tests: pm: Add constraint list API test

Add test for lock/unlock constraint lists using the new arbitrary DT
phandles macros and pm_policy_state_constraints_get/put APIs.

Signed-off-by: Declan Snyder <[email protected]>

Author: decsny

tests/subsys/pm/policy_api/app.overlay

@@ -37,6 +37,10 @@
 			substate-id = <100>;
 		};
 	};
+
+	zephyr,user {
+		test-states = <&state0 &state2>;
+	};
 };
 
 &cpu0 {

tests/subsys/pm/policy_api/src/main.c

@@ -258,6 +258,112 @@ ZTEST(policy_api, test_pm_policy_next_state_default_latency)
 	pm_policy_latency_request_remove(&req1);
 	zassert_equal(latency_cb_call_cnt, 1);
 }
+
+/**
+ * @brief Test pm_policy_state_constraints_get/put functions using devicetree
+ * test-states property and PM_STATE_CONSTRAINTS macros.
+ */
+ZTEST(policy_api, test_pm_policy_state_constraints)
+{
+	/* Define constraints list from the zephyr,user test-states property */
+	PM_STATE_CONSTRAINTS_LIST_DEFINE(DT_PATH(zephyr_user), test_states);
+
+	/* Get the constraints structure from devicetree */
+	struct pm_state_constraints test_constraints =
+		PM_STATE_CONSTRAINTS_GET(DT_PATH(zephyr_user), test_states);
+
+	/* Verify the constraints were parsed correctly from devicetree
+	 * test-states = <&state0 &state2> from app.overlay
+	 */
+	zassert_equal(test_constraints.count, 2,
+		      "Expected 2 constraints from test-states property");
+
+	/* Check that the constraints contain the expected states:
+	 * state0 (runtime-idle, substate 1) and state2 (suspend-to-ram, substate 100)
+	 */
+	bool found_runtime_idle = false;
+	bool found_suspend_to_ram = false;
+
+	for (size_t i = 0; i < test_constraints.count; i++) {
+		TC_PRINT("Constraint %zu: state=%d, substate_id=%d\n",
+			 i, test_constraints.list[i].state, test_constraints.list[i].substate_id);
+
+		if (test_constraints.list[i].state == PM_STATE_RUNTIME_IDLE &&
+		    test_constraints.list[i].substate_id == 1) {
+			found_runtime_idle = true;
+		}
+		if (test_constraints.list[i].state == PM_STATE_SUSPEND_TO_RAM &&
+		    test_constraints.list[i].substate_id == 100) {
+			found_suspend_to_ram = true;
+		}
+	}
+
+	zassert_true(found_runtime_idle,
+		     "Expected runtime-idle state with substate 1 in constraints");
+	zassert_true(found_suspend_to_ram,
+		     "Expected suspend-to-ram state with substate 100 in constraints");
+
+	/* Test that states are initially available */
+	zassert_false(pm_policy_state_lock_is_active(PM_STATE_RUNTIME_IDLE, 1),
+		      "runtime-idle substate 1 should be initially available");
+	zassert_false(pm_policy_state_lock_is_active(PM_STATE_SUSPEND_TO_RAM, 100),
+		      "suspend-to-ram substate 100 should be initially available");
+
+	/* Apply the constraints - this should lock the specified states */
+	pm_policy_state_constraints_get(&test_constraints);
+
+	/* Verify that the constrained states are now locked */
+	zassert_true(pm_policy_state_lock_is_active(PM_STATE_RUNTIME_IDLE, 1),
+		     "runtime-idle substate 1 should be locked after applying constraints");
+	zassert_true(pm_policy_state_lock_is_active(PM_STATE_SUSPEND_TO_RAM, 100),
+		     "suspend-to-ram substate 100 should be locked after applying constraints");
+
+	/* Verify that non-constrained states are still available */
+	zassert_false(pm_policy_state_lock_is_active(PM_STATE_SUSPEND_TO_RAM, 10),
+		      "suspend-to-ram substate 10 should not be locked");
+
+	/* Test that policy respects the constraints */
+	const struct pm_state_info *next;
+
+	/* This should not return the locked runtime-idle state,
+	 * but should return suspend-to-ram substate 10
+	 */
+	next = pm_policy_next_state(0U, k_us_to_ticks_floor32(1100000));
+	zassert_not_null(next, "Policy should return an available state");
+	zassert_equal(next->state, PM_STATE_SUSPEND_TO_RAM);
+	zassert_equal(next->substate_id, 10);
+
+	/* Remove the constraints - this should unlock the states */
+	pm_policy_state_constraints_put(&test_constraints);
+
+	/* Verify that the previously constrained states are now unlocked */
+	zassert_false(pm_policy_state_lock_is_active(PM_STATE_RUNTIME_IDLE, 1),
+		      "runtime-idle substate 1 should be unlocked after removing constraints");
+	zassert_false(pm_policy_state_lock_is_active(PM_STATE_SUSPEND_TO_RAM, 100),
+		      "suspend-to-ram substate 100 should be unlocked after removing constraints");
+
+	/* Verify policy works normally again */
+	next = pm_policy_next_state(0U, k_us_to_ticks_floor32(110000));
+	zassert_not_null(next, "Policy should return a state after removing constraints");
+	zassert_equal(next->state, PM_STATE_RUNTIME_IDLE);
+
+	/* Test multiple get/put cycles to verify reference counting */
+	pm_policy_state_constraints_get(&test_constraints);
+	pm_policy_state_constraints_get(&test_constraints);
+
+	zassert_true(pm_policy_state_lock_is_active(PM_STATE_RUNTIME_IDLE, 1),
+		     "runtime-idle substate 1 should remain locked with multiple gets");
+
+	/* First put should not unlock (reference count > 1) */
+	pm_policy_state_constraints_put(&test_constraints);
+	zassert_true(pm_policy_state_lock_is_active(PM_STATE_RUNTIME_IDLE, 1),
+		     "runtime-idle substate 1 should remain locked after first put");
+
+	/* Second put should unlock (reference count = 0) */
+	pm_policy_state_constraints_put(&test_constraints);
+	zassert_false(pm_policy_state_lock_is_active(PM_STATE_RUNTIME_IDLE, 1),
+		      "runtime-idle substate 1 should be unlocked after final put");
+}
 #else
 ZTEST(policy_api, test_pm_policy_next_state_default)
 {
@@ -273,6 +379,11 @@ ZTEST(policy_api, test_pm_policy_next_state_default_latency)
 {
 	ztest_test_skip();
 }
+
+ZTEST(policy_api, test_pm_policy_state_constraints)
+{
+	ztest_test_skip();
+}
 #endif /* CONFIG_PM_POLICY_DEFAULT */
 
 #ifdef CONFIG_PM_POLICY_CUSTOM