wang @ 2021-06-01  2:44 UTC (permalink / raw)
  To: Ryder Lee, Bjorn Helgaas, Rob Herring, Lorenzo Pieralisi
  Cc: Matthias Brugger, linux-pci, linux-mediatek, devicetree,
	linux-kernel, linux-arm-kernel, Jianjun Wang, Randy Wu,
	youlin.pei

MT8195 is an ARM platform SoC which has the same PCIe IP with MT8192.

Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
---
 drivers/pci/controller/pcie-mediatek-gen3.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
index 3c5b97716d40..c12e2450d0e1 100644
--- a/drivers/pci/controller/pcie-mediatek-gen3.c
+++ b/drivers/pci/controller/pcie-mediatek-gen3.c
@@ -1010,6 +1010,7 @@ static const struct dev_pm_ops mtk_pcie_pm_ops = {
 
 static const struct of_device_id mtk_pcie_of_match[] = {
 	{ .compatible = "mediatek,mt8192-pcie" },
+	{ .compatible = "mediatek,mt8195-pcie" },
 	{},
 };
 
-- 
2.18.0


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* Re: [PATCH 1/2] dt-bindings: PCI: mediatek-gen3: Add support for MT8195
  2021-06-01  2:44 ` [PATCH 1/2] dt-bindings: PCI: mediatek-gen3: Add " Jianjun Wang
@ 2021-06-01  3:53   ` Chen-Yu Tsai
  2021-06-01  5:49     ` Jianjun Wang
  0 siblings, 1 reply; 9+ messages in thread
From: Chen-Yu Tsai @ 2021-06-01  3:53 UTC (permalink / raw)
  To: Jianjun Wang
  Cc: Ryder Lee, Bjorn Helgaas, Rob Herring, Lorenzo Pieralisi,
	Matthias Brugger, linux-pci, linux-mediatek, devicetree,
	linux-kernel, linux-arm-kernel, Randy Wu, youlin.pei

Hi,

On Tue, Jun 1, 2021 at 10:50 AM Jianjun Wang <jianjun.wang@mediatek.com> wrote:
>
> MT8195 is an ARM platform SoC which has the same PCIe IP with MT8192.

Based on what I'm seeing internally, there seems to be some inconsistency
across the MediaTek platform on whether new compatible strings should be
introduced for "fully compatible" IP blocks.

If this hardware block in MT8195 is "the same" as the one in MT8192, do we
really need the new compatible string? Are there any concerns?


Thanks
ChenYu


> Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
> ---
>  Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> index e7b1f9892da4..d5e4a3e63d97 100644
> --- a/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> +++ b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> @@ -48,7 +48,9 @@ allOf:
>
>  properties:
>    compatible:
> -    const: mediatek,mt8192-pcie
> +    oneOf:
> +      - const: mediatek,mt8192-pcie
> +      - const: mediatek,mt8195-pcie
>
>    reg:
>      maxItems: 1
> --
> 2.18.0
> _______________________________________________
> Linux-mediatek mailing list
> Linux-mediatek@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-mediatek

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 1/2] dt-bindings: PCI: mediatek-gen3: Add support for MT8195
  2021-06-01  3:53   ` Chen-Yu Tsai
@ 2021-06-01  5:49     ` Jianjun Wang
  2021-06-01  6:07       ` Chen-Yu Tsai
  0 siblings, 1 reply; 9+ messages in thread
From: Jianjun Wang @ 2021-06-01  5:49 UTC (permalink / raw)
  To: Chen-Yu Tsai
  Cc: Ryder Lee, Bjorn Helgaas, Rob Herring, Lorenzo Pieralisi,
	Matthias Brugger, linux-pci, linux-mediatek, devicetree,
	linux-kernel, linux-arm-kernel, Randy Wu, youlin.pei

On Tue, 2021-06-01 at 11:53 +0800, Chen-Yu Tsai wrote:
> Hi,
> 
> On Tue, Jun 1, 2021 at 10:50 AM Jianjun Wang <jianjun.wang@mediatek.com> wrote:
> >
> > MT8195 is an ARM platform SoC which has the same PCIe IP with MT8192.
> 
> Based on what I'm seeing internally, there seems to be some inconsistency
> across the MediaTek platform on whether new compatible strings should be
> introduced for "fully compatible" IP blocks.
> 
> If this hardware block in MT8195 is "the same" as the one in MT8192, do we
> really need the new compatible string? Are there any concerns?

