soc: arm: ti_simplelink: cc13x2_cc26x2: add support for sys_poweroff

Implement sys_poweroff() hooks, based on previous SOFT_OFF
implementation.

Signed-off-by: Gerard Marull-Paretas <gerard@teslabs.com>

soc/arm/ti_simplelink/cc13x2_cc26x2/CMakeLists.txt

@@ -5,7 +5,9 @@
 zephyr_sources(soc.c)
 zephyr_sources(ccfg.c)
 
-zephyr_library_sources_ifdef(CONFIG_PM    power.c)
-zephyr_library_sources_ifdef(CONFIG_PM_DEVICE   power.c)
+if(CONFIG_PM OR CONFIG_POWEROFF)
+  zephyr_library_sources(power.c)
+endif()
+zephyr_library_sources_ifdef(CONFIG_POWEROFF poweroff.c)
 
 zephyr_linker_sources_ifdef(CONFIG_HAS_TI_CCFG SECTIONS ccfg.ld)

soc/arm/ti_simplelink/cc13x2_cc26x2/Kconfig.series

@@ -16,5 +16,6 @@ config SOC_SERIES_CC13X2_CC26X2
 	select HAS_TI_CCFG
 	select HAS_SEGGER_RTT if ZEPHYR_SEGGER_MODULE
 	select HAS_PM
+	select HAS_POWEROFF
 	help
 	  Enable support for TI SimpleLink CC13x2 / CC26x2 SoCs

soc/arm/ti_simplelink/cc13x2_cc26x2/power.c

@@ -54,7 +54,6 @@ extern PowerCC26X2_ModuleState PowerCC26X2_module;
  * Power state mapping:
  * PM_STATE_SUSPEND_TO_IDLE: Idle
  * PM_STATE_STANDBY: Standby
- * PM_STATE_SUSPEND_TO_RAM | PM_STATE_SUSPEND_TO_DISK: Shutdown
  */
 
 /* Invoke Low Power/System Off specific Tasks */
@@ -106,13 +105,6 @@ void pm_state_set(enum pm_state state, uint8_t substate_id)
 		/* go to standby mode */
 		Power_sleep(PowerCC26XX_STANDBY);
 		break;
-	case PM_STATE_SUSPEND_TO_RAM:
-		__fallthrough;
-	case PM_STATE_SUSPEND_TO_DISK:
-		__fallthrough;
-	case PM_STATE_SOFT_OFF:
-		Power_shutdown(0, 0);
-		break;
 	default:
 		LOG_DBG("Unsupported power state %u", state);
 		break;

soc/arm/ti_simplelink/cc13x2_cc26x2/poweroff.c

@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2023 Nordic Semiconductor ASA
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/sys/poweroff.h>
+#include <zephyr/toolchain.h>
+
+#include <ti/drivers/Power.h>
+
+void z_sys_poweroff(void)
+{
+	Power_shutdown(0, 0);
+
+	CODE_UNREACHABLE;
+}