soc: ti: cc23x0: Add support for RTC alarms in power.c

In power management, add support to take into account the alarms
set in RTC. Alarm from RTC is processed like any other from SYSTIM.
This prevents from missing interrupts.

Signed-off-by: Stoyan Bogdanov <sbogdanov@baylibre.com>

Author: bogdanovs

soc/ti/simplelink/cc23x0/power.c

@@ -44,6 +44,7 @@ const PowerCC23X0_Config PowerCC23X0_config = {
 #define SYSTIM_CH(idx)      (SYSTIM_O_CH0CC + idx * SYSTIM_CH_STEP)
 #define SYSTIM_TO_RTC_SHIFT 3U
 #define SYSTIM_CH_CNT       5U
+#define RTC_CH_CNT          2U
 #define RTC_NEXT(val, now)  (((val - PowerCC23X0_WAKEDELAYSTANDBY) >> SYSTIM_TO_RTC_SHIFT) + now)
 
 #endif
@@ -57,8 +58,10 @@ static void pm_cc23x0_systim_standby_restore(void);
 
 /* Global to stash the SysTimer timeouts while we enter standby */
 static uint32_t systim[SYSTIM_CH_CNT];
+static uint32_t rtc[RTC_CH_CNT];
 static uintptr_t key;
 static uint32_t systim_mask;
+static uint32_t rtc_mask;
 
 /* Shift values to convert between the different resolutions of the SysTimer
  * channels. Channel 0 can technically support either 1us or 250ns. Until the
@@ -83,7 +86,10 @@ static void pm_cc23x0_systim_standby_restore(void)
 	ULLSync();
 
 	HwiP_clearInterrupt(INT_CPUIRQ16);
+	HwiP_clearInterrupt(INT_CPUIRQ3);
+
 	HWREG(EVTSVT_BASE + EVTSVT_O_CPUIRQ16SEL) = EVTSVT_CPUIRQ16SEL_PUBID_SYSTIM0;
+	HWREG(EVTSVT_BASE + EVTSVT_O_CPUIRQ3SEL) = EVTSVT_CPUIRQ16SEL_PUBID_AON_RTC_COMB;
 
 	while (HWREG(SYSTIM_BASE + SYSTIM_O_STATUS) != SYSTIM_STATUS_VAL_RUN) {
 		;
@@ -96,9 +102,19 @@ static void pm_cc23x0_systim_standby_restore(void)
 	}
 
 	HWREG(SYSTIM_BASE + SYSTIM_O_IMASK) = systim_mask;
+	HWREG(RTC_BASE + RTC_O_IMASK) = rtc_mask;
+
+	if (rtc_mask != 0) {
+		if (rtc_mask & 0x1) {
+			HWREG(RTC_BASE + RTC_O_CH0CC8U) = rtc[0];
+		}
+		if (rtc_mask & 0x2) {
+			HWREG(RTC_BASE + RTC_O_CH1CC8U) = rtc[1];
+		}
+	}
+
 	LRFDApplyClockDependencies();
 	PowerCC23X0_notify(PowerLPF3_AWAKE_STANDBY);
-
 	HwiP_restore(key);
 }
 #endif
@@ -110,6 +126,7 @@ static void pm_cc23x0_enter_standby(void)
 	uint32_t systim_now = 0;
 	uint32_t systim_next = MAX_SYSTIMER_DELTA;
 	uint32_t systim_delta = 0;
+	uint32_t rtc_delta = 0;
 
 	key = HwiP_disable();
 
@@ -146,7 +163,23 @@ static void pm_cc23x0_enter_standby(void)
 			systim_next = MAX_SYSTIMER_DELTA;
 		}
 
+		rtc_mask = HWREG(RTC_BASE + RTC_O_IMASK);
+		if (rtc_mask != 0) {
+			rtc_now = HWREG(RTC_BASE + RTC_O_TIME8U);
+			if (rtc_mask & 0x1) {
+				rtc[0] = HWREG(RTC_BASE + RTC_O_CH0CC8U);
+				rtc_delta = (rtc[0] - rtc_now) << 3;
+				systim_next = MIN(systim_next, rtc_delta);
+			}
+			if (rtc_mask & 0x2) {
+				rtc[1] = HWREG(RTC_BASE + RTC_O_CH1CC8U);
+				rtc_delta = (rtc[1] - rtc_now) << 3;
+				systim_next = MIN(systim_next, rtc_delta);
+			}
+		}
+
 		if (systim_next > PowerCC23X0_TOTALTIMESTANDBY) {
+			HWREG(EVTSVT_BASE + EVTSVT_O_CPUIRQ3SEL) = 0;
 			HWREG(EVTSVT_BASE + EVTSVT_O_CPUIRQ16SEL) =
 			      EVTSVT_CPUIRQ16SEL_PUBID_AON_RTC_COMB;
 			HwiP_clearInterrupt(INT_CPUIRQ16);