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Re: ALL THE I2C BUSSES
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
"A potential Snark may lurk in every tree."
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