From 6256f7f7f217b2216fcb73929508325f4ee98237 Mon Sep 17 00:00:00 2001 From: Keerthy Date: Wed, 3 Apr 2019 10:27:39 +0530 Subject: rtc: OMAP: Add support for rtc-only mode 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 Acked-by: Alexandre Belloni [tony@atomide.com: folded in a fix for compile warning] Signed-off-by: Tony Lindgren --- include/linux/rtc/rtc-omap.h | 7 +++++++ 1 file changed, 7 insertions(+) create mode 100644 include/linux/rtc/rtc-omap.h (limited to 'include/linux/rtc') diff --git a/include/linux/rtc/rtc-omap.h b/include/linux/rtc/rtc-omap.h new file mode 100644 index 000000000000..9f03a329e63f --- /dev/null +++ b/include/linux/rtc/rtc-omap.h @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _LINUX_RTCOMAP_H_ +#define _LINUX_RTCOMAP_H_ + +int omap_rtc_power_off_program(struct device *dev); +#endif /* _LINUX_RTCOMAP_H_ */ -- cgit v1.2.3-59-g8ed1b