[fromlist] poweroff: nordic: streamline RAM retention strategy

drivers/retained_mem/Kconfig.nrf

@@ -13,6 +13,6 @@ config RETAINED_MEM_NRF_RAM_CTRL
 	bool "nRF RAM retention driver"
 	default y
 	depends on DT_HAS_ZEPHYR_RETAINED_RAM_ENABLED && RETAINED_MEM_ZEPHYR_RAM && POWEROFF
-	depends on SOC_FAMILY_NORDIC_NRF
+	depends on HAS_NORDIC_RAM_CTRL
 	help
 	  Enable driver for Nordic RAM retention.

drivers/retained_mem/retained_mem_nrf_ram_ctrl.c

@@ -6,6 +6,7 @@
 
 #include <zephyr/devicetree.h>
 #include <zephyr/kernel.h>
+#include <zephyr/drivers/retained_mem/nrf_retained_mem.h>
 
 #include <helpers/nrfx_ram_ctrl.h>
 
@@ -22,7 +23,7 @@ static const struct ret_mem_region ret_mem_regions[] = {
 	DT_FOREACH_STATUS_OKAY(zephyr_retained_ram, _BUILD_MEM_REGION)
 };
 
-static int retained_mem_nrf_init(void)
+int z_nrf_retained_mem_retention_apply(void)
 {
 	const struct ret_mem_region *rmr;
 
@@ -33,5 +34,3 @@ static int retained_mem_nrf_init(void)
 
 	return 0;
 }
-
-SYS_INIT(retained_mem_nrf_init, PRE_KERNEL_1, 0);

include/zephyr/drivers/retained_mem/nrf_retained_mem.h

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_INCLUDE_DRIVERS_RETAINED_MEM_NRF_RETAINED_MEM_H
+#define ZEPHYR_INCLUDE_DRIVERS_RETAINED_MEM_NRF_RETAINED_MEM_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <zephyr/drivers/retained_mem.h>
+
+#if defined(CONFIG_RETAINED_MEM_NRF_RAM_CTRL) || defined(__DOXYGEN__)
+/** @brief Apply memory retention settings.
+ *
+ * Memory retention settings to apply are derived from devicetree configuration.
+ *
+ * @retval 0 if the retention settings were applied successfully.
+ * @retval -ENOTSUP if retention configuration is not present in devicetree.
+ */
+int z_nrf_retained_mem_retention_apply(void);
+#else
+static inline int z_nrf_retained_mem_retention_apply(void)
+{
+	return -ENOTSUP;
+}
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ZEPHYR_INCLUDE_DRIVERS_RETAINED_MEM_NRF_RETAINED_MEM_H */

modules/hal_nordic/nrfx/CMakeLists.txt

@@ -109,7 +109,7 @@ zephyr_library_sources_ifdef(CONFIG_SOC_SERIES_NRF92X  ${MDK_DIR}/system_nrf92.c
 
 zephyr_library_sources(nrfx_glue.c)
 zephyr_library_sources(${HELPERS_DIR}/nrfx_flag32_allocator.c)
-zephyr_library_sources_ifdef(CONFIG_RETAINED_MEM_NRF_RAM_CTRL ${HELPERS_DIR}/nrfx_ram_ctrl.c)
+zephyr_library_sources_ifdef(CONFIG_HAS_NORDIC_RAM_CTRL       ${HELPERS_DIR}/nrfx_ram_ctrl.c)
 zephyr_library_sources_ifdef(CONFIG_NRFX_GPPI                 ${HELPERS_DIR}/nrfx_gppi_dppi.c)
 zephyr_library_sources_ifdef(CONFIG_NRFX_PPI                  ${HELPERS_DIR}/nrfx_gppi_ppi.c)
 

samples/boards/nordic/system_off/CMakeLists.txt

@@ -5,6 +5,6 @@ find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
 project(nrf_system_off)
 
 target_sources(app PRIVATE src/main.c)
-if (CONFIG_APP_USE_NRF_RETENTION OR CONFIG_APP_USE_RETAINED_MEM)
+if (CONFIG_APP_USE_RETAINED_MEM)
   target_sources(app PRIVATE src/retained.c)
 endif()

samples/boards/nordic/system_off/Kconfig

@@ -3,23 +3,9 @@
 
 mainmenu "Nordic SYSTEM_OFF demo"
 
-choice
-	prompt "Use retention"
-	optional
-
-config APP_USE_NRF_RETENTION
-	bool "Use state retention in system off using nRF POWER"
-	depends on SOC_COMPATIBLE_NRF52X && CRC
-	help
-	  On some Nordic chips this application supports retaining
-	  memory while in system off using POWER peripheral.
-	  Select this to enable the feature.
-
 config APP_USE_RETAINED_MEM
 	bool "Use state retention in system off using retained_mem driver"
-	depends on RETAINED_MEM
-
-endchoice
+	select RETAINED_MEM
 
 config GRTC_WAKEUP_ENABLE
 	bool "Use GRTC to wake up device from system off"

samples/boards/nordic/system_off/README.rst

@@ -13,10 +13,10 @@ deep sleep on Nordic platforms.
 RAM Retention
 =============
 
-This sample can also can demonstrate RAM retention. By selecting
-``CONFIG_APP_USE_NRF_RETENTION=y`` or ``CONFIG_APP_USE_RETAINED_MEM=y``
-state related to number of boots, number of times system off was entered,
-and total uptime since initial power-on are retained in a checksummed data structure.
+This sample can also demonstrate RAM retention.
+By selecting ``CONFIG_APP_USE_RETAINED_MEM=y`` state related to number of boots,
+number of times system off was entered, and total uptime since initial power-on
+are retained in a checksummed data structure.
 RAM is configured to keep the containing section powered while in system-off mode.
 
