* Lokesh Vutla <lokeshvutla@xxxxxx> [140714 21:09]: > On Monday 14 July 2014 09:53 PM, Tony Lindgren wrote: > > * Lokesh Vutla <lokeshvutla@xxxxxx> [140714 07:47]: > >> > >> In my experiments I observed that when RTC regulator is switched > >> off and switched on, there is an abort while accessing RTC registers. > > > > Right, then you know you have the right regulator :) > > Once we switch it off it is expected, but then if it is *switched on* > it is expected that we should be able to access registers. Here there > is an abort accessing these registers. Most likely you need to also reconfigure the registers or re-enable the clock or reset it at the interconnect too. > >> After discussing with hardware team, it is confirmed that this > >> LDO9 regulator powering RTC cannot be turned off when > >> SoC is active and expected to be always on. > > > > Hmm but sounds like you already proved it can be idled? So > > the regulator really should be managed by the driver? > > Actually I adapted the driver to support a power regulator. > Then I observed that if rtc is loaded as a module there is > an abort( which is happening because the regulator is disabled > once and re-enabled). So when we checked with the hardware team, > they confirmed that ldo9 should not be disabled. Hmm so how is it enabled initially then? To me it sounds like very standard stuff to reinitialize a driver for any omap device when waking from suspend or returning from off-idle. If the RTC device cannot be reset, idled and re-initialized properly, there's something wrong with the RTC driver, clocks, regulators, or hwmod data for that device. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
