linux-kernel - Re: [PATCH v4 05/13] soc: qcom: geni-se: Add resources activation/deactivation helpers

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Message-ID: <ff9a2aa3-1b2b-4001-82ce-198c61a4b637@oss.qualcomm.com>
Date: Tue, 3 Feb 2026 13:20:45 +0100
From: Konrad Dybcio <konrad.dybcio@....qualcomm.com>
To: Praveen Talari <praveen.talari@....qualcomm.com>,
        Andi Shyti <andi.shyti@...nel.org>, Rob Herring <robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley
 <conor+dt@...nel.org>,
        Mukesh Kumar Savaliya <mukesh.savaliya@....qualcomm.com>,
        Viken Dadhaniya <viken.dadhaniya@....qualcomm.com>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>, linux-arm-msm@...r.kernel.org,
        linux-i2c@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, bjorn.andersson@....qualcomm.com,
        dmitry.baryshkov@....qualcomm.com
Cc: prasad.sodagudi@....qualcomm.com, quic_vtanuku@...cinc.com,
        aniket.randive@....qualcomm.com, chandana.chiluveru@....qualcomm.com,
        jyothi.seerapu@....qualcomm.com
Subject: Re: [PATCH v4 05/13] soc: qcom: geni-se: Add resources
 activation/deactivation helpers

On 2/2/26 7:09 PM, Praveen Talari wrote:
> The GENI SE protocol drivers (I2C, SPI, UART) implement similar resource
> activation/deactivation sequences independently, leading to code
> duplication.
> 
> Introduce geni_se_resources_activate()/geni_se_resources_deactivate() to
> power on/off resources.The activate function enables ICC, clocks, and TLMM
> whereas the deactivate function disables resources in reverse order
> including OPP rate reset, clocks, ICC and TLMM.
> 
> Signed-off-by: Praveen Talari <praveen.talari@....qualcomm.com>
> ---

[...]

> +int geni_se_resources_deactivate(struct geni_se *se)
> +{
> +	int ret;
> +
> +	if (has_acpi_companion(se->dev))
> +		return 0;
> +
> +	if (se->has_opp)
> +		dev_pm_opp_set_rate(se->dev, 0);

This is still unbalanced at this point of abstraction, notably
keeping the RPMh vote at 0 permanently after the first
geni_se_resources_deactivate()  since there's no counterpart in
_activate()

That said, the serial and UART drivers do rate calculations internally,
so perhaps trying to be overly smart about it wouldn't be a good thing
either.. Let's add a note in kerneldoc that the activate must be preceded
by a dev_pm_opp_set_xyz()

[...]

> +int geni_se_resources_activate(struct geni_se *se)
> +{
> +	int ret;
> +
> +	if (has_acpi_companion(se->dev))
> +		return 0;
> +
> +	ret = geni_icc_enable(se);
> +	if (ret)
> +		return ret;
> +
> +	ret = geni_se_clks_on(se);
> +	if (ret)
> +		goto out_icc_disable;
> +
> +	ret = pinctrl_pm_select_default_state(se->dev);
> +	if (ret) {
> +		geni_se_clks_off(se);
> +		goto out_icc_disable;
> +	}
> +
> +	return ret;

nit: this 'return' always returns 0

Konrad

> +
> +out_icc_disable:
> +	geni_icc_disable(se);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(geni_se_resources_activate);
> +
>  /**
>   * geni_se_resources_init() - Initialize resources for a GENI SE device.
>   * @se: Pointer to the geni_se structure representing the GENI SE device.
> diff --git a/include/linux/soc/qcom/geni-se.h b/include/linux/soc/qcom/geni-se.h
> index c182dd0f0bde..36a68149345c 100644
> --- a/include/linux/soc/qcom/geni-se.h
> +++ b/include/linux/soc/qcom/geni-se.h
> @@ -541,6 +541,10 @@ int geni_icc_disable(struct geni_se *se);
>  
>  int geni_se_resources_init(struct geni_se *se);
>  
> +int geni_se_resources_activate(struct geni_se *se);
> +
> +int geni_se_resources_deactivate(struct geni_se *se);
> +
>  int geni_load_se_firmware(struct geni_se *se, enum geni_se_protocol_type protocol);
>  #endif
>  #endif