zephyr: test: isl923x AC prochot

Verify setting the prochot amps as well as edge conditions

BRANCH=none
BUG=b:201602829
TEST=zmake configure --test zephyr/test/drivers

Signed-off-by: Yuval Peress <peress@google.com>
Change-Id: I306adf1d74eea65a8522c61e5ed71cf8deacfe2a
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3200054
Reviewed-by: Wai-Hong Tam <waihong@google.com>

3 files changed, 103 insertions, 2 deletions

diff --git a/zephyr/emul/emul_isl923x.c b/zephyr/emul/emul_isl923x.c
index b4ab16ce68..db2a7a654a 100644
--- a/zephyr/emul/emul_isl923x.c
+++ b/zephyr/emul/emul_isl923x.c
@@ -43,6 +43,9 @@ LOG_MODULE_REGISTER(isl923x_emul, CONFIG_ISL923X_EMUL_LOG_LEVEL);
 /** Mask used for the control 1 register */
 #define REG_CONTROL1_MASK (GENMASK(15, 8) | GENMASK(6, 0))
 
+/** Mask used for the AC PROCHOT register */
+#define REG_PROCHOT_AC_MASK GENMASK(12, 7)
+
 struct isl923x_emul_data {
 	/** Common I2C data */
 	struct i2c_common_emul_data common;
@@ -62,6 +65,8 @@ struct isl923x_emul_data {
 	uint16_t control_0_reg;
 	/** Emulated control 1 register */
 	uint16_t control_1_reg;
+	/** Emulated AC PROCHOT register */
+	uint16_t ac_prochot_reg;
 };
 
 struct isl923x_emul_cfg {
@@ -69,6 +74,13 @@ struct isl923x_emul_cfg {
 	const struct i2c_common_emul_cfg common;
 };
 
+const struct device *isl923x_emul_get_parent(const struct emul *emulator)
+{
+	struct isl923x_emul_data *data = emulator->data;
+
+	return data->common.i2c;
+}
+
 struct i2c_emul *isl923x_emul_get_i2c_emul(const struct emul *emulator)
 {
 	struct isl923x_emul_data *data = emulator->data;
@@ -179,6 +191,13 @@ static int isl923x_emul_read_byte(struct i2c_emul *emul, int reg, uint8_t *val,
 		else
 			*val = (uint8_t)((data->control_1_reg >> 8) & 0xff);
 		break;
+	case ISL923X_REG_PROCHOT_AC:
+		__ASSERT_NO_MSG(bytes == 0 || bytes == 1);
+		if (bytes == 0)
+			*val = (uint8_t)(data->ac_prochot_reg & 0xff);
+		else
+			*val = (uint8_t)((data->ac_prochot_reg >> 8) & 0xff);
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -239,6 +258,14 @@ static int isl923x_emul_write_byte(struct i2c_emul *emul, int reg, uint8_t val,
 		else
 			data->control_1_reg |= (val << 8) & REG_CONTROL1_MASK;
 		break;
+	case ISL923X_REG_PROCHOT_AC:
+		__ASSERT_NO_MSG(bytes == 1 || bytes == 2);
+		if (bytes == 1)
+			data->ac_prochot_reg = val & REG_PROCHOT_AC_MASK;
+		else
+			data->ac_prochot_reg |= (val << 8) &
+						REG_PROCHOT_AC_MASK;
+		break;
 	default:
 		return -EINVAL;
 	}
diff --git a/zephyr/include/emul/emul_isl923x.h b/zephyr/include/emul/emul_isl923x.h
index 8b34f7b519..d43917a45b 100644
--- a/zephyr/include/emul/emul_isl923x.h
+++ b/zephyr/include/emul/emul_isl923x.h
@@ -6,8 +6,17 @@
 #ifndef ZEPHYR_INCLUDE_EMUL_EMUL_ISL923X_H_
 #define ZEPHYR_INCLUDE_EMUL_EMUL_ISL923X_H_
 
-#include <emul.h>
+#include <device.h>
 #include <drivers/i2c_emul.h>
+#include <emul.h>
+
+/**
+ * @brief Get the emulator's parent bus device
+ *
+ * @param emulator The emulator to look-up
+ * @return Pointer to the bus connecting to the emulator
+ */
+const struct device *isl923x_emul_get_parent(const struct emul *emulator);
 
