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 <[email protected]> > 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@cpqd:~# i2cdetect -l > > i2c-0 i2c i2c_eg20t I2C adapter > > > > root@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 > > [email protected] > > Brazil > > _______________________________________________ > > meta-intel mailing list > > [email protected] > > 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 [email protected] <[email protected]> www.cpqd.com.br
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