From mboxrd@z Thu Jan 1 00:00:00 1970 From: Antony Pavlov Subject: Re: [RFC v3 08/14] MIPS: dts: qca: introduce AR9331 devicetree Date: Mon, 14 Mar 2016 21:53:45 +0300 Message-ID: <20160314215345.00df3fa56c363061e730572e@gmail.com> References: <1453580251-2341-1-git-send-email-antonynpavlov@gmail.com> <1453580251-2341-9-git-send-email-antonynpavlov@gmail.com> <20160125234630.16098b7f@tock> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20160125234630.16098b7f@tock> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Alban Cc: linux-mips-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org, Gabor Juhos , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On Mon, 25 Jan 2016 23:46:30 +0100 Alban wrote: > On Sat, 23 Jan 2016 23:17:25 +0300 > Antony Pavlov wrote: >=20 > > This patch introduces devicetree for Atheros AR9331 SoC (AKA Hornet= ). > > The AR9331 chip is a Wi-Fi System-On-Chip (WiSOC), > > typically used in very cheap Access Points and Routers. > >=20 > > Signed-off-by: Antony Pavlov > > Cc: Gabor Juhos > > Cc: Alban Bedel > > Cc: linux-mips-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org > > Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > > --- > > arch/mips/boot/dts/qca/ar9331.dtsi | 123 +++++++++++++++++++++++++= ++++++++++++ > > 1 file changed, 123 insertions(+) > >=20 > > diff --git a/arch/mips/boot/dts/qca/ar9331.dtsi b/arch/mips/boot/dt= s/qca/ar9331.dtsi > > new file mode 100644 > > index 0000000..bf128a2 > > --- /dev/null > > +++ b/arch/mips/boot/dts/qca/ar9331.dtsi > > @@ -0,0 +1,123 @@ > > +#include > > + > > +/ { > > + compatible =3D "qca,ar9331"; > > + >=20 > [...] >=20 > > + > > + extosc: oscillator { > > + compatible =3D "fixed-clock"; > > + #clock-cells =3D <0>; > > + }; >=20 > This oscillator is on the board and not in the SoC, so it should > be in the board DTS. However oscillator is inside SoC! Please see https://en.wikipedia.org/wiki/Electronic_oscillator An electronic oscillator is an electronic circuit that produces a p= eriodic, oscillating electronic signal, often a sine wave or a square wave. Please see AR9331 data sheet: the SoC has no input for external oscilla= tor, only two pins (XTALO and XTALI) for connecting 25 MHz or 40 MHz quartz = crystal. The crystal can't produce a square wave itself! The crystal is only a p= art of a complete oscillator. So we have a good reason to put basic oscillator node into the SoC dtsi= -file. --=A0 Best regards, =A0 Antony Pavlov -- 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