Hi Chen-Yu,

It's ok to reuse the compatible string with MT8192, but I think this
will be easier to find which platforms this driver is compatible with,
especially when we have more and more platforms in the future.

Thanks. 
> 
> 
> Thanks
> ChenYu
> 
> 
> > Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
> > ---
> >  Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> > index e7b1f9892da4..d5e4a3e63d97 100644
> > --- a/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> > +++ b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> > @@ -48,7 +48,9 @@ allOf:
> >
> >  properties:
> >    compatible:
> > -    const: mediatek,mt8192-pcie
> > +    oneOf:
> > +      - const: mediatek,mt8192-pcie
> > +      - const: mediatek,mt8195-pcie
> >
> >    reg:
> >      maxItems: 1
> > --
> > 2.18.0
> > _______________________________________________
> > Linux-mediatek mailing list
> > Linux-mediatek@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-mediatek


^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 1/2] dt-bindings: PCI: mediatek-gen3: Add support for MT8195
  2021-06-01  5:49     ` Jianjun Wang
@ 2021-06-01  6:07       ` Chen-Yu Tsai
  2021-06-02 11:33         ` Matthias Brugger
  0 siblings, 1 reply; 9+ messages in thread
From: Chen-Yu Tsai @ 2021-06-01  6:07 UTC (permalink / raw)
  To: Jianjun Wang
  Cc: Ryder Lee, Bjorn Helgaas, Rob Herring, Lorenzo Pieralisi,
	Matthias Brugger, linux-pci, linux-mediatek, devicetree,
	linux-kernel, linux-arm-kernel, Randy Wu, youlin.pei

Hi,

On Tue, Jun 1, 2021 at 1:50 PM Jianjun Wang <jianjun.wang@mediatek.com> wrote:
>
> On Tue, 2021-06-01 at 11:53 +0800, Chen-Yu Tsai wrote:
> > Hi,
> >
> > On Tue, Jun 1, 2021 at 10:50 AM Jianjun Wang <jianjun.wang@mediatek.com> wrote:
> > >
> > > MT8195 is an ARM platform SoC which has the same PCIe IP with MT8192.
> >
> > Based on what I'm seeing internally, there seems to be some inconsistency
> > across the MediaTek platform on whether new compatible strings should be
> > introduced for "fully compatible" IP blocks.
> >
> > If this hardware block in MT8195 is "the same" as the one in MT8192, do we
> > really need the new compatible string? Are there any concerns?
>
> Hi Chen-Yu,
>
> It's ok to reuse the compatible string with MT8192, but I think this
> will be easier to find which platforms this driver is compatible with,
> especially when we have more and more platforms in the future.

If it's just for informational purposes, then having the MT8192 compatible
as a fallback would work, and we wouldn't need to make changes to the driver.
This works better especially if we have to support multiple operating systems
that use device tree.

So we would want

    "mediatek,mt8195-pcie", "mediatek,mt8192-pcie"

and

    "mediatek,mt8192-pcie"

be the valid options.

Personally I'm not seeing enough value to justify adding the compatible string
just for informational purposes though. One could easily discern which hardware
is used by looking at the device tree.


Regards
ChenYu


> Thanks.
> >
> >
> > Thanks
> > ChenYu
> >
> >
> > > Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
> > > ---
> > >  Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml | 4 +++-
> > >  1 file changed, 3 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> > > index e7b1f9892da4..d5e4a3e63d97 100644
> > > --- a/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> > > +++ b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> > > @@ -48,7 +48,9 @@ allOf:
> > >
> > >  properties:
> > >    compatible:
> > > -    const: mediatek,mt8192-pcie
> > > +    oneOf:
> > > +      - const: mediatek,mt8192-pcie
> > > +      - const: mediatek,mt8195-pcie
> > >
> > >    reg:
> > >      maxItems: 1
> > > --
> > > 2.18.0
> > > _______________________________________________
> > > Linux-mediatek mailing list
> > > Linux-mediatek@lists.infradead.org
> > > http://lists.infradead.org/mailman/listinfo/linux-mediatek
>

