zephyr: test: isl923x::get_vbus_voltage

Verify all the code paths in get_vbus_voltage (including calculated
mV value).

BRANCH=none
BUG=b:201819565
TEST=zmake configure --test zephyr/test/drivers

Signed-off-by: Yuval Peress <peress@google.com>
Change-Id: I508880a8af30c2d546655424b289d521f3c22626
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3201915
Reviewed-by: Fabio Baltieri <fabiobaltieri@google.com>

3 files changed, 58 insertions, 1 deletions

diff --git a/zephyr/emul/emul_isl923x.c b/zephyr/emul/emul_isl923x.c
index f97af88da0..9b3aaec4f5 100644
--- a/zephyr/emul/emul_isl923x.c
+++ b/zephyr/emul/emul_isl923x.c
@@ -82,6 +82,8 @@ struct isl923x_emul_data {
 	uint16_t ac_prochot_reg;
 	/** Emulated DC PROCHOT register */
 	uint16_t dc_prochot_reg;
+	/** Emulated ADC vbus register */
+	uint16_t adc_vbus_reg;
 };
 
 struct isl923x_emul_cfg {
@@ -137,6 +139,15 @@ void isl923x_emul_set_learn_mode_enabled(const struct emul *emulator,
 		data->control_1_reg &= ~ISL923X_C1_LEARN_MODE_ENABLE;
 }
 
+void isl923x_emul_set_adc_vbus(const struct emul *emulator,
+			       uint16_t value)
+{
+	struct isl923x_emul_data *data = emulator->data;
+
+	/* The VBUS voltage is returned in bits 13:6. The LSB is 96mV. */
+	data->adc_vbus_reg = value & GENMASK(13, 6);
+}
+
 static int isl923x_emul_read_byte(struct i2c_emul *emul, int reg, uint8_t *val,
 				  int bytes)
 {
@@ -234,6 +245,13 @@ static int isl923x_emul_read_byte(struct i2c_emul *emul, int reg, uint8_t *val,
 		else
 			*val = (uint8_t)((data->dc_prochot_reg >> 8) & 0xff);
 		break;
+	case RAA489000_REG_ADC_VBUS:
+		__ASSERT_NO_MSG(bytes == 0 || bytes == 1);
+		if (bytes == 0)
+			*val = (uint8_t)(data->adc_vbus_reg & 0xff);
+		else
+			*val = (uint8_t)((data->adc_vbus_reg >> 8) & 0xff);
+		break;
 	default:
 		return -EINVAL;
 	}
diff --git a/zephyr/include/emul/emul_isl923x.h b/zephyr/include/emul/emul_isl923x.h
index d43917a45b..3093b0cfe3 100644
--- a/zephyr/include/emul/emul_isl923x.h
+++ b/zephyr/include/emul/emul_isl923x.h
@@ -63,4 +63,13 @@ bool isl923x_emul_is_learn_mode_enabled(const struct emul *emulator);
 void isl923x_emul_set_learn_mode_enabled(const struct emul *emulator,
 					 bool enabled);
 
+/**
+ * @brief Set the emulator's ADC vbus register
+ *
+ * @param emulator The emulator to modify
+ * @param value The new ADC register value
+ */
+void isl923x_emul_set_adc_vbus(const struct emul *emulator,
+			       uint16_t value);
+
 #endif /* ZEPHYR_INCLUDE_EMUL_EMUL_ISL923X_H_ */
diff --git a/zephyr/test/drivers/src/isl923x.c b/zephyr/test/drivers/src/isl923x.c
index a2dd872c09..2753c12b26 100644
--- a/zephyr/test/drivers/src/isl923x.c
+++ b/zephyr/test/drivers/src/isl923x.c
@@ -537,6 +537,35 @@ static void test_discharge_on_ac(void)
 	zassert_true((reg_value & ISL923X_C1_LEARN_MODE_ENABLE) == 0, NULL);
 }
 
+static void test_get_vbus_voltage(void)
+{
+	const struct emul *isl923x_emul = ISL923X_EMUL;
+	struct i2c_emul *i2c_emul = isl923x_emul_get_i2c_emul(isl923x_emul);
+	int reg_values[] = { BIT(6),  BIT(7),  BIT(8),	BIT(9),
+			     BIT(10), BIT(11), BIT(12), BIT(13) };
+	int voltage;
+
+	/* Test fail to read the ADC vbus register */
+	i2c_common_emul_set_read_fail_reg(i2c_emul, RAA489000_REG_ADC_VBUS);
+	zassert_equal(EC_ERROR_INVAL,
+		      isl923x_drv.get_vbus_voltage(CHARGER_NUM, 0, &voltage),
+		      NULL);
+	i2c_common_emul_set_read_fail_reg(i2c_emul,
+					  I2C_COMMON_EMUL_NO_FAIL_REG);
+
+	for (int i = 0; i < ARRAY_SIZE(reg_values); ++i) {
+		int expected_voltage = (reg_values[i] >> 6) * 96;
+
+		isl923x_emul_set_adc_vbus(isl923x_emul, reg_values[i]);
+		zassert_ok(isl923x_drv.get_vbus_voltage(CHARGER_NUM, 0,
+							&voltage),
+			   NULL);
+		zassert_equal(expected_voltage, voltage,
+			      "Expected %dmV but got %dmV", expected_voltage,
+			      voltage);
+	}
+}
+
 void test_suite_isl923x(void)
 {
 	ztest_test_suite(isl923x,
@@ -553,6 +582,7 @@ void test_suite_isl923x(void)
 			 ztest_unit_test(test_set_ac_prochot),
 			 ztest_unit_test(test_set_dc_prochot),
 			 ztest_unit_test(test_comparator_inversion),
-			 ztest_unit_test(test_discharge_on_ac));
+			 ztest_unit_test(test_discharge_on_ac),
+			 ztest_unit_test(test_get_vbus_voltage));
 	ztest_run_test_suite(isl923x);
 }