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From:   andy.shevchenko@gmail.com
Date:   Sat, 3 Jun 2023 17:04:37 +0300
To:     Herve Codina <herve.codina@bootlin.com>
Cc:     Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Jonathan Cameron <jic23@kernel.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Jaroslav Kysela <perex@perex.cz>,
        Takashi Iwai <tiwai@suse.com>,
        Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>,
        alsa-devel@alsa-project.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Subject: Re: [PATCH v2 5/9] iio: inkern: Add a helper to query an available
 minimum raw value
Message-ID: <ZHtIdTZbULl6t4RT@surfacebook>
References: <20230523151223.109551-1-herve.codina@bootlin.com>
 <20230523151223.109551-6-herve.codina@bootlin.com>
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Tue, May 23, 2023 at 05:12:19PM +0200, Herve Codina kirjoitti:
> A helper, iio_read_max_channel_raw() exists to read the available
> maximum raw value of a channel but nothing similar exists to read the
> available minimum raw value.
> 
> This new helper, iio_read_min_channel_raw(), fills the hole and can be
> used for reading the available minimum raw value of a channel.
> It is fully based on the existing iio_read_max_channel_raw().

...

> +static int iio_channel_read_min(struct iio_channel *chan,
> +				int *val, int *val2, int *type,
> +				enum iio_chan_info_enum info)
> +{
> +	int unused;
> +	const int *vals;
> +	int length;
> +	int ret;

> +	if (!val2)
> +		val2 = &unused;

It's a single place, where this is used, can you move it there?

> +	ret = iio_channel_read_avail(chan, &vals, type, &length, info);
> +	if (ret < 0)
> +		return ret;
> +
> +	switch (ret) {
> +	case IIO_AVAIL_RANGE:
> +		switch (*type) {
> +		case IIO_VAL_INT:
> +			*val = vals[0];
> +			break;
> +		default:
> +			*val = vals[0];
> +			*val2 = vals[1];
> +		}
> +		return 0;
> +
> +	case IIO_AVAIL_LIST:
> +		if (length <= 0)
> +			return -EINVAL;
> +		switch (*type) {
> +		case IIO_VAL_INT:
> +			*val = vals[--length];

> +			while (length) {

			while (length--) {

will do the job and at the same time...


> +				if (vals[--length] < *val)
> +					*val = vals[length];

...this construction becomes less confusing (easier to parse).

> +			}
> +			break;
> +		default:
> +			/* FIXME: learn about min for other iio values */

I believe in a final version this comment won't be here.

> +			return -EINVAL;
> +		}
> +		return 0;
> +
> +	default:
> +		return -EINVAL;
> +	}
> +}

-- 
With Best Regards,
Andy Shevchenko