zephyr: lis2dw12: Add tests for set_power_mode()

 * Export set_power_mode() in case of unit tests. We need direct access
   to this function in order to exercise all of this cases, because it
   is only ever called within the driver using fixed args that don't hit
   all cases.
 * Rename set_power_mode() to lis2dw12_set_power_mode to prevent naming
   collisions
 * Add a test

BRANCH=None
BUG=b:200046770
TEST=zmake -D configure --test test-drivers; make runhosttests

Signed-off-by: Tristan Honscheid <honscheid@google.com>

Change-Id: I96b102c5a1a4c2524b775a32587afe16675a3cd1
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3296683
Reviewed-by: Aaron Massey <aaronmassey@google.com>
Tested-by: Tristan Honscheid <honscheid@google.com>
Commit-Queue: Tristan Honscheid <honscheid@google.com>

3 files changed, 49 insertions, 13 deletions

diff --git a/driver/accel_lis2dw12.c b/driver/accel_lis2dw12.c
index 1872e572f2..d1abd7c03b 100644
--- a/driver/accel_lis2dw12.c
+++ b/driver/accel_lis2dw12.c
@@ -286,7 +286,7 @@ static int lis2dw12_irq_handler(struct motion_sensor_t *s,
 #endif
 
 /**
- * set_power_mode - set sensor power mode
+ * lis2dw12_set_power_mode - set sensor power mode
  * @s: Motion sensor pointer
  * @mode: LIS2DW12_LOW_POWER, LIS2DW12_HIGH_PERF
  * @lpmode: LIS2DW12_LOW_POWER_MODE_2,
@@ -296,9 +296,10 @@ static int lis2dw12_irq_handler(struct motion_sensor_t *s,
  * TODO: LIS2DW12_LOW_POWER_MODE_1 not implemented because output differ
  *       in resolution
  */
-static int set_power_mode(const struct motion_sensor_t *s,
-			  enum lis2sw12_mode mode,
-			  enum lis2sw12_lpmode lpmode)
+STATIC_IF_NOT(CONFIG_ZTEST)
+int lis2dw12_set_power_mode(const struct motion_sensor_t *s,
+			    enum lis2sw12_mode mode,
+			    enum lis2sw12_lpmode lpmode)
 {
 	int ret = EC_SUCCESS;
 
@@ -436,9 +437,9 @@ static int set_data_rate(const struct motion_sensor_t *s, int rate, int rnd)
 	 */
 	if (!IS_ENABLED(CONFIG_ACCEL_LIS2DWL)) {
 		if (reg_val > LIS2DW12_ODR_200HZ_VAL)
-			ret = set_power_mode(s, LIS2DW12_HIGH_PERF, 0);
+			ret = lis2dw12_set_power_mode(s, LIS2DW12_HIGH_PERF, 0);
 		else
-			ret = set_power_mode(s, LIS2DW12_LOW_POWER,
+			ret = lis2dw12_set_power_mode(s, LIS2DW12_LOW_POWER,
 					LIS2DW12_LOW_POWER_MODE_2);
 	}
 
@@ -569,10 +570,10 @@ static int init(struct motion_sensor_t *s)
 		 * lis2dwl supports 14 bit resolution only
 		 * at high performance mode
 		 */
-		ret = set_power_mode(s, LIS2DW12_HIGH_PERF, 0);
+		ret = lis2dw12_set_power_mode(s, LIS2DW12_HIGH_PERF, 0);
 	else
 		/* Set default Mode and Low Power Mode. */
-		ret = set_power_mode(s, LIS2DW12_LOW_POWER,
+		ret = lis2dw12_set_power_mode(s, LIS2DW12_LOW_POWER,
 				     LIS2DW12_LOW_POWER_MODE_2);
 	if (ret != EC_SUCCESS)
 		goto err_unlock;
diff --git a/driver/accel_lis2dw12.h b/driver/accel_lis2dw12.h
index 8e1c97464c..71116cb13b 100644
--- a/driver/accel_lis2dw12.h
+++ b/driver/accel_lis2dw12.h
@@ -206,4 +206,10 @@ enum lis2dw12_fs {
  */
 #define LIS2DW12_RESOLUTION		14
 
