From: shc_work@mail.ru (=?UTF-8?B?QWxleGFuZGVyIFNoaXlhbg==?=)
Date: Sat, 08 Jun 2013 21:20:19 +0400
Subject: =?UTF-8?B?UmVbMl06IFtQQVRDSCA0LzVdIEFSTTogZHRzOiBpbXgyNy1waHl0ZWMtcGh5?=
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In-Reply-To: <20130608170840.GK32299@pengutronix.de>
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 <20130608170840.GK32299@pengutronix.de>
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To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

> On Sat, Jun 08, 2013 at 06:39:39PM +0400, Alexander Shiyan wrote:
> > This patch adds spidev device for spi0.1 which is used on ZigBee
> > PCM970 connector.  This change will help to use this connector in
> > userspace.
> > 
> > Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
> > ---
> >  arch/arm/boot/dts/imx27-phytec-phycore-rdk.dts | 6 ++++++
> >  1 file changed, 6 insertions(+)
> > 
> > diff --git a/arch/arm/boot/dts/imx27-phytec-phycore-rdk.dts b/arch/arm/boot/dts/imx27-phytec-phycore-rdk.dts
> > index e7ed978..b2dbcdd 100644
> > --- a/arch/arm/boot/dts/imx27-phytec-phycore-rdk.dts
> > +++ b/arch/arm/boot/dts/imx27-phytec-phycore-rdk.dts
> > @@ -17,6 +17,12 @@
> >  &cspi1 {
> >  	fsl,spi-num-chipselects = <2>;
> >  	cs-gpios = <&gpio4 28 0>, <&gpio4 27 0>;
> > +
> > +	zigbee: spidev at 1 {
> > +		compatible = "rohm,dh2228fv";
> > +		reg = <1>;
> > +		spi-max-frequency = <0>;
> 
> Why specify a speed of 0 here? Also, is there really a dh2228fv
> connected or is this just a hack to let the Linux spidev driver match?

Zero in this case is indicates using SPI-controller maximum speed.
This can be overriden by using SPI_IOC_RD_MAX_SPEED_HZ IOCTL
for spidev device.
About using dh2228fv, of course no. Currently this is only one dt entry
for spidev exist, so yes, this a trick.

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