[PATCH v3 05/17] dt-bindings: ufs: exynos-ufs: add sysreg regmap property

[PATCH v3 05/17] dt-bindings: ufs: exynos-ufs: add sysreg regmap property

[Chanho Park]

Add "sysreg" regmap phandle property to control io coherency setting.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Chanho Park <chanho61.park@samsung.com>
---
 .../devicetree/bindings/ufs/samsung,exynos-ufs.yaml          | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml b/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml
index b9ca8ef4f2be..c3f14f81d4b7 100644
--- a/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml
+++ b/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml
@@ -54,6 +54,11 @@ properties:
   phy-names:
     const: ufs-phy
 
+  sysreg:
+    $ref: '/schemas/types.yaml#/definitions/phandle'
+    description: phandle for FSYS sysreg interface, used to control
+                 sysreg register bit for UFS IO Coherency
+
 required:
   - compatible
   - reg
-- 
2.33.0

Re: [PATCH v3 05/17] dt-bindings: ufs: exynos-ufs: add sysreg regmap property

[Rob Herring]

On Fri, Sep 17, 2021 at 03:54:24PM +0900, Chanho Park wrote:
> Add "sysreg" regmap phandle property to control io coherency setting.
> 
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> Signed-off-by: Chanho Park <chanho61.park@samsung.com>
> ---
>  .../devicetree/bindings/ufs/samsung,exynos-ufs.yaml          | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml b/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml
> index b9ca8ef4f2be..c3f14f81d4b7 100644
> --- a/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml
> +++ b/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml
> @@ -54,6 +54,11 @@ properties:
>    phy-names:
>      const: ufs-phy
>  
> +  sysreg:

Needs a vendor prefix.

> +    $ref: '/schemas/types.yaml#/definitions/phandle'
> +    description: phandle for FSYS sysreg interface, used to control
> +                 sysreg register bit for UFS IO Coherency

Is there more than 1 FSYS? If not, you can just get the node by its 
compatible. 

Also, what about 'dma-coherent' property? The driver core needs to know.

> +
>  required:
>    - compatible
>    - reg
> -- 
> 2.33.0
> 
> 

RE: [PATCH v3 05/17] dt-bindings: ufs: exynos-ufs: add sysreg regmap property

[Chanho Park]

> > +  sysreg:
> 
> Needs a vendor prefix.

Thanks. I'll use "samsung,sysreg-phandle".

> 
> > +    $ref: '/schemas/types.yaml#/definitions/phandle'
> > +    description: phandle for FSYS sysreg interface, used to control
> > +                 sysreg register bit for UFS IO Coherency
> 
> Is there more than 1 FSYS? If not, you can just get the node by its
> compatible.

The phandle can be differed each exynos SoCs, AFAIK. I think other exynos
SoCs since exnos7 will need this but not upstreamed yet...

> 
> Also, what about 'dma-coherent' property? The driver core needs to know.

Yes. 'dma-coherent' should be listed as well.

Best Regards,
Chanho Park

Re: [PATCH v3 05/17] dt-bindings: ufs: exynos-ufs: add sysreg regmap property

[Rob Herring]

On Thu, Sep 23, 2021 at 09:47:44AM +0900, Chanho Park wrote:
> > > +  sysreg:
> > 
> > Needs a vendor prefix.
> 
> Thanks. I'll use "samsung,sysreg-phandle".

No '-phandle'.

> 
> > 
> > > +    $ref: '/schemas/types.yaml#/definitions/phandle'
> > > +    description: phandle for FSYS sysreg interface, used to control
> > > +                 sysreg register bit for UFS IO Coherency
> > 
> > Is there more than 1 FSYS? If not, you can just get the node by its
> > compatible.
> 
> The phandle can be differed each exynos SoCs, AFAIK. I think other exynos
> SoCs since exnos7 will need this but not upstreamed yet...

That's still fine. You really only need a phandle if there is more than 
1 instance on a given platform.

