Re: PCF8574 I2C configuration for 14.0-CURRENT on a RPi2B

Milan wrote:

> could you show us what's in /dev directory? Probably no iic0 file
> there. Also, you did not write which kernel are you using. For
> /dev/iic0 to appear, you need either 'device iic' in your kernel config
> or load it dynamically via 'kldload iic', in addition to working i2c
> controller.
> 
> Showing your 'dmesg' output helps to determine what's going on, along
> with DTB used as well.
> 
> All this are just basic hints what and where to look for, there are
> probably other as well, but I hope this helps.

oot@generic:~ # dmesg | grep iic

root@generic:~ # dmesg | grep gpio
gpio0: <BCM2708/2835 GPIO controller> mem 0x7e200000-0x7e2000b3 irq 7,8 on simplebus0
gpiobus0: <OFW GPIO bus> on gpio0
gpioc0: <GPIO controller> on gpio0
gpioled0: <GPIO LEDs> on ofwbus0

root@generic:~ # ls /dev/iic*
ls: /dev/iic*: No such file or directory

root@generic:~ # kldload iic
kldload: can't load iic: module already loaded or in kernel

root@generic:~ # kldstat
Id Refs Address        Size Name
 1   14 0xc0000000   d6a938 kernel
 2    1 0xc0d6b000    23358 gpioiic.ko
 3    2 0xc0d8f000    23fcc iicbb.ko
 4    1 0xc0db3000    24f48 umodem.ko
 5    2 0xc0dd8000    28328 ucom.ko

FreeBSD 11.1 automatically creates /dev/iic (unsure of the suffices).
But 11.1 is now obsolete. FDT replaced automatic IIC bit-bang driver
discovery. 
    You need to "wire" FDT beforehand. Although there's hints and 
configuration snippets all over the Inet, a full blown howto example 
eludes me thus far.

Danke,

-- 
Don, KB7RPU, https://www.qsl.net/kb7rpu
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.