Re: [RFC PATCH 1/7] pwm: rename the PWM_POLARITY_INVERSED enum - Uwe Kleine-König

From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>
Cc: Thierry Reding <thierry.reding@gmail.com>,
	devicetree@vger.kernel.org, linux-pwm@vger.kernel.org,
	Paul Barker <pbarker@konsulko.com>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Marcel Ziswiler <marcel.ziswiler@toradex.com>,
	Igor Opaniuk <igor.opaniuk@toradex.com>,
	Philippe Schenker <philippe.schenker@toradex.com>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Chen-Yu Tsai <wens@csie.org>,
	Claudiu Beznea <claudiu.beznea@microchip.com>,
	Fabio Estevam <festevam@gmail.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Heiko Stuebner <heiko@sntech.de>,
	Kevin Hilman <khilman@baylibre.com>,
	Ludovic Desroches <ludovic.desroches@microchip.com>,
	Maxime Ripard <mripard@kernel.org>,
	NXP Linux Team <linux-imx@nxp.com>,
	Nicolas Ferre <nicolas.ferre@microchip.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Paul Cercueil <paul@crapouillou.net>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Ray Jui <rjui@broadcom.com>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Scott Branden <sbranden@broadcom.com>,
	Shawn Guo <shawnguo@kernel.org>,
	bcm-kernel-feedback-list@broadcom.com,
	linux-amlogic@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org,
	linux-rockchip@lists.infradead.org
Subject: Re: [RFC PATCH 1/7] pwm: rename the PWM_POLARITY_INVERSED enum
Date: Thu, 19 Mar 2020 13:10:26 +0100	[thread overview]
Message-ID: <20200319121026.3rzcxdknfyhtkryi@pengutronix.de> (raw)
In-Reply-To: <CAGgjyvGd4y8M0L1sFMvQ1=gPcKfUPoR13dVS7F5WZx=333KG6g@mail.gmail.com>

Hello,

[dropping Tony Prisk <linux@prisktech.co.nz> from recipients]

On Thu, Mar 19, 2020 at 01:40:28PM +0200, Oleksandr Suvorov wrote:
> Thierry, I see the PWM core converts the bit field "third cell" into
> the polarity variable.
> Now I probably understand your sight and agree that we shouldn't give
> the same names to bits in bitfield (dts) and values of a variable.
> 
> But there are lots of useless "0" values of third cell of "pwms"
> option in dts files.
> 
> I see 2 ways now:
> - just remove all "0" "third cell" from "pwms" options in dts files. I
> see this "0" confuses some people.

Then you have to overwrite pwm-cells of the provider. If there are two
PWMs used from the same provider and only one is inverted this won't
work. (Not entirely sure I understood your suggestion.) So I don't like
this suggestion.

And also in my eyes this isn't clearer, just more complicated to use.

> - convert pwm_state.polarity into pwm_state.flags and use bitfield
>   directly from dtb.
>   It simplifies the parsing logic and makes adding new flags easier.

*shrug*, I don't care much.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
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