 Requirements

samples/boards/nordic/system_off/boards/nrf52840dk_nrf52840.overlay

@@ -0,0 +1,22 @@
+/ {
+	sram0@2003f000 {
+		compatible = "zephyr,memory-region", "mmio-sram";
+		reg = <0x2003f000 DT_SIZE_K(4)>;
+		zephyr,memory-region = "RetainedMem";
+		status = "okay";
+
+		retainedmem0: retainedmem {
+			compatible = "zephyr,retained-ram";
+			status = "okay";
+		};
+	};
+
+	aliases {
+		retainedmemdevice = &retainedmem0;
+	};
+};
+
+&sram0 {
+	/* Shrink SRAM size to avoid overlap with retained memory region */
+	reg = <0x20000000 DT_SIZE_K(252)>;
+};

samples/boards/nordic/system_off/boards/nrf52dk_nrf52832.overlay

@@ -0,0 +1,22 @@
+/ {
+	sram0@20007000 {
+		compatible = "zephyr,memory-region", "mmio-sram";
+		reg = <0x20007000 DT_SIZE_K(4)>;
+		zephyr,memory-region = "RetainedMem";
+		status = "okay";
+
+		retainedmem0: retainedmem {
+			compatible = "zephyr,retained-ram";
+			status = "okay";
+		};
+	};
+
+	aliases {
+		retainedmemdevice = &retainedmem0;
+	};
+};
+
+&sram0 {
+	/* Shrink SRAM size to avoid overlap with retained memory region */
+	reg = <0x20000000 DT_SIZE_K(28)>;
+};

samples/boards/nordic/system_off/sample.yaml

@@ -22,32 +22,17 @@ tests:
         - "system off demo"
         - "Retained data not supported"
         - "Entering system off; press sw0 to restart"
-  sample.boards.nrf.system_off.nrf_retained:
+  sample.boards.nrf.system_off.retained_mem:
     integration_platforms:
       - nrf52840dk/nrf52840
     platform_allow:
       - nrf52840dk/nrf52840
       - nrf52dk/nrf52832
-    extra_configs:
-      - CONFIG_APP_USE_NRF_RETENTION=y
-    harness: console
-    harness_config:
-      type: multi_line
-      ordered: true
-      regex:
-        - "system off demo"
-        - "Retained data: INVALID"
-        - "Boot count: 1"
-        - "Off count: 0"
-        - "Active Ticks:"
-        - "Entering system off; press sw0 to restart"
-  sample.boards.nrf.system_off.retained_mem:
-    extra_args: DTC_OVERLAY_FILE="boards/nrf54l15dk_nrf54l15_cpuapp_retained_mem.overlay"
-    platform_allow:
       - nrf54l15dk/nrf54l15/cpuapp
+      - nrf54l15dk/nrf54l10/cpuapp
+      - nrf54l15dk/nrf54l05/cpuapp
     extra_configs:
       - CONFIG_APP_USE_RETAINED_MEM=y
-      - CONFIG_RETAINED_MEM=y
     harness: console
     harness_config:
       type: multi_line
@@ -62,6 +47,8 @@ tests:
   sample.boards.nrf.system_off.grtc_wakeup:
     platform_allow:
       - nrf54l15dk/nrf54l15/cpuapp
+      - nrf54l15dk/nrf54l10/cpuapp
+      - nrf54l15dk/nrf54l05/cpuapp
     extra_configs:
       - CONFIG_GRTC_WAKEUP_ENABLE=y
     harness: console
@@ -79,13 +66,13 @@ tests:
         - "Retained data not supported"
         - "Entering system off; wait 2 seconds to restart"
   sample.boards.nrf.system_off.retained_mem.grtc_wakeup:
-    extra_args: DTC_OVERLAY_FILE="boards/nrf54l15dk_nrf54l15_cpuapp_retained_mem.overlay"
     platform_allow:
       - nrf54l15dk/nrf54l15/cpuapp
+      - nrf54l15dk/nrf54l10/cpuapp
+      - nrf54l15dk/nrf54l05/cpuapp
     extra_configs:
       - CONFIG_APP_USE_RETAINED_MEM=y
       - CONFIG_GRTC_WAKEUP_ENABLE=y
-      - CONFIG_RETAINED_MEM=y
     harness: console
     harness_config:
       type: multi_line

samples/boards/nordic/system_off/src/main.c

@@ -35,7 +35,7 @@ int main(void)
 
 	printf("\n%s system off demo\n", CONFIG_BOARD);
 
-	if (IS_ENABLED(CONFIG_APP_USE_NRF_RETENTION) || IS_ENABLED(CONFIG_APP_USE_RETAINED_MEM)) {
+	if (IS_ENABLED(CONFIG_APP_USE_RETAINED_MEM)) {
 		bool retained_ok = retained_validate();
 
 		/* Increment for this boot attempt and update. */
@@ -81,7 +81,7 @@ int main(void)
 		return 0;
 	}
 
-	if (IS_ENABLED(CONFIG_APP_USE_NRF_RETENTION) || IS_ENABLED(CONFIG_APP_USE_RETAINED_MEM)) {
+	if (IS_ENABLED(CONFIG_APP_USE_RETAINED_MEM)) {
 		/* Update the retained state */
 		retained.off_count += 1;
 		retained_update();