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 1/2] dt-bindings: PCI: mediatek-gen3: Add support for MT8195
  2021-06-01  6:07       ` Chen-Yu Tsai
@ 2021-06-02 11:33         ` Matthias Brugger
  2021-06-22 11:05           ` Lorenzo Pieralisi
  0 siblings, 1 reply; 9+ messages in thread
From: Matthias Brugger @ 2021-06-02 11:33 UTC (permalink / raw)
  To: Chen-Yu Tsai, Jianjun Wang
  Cc: Ryder Lee, Bjorn Helgaas, Rob Herring, Lorenzo Pieralisi,
	linux-pci, linux-mediatek, devicetree, linux-kernel,
	linux-arm-kernel, Randy Wu, youlin.pei



On 01/06/2021 08:07, Chen-Yu Tsai wrote:
> Hi,
> 
> On Tue, Jun 1, 2021 at 1:50 PM Jianjun Wang <jianjun.wang@mediatek.com> wrote:
>>
>> On Tue, 2021-06-01 at 11:53 +0800, Chen-Yu Tsai wrote:
>>> Hi,
>>>
>>> On Tue, Jun 1, 2021 at 10:50 AM Jianjun Wang <jianjun.wang@mediatek.com> wrote:
>>>>
>>>> MT8195 is an ARM platform SoC which has the same PCIe IP with MT8192.
>>>
>>> Based on what I'm seeing internally, there seems to be some inconsistency
>>> across the MediaTek platform on whether new compatible strings should be
>>> introduced for "fully compatible" IP blocks.
>>>
>>> If this hardware block in MT8195 is "the same" as the one in MT8192, do we
>>> really need the new compatible string? Are there any concerns?
>>
>> Hi Chen-Yu,
>>
>> It's ok to reuse the compatible string with MT8192, but I think this
>> will be easier to find which platforms this driver is compatible with,
>> especially when we have more and more platforms in the future.
> 
> If it's just for informational purposes, then having the MT8192 compatible
> as a fallback would work, and we wouldn't need to make changes to the driver.
> This works better especially if we have to support multiple operating systems
> that use device tree.
> 
> So we would want
> 
>     "mediatek,mt8195-pcie", "mediatek,mt8192-pcie"
> 
> and
> 
>     "mediatek,mt8192-pcie"
> 
> be the valid options.
> 
> Personally I'm not seeing enough value to justify adding the compatible string
> just for informational purposes though. One could easily discern which hardware
> is used by looking at the device tree.
> 

I agree, if no differences between the two chips are known, adding a binding
withe new compatible and a fallback is a good thing. If we later on realize that
mt8195 PCI block has differences, we can add the matching to the driver.

Regards,
Matthias

> 
> Regards
> ChenYu
> 
> 
>> Thanks.
>>>
>>>
>>> Thanks
>>> ChenYu
>>>
>>>
>>>> Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
>>>> ---
>>>>  Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml | 4 +++-
>>>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
>>>> index e7b1f9892da4..d5e4a3e63d97 100644
>>>> --- a/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
>>>> +++ b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
>>>> @@ -48,7 +48,9 @@ allOf:
>>>>
>>>>  properties:
>>>>    compatible:
>>>> -    const: mediatek,mt8192-pcie
>>>> +    oneOf:
>>>> +      - const: mediatek,mt8192-pcie
>>>> +      - const: mediatek,mt8195-pcie
>>>>
>>>>    reg:
>>>>      maxItems: 1
>>>> --
>>>> 2.18.0
>>>> _______________________________________________
>>>> Linux-mediatek mailing list
>>>> Linux-mediatek@lists.infradead.org
>>>> http://lists.infradead.org/mailman/listinfo/linux-mediatek
>>

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 1/2] dt-bindings: PCI: mediatek-gen3: Add support for MT8195
  2021-06-02 11:33         ` Matthias Brugger
@ 2021-06-22 11:05           ` Lorenzo Pieralisi
  2021-06-23  9:02             ` Jianjun Wang
  0 siblings, 1 reply; 9+ messages in thread
From: Lorenzo Pieralisi @ 2021-06-22 11:05 UTC (permalink / raw)
  To: Matthias Brugger
  Cc: Chen-Yu Tsai, Jianjun Wang, Ryder Lee, Bjorn Helgaas,
	Rob Herring, linux-pci, linux-mediatek, devicetree, linux-kernel,
	linux-arm-kernel, Randy Wu, youlin.pei

