retimer: Add emulator and unit tests for ANX7452 retimer driver

BUG=b:267589042
BRANCH=none
TEST=./twister -s drivers/drivers.anx7452 -c --coverage

Change-Id: I7b4dcef7e667cd69ecb39f6dda7a6c8570177f40
Signed-off-by: Madhurima Paruchuri <mparuchuri@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/4303379
Reviewed-by: Fabio Baltieri <fabiobaltieri@google.com>

11 files changed, 700 insertions, 0 deletions

diff --git a/zephyr/emul/CMakeLists.txt b/zephyr/emul/CMakeLists.txt
index 523e1e98b0..58eef44627 100644
--- a/zephyr/emul/CMakeLists.txt
+++ b/zephyr/emul/CMakeLists.txt
@@ -7,6 +7,7 @@ add_subdirectory("tcpc")
 
 cros_ec_library_include_directories(include)
 
+zephyr_library_sources_ifdef(CONFIG_EMUL_ANX7452	emul_anx7452.c)
 zephyr_library_sources_ifdef(CONFIG_EMUL_BB_RETIMER	emul_bb_retimer.c)
 zephyr_library_sources_ifdef(CONFIG_EMUL_BC12_DETECT_PI3USB9201	emul_pi3usb9201.c)
 zephyr_library_sources_ifdef(CONFIG_EMUL_BMA255		emul_bma255.c)
diff --git a/zephyr/emul/Kconfig b/zephyr/emul/Kconfig
index b160e430b2..ecdbfb426c 100644
--- a/zephyr/emul/Kconfig
+++ b/zephyr/emul/Kconfig
@@ -190,6 +190,17 @@ config EMUL_PCT2075
 	  Enable the PCT2075 temperature sensor emulator. It uses emulated I2C bus.
 	  Emulator API is available in zephyr/include/emul/emul_pct2075.h.
 
+config EMUL_ANX7452
+	bool "ANX7452 retimer emulator"
+	default y
+	depends on ZTEST && DT_HAS_ANALOGIX_ANX7452_ENABLED
+	select EMUL_COMMON_I2C
+	help
+	  Enable the ANX7452(Analogix) retimer emulator. This driver use
+	  emulated I2C bus. It is used to test anx7452 driver. It supports
+	  reads and writes to all emulator registers. Emulators API is
+	  available in zephyr/include/emul/emul_anx7452.h
+
 config EMUL_PS8743
 	bool "PS8743 emulator"
 	default y
diff --git a/zephyr/emul/emul_anx7452.c b/zephyr/emul/emul_anx7452.c
new file mode 100644
index 0000000000..f9854d4081
--- /dev/null
+++ b/zephyr/emul/emul_anx7452.c
@@ -0,0 +1,262 @@
+/* Copyright 2023 The ChromiumOS Authors
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "driver/retimer/anx7452.h"
+#include "emul/emul_anx7452.h"
+#include "emul/emul_common_i2c.h"
+#include "emul/emul_stub_device.h"
+
+#include <zephyr/device.h>
+#include <zephyr/drivers/emul.h>
+#include <zephyr/drivers/i2c.h>
+#include <zephyr/drivers/i2c_emul.h>
+#include <zephyr/logging/log.h>
+
+#define DT_DRV_COMPAT analogix_anx7452
+
+#define LOG_LEVEL CONFIG_I2C_LOG_LEVEL
+LOG_MODULE_REGISTER(emul_anx7452);
+
+/** Run-time data used by the emulator */
+struct anx7452_emul_data {
+	/** Common I2C data */
+	struct i2c_common_emul_data top_data;
+	struct i2c_common_emul_data ctltop_data;
+
+	/** Configuration information */
+	const struct anx7452_emul_cfg *cfg;
+
+	/** Current state of all emulated ANX7452 retimer registers */
+	uint8_t top_reg;
+
+	uint8_t ctltop_cfg0_reg;
+
+	uint8_t ctltop_cfg1_reg;
+
+	uint8_t ctltop_cfg2_reg;
+};
+
+/** Constant configuration of the emulator */
+struct anx7452_emul_cfg {
+	const struct i2c_common_emul_cfg top_cfg;
+	const struct i2c_common_emul_cfg ctltop_cfg;
+};
+
+/* Workhorse for mapping i2c reg to internal emulator data access */
+static uint8_t *anx7452_emul_get_reg_ptr(struct anx7452_emul_data *data,
+					 int reg)
+{
+	switch (reg) {
+	case ANX7452_TOP_STATUS_REG:
