[PATCH 6/8] ARM: dts: imx7d-sdb: Add GPIO expander node

Dong Aisheng
2017-04-14T16:00:17Z

On Fri, Apr 14, 2017 at 11:47:00AM +0800, Shawn Guo wrote:
> On Thu, Apr 13, 2017 at 06:32:40AM -0700, Andrey Smirnov wrote:
> > Add node for U38, a 74LV595PW serial-in shift register that acts as a
> > GPIO expander on the board.
> >
> > Cc: yurovsky at gmail.com
> > Cc: Sascha Hauer <kernel@pengutronix.de>
> > Cc: Fabio Estevam <fabio.estevam@nxp.com>
> > Cc: Rob Herring <robh+dt@kernel.org>
> > Cc: Mark Rutland <mark.rutland@arm.com>
> > Cc: Russell King <linux@armlinux.org.uk>
> > Cc: devicetree at vger.kernel.org
> > Cc: linux-kernel at vger.kernel.org
> > Cc: linux-arm-kernel at lists.infradead.org
> > Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> > ---
> > arch/arm/boot/dts/imx7d-sdb.dts | 32 ++++++++++++++++++++++++++++++++
> > 1 file changed, 32 insertions(+)
> >
> > diff --git a/arch/arm/boot/dts/imx7d-sdb.dts b/arch/arm/boot/dts/imx7d-sdb.dts
> > index 5be01a1..e0ff276 100644
> > --- a/arch/arm/boot/dts/imx7d-sdb.dts
> > +++ b/arch/arm/boot/dts/imx7d-sdb.dts
> > @@ -52,6 +52,30 @@
> > reg = <0x80000000 0x80000000>;
> > };
> >
> > + spi4 {
> > + compatible = "spi-gpio";
> > + pinctrl-names = "default";
> > + pinctrl-0 = <&pinctrl_spi1>;
> > + status = "okay";
>
> The 'status' is not needed in this case.
>
> > + gpio-sck = <&gpio1 13 0>;
> > + gpio-mosi = <&gpio1 9 0>;
> > + cs-gpios = <&gpio1 12 0>;
> > + num-chipselects = <1>;
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > +
> > + gpio_spi: gpio_spi at 0 {
>
> gpio-expander might be a better node name?
>
> > + compatible = "fairchild,74hc595";
> > + gpio-controller;
> > + #gpio-cells = <2>;
> > + reg = <0>;
> > + registers-number = <1>;
> > + /* Enable PERI_3V3, SENSOR_RST_B and HDMI_RST*/
> > + registers-default = /bits/ 8 <0x74>;
>
> I do not see this property is documented or supported by kernel.

It's FSL internal invented property to do some trick on register
intialization and should be dropped.

Regards
Dong Aisheng