From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?B?SmnFmcOtIFByY2hhbA==?= Subject: Re: [PATCH] ARM: at91: at91sam9x5: sets NPCS0 (PA14) back to GPIO Date: Fri, 25 Jul 2014 08:14:40 +0200 Message-ID: <53D1F5D0.1080006@aksignal.cz> References: <1405074175-22444-1-git-send-email-voice.shen@atmel.com> <53D10C50.50305@aksignal.cz> <20140724162645.4e19c26c@bbrezillon> <53D12103.3020103@aksignal.cz> <20140724175848.44f5da10@bbrezillon> Reply-To: jiri.prchal-cKCO0sOKHLPtwjQa/ONI9g@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20140724175848.44f5da10@bbrezillon> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Boris BREZILLON Cc: Bo Shen , nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org Dne 24.7.2014 v 17:58 Boris BREZILLON napsal(a): > On Thu, 24 Jul 2014 17:06:43 +0200 > Ji=C5=99=C3=AD Prchal wrote: > >> Hi, >> >> Dne 24.7.2014 v 16:26 Boris BREZILLON napsal(a): >>> Hello Ji=C5=99=C3=AD, >>> >>> First of all, please try to use git format-patch when submitting a >>> patch to any kernel mailing list. >> Sorry for that. >>> >>> On Thu, 24 Jul 2014 15:38:24 +0200 >>> Ji=C5=99=C3=AD Prchal wrote: >>> >>>> After ROMBOOT tries boot from flash on SPI0 NPCS0, this NPCS0 (PA1= 4) remains set to PERIPH_A. >>>> Because of that, this pin is unusable to something else. >>>> This patch sets it back to GPIO. >>> >>> The policy is to leave pins in an unknown state till some periphera= l >>> need them. >>> >>> What are you trying to use this pin for ? >> For chip select, but #3. And when SPI communicate with cs0 (PA22), i= t goes down too (PA14), so 2 devices on bus were >> selected. > > Are you using a 9x5ek board or a custom one, in the latter case could > you paste your spi0 node definition ? I'm using custom board. My spi node: spi0: spi@f0000000 { status =3D "okay"; cs-gpios =3D <&pioA 23 0 &pioA 22 0 &pioC 29 0 &pioA 14 0>; fm25@0 { compatible =3D "cypress,fm25"; spi-max-frequency =3D <40000000>; reg =3D <0>; pagesize =3D <256>; size =3D <131072>; address-width =3D <24>; }; /* ADC */ spidev@1 { compatible =3D "spidev"; reg =3D <1>; spi-max-frequency =3D <1000000>; }; /* IO expander for busaddr */ spidev@2 { compatible =3D "spidev"; reg =3D <2>; label =3D "busaddr"; spi-max-frequency =3D <10000000>; }; /* audio codec */ codec: codec@3 { compatible =3D "ti,tlv320aic3x"; spi-max-frequency =3D <1000000>; reg =3D <3>; }; }; This does not work without patch, because of 2 chips selected at one ti= me because of PA14 is periph_a. Probably ROMBOOT=20 changes that. > >>> If you just want to use it as a chip select for an spi device, take= a >>> look at [1]. >> At [1] it's OK until as cs0 is for example PA22 and cs1 is PA14. > > If you want PA14 to control cs1 and PA22 to control cs0 (both > configured as GPIOs), you'll have the following definition: > > cs-gpios =3D <&pioA 22 0>, <&pioA 14 0>, <0>, <0>; See my node. > >>> >>> Here the gpio is requested by the spi core when defining the cs-gpi= os >>> property. The gpio controller then request the listed pins to the p= in >>> controller (pinctrl driver). >> GPIO is not set in driver as GPIO, at least I didn't find it. > > Take a look at [1], which is set as the gpio_request_enable callback, > called by pinctrl core when a gpio is requested. But is this called from spi driver when requesting gpios as cs? > > > [1]http://lxr.free-electrons.com/source/drivers/pinctrl/pinctrl-at91.= c#L665 > > -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html