On Thu, 29 Nov 2012 23:11:37 +0000 "Kim, Milo" <milo....@ti.com> wrote:
> Hi Venu > > > > Enabling RTC HW block depends on the default value of TPS65910 > > register. > > > In some mode, RTC block is disabled by default.(eg. AM3517 > > Craneboard) > > > In this case, RTC_PWDN(RTC power down) bit should be cleared to > > enable > > > the RTC HW block. > > > > From the description of RTC_PWDN bit of DEVCTRL_REG in TPS65910 data > > sheet > > it is very evident that the default value of RTC_PWDN is 0. > > According to the datasheet(http://www.ti.com/lit/ds/swcs046q/swcs046q.pdf), > the default value RTC_PWDN is 1 which means power down. > > The default values are loaded from the EEPROM with BOOT_MODE 0,1 pin > connection. > The RTC is disabled by default when BOOT_MODE = 00. > The Craneboard has the BOOT_MODE 00. > > You may have other EEPROM settings, > however the official datasheet shows the RTC block is off by default. > > Could you check the silicon version number? (0x80 register - JTAGVERNUM_REG) > In my case, the read value is 0x01. > > > Probably on "AM3517 Craneboard", some code is running prior to the RTC > > driver > > which might be writing 1 on to this bit. IMO you must disable that > > write operation > > instead of just writing default value into a register. > > Thank you for your comment. > I've read the DEVCTRL register (0x3F) in mfd tps65910 driver > as soon as the regmap registration is done, however RTC_PWDN is always 1. > That means the RTC is disabled by default. > I've merged this patch into -mm for 3.8 along with a note-to-self that there might still be open issues. Venu, please let us know if the above settles things? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
