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 _______________________________________________ meta-intel mailing list [email protected] https://lists.yoctoproject.org/listinfo/meta-intel
