[nrf fromlist] soc: nordic: poweroff: add retention management

RAM retention is disabled for all RAM blocks
before entering System OFF to achieve lowest power consumption.
RAM retention can still be enabled using retained_mem driver.

Upstream PR #: 82262

Signed-off-by: Nikodem Kastelik <[email protected]>

Author: nika-nordic

soc/nordic/common/poweroff.c

@@ -5,6 +5,7 @@
 
 #include <zephyr/sys/poweroff.h>
 #include <zephyr/toolchain.h>
+#include <zephyr/drivers/retained_mem/nrf_retained_mem.h>
 
 #if defined(CONFIG_SOC_SERIES_NRF51X) || defined(CONFIG_SOC_SERIES_NRF52X)
 #include <hal/nrf_power.h>
@@ -17,8 +18,43 @@
 #include <helpers/nrfx_reset_reason.h>
 #endif
 
+#include <helpers/nrfx_ram_ctrl.h>
+
 void z_sys_poweroff(void)
 {
+#if defined(CONFIG_HAS_NORDIC_RAM_CTRL)
+	uint8_t *ram_start;
+	size_t ram_size;
+
+#if defined(NRF_MEMORY_RAM_BASE)
+	ram_start = (uint8_t *)NRF_MEMORY_RAM_BASE;
+#else
+	ram_start = (uint8_t *)NRF_MEMORY_RAM0_BASE;
+#endif
+
+	ram_size = 0;
+#if defined(NRF_MEMORY_RAM_SIZE)
+	ram_size += NRF_MEMORY_RAM_SIZE;
+#endif
+#if defined(NRF_MEMORY_RAM0_SIZE)
+	ram_size += NRF_MEMORY_RAM0_SIZE;
+#endif
+#if defined(NRF_MEMORY_RAM1_SIZE)
+	ram_size += NRF_MEMORY_RAM1_SIZE;
+#endif
+#if defined(NRF_MEMORY_RAM2_SIZE)
+	ram_size += NRF_MEMORY_RAM2_SIZE;
+#endif
+
+	/* Disable retention for all memory blocks */
+	nrfx_ram_ctrl_retention_enable_set(ram_start, ram_size, false);
+#endif
+
+#if defined(CONFIG_RETAINED_MEM_NRF_RAM_CTRL)
+	/* Restore retention for retained_mem driver regions defined in devicetree */
+	(void)z_nrf_retained_mem_retention_apply();
+#endif
+
 #if defined(CONFIG_SOC_SERIES_NRF54LX)
 	nrfx_reset_reason_clear(UINT32_MAX);
 #endif