zephyr: test: isl923x DC 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: I12cd413172bfdf395a1c60ef7e487b33687202bc
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3200055
Reviewed-by: Aaron Massey <aaronmassey@google.com>
Reviewed-by: Abe Levkoy <alevkoy@chromium.org>

2 files changed, 79 insertions, 1 deletions

diff --git a/zephyr/emul/emul_isl923x.c b/zephyr/emul/emul_isl923x.c
index db2a7a654a..5ee94dfaec 100644
--- a/zephyr/emul/emul_isl923x.c
+++ b/zephyr/emul/emul_isl923x.c
@@ -46,6 +46,9 @@ LOG_MODULE_REGISTER(isl923x_emul, CONFIG_ISL923X_EMUL_LOG_LEVEL);
 /** Mask used for the AC PROCHOT register */
 #define REG_PROCHOT_AC_MASK GENMASK(12, 7)
 
+/** Mask used for the DC PROCHOT register */
+#define REG_PROCHOT_DC_MASK GENMASK(13, 8)
+
 struct isl923x_emul_data {
 	/** Common I2C data */
 	struct i2c_common_emul_data common;
@@ -67,6 +70,8 @@ struct isl923x_emul_data {
 	uint16_t control_1_reg;
 	/** Emulated AC PROCHOT register */
 	uint16_t ac_prochot_reg;
+	/** Emulated DC PROCHOT register */
+	uint16_t dc_prochot_reg;
 };
 
 struct isl923x_emul_cfg {
@@ -198,6 +203,13 @@ static int isl923x_emul_read_byte(struct i2c_emul *emul, int reg, uint8_t *val,
 		else
 			*val = (uint8_t)((data->ac_prochot_reg >> 8) & 0xff);
 		break;
+	case ISL923X_REG_PROCHOT_DC:
+		__ASSERT_NO_MSG(bytes == 0 || bytes == 1);
+		if (bytes == 0)
+			*val = (uint8_t)(data->dc_prochot_reg & 0xff);
+		else
+			*val = (uint8_t)((data->dc_prochot_reg >> 8) & 0xff);
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -266,6 +278,14 @@ static int isl923x_emul_write_byte(struct i2c_emul *emul, int reg, uint8_t val,
 			data->ac_prochot_reg |= (val << 8) &
 						REG_PROCHOT_AC_MASK;
 		break;
+	case ISL923X_REG_PROCHOT_DC:
+		__ASSERT_NO_MSG(bytes == 1 || bytes == 2);
+		if (bytes == 1)
+			data->dc_prochot_reg = val & REG_PROCHOT_DC_MASK;
+		else
+			data->dc_prochot_reg |= (val << 8) &
+						REG_PROCHOT_DC_MASK;
+		break;
 	default:
 		return -EINVAL;
 	}
diff --git a/zephyr/test/drivers/src/isl923x.c b/zephyr/test/drivers/src/isl923x.c
index 99f0c8d7fa..908aa18766 100644
--- a/zephyr/test/drivers/src/isl923x.c
+++ b/zephyr/test/drivers/src/isl923x.c
@@ -26,8 +26,10 @@ BUILD_ASSERT(IS_ENABLED(CONFIG_CHARGER_ISL9238),
 
 #if CONFIG_CHARGER_SENSE_RESISTOR == 10
 #define EXPECTED_CURRENT_MA(n) (n)
+#define EXPECTED_CURRENT_REG(n) (n)
 #else
 #define EXPECTED_CURRENT_MA(n) (n * 2)
+#define EXPECTED_CURRENT_REG(n) (n / 2)
 #endif
 
 #if CONFIG_CHARGER_SENSE_RESISTOR_AC == 20
@@ -374,6 +376,61 @@ void test_set_ac_prochot(void)
 			      current_milli_amps);
 	}
 }
+void test_set_dc_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_CURRENT_MA(256),  EXPECTED_CURRENT_MA(512),
+		EXPECTED_CURRENT_MA(1024), EXPECTED_CURRENT_MA(2048),
+		EXPECTED_CURRENT_MA(4096), EXPECTED_CURRENT_MA(8192)
+	};
+	uint16_t current_milli_amps;
+
+	/* Test can't set current above max */
+	zassert_equal(EC_ERROR_INVAL,
+		      isl923x_set_dc_prochot(
+			      CHARGER_NUM, ISL923X_DC_PROCHOT_CURRENT_MAX + 1),
+		      NULL);
+
+	/* Test failed I2C write to prochot register */
+	i2c_common_emul_set_write_fail_reg(i2c_emul, ISL923X_REG_PROCHOT_DC);
+	zassert_equal(EC_ERROR_INVAL, isl923x_set_dc_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_DC;
+
+		/*
+		 * 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_DC_PROCHOT_CURRENT_MAX) {
+			continue;
+		}
+		zassert_ok(isl923x_set_dc_prochot(
+				   CHARGER_NUM, expected_current_milli_amps[i]),
+			   "Failed to set DC 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 DC prochot register");
+		zassert_equal(
+			EXPECTED_CURRENT_REG(expected_current_milli_amps[i]),
+			current_milli_amps,
+			"AC prochot expected %dmA but got %dmA",
+			EXPECTED_CURRENT_REG(expected_current_milli_amps[i]),
+			current_milli_amps);
+	}
+}
 
 void test_suite_isl923x(void)
 {
@@ -388,6 +445,7 @@ void test_suite_isl923x(void)
 			 ztest_unit_test(test_status),
 			 ztest_unit_test(test_set_mode),
 			 ztest_unit_test(test_post_init),
-			 ztest_unit_test(test_set_ac_prochot));
+			 ztest_unit_test(test_set_ac_prochot),
+			 ztest_unit_test(test_set_dc_prochot));
 	ztest_run_test_suite(isl923x);
 }