[meta-intel] i2c not working with eg20t - poky-dylan-9.0

[João Marinho de Castro Assis]

Hi Darren,

Thanks for the information, I will let you know if I find anything new, but
it may be due to our hardware.

Best Regards,

Joao Assis


2013/10/18 Darren Hart <dvhart at linux.intel.com>

> On Thu, 2013-10-10 at 15:14 -0300, João Marinho de Castro Assis wrote:
> > Hi all,
> >
> >
> > I am not sure if is the correct list to send this question. If not,
> > please let me know.
> >
> >
> > I have an issue with i2c not working with a COM Express board (Atom
> > e620 and EG20t platform controller) and Yocto Linux poky-dylan-9.0.2
> > with kernel 3.8. I enabled i2c for eg20t pch/lapis.
> >
> >
> > In Linux startup I can see i2c module starting:
> >
> > ...
> > i2c /dev entries driver
> > i2c_eg20t 0000:02:0c.2: pch_i2c_probe :Entered.
> > i2c_eg20t 0000:02:0c.2: pch_i2c_init :I2CCTL=380 pch_i2cbc=3f
> > pch_i2ctmr=186a Enable interrupts
> > i2c-dev: adapter [i2c_eg20t] registered as minor 0
> > i2c i2c-0: adapter [i2c_eg20t] registered
> > i2c_eg20t 0000:02:0c.2: pch_i2c_probe :returns 0.
> > ...
> >
> > Using i2c-tools, I have the following:
> >
> > root at cpqd:~# i2cdetect -l
> > i2c-0    i2c           i2c_eg20t                           I2C adapter
> >
> > root at cpqd:~# i2cdetect 0
> > WARNING! This program can confuse your I2C bus, cause data loss and
> > worse!
> > I will probe file /dev/i2c-0.
> > I will probe address range 0x03-0x77.
> > Continue? [Y/n]
> >      0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
> > 00:          -- -- -- -- -- -- -- -- -- -- -- -- --
> > 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 70: -- -- -- -- -- -- -- --
>
>
> Hrm, all I can say is I have seen this working on another eg20t device,
> but without your specific hardware, I don't have any advice right off
> the top of my head to help out. I haven't tried this in a while, but
> I'll pay close attention next time I test and let you know if there is
> something missing from the above.
>
> --
> Darren
>
> > In dmesg we see a lot of messages from i2c, like:
> >
> > i2c i2c-0: ioctl, cmd=0x705, arg=0xbfcfd420
> > i2c i2c-0: ioctl, cmd=0x705, arg=0xbfcb8998
> > i2c i2c-0: ioctl, cmd=0x703, arg=0x03
> > i2c i2c-0: ioctl, cmd=0x720, arg=0xbfcb899c
> > i2c i2c-0: master_xfer[0] W, addr=0x03, len=0
> > i2c_eg20t 0000:02:0c.2:
> > pch_i2c_xfer :adap->p_adapter_info->pch_i2c_suspended is 0
> > i2c_eg20t 0000:02:0c.2: pch_i2c_xfer :After invoking
> > I2C_MODE_SEL :flag= 0x0
> > i2c_eg20t 0000:02:0c.2: pch_i2c_writebytes :I2CCTL = 390 msgs->len = 0
> > i2c_eg20t 0000:02:0c.2: pch_i2c_start :I2CCTL = 390
> > i2c_eg20t 0000:02:0c.2: pch_i2c_cb :PCH_I2CSR = 9
> > i2c_eg20t 0000:02:0c.2: pch_i2c_getack :return-71
> > i2c_eg20t 0000:02:0c.2: pch_i2c_wait_for_check_xfer :Receive NACK for
> > slave addresssetting
> >
> > If I use get or write commands, the logs from i2c_eg20t are the same.
> >
> > Using an oscilloscope, we can see the clock and data on up level
> > (according to i2c specs). But whenever we issue a i2c command, the
> > clock doesn't go down as expected. So it looks like a software issue.
> > We do have some i2c devices connected to the bus.
> >
> >
> > Do you have any idea what we should do?
> >
> >
> > Thanks very much!
> >
> > --
> > João Marinho Assis
> >
> > CPqD
> > Tel.: +55 19 3705-4996
> > jassis at cpqd.com.br
> > Brazil
> > _______________________________________________
> > meta-intel mailing list
> > meta-intel at yoctoproject.org
> > https://lists.yoctoproject.org/listinfo/meta-intel
>
> --
> Darren Hart
> Intel Open Source Technology Center
> Yocto Project - Linux Kernel
>
>
>


-- 
João Marinho Assis
CPqD – Gerência de Sistemas Ópticos Embarcados
Tel.: +55 19 3705-4996
jassis at cpqd.com.br <asassi at cpqd.com.br>
www.cpqd.com.br
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