+		return &(data->top_reg);
+	case ANX7452_CTLTOP_CFG0_REG:
+		return &(data->ctltop_cfg0_reg);
+	case ANX7452_CTLTOP_CFG1_REG:
+		return &(data->ctltop_cfg1_reg);
+	case ANX7452_CTLTOP_CFG2_REG:
+		return &(data->ctltop_cfg2_reg);
+	default:
+		__ASSERT(false, "Unimplemented Register Access Error on 0x%x",
+			 reg);
+		/* Statement never reached, required for compiler warnings */
+		return NULL;
+	}
+}
+
+/** Check description in emul_anx7452.h */
+void anx7452_emul_set_reg(const struct emul *emul, int reg, uint8_t val)
+{
+	struct anx7452_emul_data *data = emul->data;
+
+	uint8_t *reg_to_write = anx7452_emul_get_reg_ptr(data, reg);
+	*reg_to_write = val;
+}
+
+/** Check description in emul_anx7452.h */
+uint8_t anx7452_emul_get_reg(const struct emul *emul, int reg)
+{
+	struct anx7452_emul_data *data = emul->data;
+	uint8_t *reg_to_read = anx7452_emul_get_reg_ptr(data, reg);
+
+	return *reg_to_read;
+}
+
+/** Check description in emul_anx7452.h */
+void anx7452_emul_reset(const struct emul *emul)
+{
+	struct anx7452_emul_data *data;
+
+	data = emul->data;
+
+	data->top_reg = 0xFF;
+
+	data->ctltop_cfg0_reg = 0x00;
+
+	data->ctltop_cfg1_reg = 0x00;
+
+	data->ctltop_cfg2_reg = 0x00;
+}
+
+static int anx7452_emul_write_byte(const struct emul *emul, int reg,
+				   uint8_t val, int bytes)
+{
+	struct anx7452_emul_data *data = emul->data;
+
+	uint8_t *reg_to_write = anx7452_emul_get_reg_ptr(data, reg);
+	*reg_to_write = val;
+
+	return 0;
+}
+
+static int anx7452_emul_read_byte(const struct emul *emul, int reg,
+				  uint8_t *val, int bytes)
+{
+	struct anx7452_emul_data *data = emul->data;
+	uint8_t *reg_to_read = anx7452_emul_get_reg_ptr(data, reg);
+
+	*val = *reg_to_read;
+
+	return 0;
+}
+
+/**
+ * Emulate an I2C transfer for ANX7452
+ *
+ * This handles simple reads and writes
+ *
+ * @param emul I2C emulation information
+ * @param msgs List of messages to process
+ * @param num_msgs Number of messages to process
+ * @param addr Address of the I2C target device
+ *
+ * @retval 0 If successful
+ * @retval -EIO General input / output error
+ */
+static int anx7452_emul_transfer(const struct emul *emul, struct i2c_msg *msgs,
+				 int num_msgs, int addr)
+{
+	const struct anx7452_emul_cfg *cfg;
+	struct anx7452_emul_data *data;
+	struct i2c_common_emul_data *common_data;
+
+	data = emul->data;
+	cfg = emul->cfg;
+
+	if (addr == cfg->top_cfg.addr) {
+		const struct i2c_common_emul_cfg *common_cfg = &cfg->top_cfg;
+
+		common_data = &data->top_data;
+		return i2c_common_emul_transfer_workhorse(
+			emul, common_data, common_cfg, msgs, num_msgs, addr);
+	} else if (addr == cfg->ctltop_cfg.addr) {
+		const struct i2c_common_emul_cfg *common_cfg = &cfg->ctltop_cfg;
+
+		common_data = &data->ctltop_data;
+		return i2c_common_emul_transfer_workhorse(
+			emul, common_data, common_cfg, msgs, num_msgs, addr);
+	}
+
+	LOG_ERR("Cannot map address %02x", addr);
+	return -EIO;
+}
+
+/* Device instantiation */
+
+static struct i2c_emul_api anx7452_emul_api = {
+	.transfer = anx7452_emul_transfer,
+};
+
+/* Device instantiation */
+
+/**
+ * @brief Set up a new ANX7452 retimer emulator
+ *
+ * This should be called for each ANX7452 retimer device that needs to be
+ * emulated. It registers it with the I2C emulation controller.
