2018-09-25 15:07:58

by Veerabhadrarao Badiganti

[permalink] [raw]
Subject: [PATCH 1/2] dt-bindings: mmc: sdhci-msm: Add flag for restoring dll

The dll settings of SDHC controller needs to be restored whenever
controller clocks are gated. This restoration is needed only on
few SDHCI-MSM controllers. This dt flag indicates whether dll
restoration is needed or not.

Signed-off-by: Veerabhadrarao Badiganti <[email protected]>
---
Documentation/devicetree/bindings/mmc/sdhci-msm.txt | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
index 3720385..207ce36 100644
--- a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
+++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
@@ -31,6 +31,8 @@ Optional properties:
BUS_OFF states in power irq. Should be specified in
pairs (lpm, hpm), for BUS_OFF and BUS_ON respectively.
Units uA.
+- qcom,restore-dll-config - Flag indicates that restoration of dll config after clock gating
+ is needed on given platform. This wouldn't be needed for every MSM.
Example:

sdhc_1: sdhci@f9824900 {
@@ -49,6 +51,8 @@ Example:

clocks = <&gcc GCC_SDCC1_APPS_CLK>, <&gcc GCC_SDCC1_AHB_CLK>;
clock-names = "core", "iface";
+
+ qcom,restore-dll-config;
};

sdhc_2: sdhci@f98a4900 {
--
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Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project



2018-09-25 17:41:32

by Evan Green

[permalink] [raw]
Subject: Re: [PATCH 1/2] dt-bindings: mmc: sdhci-msm: Add flag for restoring dll

On Tue, Sep 25, 2018 at 8:05 AM Veerabhadrarao Badiganti
<[email protected]> wrote:
>
> The dll settings of SDHC controller needs to be restored whenever
> controller clocks are gated. This restoration is needed only on
> few SDHCI-MSM controllers. This dt flag indicates whether dll
> restoration is needed or not.
>
> Signed-off-by: Veerabhadrarao Badiganti <[email protected]>
> ---
> Documentation/devicetree/bindings/mmc/sdhci-msm.txt | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
> index 3720385..207ce36 100644
> --- a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
> +++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
> @@ -31,6 +31,8 @@ Optional properties:
> BUS_OFF states in power irq. Should be specified in
> pairs (lpm, hpm), for BUS_OFF and BUS_ON respectively.
> Units uA.
> +- qcom,restore-dll-config - Flag indicates that restoration of dll config after clock gating
> + is needed on given platform. This wouldn't be needed for every MSM.
> Example:
>
> sdhc_1: sdhci@f9824900 {
> @@ -49,6 +51,8 @@ Example:
>
> clocks = <&gcc GCC_SDCC1_APPS_CLK>, <&gcc GCC_SDCC1_AHB_CLK>;
> clock-names = "core", "iface";
> +
> + qcom,restore-dll-config;

Hi Veera,
I'm not sure this is the best approach. It might be better to key this
behavior off of the compatible string. Actually I'm noticing now that
the binding for this device doesn't include an SoC-specific compatible
string, which I think is now the preferred way (eg
"qcom,sdm845-sdhci", "qcom,sdhci-msm-v5"). I think we should add that
to sdhci-msm.txt, then use the compatible string to enable this
behavior you're adding now.

-Evan

2018-09-27 11:23:30

by Veerabhadrarao Badiganti

[permalink] [raw]
Subject: Re: [PATCH 1/2] dt-bindings: mmc: sdhci-msm: Add flag for restoring dll



On 9/25/2018 11:08 PM, Evan Green wrote:
> On Tue, Sep 25, 2018 at 8:05 AM Veerabhadrarao Badiganti
> <[email protected]> wrote:
>> The dll settings of SDHC controller needs to be restored whenever
>> controller clocks are gated. This restoration is needed only on
>> few SDHCI-MSM controllers. This dt flag indicates whether dll
>> restoration is needed or not.
>>
>> Signed-off-by: Veerabhadrarao Badiganti <[email protected]>
>> ---
>> Documentation/devicetree/bindings/mmc/sdhci-msm.txt | 4 ++++
>> 1 file changed, 4 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
>> index 3720385..207ce36 100644
>> --- a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
>> +++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
>> @@ -31,6 +31,8 @@ Optional properties:
>> BUS_OFF states in power irq. Should be specified in
>> pairs (lpm, hpm), for BUS_OFF and BUS_ON respectively.
>> Units uA.
>> +- qcom,restore-dll-config - Flag indicates that restoration of dll config after clock gating
>> + is needed on given platform. This wouldn't be needed for every MSM.
>> Example:
>>
>> sdhc_1: sdhci@f9824900 {
>> @@ -49,6 +51,8 @@ Example:
>>
>> clocks = <&gcc GCC_SDCC1_APPS_CLK>, <&gcc GCC_SDCC1_AHB_CLK>;
>> clock-names = "core", "iface";
>> +
>> + qcom,restore-dll-config;
> Hi Veera,
> I'm not sure this is the best approach. It might be better to key this
> behavior off of the compatible string. Actually I'm noticing now that
> the binding for this device doesn't include an SoC-specific compatible
> string, which I think is now the preferred way (eg
> "qcom,sdm845-sdhci", "qcom,sdhci-msm-v5"). I think we should add that
> to sdhci-msm.txt, then use the compatible string to enable this
> behavior you're adding now.

Thanks Evan. I will update this one.

> -Evan

Thanks,
Veera