linux-kernel - Re: [v2 3/4] regulator: qcom: Add labibb driver

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Message-ID: <20200511103937.GC8216@sirena.org.uk>
Date:   Mon, 11 May 2020 11:39:37 +0100
From:   Mark Brown <broonie@...nel.org>
To:     Sumit Semwal <sumit.semwal@...aro.org>
Cc:     agross@...nel.org, bjorn.andersson@...aro.org, lgirdwood@...il.com,
        robh+dt@...nel.org, nishakumari@...eaurora.org,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org,
        devicetree@...r.kernel.org, kgunda@...eaurora.org,
        rnayak@...eaurora.org
Subject: Re: [v2 3/4] regulator: qcom: Add labibb driver

On Sat, May 09, 2020 at 02:11:59AM +0530, Sumit Semwal wrote:

> +	ret = regmap_bulk_read(reg->regmap, reg->base +
> +			       REG_LABIBB_STATUS1, &val, 1);
> +	if (ret < 0) {
> +		dev_err(reg->dev, "Read register failed ret = %d\n", ret);
> +		return ret;
> +	}

Why a bulk read of a single register?

> +static int _check_enabled_with_retries(struct regulator_dev *rdev,
> +			int retries, int enabled)
> +{

This is not retrying, this is polling to see if the regulator actually
enabled.

> +static int qcom_labibb_regulator_enable(struct regulator_dev *rdev)
> +{

> +	ret = _check_enabled_with_retries(rdev, retries, 1);
> +	if (ret < 0) {
> +		dev_err(reg->dev, "retries exhausted: enable %s regulator\n",
> +			reg->desc.name);
> +		return ret;
> +	}

If this is useful factor it out into a helper or the core, other devices
also have status bits saying if the regulator is enabled.  It looks like
this may be mainly trying to open code something like enable_time, with
possibly some issues where the time taken to enable varies a lot.

> +	if (ret)
> +		return 0;
> +
> +
> +	dev_err(reg->dev, "Can't enable %s\n", reg->desc.name);
> +	return -EINVAL;

Return the actual error code (the logic here is quite convoluted).

> +	ret = regulator_disable_regmap(rdev);
> +
> +	if (ret < 0) {

You have lots of blank lines between operations and checking their
return codes?

> +	ret = _check_enabled_with_retries(rdev, retries, 0);
> +	if (ret < 0) {
> +		dev_err(reg->dev, "retries exhausted: disable %s regulator\n",
> +			reg->desc.name);
> +		return ret;
> +	}

Similarly to the enable path, but is this one about off_on_delay rather
than enable_time?

> +	if (reg_data->type == QCOM_LAB_TYPE) {
> +		reg = &labibb->lab;
> +		reg->desc.enable_mask = LAB_ENABLE_CTL_MASK;
> +	} else {
> +		reg = &labibb->ibb;
> +		reg->desc.enable_mask = IBB_ENABLE_CTL_MASK;
> +	}

Write a switch statement so this is extensible.

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