+ *
+ * @param emul Emulation information
+ * @param parent Device to emulate
+ *
+ * @return 0 indicating success (always)
+ */
+static int anx7452_emul_init(const struct emul *emul,
+			     const struct device *parent)
+{
+	const struct anx7452_emul_cfg *cfg;
+	struct anx7452_emul_data *data;
+	int ret = 0;
+
+	data = emul->data;
+	cfg = emul->cfg;
+
+	data->top_data.emul.api = &anx7452_emul_api;
+	data->top_data.emul.addr = cfg->top_cfg.addr;
+	data->top_data.emul.target = emul;
+	data->top_data.i2c = parent;
+	data->top_data.cfg = &cfg->top_cfg;
+	i2c_common_emul_init(&data->top_data);
+
+	data->ctltop_data.emul.api = &anx7452_emul_api;
+	data->ctltop_data.emul.addr = cfg->ctltop_cfg.addr;
+	data->ctltop_data.emul.target = emul;
+	data->ctltop_data.i2c = parent;
+	data->ctltop_data.cfg = &cfg->ctltop_cfg;
+	i2c_common_emul_init(&data->ctltop_data);
+
+	ret |= i2c_emul_register(parent, &data->top_data.emul);
+	ret |= i2c_emul_register(parent, &data->ctltop_data.emul);
+
+	anx7452_emul_reset(emul);
+
+	return ret;
+}
+
+#define ANX7452_EMUL(n)                                                   \
+	static struct anx7452_emul_data anx7452_emul_data_##n = {	  \
+		.top_data = {						  \
+			.write_byte = anx7452_emul_write_byte,		  \
+			.read_byte = anx7452_emul_read_byte,		  \
+		},                                                        \
+		.ctltop_data = {					  \
+			.write_byte = anx7452_emul_write_byte,		  \
+			.read_byte = anx7452_emul_read_byte,		  \
+		},							  \
+	};     \
+	static const struct anx7452_emul_cfg anx7452_emul_cfg_##n = {	\
+		.top_cfg = {						\
+			.dev_label = DT_NODE_FULL_NAME(DT_DRV_INST(n)), \
+			.data = &anx7452_emul_data_##n.top_data,	\
+			.addr = DT_INST_REG_ADDR(n),		\
+		},							\
+		.ctltop_cfg = {						\
+			.dev_label = DT_NODE_FULL_NAME(DT_DRV_INST(n)), \
+			.data = &anx7452_emul_data_##n.ctltop_data,	\
+			.addr = ANX7452_I2C_ADDR_CTLTOP_FLAGS,		\
+		},		                                        \
+	};   \
+	EMUL_DT_INST_DEFINE(n, anx7452_emul_init, &anx7452_emul_data_##n, \
+			    &anx7452_emul_cfg_##n, &anx7452_emul_api, NULL)
+
+DT_INST_FOREACH_STATUS_OKAY(ANX7452_EMUL);
+
+DT_INST_FOREACH_STATUS_OKAY(EMUL_STUB_DEVICE);
+
+struct i2c_common_emul_data *
+emul_anx7452_get_i2c_common_data(const struct emul *emul,
+				 enum anx7452_emul_port port)
+{
+	struct anx7452_emul_data *data;
+
+	data = emul->data;
+
+	switch (port) {
+	case TOP_EMUL_PORT:
+		return &data->top_data;
+	case CTLTOP_EMUL_PORT:
+		return &data->ctltop_data;
+	default:
+		return NULL;
+	}
+}
diff --git a/zephyr/include/emul/emul_anx7452.h b/zephyr/include/emul/emul_anx7452.h
new file mode 100644
index 0000000000..455958f664
--- /dev/null
+++ b/zephyr/include/emul/emul_anx7452.h
@@ -0,0 +1,81 @@
+/* Copyright 2023 The ChromiumOS Authors
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/**
+ * @file
+ *
+ * @brief Backend API for ANX7452 retimer emulator
+ */
+
+#ifndef __EMUL_ANX7452_H
+#define __EMUL_ANX7452_H
+
