diff --git a/include/drivers/arm/css/scmi.h b/include/drivers/arm/css/scmi.h
index 1f8dc6c..e8a2863 100644
--- a/include/drivers/arm/css/scmi.h
+++ b/include/drivers/arm/css/scmi.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2020, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -162,7 +162,7 @@
 int scmi_ap_core_get_reset_addr(void *p, uint64_t *reset_addr, uint32_t *attr);
 
 /* API to get the platform specific SCMI channel information. */
-scmi_channel_plat_info_t *plat_css_get_scmi_info(void);
+scmi_channel_plat_info_t *plat_css_get_scmi_info(int channel_id);
 
 /* API to override default PSCI callbacks for platforms that support SCMI. */
 const plat_psci_ops_t *css_scmi_override_pm_ops(plat_psci_ops_t *ops);
diff --git a/include/plat/arm/css/common/css_pm.h b/include/plat/arm/css/common/css_pm.h
index 93f8616..e5357f5 100644
--- a/include/plat/arm/css/common/css_pm.h
+++ b/include/plat/arm/css/common/css_pm.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2020, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -44,4 +44,15 @@
  */
 extern const uint32_t plat_css_core_pos_to_scmi_dmn_id_map[];
 
+#define SCMI_DOMAIN_ID_MASK		U(0xFFFF)
+#define SCMI_CHANNEL_ID_MASK		U(0xFFFF)
+#define SCMI_CHANNEL_ID_SHIFT		U(16)
+
+#define SET_SCMI_CHANNEL_ID(n)		(((n) & SCMI_CHANNEL_ID_MASK) << \
+					 SCMI_CHANNEL_ID_SHIFT)
+#define SET_SCMI_DOMAIN_ID(n)		((n) & SCMI_DOMAIN_ID_MASK)
+#define GET_SCMI_CHANNEL_ID(n)		(((n) >> SCMI_CHANNEL_ID_SHIFT) & \
+					 SCMI_CHANNEL_ID_MASK)
+#define GET_SCMI_DOMAIN_ID(n)		((n) & SCMI_DOMAIN_ID_MASK)
+
 #endif /* CSS_PM_H */