[MinnowBoard] [edk2] i2cdetect inconsistency/problem

[Gerard Bucas]

Hi Bill

Thanks for your fast response!

You are right of course BUT why does one need the "Synopsis Designware I2c adapter"!? As I don't really know what it is, I assume I don't need it!!

The fact that Ubuntu includes it, of course explains why it shows those extra two buses in ubuntu. So that answers my first question!
How about my 2nd queston? BOTH yocto and Ubuntu show the same i2c devices detected on the "5th i2c bus (# 4 in yocto and #6 in Ubuntu which makes sense when one compensates for the two Designware buses detected)?

Including my questions again below, so you don't have to go and search for it.

I have two questions:

1. Where does i2cdetect get the "i2c adapter" bus names? How can they be different with same firmware & hardware & linux kernel (between yocto & Ubuntu)? Is this from some firmware or OS config? OK - explained by the fact that Ubuntu includes two "Synopsis Designware" i2c buses.

2. Why are all those i2c devices detected by BOTH yocto linux and Ubuntu!?
Where do they come from? Is this due to some firmware or OS config? 

Below are the i2cdetect outputs from both my yocto and Ubuntu OS's (NOTE:
both are using the linux 3.19 kernel):

YOCTO:
# uname -a
Linux intel-corei7-64 3.19.5-yocto-standard #1 SMP PREEMPT Fri Aug 14
00:21:30 UTC 2015 x86_64 GNU/Linux

#modprobe i2c-dev
#i2cdetect -l
i2c-0	i2c       	i915 gmbus ssc                  	I2C adapter
i2c-1	i2c       	i915 gmbus vga                  	I2C adapter
i2c-2	i2c       	i915 gmbus panel                	I2C adapter
i2c-3	i2c       	i915 gmbus dpc                  	I2C adapter
i2c-4	i2c       	i915 gmbus dpb                  	I2C adapter
i2c-5	i2c       	i915 gmbus dpd                  	I2C adapter
i2c-6	i2c       	DPDDC-B                         	I2C adapter

#i2cdetect -y 4
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: 30 -- -- -- -- -- -- 37 -- -- 3a -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- 4a 4b -- -- -- --
50: 50 51 52 53 54 55 56 57 -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- --                         

UBUNTU:
# uname -a
Linux tekmagic 3.19.0-26-generic #28~14.04.1-Ubuntu SMP Wed Aug 12 14:09:17 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

# modprobe i2c-dev

# i2cdetect -l
i2c-0	i2c       	Synopsys DesignWare I2C adapter 	I2C adapter
i2c-1	i2c       	Synopsys DesignWare I2C adapter 	I2C adapter
i2c-2	i2c       	i915 gmbus ssc                  	I2C adapter
i2c-3	i2c       	i915 gmbus vga                  	I2C adapter
i2c-4	i2c       	i915 gmbus panel                	I2C adapter
i2c-5	i2c       	i915 gmbus dpc                  	I2C adapter
i2c-6	i2c       	i915 gmbus dpb                  	I2C adapter
i2c-7	i2c       	i915 gmbus dpd                  	I2C adapter
i2c-8	i2c       	DPDDC-B                         	I2C adapter

# i2cdetect -y 6
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: 30 -- -- -- -- -- -- 37 -- -- 3a -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- 4a 4b -- -- -- --
50: 50 51 52 53 54 55 56 57 -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- --                         

Thanks!!

Gerard
 

-----Original Message-----
From: Bill Traynor [mailto:btraynor at gmail.com] 
Sent: Monday, August 17, 2015 4:38 PM
To: gerard.b at tekmagic.net; MinnowBoard Development and Community Discussion <elinux-minnowboard at lists.elinux.org>
Subject: Re: [MinnowBoard] [edk2] i2cdetect inconsistency/problem

Are you using identical kernel configurations for each build?

It looks to me like you may not have configured for the Synopsys DesignWare I2C adapter in the Yocto build.


On Mon, Aug 17, 2015 at 4:30 PM, Gerard Bucas <gerard.b at tekmagic.net> wrote:
> Synopsys DesignWare I2C adapter