+#include <zephyr/drivers/emul.h>
+#include <zephyr/drivers/i2c.h>
+#include <zephyr/drivers/i2c_emul.h>
+
+/** Types of "hidden" I2C devices */
+enum anx7452_emul_port {
+	TOP_EMUL_PORT,
+	CTLTOP_EMUL_PORT,
+};
+
+/**
+ * @brief ANX7452 retimer emulator backend API
+ * @defgroup anx7452_emul ANX7452 retimer emulator
+ * @{
+ *
+ * ANX7452 retimer emulator supports access to all its registers using I2C
+ * messages. Application may alter emulator state:
+ *
+ * - call @ref anx7452_emul_set_reg and @ref anx7452_emul_get_reg to set and get
+ * value of ANX7452 retimers registers
+ * - call anx7452_emul_set_err_* to change emulator behaviour on inadvisable
+ * driver behaviour
+ * - call functions from emul_common_i2c.h to setup custom handlers for I2C
+ *   messages
+ */
+
+/**
+ * @brief Set value of given register of ANX7452 retimer
+ *
+ * @param emul Pointer to ANX7452 retimer emulator
+ * @param reg Register address which value will be changed
+ * @param val New value of the register
+ */
+void anx7452_emul_set_reg(const struct emul *emul, int reg, uint8_t val);
+
+/**
+ * @brief Get value of given register of ANX7452 retimer
+ *
+ * @param emul Pointer to ANX7452 retimer emulator
+ * @param reg Register address
+ *
+ * @return Value of the register
+ */
+uint8_t anx7452_emul_get_reg(const struct emul *emul, int reg);
+
+/**
+ * @brief Reset the anx7452 emulator
+ *
+ * @param emul The emulator to reset
+ */
+void anx7452_emul_reset(const struct emul *emul);
+
+/**
+ * @brief Returns pointer to i2c_common_emul_data for given emul
+ *
+ * @param emul Pointer to anx7452 retimer emulator
+ * @return Pointer to i2c_common_emul_data for emul argument
+ */
+struct i2c_common_emul_data *
+emul_anx7452_get_i2c_common_data(const struct emul *emul,
+				 enum anx7452_emul_port port);
+
+/**
+ * @}
+ */
+
+#endif /* __EMUL_ANX7452 */
diff --git a/zephyr/test/drivers/CMakeLists.txt b/zephyr/test/drivers/CMakeLists.txt
index 2d7fc8a56b..2b2688ce4d 100644
--- a/zephyr/test/drivers/CMakeLists.txt
+++ b/zephyr/test/drivers/CMakeLists.txt
@@ -73,6 +73,7 @@ add_subdirectory_ifdef(CONFIG_LINK_TEST_SUITE_LED_COMMON led_common)
 add_subdirectory_ifdef(CONFIG_LINK_TEST_SUITE_PS8XXX ps8xxx)
 add_subdirectory_ifdef(CONFIG_LINK_TEST_SUITE_GPIO_UNHOOK gpio_unhook)
 add_subdirectory_ifdef(CONFIG_LINK_TEST_SUITE_HOST_COMMAND_MEMORY_DUMP host_command_memory_dump)
+add_subdirectory_ifdef(CONFIG_LINK_TEST_SUITE_ANX7452 anx7452)
 
 get_target_property(TEST_SOURCES_NEW app SOURCES)
 
diff --git a/zephyr/test/drivers/Kconfig b/zephyr/test/drivers/Kconfig
index 256e086bd4..726859068f 100644
--- a/zephyr/test/drivers/Kconfig
+++ b/zephyr/test/drivers/Kconfig
@@ -236,4 +236,10 @@ config LINK_TEST_SUITE_LED_COMMON
 config LINK_TEST_SUITE_HOST_COMMAND_MEMORY_DUMP
 	bool "Link and test memory dump host commands tests"
 
+config LINK_TEST_SUITE_ANX7452
+	bool "Link and test the anx7452 tests"
+	help
+	  Include the test suite of ANX7452 retimer in the binary. The tests
+	  use I2C emulation.
