On 3/23/2019 12:02 AM, Russell King - ARM Linux admin wrote:
On Fri, Mar 22, 2019 at 10:46:14PM +0530, Keerthy wrote:
RTC plus DDR in self-refresh is power a saving mode where in the entire
"a power" ?
Will correct the above typo.
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
As explained above All the voltage rails of PMIC are shut off except for
RTC and DDR Rails.
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
Doesn't make sense.
and RTC Ticking. After a predetermined time an RTC ALARM1 triggers waking
up the system.
Huh, you start off explaining the wiring above... how does RTC ALARM1
trigger waking up the system if RTC ALARM2 is connected to the PMIC
and all other power is shut down?
The entire PMIC is shutdown but for RTC rail. RTC is a separate voltage
domain and is powered up during this power save mode.
http://www.ti.com/lit/ug/spruhl7h/spruhl7h.pdf Page 2884.
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.
The patch series adds rtc-only + DDR mode support am am437x
Tested DS0, rtc+ddr back and forth on am437x-gp-evm board.
This mode works only with u-boot built with am43xx_evm_rtconly_defconfig
Additional patch is needed for omap-gpio save restore which will
come as fixes later.
Keerthy (5):
rtc: OMAP: Add support for rtc-only mode
rtc: interface: Add power_off_program to rtc_class_ops
arm: mach-omap2: pm33xx: Add support for rtc+ddr in self refresh mode
soc: ti: pm33xx: Push the am33xx_push_sram_idle to the top
soc: ti: pm33xx: AM437X: Add rtc_only with ddr in self-refresh support
arch/arm/mach-omap2/pm33xx-core.c | 76 +++++++-
drivers/rtc/interface.c | 12 ++
drivers/rtc/rtc-omap.c | 49 ++++-
drivers/soc/ti/Kconfig | 5 +-
drivers/soc/ti/pm33xx.c | 272 ++++++++++++++++++++++-----
include/linux/platform_data/pm33xx.h | 5 +
include/linux/rtc.h | 2 +
7 files changed, 360 insertions(+), 61 deletions(-)
--
2.17.1
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