+#ifdef CONFIG_ZTEST
+int lis2dw12_set_power_mode(const struct motion_sensor_t *s,
+			    enum lis2sw12_mode mode,
+			    enum lis2sw12_lpmode lpmode);
+#endif
+
 #endif /* __CROS_EC_ACCEL_LIS2DW12_H */
diff --git a/zephyr/test/drivers/src/lis2dw12.c b/zephyr/test/drivers/src/lis2dw12.c
index 287430e65b..c6117e2191 100644
--- a/zephyr/test/drivers/src/lis2dw12.c
+++ b/zephyr/test/drivers/src/lis2dw12.c
@@ -97,23 +97,52 @@ static void test_lis2dw12_init__fail_set_bdu(void)
 		      "expected at least one soft reset");
 }
 
+static void test_lis2dw12_set_power_mode(void)
+{
+	const struct emul *emul = emul_get_binding(EMUL_LABEL);
+	struct motion_sensor_t *ms = &motion_sensors[LIS2DW12_SENSOR_ID];
+	int rv;
+
+	/* Part 1: happy path */
+	rv = lis2dw12_set_power_mode(ms, LIS2DW12_LOW_POWER,
+				     LIS2DW12_LOW_POWER_MODE_2);
+	zassert_equal(rv, EC_SUCCESS, "Expected %d but got %d", EC_SUCCESS, rv);
+
+	/* Part 2: unimplemented modes */
+	rv = lis2dw12_set_power_mode(ms, LIS2DW12_LOW_POWER,
+				     LIS2DW12_LOW_POWER_MODE_1);
+	zassert_equal(rv, EC_ERROR_UNIMPLEMENTED, "Expected %d but got %d",
+		      EC_ERROR_UNIMPLEMENTED, rv);
+
+	/* Part 3: attempt to set mode but cannot modify reg. */
+	i2c_common_emul_set_read_fail_reg(lis2dw12_emul_to_i2c_emul(emul),
+					  LIS2DW12_ACC_MODE_ADDR);
+	rv = lis2dw12_set_power_mode(ms, LIS2DW12_LOW_POWER,
+				     LIS2DW12_LOW_POWER_MODE_2);
+	zassert_equal(rv, EC_ERROR_INVAL, "Expected %d but got %d",
+		      EC_ERROR_INVAL, rv);
+}
+
 void test_suite_lis2dw12(void)
 {
 	ztest_test_suite(lis2dw12,
 			 ztest_unit_test_setup_teardown(
 				 test_lis2dw12_init__fail_read_who_am_i,
-				 lis2dw12_setup, unit_test_noop),
+				 lis2dw12_setup, lis2dw12_setup),
 			 ztest_unit_test_setup_teardown(
 				 test_lis2dw12_init__fail_who_am_i,
-				 lis2dw12_setup, unit_test_noop),
+				 lis2dw12_setup, lis2dw12_setup),
 			 ztest_unit_test_setup_teardown(
 				 test_lis2dw12_init__fail_write_soft_reset,
-				 lis2dw12_setup, unit_test_noop),
+				 lis2dw12_setup, lis2dw12_setup),
 			 ztest_unit_test_setup_teardown(
 				 test_lis2dw12_init__timeout_read_soft_reset,
-				 lis2dw12_setup, unit_test_noop),
+				 lis2dw12_setup, lis2dw12_setup),
 			 ztest_unit_test_setup_teardown(
 				 test_lis2dw12_init__fail_set_bdu,
-				 lis2dw12_setup, unit_test_noop));
+				 lis2dw12_setup, lis2dw12_setup),
+			 ztest_unit_test_setup_teardown(
+				 test_lis2dw12_set_power_mode,
+				 lis2dw12_setup, lis2dw12_setup));
 	ztest_run_test_suite(lis2dw12);
 }