On Wed, Jun 02, 2021 at 01:33:07PM +0200, Matthias Brugger wrote:
> 
> 
> On 01/06/2021 08:07, Chen-Yu Tsai wrote:
> > Hi,
> > 
> > On Tue, Jun 1, 2021 at 1:50 PM Jianjun Wang <jianjun.wang@mediatek.com> wrote:
> >>
> >> On Tue, 2021-06-01 at 11:53 +0800, Chen-Yu Tsai wrote:
> >>> Hi,
> >>>
> >>> On Tue, Jun 1, 2021 at 10:50 AM Jianjun Wang <jianjun.wang@mediatek.com> wrote:
> >>>>
> >>>> MT8195 is an ARM platform SoC which has the same PCIe IP with MT8192.
> >>>
> >>> Based on what I'm seeing internally, there seems to be some inconsistency
> >>> across the MediaTek platform on whether new compatible strings should be
> >>> introduced for "fully compatible" IP blocks.
> >>>
> >>> If this hardware block in MT8195 is "the same" as the one in MT8192, do we
> >>> really need the new compatible string? Are there any concerns?
> >>
> >> Hi Chen-Yu,
> >>
> >> It's ok to reuse the compatible string with MT8192, but I think this
> >> will be easier to find which platforms this driver is compatible with,
> >> especially when we have more and more platforms in the future.
> > 
> > If it's just for informational purposes, then having the MT8192 compatible
> > as a fallback would work, and we wouldn't need to make changes to the driver.
> > This works better especially if we have to support multiple operating systems
> > that use device tree.
> > 
> > So we would want
> > 
> >     "mediatek,mt8195-pcie", "mediatek,mt8192-pcie"
> > 
> > and
> > 
> >     "mediatek,mt8192-pcie"
> > 
> > be the valid options.
> > 
> > Personally I'm not seeing enough value to justify adding the compatible string
> > just for informational purposes though. One could easily discern which hardware
> > is used by looking at the device tree.
> > 
> 
> I agree, if no differences between the two chips are known, adding a
> binding withe new compatible and a fallback is a good thing. If we
> later on realize that mt8195 PCI block has differences, we can add the
> matching to the driver.

So this series can be dropped, right ?

Thanks,
Lorenzo

> Regards,
> Matthias
> 
> > 
> > Regards
> > ChenYu
> > 
> > 
> >> Thanks.
> >>>
> >>>
> >>> Thanks
> >>> ChenYu
> >>>
> >>>
> >>>> Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
> >>>> ---
> >>>>  Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml | 4 +++-
> >>>>  1 file changed, 3 insertions(+), 1 deletion(-)
> >>>>
> >>>> diff --git a/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> >>>> index e7b1f9892da4..d5e4a3e63d97 100644
> >>>> --- a/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> >>>> +++ b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> >>>> @@ -48,7 +48,9 @@ allOf:
> >>>>
> >>>>  properties:
> >>>>    compatible:
> >>>> -    const: mediatek,mt8192-pcie
> >>>> +    oneOf:
> >>>> +      - const: mediatek,mt8192-pcie
> >>>> +      - const: mediatek,mt8195-pcie
> >>>>
> >>>>    reg:
> >>>>      maxItems: 1
> >>>> --
> >>>> 2.18.0
> >>>> _______________________________________________
> >>>> Linux-mediatek mailing list
> >>>> Linux-mediatek@lists.infradead.org
> >>>> http://lists.infradead.org/mailman/listinfo/linux-mediatek
> >>

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 1/2] dt-bindings: PCI: mediatek-gen3: Add support for MT8195
  2021-06-22 11:05           ` Lorenzo Pieralisi
@ 2021-06-23  9:02             ` Jianjun Wang
  0 siblings, 0 replies; 9+ messages in thread
From: Jianjun Wang @ 2021-06-23  9:02 UTC (permalink / raw)
  To: Lorenzo Pieralisi
  Cc: Matthias Brugger, Chen-Yu Tsai, Ryder Lee, Bjorn Helgaas,
	Rob Herring, linux-pci, linux-mediatek, devicetree, linux-kernel,
	linux-arm-kernel, Randy Wu, youlin.pei

