diff --git a/src/drivers/elog/gsmi.c b/src/drivers/elog/gsmi.c
index cd94cf61b6..42bfd0f183 100644
--- a/src/drivers/elog/gsmi.c
+++ b/src/drivers/elog/gsmi.c
@@ -25,6 +25,8 @@
 
 #define GSMI_CMD_SET_EVENT_LOG		0x08
 #define GSMI_CMD_CLEAR_EVENT_LOG	0x09
+#define GSMI_CMD_LOG_S0IX_SUSPEND	0x0a
+#define GSMI_CMD_LOG_S0IX_RESUME	0x0b
 #define GSMI_CMD_HANDSHAKE_TYPE		0xc1
 
 #define GSMI_HANDSHAKE_NONE		0x7f
@@ -46,6 +48,16 @@ struct gsmi_clear_eventlog_param {
 	u32 data_type;
 } __packed;
 
+void __attribute__((weak)) elog_gsmi_cb_platform_log_wake_source(void)
+{
+	/* Default weak implementation, does nothing. */
+}
+
+void __attribute__((weak)) elog_gsmi_cb_mainboard_log_wake_source(void)
+{
+	/* Default weak implementation, does nothing. */
+}
+
 /* Param is usually EBX, ret in EAX */
 u32 gsmi_exec(u8 command, u32 *param)
 {
@@ -105,6 +117,19 @@ u32 gsmi_exec(u8 command, u32 *param)
 			ret = GSMI_RET_SUCCESS;
 		break;
 
+	case GSMI_CMD_LOG_S0IX_SUSPEND:
+	case GSMI_CMD_LOG_S0IX_RESUME:
+		ret = GSMI_RET_SUCCESS;
+
+		if (command == GSMI_CMD_LOG_S0IX_SUSPEND)
+			elog_add_event(ELOG_TYPE_S0IX_ENTER);
+		else {
+			elog_add_event(ELOG_TYPE_S0IX_EXIT);
+			elog_gsmi_cb_platform_log_wake_source();
+			elog_gsmi_cb_mainboard_log_wake_source();
+		}
+		break;
+
 	default:
 		printk(BIOS_DEBUG, "GSMI Unknown: 0x%02x\n", command);
 		break;
diff --git a/src/include/elog.h b/src/include/elog.h
index bab7eb0594..0f6a811bbd 100644
--- a/src/include/elog.h
+++ b/src/include/elog.h
@@ -215,6 +215,10 @@ struct elog_event_mem_cache_update {
 #define ELOG_EC_DEVICE_EVENT_DSP            0x02
 #define ELOG_EC_DEVICE_EVENT_WIFI           0x03
 
+/* S0ix sleep/wake */
+#define ELOG_TYPE_S0IX_ENTER              0xaf
+#define ELOG_TYPE_S0IX_EXIT               0xb0
+
 #if IS_ENABLED(CONFIG_ELOG)
 /* Eventlog backing storage must be initialized before calling elog_init(). */
 extern int elog_init(void);
@@ -249,4 +253,16 @@ extern u32 gsmi_exec(u8 command, u32 *param);
 u32 boot_count_read(void);
 u32 boot_count_increment(void);
 
+/*
+ * Callback from GSMI handler to allow platform to log any wake source
+ * information.
+ */
+void elog_gsmi_cb_platform_log_wake_source(void);
+
+/*
+ * Callback from GSMI handler to allow mainboard to log any wake source
+ * information.
+ */
+void elog_gsmi_cb_mainboard_log_wake_source(void);
+
 #endif /* ELOG_H_ */