Re: [PATCH] dt-bindings: ufs: qcom: Add reg-names property for ICE

[Eric Biggers <ebiggers@kernel.org>]

On Fri, Dec 09, 2022 at 04:19:20PM +0100, Krzysztof Kozlowski wrote:
> On 09/12/2022 16:11, Luca Weiss wrote:
> > On Fri Dec 9, 2022 at 4:05 PM CET, Krzysztof Kozlowski wrote:
> >> On 09/12/2022 15:29, Luca Weiss wrote:
> >>> The code in ufs-qcom-ice.c needs the ICE reg to be named "ice". Add this
> >>> in the bindings so the existing dts can validate successfully.
> >>>
> >>> Also sm8450 is using ICE since commit 276ee34a40c1 ("arm64: dts: qcom:
> >>> sm8450: add Inline Crypto Engine registers and clock") so move the
> >>> compatible to the correct if.
> >>>
> >>> Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
> >>> ---
> >>> (no cover subject)
> >>>
> >>> The only remaining validation issues I see is the following on sc8280xp-crd.dtb
> >>> and sa8540p-ride.dtb:
> >>>
> >>>   Unevaluated properties are not allowed ('required-opps', 'dma-coherent' were unexpected)
> >>>
> >>> Maybe someone who knows something about this can handle this?
> >>>
> >>> And the patch adding qcom,sm6115-ufshc hasn't been applied yet.
> >>> ---
> >>>  Documentation/devicetree/bindings/ufs/qcom,ufs.yaml | 8 +++++++-
> >>>  1 file changed, 7 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/Documentation/devicetree/bindings/ufs/qcom,ufs.yaml b/Documentation/devicetree/bindings/ufs/qcom,ufs.yaml
> >>> index f2d6298d926c..58a2fb2c83c3 100644
> >>> --- a/Documentation/devicetree/bindings/ufs/qcom,ufs.yaml
> >>> +++ b/Documentation/devicetree/bindings/ufs/qcom,ufs.yaml
> >>> @@ -102,7 +102,6 @@ allOf:
> >>>                - qcom,sc8280xp-ufshc
> >>>                - qcom,sm8250-ufshc
> >>>                - qcom,sm8350-ufshc
> >>> -              - qcom,sm8450-ufshc
> >>>      then:
> >>>        properties:
> >>>          clocks:
> >>> @@ -130,6 +129,7 @@ allOf:
> >>>                - qcom,sdm845-ufshc
> >>>                - qcom,sm6350-ufshc
> >>>                - qcom,sm8150-ufshc
> >>> +              - qcom,sm8450-ufshc
> >>>      then:
> >>>        properties:
> >>>          clocks:
> >>> @@ -149,6 +149,12 @@ allOf:
> >>>          reg:
> >>>            minItems: 2
> >>>            maxItems: 2
> >>> +        reg-names:
> >>
> >> There are no reg-names in top-level, so it's surprising to see its
> >> customized here. It seems no one ever documented that usage...
> > 
> > From what I can tell, from driver side all devices not using ICE don't
> > need reg-names, only the "ice" reg is referenced by name in the driver.
> > 
> > I didn't add it top-level because with only one reg I think we're not
> > supposed to use reg-names, right?
> 
> And you still won't need to use. Yet property should be rather described
> in top-level which also will unify the items here (so no different
> 2-item reg-names in variants).
> 
> Just add it to top-level with minItems: 1 and per variant customize:
> 1. maxItems: 1
> 2. minItems: 2 + required
> 
> The "required" is a bit questionable... this was never added by Eric to
> the bindings. Driver support and DTS were added completely skipping
> bindings...
> 

Sorry about that.  At the time
(https://lore.kernel.org/linux-scsi/20200722051143.GU388985@builder.lan/T/#t)
I didn't know there was a Documentation file that should have been updated.

The UFS core assumes that the reg at index 0 is the UFS standard registers.
It is not referenced by name.

ufs-qcom already had an optional reg at index 1.  I needed to add another
optional reg.  So I made the regs at index 1 and later be optional named regs:
dev_ref_clk_ctrl_mem and ice.  That seemed better than hardcoding the indices.

Is it causing a problem that the UFS standard reg at index 0 is being mixed with
named regs in the same list?

- Eric