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Message-ID: <612d1ee6-aa25-20f8-081a-e6cdfeeafce0@canonical.com>
Date:   Tue, 8 Mar 2022 19:09:11 +0100
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Subject: Re: [PATCH v3 04/15] dt-bindings: devfreq: rk3399_dmc: Specify idle
 params in nanoseconds
Content-Language: en-US
To:     Brian Norris <briannorris@chromium.org>,
        MyungJoo Ham <myungjoo.ham@samsung.com>,
        Kyungmin Park <kyungmin.park@samsung.com>,
        Chanwoo Choi <cw00.choi@samsung.com>,
        Rob Herring <robh+dt@kernel.org>
Cc:     Lin Huang <hl@rock-chips.com>, Heiko Stuebner <heiko@sntech.de>,
        Derek Basehore <dbasehore@chromium.org>,
        linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-pm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, Rob Herring <robh@kernel.org>
References: <20220308000945.706701-1-briannorris@chromium.org>
 <20220307160918.v3.4.I01c6a2b2db578136686b42d463af985cfdff2fd9@changeid>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
In-Reply-To: <20220307160918.v3.4.I01c6a2b2db578136686b42d463af985cfdff2fd9@changeid>
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Precedence: bulk

On 08/03/2022 01:09, Brian Norris wrote:
> It's inefficient to use the same number of cycles for all OPPs, since
> lower frequencies make for longer idle times. Let's specify the idle
> time instead, so software can pick the optimal number of cycles on its
> own.
> 
> NB: these bindings aren't used anywhere yet.
> 
> Signed-off-by: Brian Norris <briannorris@chromium.org>
> Reviewed-by: Rob Herring <robh@kernel.org>
> ---
> 
> Changes in v3:
>  * Add Reviewed-by
> 
> Changes in v2:
>  * New patch
> 
>  .../bindings/devfreq/rk3399_dmc.yaml          | 50 +++++++++++++++++--
>  1 file changed, 45 insertions(+), 5 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/devfreq/rk3399_dmc.yaml b/Documentation/devicetree/bindings/devfreq/rk3399_dmc.yaml
> index 2904ae4115f3..6a33a7b44741 100644
> --- a/Documentation/devicetree/bindings/devfreq/rk3399_dmc.yaml
> +++ b/Documentation/devicetree/bindings/devfreq/rk3399_dmc.yaml
> @@ -56,42 +56,52 @@ properties:
>        being used.
>  
>    rockchip,pd_idle:
> +    deprecated: true
>      $ref: /schemas/types.yaml#/definitions/uint32
>      description:
>        Configure the PD_IDLE value. Defines the power-down idle period in which
>        memories are placed into power-down mode if bus is idle for PD_IDLE DFI
>        clock cycles.
> +      See also rockchip,pd-idle-ns.
>  
>    rockchip,sr_idle:
> +    deprecated: true
>      $ref: /schemas/types.yaml#/definitions/uint32
>      description:
>        Configure the SR_IDLE value. Defines the self-refresh idle period in
>        which memories are placed into self-refresh mode if bus is idle for
>        SR_IDLE * 1024 DFI clock cycles (DFI clocks freq is half of DRAM clock).
>        Default value is "0".
> +      See also rockchip,sr-idle-ns.
>  
>    rockchip,sr_mc_gate_idle:
> +    deprecated: true
>      $ref: /schemas/types.yaml#/definitions/uint32
>      description:
>        Defines the memory self-refresh and controller clock gating idle period.
>        Memories are placed into self-refresh mode and memory controller clock
>        arg gating started if bus is idle for sr_mc_gate_idle*1024 DFI clock
>        cycles.
> +      See also rockchip,sr-mc-gate-idle-ns.
>  
>    rockchip,srpd_lite_idle:
> +    deprecated: true
>      $ref: /schemas/types.yaml#/definitions/uint32
>      description:
>        Defines the self-refresh power down idle period in which memories are
>        placed into self-refresh power down mode if bus is idle for
>        srpd_lite_idle * 1024 DFI clock cycles. This parameter is for LPDDR4
>        only.
> +      See also rockchip,srpd-lite-idle-ns.
>  
>    rockchip,standby_idle:
> +    deprecated: true
>      $ref: /schemas/types.yaml#/definitions/uint32
>      description:
>        Defines the standby idle period in which memories are placed into
>        self-refresh mode. The controller, pi, PHY and DRAM clock will be gated
>        if bus is idle for standby_idle * DFI clock cycles.
> +      See also rockchip,standby-idle-ns.
>  
>    rockchip,dram_dll_dis_freq:
>      deprecated: true
> @@ -260,6 +270,36 @@ properties:
>        When the DRAM type is LPDDR4, this parameter defines the PHY side ODT
>        strength. Default value is 60.
>  
> +  rockchip,pd-idle-ns:
> +    description:
> +      Configure the PD_IDLE value in nanoseconds. Defines the power-down idle
> +      period in which memories are placed into power-down mode if bus is idle
> +      for PD_IDLE nanoseconds.
> +
> +  rockchip,sr-idle-ns:
> +    description:
> +      Configure the SR_IDLE value in nanoseconds. Defines the self-refresh idle
> +      period in which memories are placed into self-refresh mode if bus is idle
> +      for SR_IDLE nanoseconds. Default value is "0".

Use "default: 0".


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>


Best regards,
Krzysztof