+
 source "Kconfig.zephyr"
diff --git a/zephyr/test/drivers/anx7452/CMakeLists.txt b/zephyr/test/drivers/anx7452/CMakeLists.txt
new file mode 100644
index 0000000000..a61fa0a1c6
--- /dev/null
+++ b/zephyr/test/drivers/anx7452/CMakeLists.txt
@@ -0,0 +1,6 @@
+# Copyright 2023 The ChromiumOS Authors
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# Add source files
+target_sources(app PRIVATE src/anx7452.c)
diff --git a/zephyr/test/drivers/anx7452/prj.conf b/zephyr/test/drivers/anx7452/prj.conf
new file mode 100644
index 0000000000..96bb372274
--- /dev/null
+++ b/zephyr/test/drivers/anx7452/prj.conf
@@ -0,0 +1,3 @@
+# Copyright 2023 The ChromiumOS Authors
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
diff --git a/zephyr/test/drivers/anx7452/src/anx7452.c b/zephyr/test/drivers/anx7452/src/anx7452.c
new file mode 100644
index 0000000000..f456dea845
--- /dev/null
+++ b/zephyr/test/drivers/anx7452/src/anx7452.c
@@ -0,0 +1,288 @@
+/* Copyright 2023 The ChromiumOS Authors
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "chipset.h"
+#include "common.h"
+#include "console.h"
+#include "driver/retimer/anx7452.h"
+#include "driver/retimer/anx7452_public.h"
+#include "emul/emul_anx7452.h"
+#include "emul/emul_common_i2c.h"
+#include "i2c.h"
+#include "test/drivers/stubs.h"
+#include "test/drivers/test_mocks.h"
+#include "test/drivers/test_state.h"
+#include "timer.h"
+#include "usb_mux.h"
+
+#include <zephyr/device.h>
+#include <zephyr/devicetree.h>
+#include <zephyr/drivers/emul.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/drivers/gpio/gpio_emul.h>
+#include <zephyr/fff.h>
+#include <zephyr/kernel.h>
+#include <zephyr/ztest.h>
+
+#define GPIO_USB_C1_USB_EN_PATH NAMED_GPIOS_GPIO_NODE(usb_c1_ls_en)
+#define GPIO_USB_C1_USB_EN_PORT DT_GPIO_PIN(GPIO_USB_C1_USB_EN_PATH, gpios)
+#define GPIO_USB_C1_DP_EN_PATH NAMED_GPIOS_GPIO_NODE(usb_c1_rt_rst_odl)
+#define GPIO_USB_C1_DP_EN_PORT DT_GPIO_PIN(GPIO_USB_C1_DP_EN_PATH, gpios)
+
+#define ANX7452_NODE DT_NODELABEL(usb_c1_anx7452_emul)
+#define EMUL EMUL_DT_GET(ANX7452_NODE)
+#define COMMON_DATA(port) emul_anx7452_get_i2c_common_data(EMUL, port)
+
+ZTEST(anx7452, test_anx7452_init)
+{
+	const struct device *gpio_dev =
+		DEVICE_DT_GET(DT_GPIO_CTLR(GPIO_USB_C1_USB_EN_PATH, gpios));
+
+	zassert_not_null(gpio_dev, "Cannot get GPIO device");
+
+	/* Test successful init */
+	zassert_equal(anx7452_emul_get_reg(EMUL, ANX7452_TOP_STATUS_REG), 0xFF,
+		      NULL);
+	zassert_equal(
+		EC_SUCCESS,
+		anx7452_usb_retimer_driver.init(usb_muxes[USBC_PORT_C1].mux),
