linux-kernel - Re: [PATCH v4] hwmon: (pmbus/core): Implement regulator get

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Date:   Tue, 22 Nov 2022 10:48:28 -0800
From:   Guenter Roeck <linux@...ck-us.net>
To:     Naresh Solanki <naresh.solanki@...ements.com>
Cc:     linux-hwmon@...r.kernel.org, Jean Delvare <jdelvare@...e.com>,
        broonie@...nel.org,
        Patrick Rudolph <patrick.rudolph@...ements.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4] hwmon: (pmbus/core): Implement regulator get_status

On Tue, Nov 22, 2022 at 10:03:02AM +0100, Naresh Solanki wrote:
> From: Patrick Rudolph <patrick.rudolph@...ements.com>
> 
> Add get_status for pmbus_regulator_ops.
> ---
> Changes:
> - use lock throughout the function
> - Avoid line continuation upto 100 column
> - Optimize use of & and | operator
> - Check for VOUT, IOUT, TEMPERATURE bit in status word before checking
>   respective status register for fault.
> - Report regulator current status.
> - Utilize get_error_flag to check for regulator errors.
> 
> Signed-off-by: Patrick Rudolph <patrick.rudolph@...ements.com>
> Signed-off-by: Naresh Solanki <Naresh.Solanki@...ements.com>
> ---
>  drivers/hwmon/pmbus/pmbus_core.c | 41 ++++++++++++++++++++++++++++++++
>  1 file changed, 41 insertions(+)
> 
> 
> base-commit: 27fea302952d8c90cafbdbee96bafeca03544401
> 
> diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
> index 7ec04934747e..5df2aee549e6 100644
> --- a/drivers/hwmon/pmbus/pmbus_core.c
> +++ b/drivers/hwmon/pmbus/pmbus_core.c
> @@ -2851,6 +2851,46 @@ static int pmbus_regulator_get_error_flags(struct regulator_dev *rdev, unsigned
>  	return 0;
>  }
>  
> +static int pmbus_regulator_get_status(struct regulator_dev *rdev)
> +{
> +	struct device *dev = rdev_get_dev(rdev);
> +	struct i2c_client *client = to_i2c_client(dev->parent);
> +	struct pmbus_data *data = i2c_get_clientdata(client);
> +	u8 page = rdev_get_id(rdev);
> +	int status, ret;
> +
> +	mutex_lock(&data->update_lock);
> +	status = pmbus_get_status(client, page, PMBUS_STATUS_WORD);
> +	if (status < 0) {
> +		ret = status;
> +		goto unlock;
> +	}
> +
> +	if (status & PB_STATUS_OFF) {
> +		ret = REGULATOR_STATUS_OFF;
> +		goto unlock;
> +	}
> +
> +	/* If regulator is ON & reports power good then return ON */
> +	if (!(status & PB_STATUS_POWER_GOOD_N)) {
> +		ret = REGULATOR_STATUS_ON;
> +		goto unlock;
> +	}
> +
> +	if (rdev->desc->ops->get_error_flags)
> +		ret = rdev->desc->ops->get_error_flags(rdev, &status);
> +

What about checking ret ?

> +	if (status & (REGULATOR_ERROR_UNDER_VOLTAGE | REGULATOR_ERROR_OVER_CURRENT |
> +	   REGULATOR_ERROR_REGULATION_OUT | REGULATOR_ERROR_FAIL | REGULATOR_ERROR_OVER_TEMP))
> +		ret = REGULATOR_STATUS_ERROR;
> +	else
> +		ret = REGULATOR_STATUS_UNDEFINED;

This part has to be inside "if (rdev->desc->ops->get_error_flags)"
or status will still contain the status word.

Guenter

> +
> +unlock:
> +	mutex_unlock(&data->update_lock);
> +	return ret;
> +}
> +
>  static int pmbus_regulator_get_low_margin(struct i2c_client *client, int page)
>  {
>  	struct pmbus_data *data = i2c_get_clientdata(client);
> @@ -2991,6 +3031,7 @@ const struct regulator_ops pmbus_regulator_ops = {
>  	.disable = pmbus_regulator_disable,
>  	.is_enabled = pmbus_regulator_is_enabled,
>  	.get_error_flags = pmbus_regulator_get_error_flags,
> +	.get_status = pmbus_regulator_get_status,
>  	.get_voltage = pmbus_regulator_get_voltage,
>  	.set_voltage = pmbus_regulator_set_voltage,
>  	.list_voltage = pmbus_regulator_list_voltage,