PSCI: Demonstrate support for composite power states

This patch adds support to the Juno and FVP ports for composite power states
with both the original and extended state-id power-state formats. Both the
platform ports use the recommended state-id encoding as specified in
Section 6.5 of the PSCI specification (ARM DEN 0022C). The platform build flag
ARM_RECOM_STATE_ID_ENC is used to include this support.

By default, to maintain backwards compatibility, the original power state
parameter format is used and the state-id field is expected to be zero.

Change-Id: Ie721b961957eaecaca5bf417a30952fe0627ef10
diff --git a/include/plat/arm/common/plat_arm.h b/include/plat/arm/common/plat_arm.h
index 29f1c90..56b5eda 100644
--- a/include/plat/arm/common/plat_arm.h
+++ b/include/plat/arm/common/plat_arm.h
@@ -148,6 +148,35 @@
 
 #endif /* IMAGE_BL31 */
 
+#if ARM_RECOM_STATE_ID_ENC
+/*
+ * Macros used to parse state information from State-ID if it is using the
+ * recommended encoding for State-ID.
+ */
+#define ARM_LOCAL_PSTATE_WIDTH		4
+#define ARM_LOCAL_PSTATE_MASK		((1 << ARM_LOCAL_PSTATE_WIDTH) - 1)
+
+/* Macros to construct the composite power state */
+
+/* Make composite power state parameter till power level 0 */
+#if PSCI_EXTENDED_STATE_ID
+
+#define arm_make_pwrstate_lvl0(lvl0_state, pwr_lvl, type) \
+		(((lvl0_state) << PSTATE_ID_SHIFT) | ((type) << PSTATE_TYPE_SHIFT))
+#else
+#define arm_make_pwrstate_lvl0(lvl0_state, pwr_lvl, type) \
+		(((lvl0_state) << PSTATE_ID_SHIFT) | \
+		((pwr_lvl) << PSTATE_PWR_LVL_SHIFT) | \
+		((type) << PSTATE_TYPE_SHIFT))
+#endif /* __PSCI_EXTENDED_STATE_ID__ */
+
+/* Make composite power state parameter till power level 1 */
+#define arm_make_pwrstate_lvl1(lvl1_state, lvl0_state, pwr_lvl, type) \
+		(((lvl1_state) << ARM_LOCAL_PSTATE_WIDTH) | \
+		arm_make_pwrstate_lvl0(lvl0_state, pwr_lvl, type))
+
+#endif /* __ARM_RECOM_STATE_ID_ENC__ */
+
 
 /* CCI utility functions */
 void arm_cci_init(void);