From mboxrd@z Thu Jan  1 00:00:00 1970
From: Lothar =?UTF-8?B?V2HDn21hbm4=?= <LW@KARO-electronics.de>
Subject: Re: [PATCH 2/2] pwm: imx: support polarity inversion
Date: Mon, 13 Jan 2014 13:26:25 +0100
Message-ID: <20140113132625.4409abfc@ipc1.ka-ro>
References: <1389608988-10981-1-git-send-email-LW@KARO-electronics.de>
	<1389608988-10981-3-git-send-email-LW@KARO-electronics.de>
	<11504930.fjG2AZiQ4e@wuerfel>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: QUOTED-PRINTABLE
Return-path: <linux-pwm-owner@vger.kernel.org>
In-Reply-To: <11504930.fjG2AZiQ4e@wuerfel>
Sender: linux-pwm-owner@vger.kernel.org
To: Arnd Bergmann <arnd@arndb.de>
Cc: linux-arm-kernel@lists.infradead.org, Shawn Guo <shawn.guo@linaro.org>, Sascha Hauer <kernel@pengutronix.de>, Rob Herring <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>, Mark Rutland <mark.rutland@arm.com>, Ian Campbell <ijc+devicetree@hellion.org.uk>, Kumar Gala <galak@codeaurora.org>, Russell King <linux@arm.linux.org.uk>, Thierry Reding <thierry.reding@gmail.com>, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pwm@vger.kernel.org
List-Id: devicetree@vger.kernel.org

Hi,

Arnd Bergmann wrote:
> On Monday 13 January 2014 11:29:48 Lothar Wa=C3=9Fmann wrote:
>=20
> > diff --git a/arch/arm/boot/dts/imx50.dtsi b/arch/arm/boot/dts/imx50=
=2Edtsi
> > index 01c0499..e3647a8 100644
> > --- a/arch/arm/boot/dts/imx50.dtsi
> > +++ b/arch/arm/boot/dts/imx50.dtsi
> > @@ -273,7 +273,7 @@
> >  			};
> > =20
> >  			pwm1: pwm@53fb4000 {
> > -				#pwm-cells =3D <2>;
> > +				#pwm-cells =3D <3>;
> >  				compatible =3D "fsl,imx50-pwm", "fsl,imx27-pwm";
> >  				reg =3D <0x53fb4000 0x4000>;
> >  				clocks =3D <&clks IMX5_CLK_PWM1_IPG_GATE>,
> ...
> > @@ -271,6 +293,13 @@ static int imx_pwm_probe(struct platform_devic=
e *pdev)
> >  		return PTR_ERR(imx->mmio_base);
> > =20
> >  	data =3D of_id->data;
> > +	if (data->output_polarity) {
> > +		dev_info(&pdev->dev, "PWM supports inversion\n");
> > +		imx_pwm_ops.set_polarity =3D imx_pwm_set_polarity;
> > +		imx->chip.of_xlate =3D of_pwm_xlate_with_flags;
> > +		imx->chip.of_pwm_n_cells =3D 3;
> > +	}
> > +
> >  	imx->config =3D data->config;
> >  	imx->set_enable =3D data->set_enable;
>=20
> This looks like you are breaking compatibility with the binding,
> which requires #pwm-cells to be <2>. You can extend the binding
> to allow both <2> and <3>, but then you have to not only document
> that change in the binding, but also ensure that the pwm driver
> is able to use either variant.
>=20
Good point. I'll try to change the driver to cope with either binding,
so the changes to the dts files of the current users will not be
necessary.


Lothar Wa=C3=9Fmann
--=20
___________________________________________________________

Ka-Ro electronics GmbH | Pascalstra=C3=9Fe 22 | D - 52076 Aachen
Phone: +49 2408 1402-0 | Fax: +49 2408 1402-10
Gesch=C3=A4ftsf=C3=BChrer: Matthias Kaussen
Handelsregistereintrag: Amtsgericht Aachen, HRB 4996

www.karo-electronics.de | info@karo-electronics.de
___________________________________________________________