* Ivaylo Dimitrov <ivo.g.dimitrov...@gmail.com> [160317 06:11]: > Hi, > > On 17.03.2016 15:01, Pali Rohár wrote: > >On Thursday 17 March 2016 09:56:22 Ivaylo Dimitrov wrote: > >>Hi, > >> > > > >Is camera on same bus as tpa? Maybe this is reason why camera is > >non-functional too? > > > > It doesn't matter, all the i2c busses are missing the pullups. > > >>Will fix the board DTS file later on an will report > > > >Thanks for investigation! Is that problem in both DTS and also legacy > >board code? > > > > I guess legacy board code does not set i2c pull-ups either, as we > have that problem since the beginning of time. Anyway, let me first > check if enabling pullups really solves the issue, I hope to test that in a > couple of hours when I am back home. > > Or you can do it yourself, it is just a matter of replacing PIN_INPUT with > PIN_INPUT_PULLUP in > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/omap3-n900.dts?id=refs/tags/v4.5#n199 > for all the 3 ic2 busses
Check the schematics. If the hardware has external pull-ups on a line then don't enable the internal pull-ups. Otherwise both the external and intenal pulls are parallel the pull value will be wrong. My guess is that on n900 all the i2c lines have external pulls. Regards, Tony
