linux-kernel - Re: [PATCH v2 8/8] rtc: isl12022: implement support for the #clock-cells DT property

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Date:   Tue, 13 Jun 2023 18:25:01 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Rasmus Villemoes <linux@...musvillemoes.dk>
Cc:     Alessandro Zummo <a.zummo@...ertech.it>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>,
        devicetree@...r.kernel.org, Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Conor Dooley <conor+dt@...nel.org>, linux-rtc@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 8/8] rtc: isl12022: implement support for the
 #clock-cells DT property

On Tue, Jun 13, 2023 at 03:00:10PM +0200, Rasmus Villemoes wrote:
> If device tree implies that the chip's IRQ/F_OUT pin is used as a
> clock, expose that in the driver. For now, pretend it is a
> fixed-rate (32kHz) clock; if other use cases appear the driver can be
> updated to provide its own clk_ops etc.
> 
> When the clock output is not used on a given board, one can prolong
> the battery life by ensuring that the FOx bits are 0. For the hardware
> I'm currently working on, the RTC draws 1.2uA with the FOx bits at
> their default 0001 value, dropping to 0.88uA when those bits are
> cleared.

...

> +#define ISL12022_INT_FO_MASK	GENMASK(3, 0)
> +#define ISL12022_INT_FO_OFF	0x0
> +#define ISL12022_INT_FO_32K	0x1

A nit-pick. Are they decimal or bit fields? To me seems like
the 0x can be dropped.

...

> +	ret = regmap_update_bits(regmap, ISL12022_REG_INT, ISL12022_INT_FO_MASK, ISL12022_INT_FO_32K);

Seems too long even for 100 limit.
Maybe:

	ret = regmap_update_bits(regmap, ISL12022_REG_INT,
				 ISL12022_INT_FO_MASK, ISL12022_INT_FO_32K);

?

-- 
With Best Regards,
Andy Shevchenko