Add optional "limit-hs-gear" and "limit-rate" properties to the
UFS controller common binding. These properties allow limiting
the maximum HS gear and rate.

This is useful in cases where the customer board may have signal
integrity, clock configuration or layout issues that prevent reliable
operation at higher gears. Such limitations are especially critical in
those platforms, where stability is prioritized over peak performance.

Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
---
 .../devicetree/bindings/ufs/ufs-common.yaml      | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/Documentation/devicetree/bindings/ufs/ufs-common.yaml b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
index 31fe7f30ff5b..8ffed71c5f6a 100644
--- a/Documentation/devicetree/bindings/ufs/ufs-common.yaml
+++ b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
@@ -89,6 +89,22 @@ properties:
 
   msi-parent: true
 
+  limit-hs-gear:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 6
+    default: 6
+    description:
+      Restricts the maximum HS gear used in both TX and RX directions.
+
+  limit-rate:
+    $ref: /schemas/types.yaml#/definitions/string
+    enum: [rate-a, rate-b]
+    default: rate-b
+    description:
+      Restricts the UFS controller to rate-a or rate-b for both TX and
+      RX directions.
+
 dependencies:
   freq-table-hz: [ clocks ]
   operating-points-v2: [ clocks, clock-names ]
-- 
2.50.1

On Tue, Sep 02, 2025 at 10:18:57PM +0530, Ram Kumar Dwivedi wrote:
> Add optional "limit-hs-gear" and "limit-rate" properties to the
> UFS controller common binding. These properties allow limiting
> the maximum HS gear and rate.
> 
> This is useful in cases where the customer board may have signal
> integrity, clock configuration or layout issues that prevent reliable
> operation at higher gears. Such limitations are especially critical in
> those platforms, where stability is prioritized over peak performance.
> 
> Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
> ---
>  .../devicetree/bindings/ufs/ufs-common.yaml      | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

On 03-Sep-25 12:14 PM, Krzysztof Kozlowski wrote:
> On Tue, Sep 02, 2025 at 10:18:57PM +0530, Ram Kumar Dwivedi wrote:
>> Add optional "limit-hs-gear" and "limit-rate" properties to the
>> UFS controller common binding. These properties allow limiting
>> the maximum HS gear and rate.
>>
>> This is useful in cases where the customer board may have signal
>> integrity, clock configuration or layout issues that prevent reliable
>> operation at higher gears. Such limitations are especially critical in
>> those platforms, where stability is prioritized over peak performance.
>>
>> Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
>> ---
>>  .../devicetree/bindings/ufs/ufs-common.yaml      | 16 ++++++++++++++++
>>  1 file changed, 16 insertions(+)
> 
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Hi Krzysztof,

Alim has recommended renaming the "limit-rate" property to "limit-gear-rate".
Please let me know if you have any concerns.

Also, may I retain your "Reviewed-by" tag in the next patchset?

Thanks,
Ram.> 
> Best regards,
> Krzysztof
>

On 09-Sep-25 8:28 PM, Ram Kumar Dwivedi wrote:
> 
> 
> On 03-Sep-25 12:14 PM, Krzysztof Kozlowski wrote:
>> On Tue, Sep 02, 2025 at 10:18:57PM +0530, Ram Kumar Dwivedi wrote:
>>> Add optional "limit-hs-gear" and "limit-rate" properties to the
>>> UFS controller common binding. These properties allow limiting
>>> the maximum HS gear and rate.
>>>
>>> This is useful in cases where the customer board may have signal
>>> integrity, clock configuration or layout issues that prevent reliable
>>> operation at higher gears. Such limitations are especially critical in
>>> those platforms, where stability is prioritized over peak performance.
>>>
>>> Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
>>> ---
>>>  .../devicetree/bindings/ufs/ufs-common.yaml      | 16 ++++++++++++++++
>>>  1 file changed, 16 insertions(+)
>>
>> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> 
> Hi Krzysztof,
> 
> Alim has recommended renaming the "limit-rate" property to "limit-gear-rate".
> Please let me know if you have any concerns.
> 
> Also, may I retain your "Reviewed-by" tag in the next patchset?
>
Hi Krzysztof,

Just a friendly reminder,
Would appreciate your feedback when you have time.

Thanks,
Ram.> Thanks,
> Ram.> 
>> Best regards,
>> Krzysztof
>>
>

On 12-Sep-25 9:14 PM, Ram Kumar Dwivedi wrote:
> 
> 
> On 09-Sep-25 8:28 PM, Ram Kumar Dwivedi wrote:
>>
>>
>> On 03-Sep-25 12:14 PM, Krzysztof Kozlowski wrote:
>>> On Tue, Sep 02, 2025 at 10:18:57PM +0530, Ram Kumar Dwivedi wrote:
>>>> Add optional "limit-hs-gear" and "limit-rate" properties to the
>>>> UFS controller common binding. These properties allow limiting
>>>> the maximum HS gear and rate.
>>>>
>>>> This is useful in cases where the customer board may have signal
>>>> integrity, clock configuration or layout issues that prevent reliable
>>>> operation at higher gears. Such limitations are especially critical in
>>>> those platforms, where stability is prioritized over peak performance.
>>>>
>>>> Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
>>>> ---
>>>>  .../devicetree/bindings/ufs/ufs-common.yaml      | 16 ++++++++++++++++
>>>>  1 file changed, 16 insertions(+)
>>>
>>> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
>>
>> Hi Krzysztof,
>>
>> Alim has recommended renaming the "limit-rate" property to "limit-gear-rate".
>> Please let me know if you have any concerns.
>>
>> Also, may I retain your "Reviewed-by" tag in the next patchset?
>>
> Hi Krzysztof,
> 
> Just a friendly reminder,
> Would appreciate your feedback when you have time.

Hi Krzysztof,

I am retaining your Reviewed-by tag in the next patchset.

Thanks,
Ram.> 
> Thanks,
> Ram.> Thanks,
>> Ram.> 
>>> Best regards,
>>> Krzysztof
>>>
>>
> 
>