cpuidle: psci: Split psci_dt_cpu_init_idle()

To make the code a bit more readable, let's move the OSI specific
initialization out of the psci_dt_cpu_init_idle() and into a separate
function.
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpuidle/cpuidle-psci.c

@@ -160,6 +160,29 @@ int __init psci_dt_parse_state_node(struct device_node *np, u32 *state)
 	return 0;
 }
 
+static int __init psci_dt_cpu_init_topology(struct cpuidle_driver *drv,
+					    struct psci_cpuidle_data *data,
+					    unsigned int state_count, int cpu)
+{
+	/* Currently limit the hierarchical topology to be used in OSI mode. */
+	if (!psci_has_osi_support())
+		return 0;
+
+	data->dev = psci_dt_attach_cpu(cpu);
+	if (IS_ERR_OR_NULL(data->dev))
+		return PTR_ERR_OR_ZERO(data->dev);
+
+	/*
+	 * Using the deepest state for the CPU to trigger a potential selection
+	 * of a shared state for the domain, assumes the domain states are all
+	 * deeper states.
+	 */
+	drv->states[state_count - 1].enter = psci_enter_domain_idle_state;
+	psci_cpuidle_use_cpuhp = true;
+
+	return 0;
+}
+
 static int __init psci_dt_cpu_init_idle(struct cpuidle_driver *drv,
 					struct device_node *cpu_node,
 					unsigned int state_count, int cpu)
@@ -193,25 +216,10 @@ static int __init psci_dt_cpu_init_idle(struct cpuidle_driver *drv,
 		goto free_mem;
 	}
 
-	/* Currently limit the hierarchical topology to be used in OSI mode. */
-	if (psci_has_osi_support()) {
-		data->dev = psci_dt_attach_cpu(cpu);
-		if (IS_ERR(data->dev)) {
-			ret = PTR_ERR(data->dev);
+	/* Initialize optional data, used for the hierarchical topology. */
+	ret = psci_dt_cpu_init_topology(drv, data, state_count, cpu);
+	if (ret < 0)
 		goto free_mem;
-		}
-
-		/*
-		 * Using the deepest state for the CPU to trigger a potential
-		 * selection of a shared state for the domain, assumes the
-		 * domain states are all deeper states.
-		 */
-		if (data->dev) {
-			drv->states[state_count - 1].enter =
-				psci_enter_domain_idle_state;
-			psci_cpuidle_use_cpuhp = true;
-		}
-	}
 
 	/* Idle states parsed correctly, store them in the per-cpu struct. */
 	data->psci_states = psci_states;