I2C_SLAVE_FORCE got the job done - thank you very much for the suggestion, William. My additional manufacturing and cal information is now fat and happy on the EEPROM.
Had to leave a much longer delay between writes than I'd expected, though. On Tue, Aug 9, 2016 at 2:13 PM William Hermans <[email protected]> wrote: > Additionally, you should make absolutely positive that you know what > you're doing. When writing to that eeprom. Otherwise you'll end up > rendering your beaglebone non bootable. Until you hard code which board > file to load at boot, or you reflash the eeprom. > > On Tue, Aug 9, 2016 at 1:09 PM, William Hermans <[email protected]> wrote: > >> When attempting to use an I2C device that is already in use by the >> kernel. You can't use I2C_SLAVE, you must use I2C_SLAVE_FORCE. >> >> On Tue, Aug 9, 2016 at 1:06 PM, William Hermans <[email protected]> >> wrote: >> >>> william@beaglebone:~$ sudo dd count=30 bs=1 >>> if=/sys/bus/i2c/devices/0-0050/0-00500/nvmem >>> ▒U3▒A335BNLT00C03214BBBK0403▒▒30+0 records in >>> 30+0 records out >>> 30 bytes (30 B) copied, 0.0114076 s, 2.6 kB/s >>> >>> >>> On Tue, Aug 9, 2016 at 12:50 PM, Phil Mills <[email protected]> >>> wrote: >>> >>>> Naturally - that's part of the test jig. I have a very special >>>> paperclip all modeled up in solidworks. >>>> >>>> But the first problem is that ioctl (or the i2cdump utility) won't >>>> touch that address even for a read operation because it's in use by the >>>> kernel. That's the bit I'd like to get around. >>>> >>>> >>>> On Tue, Aug 9, 2016 at 1:43 PM Gerald Coley <[email protected]> >>>> wrote: >>>> >>>>> You will need to modify the hardware to remove the write protect >>>>> before you can do any writes.. >>>>> >>>>> Gerald >>>>> >>>>> On Tue, Aug 9, 2016 at 2:41 PM, Phil Mills <[email protected]> >>>>> wrote: >>>>> >>>>>> I'd like to be able to read/write data from the BBB's on-board EEPROM >>>>>> programatically using the ioctl(...) interface just like any other i2c >>>>>> eeprom my software might be asked to go deal with. >>>>>> >>>>>> Of course the kernel claims that device for itself pretty quickly >>>>>> upon boot which means I can't get to it that way (fails to set address, >>>>>> device in use). >>>>>> >>>>>> Is there a relatively simple way of getting the Kernel to release >>>>>> that device ? >>>>>> >>>>>> -- >>>>>> For more options, visit http://beagleboard.org/discuss >>>>>> --- >>>>>> >>>>> You received this message because you are subscribed to the Google >>>>>> Groups "BeagleBoard" group. >>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>> send an email to [email protected]. >>>>> >>>>> >>>>>> To view this discussion on the web visit >>>>>> https://groups.google.com/d/msgid/beagleboard/fab7a669-a56e-4c30-901f-89552495aa50%40googlegroups.com >>>>>> <https://groups.google.com/d/msgid/beagleboard/fab7a669-a56e-4c30-901f-89552495aa50%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>>> . >>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>> >>>>> >>>>> >>>>> >>>>> -- >>>>> Gerald >>>>> >>>>> [email protected] >>>>> http://beagleboard.org/ >>>>> [email protected] >>>>> >>>>> -- >>>>> For more options, visit http://beagleboard.org/discuss >>>>> --- >>>>> You received this message because you are subscribed to a topic in the >>>>> Google Groups "BeagleBoard" group. >>>>> To unsubscribe from this topic, visit >>>>> https://groups.google.com/d/topic/beagleboard/EuSRwT-Zs3U/unsubscribe. >>>>> To unsubscribe from this group and all its topics, send an email to >>>>> [email protected]. >>>>> To view this discussion on the web visit >>>>> https://groups.google.com/d/msgid/beagleboard/CAHK_S%2BdxZac2kZwE%2BmSN8ShMWT0siaGhQfCOw%2BaJuiTjwurY1w%40mail.gmail.com >>>>> <https://groups.google.com/d/msgid/beagleboard/CAHK_S%2BdxZac2kZwE%2BmSN8ShMWT0siaGhQfCOw%2BaJuiTjwurY1w%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> For more options, visit https://groups.google.com/d/optout. >>>>> >>>> -- >>>> For more options, visit http://beagleboard.org/discuss >>>> --- >>>> You received this message because you are subscribed to the Google >>>> Groups "BeagleBoard" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/beagleboard/CAOCPF%2BsVrR98rp22_%3Df%3D7ZMTVp%3DD4vdC6mq65jdqZd-NmygnLQ%40mail.gmail.com >>>> <https://groups.google.com/d/msgid/beagleboard/CAOCPF%2BsVrR98rp22_%3Df%3D7ZMTVp%3DD4vdC6mq65jdqZd-NmygnLQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> >> > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to a topic in the > Google Groups "BeagleBoard" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/beagleboard/EuSRwT-Zs3U/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/CALHSORpxNUmVRowcoFnbo3UHL9JcqjM_RajYbOHLnDuX0fkjew%40mail.gmail.com > <https://groups.google.com/d/msgid/beagleboard/CALHSORpxNUmVRowcoFnbo3UHL9JcqjM_RajYbOHLnDuX0fkjew%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. 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