drivers: hwinfo: silabs: Add hwinfo driver for Series 2

Add hwinfo driver for Silicon Labs Series 2 devices. The driver
is separate from the Series 0/1 Gecko driver because the available
reset causes are completely different.

Signed-off-by: Aksel Skauge Mellbye <aksel.mellbye@silabs.com>

boards/silabs/dev_kits/xg24_dk2601b/xg24_dk2601b.yaml

@@ -18,5 +18,4 @@ supported:
 testing:
   ignore_tags:
     - pm
-    - hwinfo
 vendor: silabs

boards/silabs/dev_kits/xg24_ek2703a/xg24_ek2703a.yaml

@@ -17,5 +17,4 @@ supported:
 testing:
   ignore_tags:
     - pm
-    - hwinfo
 vendor: silabs

boards/silabs/radio_boards/xg24_rb4187c/xg24_rb4187c.yaml

@@ -17,5 +17,4 @@ supported:
 testing:
   ignore_tags:
     - pm
-    - hwinfo
 vendor: silabs

drivers/hwinfo/CMakeLists.txt

@@ -31,6 +31,7 @@ zephyr_library_sources_ifdef(CONFIG_HWINFO_SAM         hwinfo_sam.c)
 zephyr_library_sources_ifdef(CONFIG_HWINFO_SAM0        hwinfo_sam0.c)
 zephyr_library_sources_ifdef(CONFIG_HWINFO_SAM4L       hwinfo_sam4l.c)
 zephyr_library_sources_ifdef(CONFIG_HWINFO_SAM_RSTC    hwinfo_sam_rstc.c)
+zephyr_library_sources_ifdef(CONFIG_HWINFO_SILABS_S2   hwinfo_silabs_series2.c)
 zephyr_library_sources_ifdef(CONFIG_HWINFO_SMARTBOND   hwinfo_smartbond.c)
 zephyr_library_sources_ifdef(CONFIG_HWINFO_STM32       hwinfo_stm32.c)
 # zephyr-keep-sorted-stop

drivers/hwinfo/Kconfig

@@ -204,14 +204,21 @@ config HWINFO_PSOC6
 config HWINFO_GECKO
 	bool "GECKO hwinfo"
 	default y
-	depends on SOC_FAMILY_SILABS_S0 || SOC_FAMILY_SILABS_S1 || SOC_FAMILY_SILABS_S2
+	depends on SOC_FAMILY_SILABS_S0 || SOC_FAMILY_SILABS_S1
-	depends on !SOC_SERIES_EFR32MG21
-	depends on !SOC_SERIES_EFR32BG22
 	select HWINFO_HAS_DRIVER
 	select SOC_GECKO_RMU
 	help
 	  Enable Silabs GECKO hwinfo driver.
 
+config HWINFO_SILABS_S2
+	bool "Silabs Series 2 hwinfo"
+	default y
+	depends on SOC_FAMILY_SILABS_S2
+	select HWINFO_HAS_DRIVER
+	select SOC_GECKO_RMU
+	help
+	  Enable Silabs Series 2 hwinfo driver.
+
 config HWINFO_ANDES
 	bool "Andes system ID"
 	default y