On Tue, 2021-06-22 at 12:05 +0100, Lorenzo Pieralisi wrote:
> On Wed, Jun 02, 2021 at 01:33:07PM +0200, Matthias Brugger wrote:
> > 
> > 
> > On 01/06/2021 08:07, Chen-Yu Tsai wrote:
> > > Hi,
> > > 
> > > On Tue, Jun 1, 2021 at 1:50 PM Jianjun Wang <jianjun.wang@mediatek.com> wrote:
> > >>
> > >> On Tue, 2021-06-01 at 11:53 +0800, Chen-Yu Tsai wrote:
> > >>> Hi,
> > >>>
> > >>> On Tue, Jun 1, 2021 at 10:50 AM Jianjun Wang <jianjun.wang@mediatek.com> wrote:
> > >>>>
> > >>>> MT8195 is an ARM platform SoC which has the same PCIe IP with MT8192.
> > >>>
> > >>> Based on what I'm seeing internally, there seems to be some inconsistency
> > >>> across the MediaTek platform on whether new compatible strings should be
> > >>> introduced for "fully compatible" IP blocks.
> > >>>
> > >>> If this hardware block in MT8195 is "the same" as the one in MT8192, do we
> > >>> really need the new compatible string? Are there any concerns?
> > >>
> > >> Hi Chen-Yu,
> > >>
> > >> It's ok to reuse the compatible string with MT8192, but I think this
> > >> will be easier to find which platforms this driver is compatible with,
> > >> especially when we have more and more platforms in the future.
> > > 
> > > If it's just for informational purposes, then having the MT8192 compatible
> > > as a fallback would work, and we wouldn't need to make changes to the driver.
> > > This works better especially if we have to support multiple operating systems
> > > that use device tree.
> > > 
> > > So we would want
> > > 
> > >     "mediatek,mt8195-pcie", "mediatek,mt8192-pcie"
> > > 
> > > and
> > > 
> > >     "mediatek,mt8192-pcie"
> > > 
> > > be the valid options.
> > > 
> > > Personally I'm not seeing enough value to justify adding the compatible string
> > > just for informational purposes though. One could easily discern which hardware
> > > is used by looking at the device tree.
> > > 
> > 
> > I agree, if no differences between the two chips are known, adding a
> > binding withe new compatible and a fallback is a good thing. If we
> > later on realize that mt8195 PCI block has differences, we can add the
> > matching to the driver.
> 
> So this series can be dropped, right ?

Yes, we will send dt-bindings with dts changes in another series,
thanks.
> 
> Thanks,
> Lorenzo
> 
> > Regards,
> > Matthias
> > 
> > > 
> > > Regards
> > > ChenYu
> > > 
> > > 
> > >> Thanks.
> > >>>
> > >>>
> > >>> Thanks
> > >>> ChenYu
> > >>>
> > >>>
> > >>>> Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
> > >>>> ---
> > >>>>  Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml | 4 +++-
> > >>>>  1 file changed, 3 insertions(+), 1 deletion(-)
> > >>>>
> > >>>> diff --git a/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> > >>>> index e7b1f9892da4..d5e4a3e63d97 100644
> > >>>> --- a/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> > >>>> +++ b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> > >>>> @@ -48,7 +48,9 @@ allOf:
> > >>>>
> > >>>>  properties:
> > >>>>    compatible:
> > >>>> -    const: mediatek,mt8192-pcie
> > >>>> +    oneOf:
> > >>>> +      - const: mediatek,mt8192-pcie
> > >>>> +      - const: mediatek,mt8195-pcie
> > >>>>
> > >>>>    reg:
> > >>>>      maxItems: 1
> > >>>> --
> > >>>> 2.18.0
> > >>>> _______________________________________________
> > >>>> Linux-mediatek mailing list
> > >>>> Linux-mediatek@lists.infradead.org
> > >>>> http://lists.infradead.org/mailman/listinfo/linux-mediatek
> > >>


^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2021-06-23  9:02 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-06-01  2:44 [PATCH 0/2] PCI: mediatek-gen3: Add controller support for MT8195 Jianjun Wang
2021-06-01  2:44 ` [PATCH 1/2] dt-bindings: PCI: mediatek-gen3: Add " Jianjun Wang
2021-06-01  3:53   ` Chen-Yu Tsai
2021-06-01  5:49     ` Jianjun Wang
2021-06-01  6:07       ` Chen-Yu Tsai
2021-06-02 11:33         ` Matthias Brugger
2021-06-22 11:05           ` Lorenzo Pieralisi
2021-06-23  9:02             ` Jianjun Wang
2021-06-01  2:44 ` [PATCH 2/2] PCI: mediatek-gen3: Add controller " Jianjun Wang

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).