Re: ALL THE I2C BUSSES

[mlelstv%serpens.de@localhost (Michael van Elst)]

thorpej%me.com@localhost (Jason Thorpe) writes:

>Iâ??m a little confused about how to map the prevailing documentation on the RPI and itâ??s Broadcom SoC to NetBSDâ??s treatment of the device tree.  NetBSD shows 3 i2c controllers (iic0, iic1, iic2).  I also know the 40-pin Pi models with newer firmware have a dedicated ID EERPOM i2c bus brought out to pins 27 and 28.  All of the pinout diagrams Iâ??ve seen show the i2c thatâ??s on pins 3 and 5 as SDA1 / SCL1.  I always assumed that the first i2c bus wasnâ??t brought out to the 40-pin header, but rather used on-board only.


This is the hardware:

BSC0 <0x7e205000 0x1000>
- gpio0,1 ALT0     (that's the EEPROM i2c bus)
- gpio28,29 ALT0   (the netbsd-8 dts file says gpio32,34)
- gpio44,45 ALT1
 
BSC1 <0x7e804000 0x1000>
- gpio2,3 ALT0
- gpio44,45 ALT2
 
BSC2 <0x7e805000 0x1000>
- HDMI DDC



However, the bsciic* instances are not attached in that order...

on the RPI2 here I get:

bsciic0 at sc_ioh=0xf3805000 -> BSC2
bsciic1 at sc_ioh=0xf3205000 -> BSC0
bsciic2 at sc_ioh=0xf3804000 -> BSC1

That's why you can reach the rtc at iic2.

-- 
-- 
                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."