drivers/hwinfo/hwinfo_silabs_series2.c

@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2025 Silicon Laboratories Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/drivers/hwinfo.h>
+#include <zephyr/sys/byteorder.h>
+
+#include <string.h>
+
+#include <em_system.h>
+#include <em_rmu.h>
+
+/* Ensure that all possible reset causes have a definition */
+#ifndef EMU_RSTCAUSE_BOOSTON
+#define EMU_RSTCAUSE_BOOSTON 0
+#endif
+#ifndef EMU_RSTCAUSE_WDOG1
+#define EMU_RSTCAUSE_WDOG1 0
+#endif
+#ifndef EMU_RSTCAUSE_IOVDD1BOD
+#define EMU_RSTCAUSE_IOVDD1BOD 0
+#endif
+#ifndef EMU_RSTCAUSE_IOVDD2BOD
+#define EMU_RSTCAUSE_IOVDD2BOD 0
+#endif
+#ifndef EMU_RSTCAUSE_SETAMPER
+#define EMU_RSTCAUSE_SETAMPER 0
+#endif
+#ifndef EMU_RSTCAUSE_SESYSREQ
+#define EMU_RSTCAUSE_SESYSREQ 0
+#endif
+#ifndef EMU_RSTCAUSE_SELOCKUP
+#define EMU_RSTCAUSE_SELOCKUP 0
+#endif
+#ifndef EMU_RSTCAUSE_DCI
+#define EMU_RSTCAUSE_DCI 0
+#endif
+
+/* The Zephyr API expects hwinfo_get_reset_cause() to return 0 after hwinfo_clear_reset_cause() has
+ * been called. This matches the hardware behavior on Series 2, but not the HAL API. The HAL stores
+ * the reset cause upon first read, and returns this cached value on subsequent calls to the API
+ * to allow multiple subsystems to read the reset cause despite it having been cleared in hardware
+ * already. Emulate the hardware behavior while staying compatible with other users of the HAL API
+ * by keeping track of whether the reset cause should be considered cleared or not ourselves.
+ */
+static bool reset_cleared;
+
+ssize_t z_impl_hwinfo_get_device_id(uint8_t *buffer, size_t length)
+{
+	uint64_t unique_id = sys_cpu_to_be64(SYSTEM_GetUnique());
+
+	if (length > sizeof(unique_id)) {
+		length = sizeof(unique_id);
+	}
+
+	memcpy(buffer, &unique_id, length);
+
+	return length;
+}
+
+int z_impl_hwinfo_get_reset_cause(uint32_t *cause)
+{
+	uint32_t flags = 0;
+	uint32_t rmu = RMU_ResetCauseGet();
+
+	if (reset_cleared) {
+		*cause = 0;
+		return 0;
+	}
+
+	if (rmu & EMU_RSTCAUSE_POR) {
+		flags |= RESET_POR;
+	}
+
+	if (rmu & EMU_RSTCAUSE_PIN) {
+		flags |= RESET_PIN;
+	}
+
+	if (rmu & (EMU_RSTCAUSE_EM4 | EMU_RSTCAUSE_BOOSTON)) {
+		flags |= RESET_LOW_POWER_WAKE;
+	}
+
+	if (rmu & (EMU_RSTCAUSE_WDOG0 | EMU_RSTCAUSE_WDOG1)) {
+		flags |= RESET_WATCHDOG;
+	}
+
+	if (rmu & EMU_RSTCAUSE_LOCKUP) {
+		flags |= RESET_CPU_LOCKUP;
+	}
+
+	if (rmu & EMU_RSTCAUSE_SYSREQ) {
+		flags |= RESET_SOFTWARE;
+	}
+
+	if (rmu & (EMU_RSTCAUSE_DVDDBOD | EMU_RSTCAUSE_DVDDLEBOD | EMU_RSTCAUSE_DECBOD |
+		   EMU_RSTCAUSE_AVDDBOD | EMU_RSTCAUSE_IOVDD0BOD |
+		   EMU_RSTCAUSE_IOVDD1BOD | EMU_RSTCAUSE_IOVDD2BOD)) {
+		flags |= RESET_BROWNOUT;
+	}
+
+	if (rmu & (EMU_RSTCAUSE_SETAMPER | EMU_RSTCAUSE_SESYSREQ |
+		   EMU_RSTCAUSE_SELOCKUP | EMU_RSTCAUSE_DCI)) {
+		flags |= RESET_SECURITY;
+	}
+
+	*cause = flags;
+	return 0;
+}
+
+int z_impl_hwinfo_clear_reset_cause(void)
+{
+	RMU_ResetCauseClear();
+	reset_cleared = true;
+	return 0;
+}
+
+int z_impl_hwinfo_get_supported_reset_cause(uint32_t *supported)
+{
+	*supported = RESET_PIN | RESET_SOFTWARE | RESET_BROWNOUT | RESET_POR | RESET_WATCHDOG |
+		     RESET_SECURITY | RESET_LOW_POWER_WAKE | RESET_CPU_LOCKUP;
+	return 0;
+}