 /**
  * @brief Get the I2C emulator struct
diff --git a/zephyr/test/drivers/src/isl923x.c b/zephyr/test/drivers/src/isl923x.c
index ecb4435306..99f0c8d7fa 100644
--- a/zephyr/test/drivers/src/isl923x.c
+++ b/zephyr/test/drivers/src/isl923x.c
@@ -32,8 +32,10 @@ BUILD_ASSERT(IS_ENABLED(CONFIG_CHARGER_ISL9238),
 
 #if CONFIG_CHARGER_SENSE_RESISTOR_AC == 20
 #define EXPECTED_INPUT_CURRENT_MA(n) (n)
+#define EXPECTED_INPUT_CURRENT_REG(n) (n)
 #else
 #define EXPECTED_INPUT_CURRENT_MA(n) (n * 2)
+#define EXPECTED_INPUT_CURRENT_REG(n) (n / 2)
 #endif
 
 #define CHARGER_NUM get_charger_num(&isl923x_drv)
@@ -311,6 +313,68 @@ void test_post_init(void)
 	zassert_ok(isl923x_drv.post_init(CHARGER_NUM), NULL);
 }
 
+void test_set_ac_prochot(void)
+{
+	const struct emul *isl923x_emul = ISL923X_EMUL;
+	const struct device *i2c_dev = isl923x_emul_get_parent(isl923x_emul);
+	struct i2c_emul *i2c_emul = isl923x_emul_get_i2c_emul(isl923x_emul);
+	uint16_t expected_current_milli_amps[] = {
+		EXPECTED_INPUT_CURRENT_MA(0),
+		EXPECTED_INPUT_CURRENT_MA(128),
+		EXPECTED_INPUT_CURRENT_MA(256),
+		EXPECTED_INPUT_CURRENT_MA(512),
+		EXPECTED_INPUT_CURRENT_MA(1024),
+		EXPECTED_INPUT_CURRENT_MA(2048),
+		EXPECTED_INPUT_CURRENT_MA(4096)
+	};
+	uint16_t current_milli_amps;
+
+	/* Test can't set current above max */
+	zassert_equal(EC_ERROR_INVAL,
+		      isl923x_set_ac_prochot(
+			      CHARGER_NUM, ISL923X_AC_PROCHOT_CURRENT_MAX + 1),
+		      NULL);
+
+	/* Test failed I2C write to prochot register */
+	i2c_common_emul_set_write_fail_reg(i2c_emul, ISL923X_REG_PROCHOT_AC);
+	zassert_equal(EC_ERROR_INVAL, isl923x_set_ac_prochot(CHARGER_NUM, 0),
+		      NULL);
+
+	/* Clear write fail reg */
+	i2c_common_emul_set_write_fail_reg(i2c_emul,
+					   I2C_COMMON_EMUL_NO_FAIL_REG);
+
+	for (int i = 0; i < ARRAY_SIZE(expected_current_milli_amps); ++i) {
+		uint8_t reg_addr = ISL923X_REG_PROCHOT_AC;
+
+		/*
+		 * Due to resistor multiplying the current, the upper end of the
+		 * test data might be out of bounds (which is already tested
+		 * above). Skip the test.
+		 */
+		if (expected_current_milli_amps[i] >
+		    ISL923X_AC_PROCHOT_CURRENT_MAX) {
+			continue;
+		}
+
+		zassert_ok(isl923x_set_ac_prochot(
+				   CHARGER_NUM, expected_current_milli_amps[i]),
+			   "Failed to set AC prochot to %dmA",
+			   expected_current_milli_amps[i]);
+		zassert_ok(i2c_write_read(i2c_dev, i2c_emul->addr, &reg_addr,
+					  sizeof(reg_addr), &current_milli_amps,
+					  sizeof(current_milli_amps)),
+			   "Failed to read AC prochot register");
+		zassert_equal(EXPECTED_INPUT_CURRENT_REG(
+				      expected_current_milli_amps[i]),
+			      current_milli_amps,
+			      "AC prochot expected %dmA but got %dmA",
+			      EXPECTED_INPUT_CURRENT_REG(
+				      expected_current_milli_amps[i]),
+			      current_milli_amps);
+	}
+}
+
 void test_suite_isl923x(void)
 {
 	ztest_test_suite(isl923x,
@@ -323,6 +387,7 @@ void test_suite_isl923x(void)
 			 ztest_unit_test(test_get_info),
 			 ztest_unit_test(test_status),
 			 ztest_unit_test(test_set_mode),
-			 ztest_unit_test(test_post_init));
+			 ztest_unit_test(test_post_init),
+			 ztest_unit_test(test_set_ac_prochot));
 	ztest_run_test_suite(isl923x);
 }