Re: [PATCH] ARM: dts: Provide support for reading ID code from MVB device (BK4)

From: Lukasz Majewski
Date: Mon Dec 03 2018 - 04:33:50 EST


Hi Shawn,

Thank you for the review.

> On Tue, Nov 13, 2018 at 01:12:13PM +0100, Lukasz Majewski wrote:
> > The procedure to read this ID value is as follows:
> >
> > rmmod spi_fsl_dspi
> > insmod spi-gpio.ko
> >
> > echo 504 > /sys/class/gpio/export
> > cat /sys/class/gpio/gpio504/value
> > ...
> > echo 511 > /sys/class/gpio/export
> > cat /sys/class/gpio/gpio511/value
> >
> > rmmod spi-gpio.ko
> > insmod spi_fsl_dspi
> >
> > Signed-off-by: Lukasz Majewski <lukma@xxxxxxx>
>
> A prefix like 'ARM: dts: vf610-bk4: ...' might be better.

Ok.

>
> > ---
> > arch/arm/boot/dts/vf610-bk4.dts | 31
> > +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+)
> >
> > diff --git a/arch/arm/boot/dts/vf610-bk4.dts
> > b/arch/arm/boot/dts/vf610-bk4.dts index cab95714c058..f01c735807ae
> > 100644 --- a/arch/arm/boot/dts/vf610-bk4.dts
> > +++ b/arch/arm/boot/dts/vf610-bk4.dts
> > @@ -59,6 +59,29 @@
> > regulator-min-microvolt = <3300000>;
> > regulator-max-microvolt = <3300000>;
> > };
> > +
> > + spi_gpio {
>
> We recommend hyphen rather than underscore be used in node name.

Ok. I will change it to spi-gpio

>
> > + compatible = "spi-gpio";
> > + pinctrl-0 = <&pinctrl_gpio_spi>;
> > + pinctrl-names = "default";
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > + /* PTD12 ->RPIO[91] */
> > + sck-gpios = <&gpio2 27 GPIO_ACTIVE_LOW>;
> > + /* PTD10 ->RPIO[89] */
> > + miso-gpios = <&gpio2 25 GPIO_ACTIVE_HIGH>;
> > + num-chipselects = <0>;
> > +
> > + 72xx165@0 {
>
> Please use a generic name for the node.

This is a bit tricky.

Other DTS definitions for this compatible:

sn65hvs882: sn65hvs882@0 {
compatible = "pisosr-gpio";
...
}

They use the exact used IC name - sn65hvs882, which IMHO is the way how
this node shall be described.

The reason is that the compatible is "pisosr-gpio" -> parallel input
serial output shift regsiter - gpio.

By adding the exact name of connected electronic IC - sn65hvs882 and in
my case IC from the 72xx165 family provides good description of the HW.

Maybe you have other idea how to provide the name of the IC connected?

>
> Shawn
>
> > + compatible = "pisosr-gpio";
> > + reg = <0>;
> > + gpio-controller;
> > + #gpio-cells = <2>;
> > + /* PTB18 -> RGPIO[40] */
> > + load-gpios = <&gpio1 8 GPIO_ACTIVE_LOW>;
> > + spi-max-frequency = <100000>;
> > + };
> > + };
> > };
> >
> > &adc0 {
> > @@ -430,6 +453,14 @@
> > >;
> > };
> >
> > + pinctrl_gpio_spi: pinctrl-gpio-spi {
> > + fsl,pins = <
> > + VF610_PAD_PTB18__GPIO_40 0x1183
> > + VF610_PAD_PTD10__GPIO_89 0x1183
> > + VF610_PAD_PTD12__GPIO_91 0x1183
> > + >;
> > + };
> > +
> > pinctrl_i2c2: i2c2grp {
> > fsl,pins = <
> > VF610_PAD_PTA22__I2C2_SCL
> > 0x34df --
> > 2.11.0
> >




Best regards,

Lukasz Majewski

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