On Wed, Jul 15, 2015 at 7:45 AM, <[email protected]> wrote: > Hi, > > I would like to change the i2c frequency from 100 kHz to 400 kHz for the i2c > busses which are not used for HDMI. > > If I check the dmesg during boot I get: > > (dmese | grep "i2c") > 0.134577] omap_i2c 44e0b000.i2c: bus 0 rev0.11 at 400 kHz > [ 0.135557] input: tps65217_pwr_but as > /devices/ocp.3/44e0b000.i2c/i2c-0/0-0024/input/input0 > [ 0.144248] omap_i2c 44e0b000.i2c: unable to select pin group > [ 0.144783] omap_i2c 4819c000.i2c: bus 1 rev0.11 at 100 kHz > [ 0.146172] omap_i2c 4819c000.i2c: unable to select pin group > [ 0.742131] i2c /dev entries driver > [ 9.442219] omap_i2c 4802a000.i2c: bus 2 rev0.11 at 100 kHz > [ 9.442248] omap_i2c 4802a000.i2c: unable to select pin group > > > So I changed the all clock frequencies from 100 k to 400 k inside the dtb > files which are loaded during boot: > am335x-bone.dtb > am335x-boneblack.dtb > omap3-beagle.dtb > > But no reaction at all. I double checked with the osci but still only 10 us > clock period (100 k). > Then I ve checked the the clock frequency register and there it is the same > too: > > od -bc /proc/device-tree/ocp/i2c\@4802a000/clock-frequency > > I could try to change the values there using mmap but I would prefer a > solution using the overlays. > Or is it not possible to change it.
Double check what *.dtb you are loading, because it sounds like your not loading what you think your loading.. (making the change in the dtb is all that's required.) Regards, -- Robert Nelson https://rcn-ee.com/ -- 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]. For more options, visit https://groups.google.com/d/optout.
