linux-kernel - Re: [PATCH v3 1/2] hwmon: (adm1275) Allow setting sample averaging

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Date:   Mon, 28 Feb 2022 10:12:39 -0800
From:   Guenter Roeck <linux@...ck-us.net>
To:     Potin Lai <potin.lai@...ntatw.com>,
        Jean Delvare <jdelvare@...e.com>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzk@...nel.org>
Cc:     Patrick Williams <patrick@...cx.xyz>, linux-hwmon@...r.kernel.org,
        linux-kernel@...r.kernel.org, devicetree@...r.kernel.org
Subject: Re: [PATCH v3 1/2] hwmon: (adm1275) Allow setting sample averaging

On 2/28/22 02:37, Potin Lai wrote:
> Current driver assume PWR_AVG and VI_AVG as 1 by default, and user needs
> to set sample averaging via sysfs manually.
> 
> This patch parses the properties below from device tree, and setting
> sample averaging during probe. Allowed input value from 1 to 128. If the
> inputed value is not power of 2, the sample averaging number will be
> configured with the smaller and cloest power of 2.
> 
> - adi,power-sample-average
> - adi,volt-curr-sample-average
> 
> Signed-off-by: Potin Lai <potin.lai@...ntatw.com>
> ---
>   drivers/hwmon/pmbus/adm1275.c | 36 +++++++++++++++++++++++++++++++++++
>   1 file changed, 36 insertions(+)
> 
> diff --git a/drivers/hwmon/pmbus/adm1275.c b/drivers/hwmon/pmbus/adm1275.c
> index d311e0557401..212c7f3c59b0 100644
> --- a/drivers/hwmon/pmbus/adm1275.c
> +++ b/drivers/hwmon/pmbus/adm1275.c
> @@ -475,6 +475,7 @@ static int adm1275_probe(struct i2c_client *client)
>   	int vindex = -1, voindex = -1, cindex = -1, pindex = -1;
>   	int tindex = -1;
>   	u32 shunt;
> +	u32 avg;
>   
>   	if (!i2c_check_functionality(client->adapter,
>   				     I2C_FUNC_SMBUS_READ_BYTE_DATA
> @@ -756,6 +757,41 @@ static int adm1275_probe(struct i2c_client *client)
>   		return -ENODEV;
>   	}
>   
> +	if (data->have_power_sampling &&
> +	    of_property_read_u32(client->dev.of_node,
> +				"adi,power-sample-average", &avg) == 0) {
> +		if (avg > ADM1275_SAMPLES_AVG_MAX || avg < 1)
> +			return -EINVAL;
> +		dev_info(&client->dev,
> +			"Setting power sample averaging number to %u",
> +			BIT(ilog2(avg)));
> +		ret = adm1275_write_pmon_config(data, client, true,
> +						ilog2(avg));
> +		if (ret < 0) {
> +			dev_err(&client->dev,
> +				"Setting power sample averaging failed with error %d",
> +				ret);
> +			return ret;
> +		}
> +	}
> +
> +	if (of_property_read_u32(client->dev.of_node,
> +				"adi,volt-curr-sample-average", &avg) == 0) {
> +		if (avg > ADM1275_SAMPLES_AVG_MAX || avg < 1)
> +			return -EINVAL;
> +		dev_info(&client->dev,
> +			"Setting voltage and current sample averaging number to %u",
> +			BIT(ilog2(avg)));

Please no such logging noise. Imagine if everyone would do that -
the log would be full with similar messages.

Thanks,
Guenter

> +		ret = adm1275_write_pmon_config(data, client, false,
> +						ilog2(avg));
> +		if (ret < 0) {
> +			dev_err(&client->dev,
> +				"Setting voltage and current sample averaging failed with error %d",
> +				ret);
> +			return ret;
> +		}
> +	}
> +
>   	if (voindex < 0)
>   		voindex = vindex;
>   	if (vindex >= 0) {