Of course you could end up with multiple compatible strings to deal 
with, but you might need that anyway as the registers are likely to be 
different. That can sometimes be mitigated by putting register offsets 
into the DT property (something to consider here).  This is the problem 
with drivers directly twiddling bits in  other h/w blocks and why we 
have common interfaces for clocks, resets, etc.

I leave it to you to decide how you want to do it.

BTW, If you want to see another way to handle the same problem, see 
highbank_platform_notifier(). Notifiers aren't great either, but it 
keeps some SoC specifics out of the driver.

Rob

RE: [PATCH v3 05/17] dt-bindings: ufs: exynos-ufs: add sysreg regmap property

[Chanho Park]

> > > > +  sysreg:
> > >
> > > Needs a vendor prefix.
> >
> > Thanks. I'll use "samsung,sysreg-phandle".
> 
> No '-phandle'.

Will use "samsung,sysreg" next patch series.

> 
> >
> > >
> > > > +    $ref: '/schemas/types.yaml#/definitions/phandle'
> > > > +    description: phandle for FSYS sysreg interface, used to control
> > > > +                 sysreg register bit for UFS IO Coherency
> > >
> > > Is there more than 1 FSYS? If not, you can just get the node by its
> > > compatible.
> >
> > The phandle can be differed each exynos SoCs, AFAIK. I think other
> > exynos SoCs since exnos7 will need this but not upstreamed yet...
> 
> That's still fine. You really only need a phandle if there is more than
> 1 instance on a given platform.
> 
> Of course you could end up with multiple compatible strings to deal with,
> but you might need that anyway as the registers are likely to be
different.
> That can sometimes be mitigated by putting register offsets into the DT
> property (something to consider here).  This is the problem with drivers
> directly twiddling bits in  other h/w blocks and why we have common
> interfaces for clocks, resets, etc.

Regarding ufs-exynos, it can have multiple instances (ufs_0/1/22). I'm also
preparing to support ufs_1 for exynosautov9 SoC but not yet finished due to
ufs phy control. Each instances has their own sysreg offset. To support
secondary ufs, I need to rework this patch and add the offset field as DT
propery.

+#define UFS_SHAREABILITY_OFFSET        0x710

For UFS1, this should be 0x714.

> 
> I leave it to you to decide how you want to do it.
> 
> BTW, If you want to see another way to handle the same problem, see
> highbank_platform_notifier(). Notifiers aren't great either, but it keeps
> some SoC specifics out of the driver.
> 

I checked highbank_platform_notifier() implementation but I need to keep
this way to have further support multiple ufs instances and can be used for
exynos8/9 SoCs as well.

Best Regards,
Chanho Park

[PATCH v3 17/17] dt-bindings: ufs: exynos-ufs: add exynosautov9 compatible

[Chanho Park]

Below two compatibles can be used for exynosautov9 SoC UFS controller.

- samsung,exynosautov9-ufs: ExynosAutov9 UFS Physical Host
- samsung,exynosautov9-ufs-vh: ExynosAutov9 UFS Virtual Host

Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Chanho Park <chanho61.park@samsung.com>
---
 Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml b/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml
index c3f14f81d4b7..832f0770433e 100644
--- a/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml
+++ b/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml
@@ -20,6 +20,8 @@ properties:
   compatible:
     enum:
       - samsung,exynos7-ufs
+      - samsung,exynosautov9-ufs
+      - samsung,exynosautov9-ufs-vh
 
   reg:
     items:
-- 
2.33.0

Re: [PATCH v3 17/17] dt-bindings: ufs: exynos-ufs: add exynosautov9 compatible

[Rob Herring]

On Fri, 17 Sep 2021 15:54:36 +0900, Chanho Park wrote:
> Below two compatibles can be used for exynosautov9 SoC UFS controller.
> 
> - samsung,exynosautov9-ufs: ExynosAutov9 UFS Physical Host
> - samsung,exynosautov9-ufs-vh: ExynosAutov9 UFS Virtual Host
> 
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> Signed-off-by: Chanho Park <chanho61.park@samsung.com>
> ---
>  Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml | 2 ++
>  1 file changed, 2 insertions(+)
> 

Acked-by: Rob Herring <robh@kernel.org>