BBAI and HW MCSPI3 ch 0 (linux spidev 2.0) custom usage in Linux

[Raul Rathmann]

Hi,

I've got a custom board where I need/want to use the MCSPI3 CS0, CS2 and CS3 hw lines for SPI.

When I configure and enable mcspi3 in a custom DTS for the Linux image, with  I get the following message viewable with dmesg:

[ 1.189920] omap2_mcspi 480b8000.spi: chipselect 0 already in use
[ 1.196085] spi_master spi2: spi_device register error /ocp/spi@480b8000/channel@0
[ 1.203721] spi_master spi2: Failed to create SPI device for /ocp/spi@480b8000/channel@0

So, channel 0 seems to be conflicting with some other driver or usage.

I finally figured out that the "am5729-beagleboneai.dts" file has a reference to mcspi3:

&mcspi3 {
status = "okay";
ti,pindir-d0-out-d1-in;

sn65hvs882: sn65hvs882@0 {
compatible = "pisosr-gpio";
gpio-controller;
#gpio-cells = <2>;

reg = <0>;
spi-max-frequency = <1000000>;
spi-cpol;
};
};

My question is can I disable/override this usage?

I don't know the system purpose of the "pisosr-gpio"/sn65hvs882 device and what the effect will be if Linux access is disabled. Since I'll have a custom device on linux spidev2.0, I don't want some other part of the system trying to access that SPI bus/channel and causing problems with my device.

Thanks for any insights.

Raul

[jis...@gmail.com]

2020년 7월 20일 월요일 오전 4시 10분 40초 UTC+9, Raul Rathmann 님의 말: