On 09/07/2018 09:55:53+0200, Johan Hovold wrote: > On Mon, Jul 09, 2018 at 11:41:49AM +0530, Keerthy wrote: > > Prepare rtc driver for rtc-only with DDR in self-refresh mode. > > omap_rtc_power_off now should cater to two features: > > > > 1) RTC plus DDR in self-refresh is power a saving mode where in the > > entire system including the different voltage rails from PMIC are > > shutdown except the ones feeding on to RTC and DDR. DDR is kept in > > self-refresh hence the contents are preserved. RTC ALARM2 is connected > > to PMIC_EN line once we the ALARM2 is triggered we enter the mode with > > DDR in self-refresh and RTC Ticking. After a predetermined time an RTC > > ALARM1 triggers waking up the system[1]. The control goes to bootloader. > > The bootloader then checks RTC scratchpad registers to confirm it was an > > rtc_only wakeup and follows a different path, configure bare minimal > > clocks for ddr and then jumps to the resume address in another RTC > > scratchpad registers and transfers the control to Kernel. Kernel then > > restores the saved context. omap_rtc_power_off_program does the ALARM2 > > programming part. > > > > [1] http://www.ti.com/lit/ug/spruhl7h/spruhl7h.pdf Page 2884 > > > > 2) Power-off: This is usual poweroff mode. omap_rtc_power_off calls the > > above omap_rtc_power_off_program function and in addition to that > > programs the OMAP_RTC_PMIC_REG for any external wake ups for PMIC like > > the pushbutton and shuts off the PMIC. > > > > Hence the split in omap_rtc_power_off. > > > > Signed-off-by: Keerthy <j-keerthy@xxxxxx> > > --- > > > > Changes in v2: > > > > * Add details in the commit log. > > * Use of_device_is_system_power_controller to check if rtc node is > > indeed the system power control instead of manually reading property. > > > > drivers/rtc/interface.c | 12 ++++ > > drivers/rtc/rtc-omap.c | 167 +++++++++++++++++++++++++++++++++--------------- > > include/linux/rtc.h | 2 + > > 3 files changed, 131 insertions(+), 50 deletions(-) > > > > diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c > > index 6d4012d..d8b70f0 100644 > > --- a/drivers/rtc/interface.c > > +++ b/drivers/rtc/interface.c > > @@ -1139,3 +1139,15 @@ int rtc_set_offset(struct rtc_device *rtc, long offset) > > trace_rtc_set_offset(offset, ret); > > return ret; > > } > > + > > +/** > > + * rtc_power_off_program - Some of the rtc are hooked on to PMIC_EN > > + * line and can be used to power off the SoC. > > + * > > + * Kernel interface to program rtc to power off > > + */ > > +void rtc_power_off_program(struct rtc_device *rtc) > > +{ > > + rtc->ops->power_off_program(rtc->dev.parent); > > +} > > +EXPORT_SYMBOL_GPL(rtc_power_off_program); > > We typically do not add new interfaces without any users, so this will > probably have to go in along with the corresponding omap changes for > rtc-only mode. > I'm probably not smart enough but I still don't get why you need to add an interface at all, especially one that will result in a NULL pointer dereference on 99.6% of the drivers. This is so specific to your use case that this has zero chance to be reused by another driver. -- Alexandre Belloni, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com -- 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
