i2c on Pi3?

[Oleksandr Tymoshenko]

Karl Denninger (karl at denninger.net) wrote:
> 
> On 3/23/2017 12:53, Oleksandr Tymoshenko wrote:
> > Karl Denninger (karl at denninger.net) wrote:
> >> On 3/23/2017 12:34, John Howie wrote:
> >>
> >>> Hi Karl,
> >>>
> >>> I can only speak to the Raspberry Pi 2 kernel, but I2C is supported. For an example how to use it from userland, check out a project I posted on github eighteen months ago, that was for the PiFace RTC.
> >>>
> >>> https://github.com/jhowie/FreeBSDPiFaceRTC
> >>>
> >>> There are useful routines I created for working with devices on the I2C bus, which you are free to use. They are not RPI2-specific, so they should work on other boards. 
> > .. skipped ..
> >> It works on the Pi2; I am using it in production.
> >>
> >> The driver appears to be /missing /in the Pi3 kernel.
> > Probably it's not enabled in DTB. Try adding this line to config.txt:
> >
> > dtparam=i2c_arm=on,spi=on
> >
> Nope, already in the base config.txt file:
> 
> arm_control=0x200
> dtparam=audio=on,i2c_arm=on,spi=on
> dtoverlay=mmc
> dtoverlay=pi3-disable-bt
> device_tree_address=0x4000
> kernel=u-boot.bin

I just built latest HEAD, i2c driver is available in GENERIC kernel:
# dmesg | grep iic
iichb0: <BCM2708/2835 BSC controller> mem 0x7e804000-0x7e804fff irq 31
on simplebus0
iicbus0: <OFW I2C bus> on iichb0
random: harvesting attach, 8 bytes (4 bits) from iicbus0
random: harvesting attach, 8 bytes (4 bits) from iichb0

The driver itself is sys/arm/broadcom/bcm2835/bcm2835_bsc.c

Could you run this command on your Pi3 and send output? Thanks

 sysctl -b hw.fdt.dtb | dtc -I dtb | grep -A 13 'i2c at .*{'


-- 
gonzo