Re: [PATCH v2] hwmon: (ntc_thermistor): try reading processed

From: Chris Lesiak <chris.lesiak@licor.com>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: Jean Delvare <jdelvare@suse.com>,
	Guenter Roeck <linux@roeck-us.net>,
	"linux-hwmon@vger.kernel.org" <linux-hwmon@vger.kernel.org>,
	Peter Rosin <peda@axentia.se>, Jonathan Cameron <jic23@cam.ac.uk>,
	"linux-iio@vger.kernel.org" <linux-iio@vger.kernel.org>
Subject: Re: [PATCH v2] hwmon: (ntc_thermistor): try reading processed
Date: Sun, 27 Dec 2020 18:54:19 +0000	[thread overview]
Message-ID: <SN6PR08MB55654976327EF62990D4DD919ADA0@SN6PR08MB5565.namprd08.prod.outlook.com> (raw)
In-Reply-To: <CACRpkdbxzuYrFeU2H2LGaWb3kKqfZ4-SpWu5FiXdFVyz82-zWw@mail.gmail.com>

Linus Walleij <linus.walleij@linaro.org> wrote:
> But do you agree with the general stance that we should
> give precedence to using iio_read_channel_processed()
> and multiply the result with 1000? It should work with
> any driver I think.

In order to preserve resolution of the microVolt value for existing code,
I'd prefer a solution similar to the existing implementation of
iio_read_channel_processed.   Sans error handling:

int uv;
if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_PROCESSED)) {
        int mv;
        iio_read_channel_processed(channel, &mv);
        uv = 1000 * mv;
} else {
        int raw;
        iio_read_channel_raw(channel, &raw);
        iio_convert_raw_to_processed(channel, raw, &uv, 1000);
}
return uv;