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Message-ID: <3e915435-b4d0-e792-6bdc-02bbf8f08362@ideasonboard.com>
Date:   Mon, 19 Jun 2023 14:11:09 +0300
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Subject: Re: [PATCH v14 17/18] media: i2c: ds90ub953: Restructure clkout
 management
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To:     Andy Shevchenko <andriy.shevchenko@intel.com>
Cc:     linux-media@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org,
        Luca Ceresoli <luca.ceresoli@bootlin.com>,
        Matti Vaittinen <Matti.Vaittinen@fi.rohmeurope.com>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Wolfram Sang <wsa@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Peter Rosin <peda@axentia.se>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Michael Tretter <m.tretter@pengutronix.de>,
        Hans Verkuil <hverkuil@xs4all.nl>,
        Mike Pagano <mpagano@gentoo.org>,
        =?UTF-8?Q?Krzysztof_Ha=c5=82asa?= <khalasa@piap.pl>,
        Marek Vasut <marex@denx.de>,
        Satish Nagireddy <satish.nagireddy@getcruise.com>
References: <20230616135922.442979-1-tomi.valkeinen@ideasonboard.com>
 <20230616135922.442979-18-tomi.valkeinen@ideasonboard.com>
 <ZIxzsUbuUz3ysA31@smile.fi.intel.com>
 <002e0475-23dd-5106-6f5c-e4b50a0c506f@ideasonboard.com>
 <ZJAxqFuJ/Tj5dIT8@smile.fi.intel.com>
From:   Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
In-Reply-To: <ZJAxqFuJ/Tj5dIT8@smile.fi.intel.com>
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On 19/06/2023 13:44, Andy Shevchenko wrote:
> On Mon, Jun 19, 2023 at 01:14:34PM +0300, Tomi Valkeinen wrote:
>> On 16/06/2023 17:37, Andy Shevchenko wrote:
>>> On Fri, Jun 16, 2023 at 04:59:21PM +0300, Tomi Valkeinen wrote:
>>>> Separate clkout calculations and register writes into two functions:
>>>> ub953_calc_clkout_params and ub953_write_clkout_regs, and add a struct
>>>> ub953_clkout_data that is used to store the clkout parameters.
> 
> ...
> 
>>>> +struct ub953_clkout_data {
>>>> +	u32 hs_div;
>>>> +	u32 m;
>>>> +	u32 n;
>>>
>>> Please, use struxt u32_fract instead of m/n.
>>
>> I'm not sure how that helps. The documentation talks about m and n. Using
>> different terms will make it more difficult to compare the code and the
>> docs.
> 
> You can always add a comment.
> 
> (For example in drivers/clk/clk-fractional-divider.c our documentation also
>   says about m/n, but most of the people understands that this is about
>   fractional divider and actually with properly spelled parameters it will
>   help others who are not experts in the CLK hardware.)

Yes, I would agree with you if this was a generic piece of code, but I 
don't see the reasoning as valid as this is specific to a piece of 
hardware. Here, I think, matching the code to the HW documentation is 
more important than possibly making the code more understandable to 
people who are not familiar with the HW.

Especially as for non-English people seeing "numerator" and 
"denominator" might require a check to figure out which one is which, 
whereas m and n are (I would guess) a bit more universal (or maybe it's 
just me).

  Tomi