linux-kernel - Re: [PATCH 2/4] iio: adc: Add support for the Renesas RZ/N1 ADC

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aPIIVUlHnvi0BXtN@shikoro>
Date: Fri, 17 Oct 2025 11:11:49 +0200
From: Wolfram Sang <wsa+renesas@...g-engineering.com>
To: "Herve Codina (Schneider Electric)" <herve.codina@...tlin.com>
Cc: Jonathan Cameron <jic23@...nel.org>,
	David Lechner <dlechner@...libre.com>,
	Nuno Sá <nuno.sa@...log.com>,
	Andy Shevchenko <andy@...nel.org>, Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Geert Uytterhoeven <geert+renesas@...der.be>,
	Magnus Damm <magnus.damm@...il.com>,
	Liam Girdwood <lgirdwood@...il.com>,
	Mark Brown <broonie@...nel.org>, linux-iio@...r.kernel.org,
	linux-renesas-soc@...r.kernel.org, devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Pascal Eberhard <pascal.eberhard@...com>,
	Miquel Raynal <miquel.raynal@...tlin.com>,
	Thomas Petazzoni <thomas.petazzoni@...tlin.com>
Subject: Re: [PATCH 2/4] iio: adc: Add support for the Renesas RZ/N1 ADC


> +static int rzn1_adc_read_raw_ch(struct rzn1_adc *rzn1_adc, unsigned int chan, int *val)
> +{
> +	u32 *adc1_data, *adc2_data;
> +	int adc1_ch, adc2_ch;
> +	u32 adc_data;
> +	int ret;
> +
> +	if (chan < 8) {
> +		/* chan 0..7 used to get ADC1 ch 0..7 */
> +		adc1_ch = chan;
> +		adc1_data = &adc_data;
> +		adc2_ch = -1;
> +		adc2_data = NULL;
> +	} else if (chan < 16) {
> +		/* chan 8..15 used to get ADC2 ch 0..7 */
> +		adc1_ch = -1;
> +		adc1_data = NULL;
> +		adc2_ch = chan - 8;
> +		adc2_data = &adc_data;
> +	} else {
> +		return -EINVAL;
> +	}

How about putting part of the logic into the setup function? So, here
only:

	if (chan >= 16)
		return -EINVAL

> +
> +	ret = pm_runtime_resume_and_get(rzn1_adc->dev);
> +	if (ret < 0)
> +		return ret;
> +
> +	mutex_lock(&rzn1_adc->lock);
> +
> +	rzn1_adc_vc_setup_conversion(rzn1_adc, chan, adc1_ch, adc2_ch);

	rzn1_adc_vc_setup_conversion(rzn1_adc, chan);

And in that function:

> +static void rzn1_adc_vc_setup_conversion(struct rzn1_adc *rzn1_adc, u32 ch,
> +					 int adc1_ch, int adc2_ch)
> +{
> +	u32 vc = 0;
> +
> +	if (adc1_ch != -1)
> +		vc |= RZN1_ADC_VC_ADC1_ENABLE | RZN1_ADC_VC_ADC1_CHANNEL_SEL(adc1_ch);
> +
> +	if (adc2_ch != -1)
> +		vc |= RZN1_ADC_VC_ADC2_ENABLE | RZN1_ADC_VC_ADC2_CHANNEL_SEL(adc2_ch);
> +
> +	writel(vc, rzn1_adc->regs + RZN1_ADC_VC_REG(ch));
> +}

	if (ch < 8)
		vc |= RZN1_ADC_VC_ADC1_ENABLE | RZN1_ADC_VC_ADC1_CHANNEL_SEL(ch);
	else
		vc |= RZN1_ADC_VC_ADC2_ENABLE | RZN1_ADC_VC_ADC2_CHANNEL_SEL(ch - 8);

And a similar simplification for rzn1_adc_vc_wait_conversion().

Should work and the code is even more readable, I'd say. And has less
lines.


Download attachment "signature.asc" of type "application/pgp-signature" (834 bytes)