Re: [PATCH] regulator: qcom-rpmh: Implement get_optimum_mode(), not set_load()

[Andrew Halaney <ahalaney@redhat.com>]

Hey Douglas,

On Tue, Jul 26, 2022 at 10:20:29AM -0700, Douglas Anderson wrote:
> Since we don't actually pass the load to the firmware, switch to using
> get_optimum_mode() instead of open-coding it.
> 
> This is intended to have no effect other than cleanup.

I hate to post something without looking into it very deeply, but with
this statement about no effect I figured I'd report what I'm noticing
before diving deeper.

I'm currently playing with the dts patches in [0], and without this
patch (and a hack patch applied that is unrelated to this) the board boots
fine. With this patch applied I get the messages reported in [1] (which I
think is still a clean up that should be applied) and the board fails to
boot due to regulator_enable() failing at the first invocation I see.

Is that something you expect?

Here's the ultimate failure message for regulator_enable():

    [    1.213419] ufshcd-qcom 1d84000.ufs: Adding to iommu group 0
    [    1.219492] ufshcd-qcom 1d84000.ufs: ufshcd_populate_vreg: Unable to find vdd-hba-supply regulator, assuming enabled
    [    1.230287] ufshcd-qcom 1d84000.ufs: ufshcd_populate_vreg: Unable to find vccq2-supply regulator, assuming enabled
    [    1.241079] vreg_l17c: invalid input voltage found
    [    1.246002] ufshcd-qcom 1d84000.ufs: ufshcd_enable_vreg: vcc enable failed, err=-22
    [    1.253952] ufshcd-qcom 1d84000.ufs: Initialization failed
    [    1.259622] ufshcd-qcom 1d84000.ufs: ufshcd_pltfrm_init() failed -22
    [    1.266151] ufshcd-qcom: probe of 1d84000.ufs failed with error -22

[0] https://lore.kernel.org/all/20220722143711.17563-1-quic_ppareek@quicinc.com/
[1] https://lore.kernel.org/all/166118500944.215002.10320899094541954077.b4-ty@kernel.org/

Thanks,
Andrew

> 
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
> 
>  drivers/regulator/qcom-rpmh-regulator.c | 17 ++++++++---------
>  1 file changed, 8 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/regulator/qcom-rpmh-regulator.c b/drivers/regulator/qcom-rpmh-regulator.c
> index 561de6b2e6e3..b2debde79361 100644
> --- a/drivers/regulator/qcom-rpmh-regulator.c
> +++ b/drivers/regulator/qcom-rpmh-regulator.c
> @@ -306,9 +306,10 @@ static unsigned int rpmh_regulator_vrm_get_mode(struct regulator_dev *rdev)
>  }
>  
>  /**
> - * rpmh_regulator_vrm_set_load() - set the regulator mode based upon the load
> - *		current requested
> + * rpmh_regulator_vrm_get_optimum_mode() - get the mode based on the  load
>   * @rdev:		Regulator device pointer for the rpmh-regulator
> + * @input_uV:		Input voltage
> + * @output_uV:		Output voltage
>   * @load_uA:		Aggregated load current in microamps
>   *
>   * This function is used in the regulator_ops for VRM type RPMh regulator
> @@ -316,17 +317,15 @@ static unsigned int rpmh_regulator_vrm_get_mode(struct regulator_dev *rdev)
>   *
>   * Return: 0 on success, errno on failure
>   */
> -static int rpmh_regulator_vrm_set_load(struct regulator_dev *rdev, int load_uA)
> +static unsigned int rpmh_regulator_vrm_get_optimum_mode(
> +	struct regulator_dev *rdev, int input_uV, int output_uV, int load_uA)
>  {
>  	struct rpmh_vreg *vreg = rdev_get_drvdata(rdev);
> -	unsigned int mode;
>  
>  	if (load_uA >= vreg->hw_data->hpm_min_load_uA)
> -		mode = REGULATOR_MODE_NORMAL;
> +		return REGULATOR_MODE_NORMAL;
>  	else
> -		mode = REGULATOR_MODE_IDLE;
> -
> -	return rpmh_regulator_vrm_set_mode(rdev, mode);
> +		return REGULATOR_MODE_IDLE;
>  }
>  
>  static int rpmh_regulator_vrm_set_bypass(struct regulator_dev *rdev,
> @@ -375,7 +374,7 @@ static const struct regulator_ops rpmh_regulator_vrm_drms_ops = {
>  	.list_voltage		= regulator_list_voltage_linear_range,
>  	.set_mode		= rpmh_regulator_vrm_set_mode,
>  	.get_mode		= rpmh_regulator_vrm_get_mode,
> -	.set_load		= rpmh_regulator_vrm_set_load,
> +	.get_optimum_mode	= rpmh_regulator_vrm_get_optimum_mode,
>  };
>  
>  static const struct regulator_ops rpmh_regulator_vrm_bypass_ops = {
> -- 
> 2.37.1.359.gd136c6c3e2-goog
>