Tegra194: CC6 state from last offline CPU in the cluster

This patch enables the CC6 cluster state for the cluster, if the
current CPU being offlined is the last CPU in the cluster.

Change-Id: I3380a969b534fcd14f9c46433471cc1c2adf6011
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

plat/nvidia/tegra/soc/t194/plat_psci_handlers.c

@@ -179,24 +179,39 @@ int32_t tegra_soc_pwr_domain_suspend(const psci_power_state_t *target_state)
 }
 
 /*******************************************************************************
- * Platform handler to calculate the proper target power level at the
- * specified affinity level
+ * Helper function to check if this is the last ON CPU in the cluster
  ******************************************************************************/
-plat_local_state_t tegra_soc_get_target_pwr_state(uint32_t lvl,
-					     const plat_local_state_t *states,
+static bool tegra_last_on_cpu_in_cluster(const plat_local_state_t *states,
 			uint32_t ncpu)
 {
-	plat_local_state_t target = *states;
-	int32_t cluster_powerdn = 1;
-	uint32_t core_pos = (uint32_t)read_mpidr() & MPIDR_CPU_MASK;
+	plat_local_state_t target;
+	bool last_on_cpu = true;
 	uint32_t num_cpus = ncpu, pos = 0;
-	mce_cstate_info_t cstate_info = { 0 };
 
-	/* get the current core's power state */
-	target = states[core_pos];
+	do {
+		target = states[pos];
+		if (target != PLAT_MAX_OFF_STATE) {
+			last_on_cpu = false;
+		}
+		--num_cpus;
+		pos++;
+	} while (num_cpus != 0U);
+
+	return last_on_cpu;
+}
+
+/*******************************************************************************
+ * Helper function to get target power state for the cluster
+ ******************************************************************************/
+static plat_local_state_t tegra_get_afflvl1_pwr_state(const plat_local_state_t *states,
+			uint32_t ncpu)
+{
+	uint32_t core_pos = (uint32_t)read_mpidr() & (uint32_t)MPIDR_CPU_MASK;
+	plat_local_state_t target = states[core_pos];
+	mce_cstate_info_t cstate_info = { 0 };
 
 	/* CPU suspend */
-	if ((lvl == MPIDR_AFFLVL1) && (target == PSTATE_ID_CORE_POWERDN)) {
+	if (target == PSTATE_ID_CORE_POWERDN) {
 
 		/* Program default wake mask */
 		cstate_info.wake_mask = TEGRA194_CORE_WAKE_MASK;
@@ -205,45 +220,51 @@ plat_local_state_t tegra_soc_get_target_pwr_state(uint32_t lvl,
 	}
 
 	/* CPU off */
-	if ((lvl == MPIDR_AFFLVL1) && (target == PLAT_MAX_OFF_STATE)) {
-
-		/* find out the number of ON cpus in the cluster */
-		do {
-			target = states[pos];
-			if (target != PLAT_MAX_OFF_STATE) {
-				cluster_powerdn = 0;
-			}
-			--num_cpus;
-			pos++;
-		} while (num_cpus != 0U);
+	if (target == PLAT_MAX_OFF_STATE) {
 
 		/* Enable cluster powerdn from last CPU in the cluster */
-		if (cluster_powerdn != 0) {
-
-			/* Enable CC6 */
-			/* todo */
+		if (tegra_last_on_cpu_in_cluster(states, ncpu)) {
 
-			/* If cluster group needs to be railgated, request CG7 */
-			/* todo */
-
-			/* Turn off wake mask */
+			/* Enable CC6 state and turn off wake mask */
+			cstate_info.cluster = (uint32_t)TEGRA_NVG_CLUSTER_CC6;
 			cstate_info.update_wake_mask = 1U;
 			mce_update_cstate_info(&cstate_info);
 
 		} else {
+
 			/* Turn off wake_mask */
 			cstate_info.update_wake_mask = 1U;
 			mce_update_cstate_info(&cstate_info);
+			target = PSCI_LOCAL_STATE_RUN;
 		}
 	}
 
+	return target;
+}
+
+/*******************************************************************************
+ * Platform handler to calculate the proper target power level at the
+ * specified affinity level
+ ******************************************************************************/
+plat_local_state_t tegra_soc_get_target_pwr_state(uint32_t lvl,
+					     const plat_local_state_t *states,
+					     uint32_t ncpu)
+{
+	plat_local_state_t target = PSCI_LOCAL_STATE_RUN;
+	uint32_t cpu = plat_my_core_pos();
+
 	/* System Suspend */
-	if ((lvl == MPIDR_AFFLVL2) || (target == PSTATE_ID_SOC_POWERDN)) {
-		return PSTATE_ID_SOC_POWERDN;
+	if ((lvl == (uint32_t)MPIDR_AFFLVL2) && (states[cpu] == PSTATE_ID_SOC_POWERDN)) {
+		target = PSTATE_ID_SOC_POWERDN;
+	}
+
+	/* CPU off, CPU suspend */
+	if (lvl == (uint32_t)MPIDR_AFFLVL1) {
+		target = tegra_get_afflvl1_pwr_state(states, ncpu);
 	}
 
-	/* default state */
-	return PSCI_LOCAL_STATE_RUN;
+	/* target cluster/system state */
+	return target;
 }
 
 int32_t tegra_soc_pwr_domain_power_down_wfi(const psci_power_state_t *target_state)