+		NULL);
+	zassert_equal(anx7452_emul_get_reg(EMUL, ANX7452_TOP_STATUS_REG),
+		      ANX7452_TOP_REG_EN, NULL);
+	zassert_equal(1,
+		      gpio_emul_output_get(gpio_dev, GPIO_USB_C1_USB_EN_PORT),
+		      NULL);
+
+	/* Setup emulator fail on write */
+	i2c_common_emul_set_write_fail_reg(COMMON_DATA(TOP_EMUL_PORT),
+					   ANX7452_TOP_STATUS_REG);
+	/* With reg read fail, init should fail and pins should be unset */
+	zassert_equal(
+		EC_ERROR_INVAL,
+		anx7452_usb_retimer_driver.init(usb_muxes[USBC_PORT_C1].mux),
+		NULL);
+	zassert_equal(1,
+		      gpio_emul_output_get(gpio_dev, GPIO_USB_C1_USB_EN_PORT),
+		      NULL);
+
+	/* Do not fail on write */
+	i2c_common_emul_set_write_fail_reg(COMMON_DATA(TOP_EMUL_PORT),
+					   I2C_COMMON_EMUL_NO_FAIL_REG);
+	/* Setup emulator fail on read */
+	i2c_common_emul_set_read_fail_reg(COMMON_DATA(TOP_EMUL_PORT),
+					  ANX7452_TOP_STATUS_REG);
+	/* With reg read fail, init should fail and pins should be unset */
+	zassert_equal(
+		EC_ERROR_TIMEOUT,
+		anx7452_usb_retimer_driver.init(usb_muxes[USBC_PORT_C1].mux),
+		NULL);
+	zassert_equal(1,
+		      gpio_emul_output_get(gpio_dev, GPIO_USB_C1_USB_EN_PORT),
+		      NULL);
+
+	/* Do not fail on read */
+	i2c_common_emul_set_read_fail_reg(COMMON_DATA(TOP_EMUL_PORT),
+					  I2C_COMMON_EMUL_NO_FAIL_REG);
+	/* Setup emulator fail on read */
+	i2c_common_emul_set_read_fail_reg(COMMON_DATA(TOP_EMUL_PORT),
+					  ANX7452_TOP_STATUS_REG);
+	const uint32_t start_ms = k_uptime_get();
+	/* With reg read fail, init should fail and pins should be unset */
+	zassert_equal(
+		EC_ERROR_TIMEOUT,
+		anx7452_usb_retimer_driver.init(usb_muxes[USBC_PORT_C1].mux),
+		NULL);
+	const uint32_t end_ms = k_uptime_get();
+	/* With timeout caused by read fail, the time took should be greater
+	 * than or equal to configured timeout value
+	 */
+	zassert_true((end_ms - start_ms) >= ANX7452_I2C_WAKE_TIMEOUT_MS, NULL);
+	zassert_equal(1,
+		      gpio_emul_output_get(gpio_dev, GPIO_USB_C1_USB_EN_PORT),
+		      NULL);
+}
+
+ZTEST(anx7452, test_anx7452_get)
+{
+	mux_state_t mux_state = 0;
+
+	zassert_equal(EC_SUCCESS,
+		      anx7452_usb_retimer_driver.get(
+			      usb_muxes[USBC_PORT_C1].mux, &mux_state));
+
+	anx7452_emul_set_reg(EMUL, ANX7452_TOP_STATUS_REG,
+			     ANX7452_TOP_REG_EN | ANX7452_TOP_FLIP_INFO);
+	zassert_equal(EC_SUCCESS,
+		      anx7452_usb_retimer_driver.get(
+			      usb_muxes[USBC_PORT_C1].mux, &mux_state));
+	zassert_equal(mux_state, USB_PD_MUX_POLARITY_INVERTED);
+
+	anx7452_emul_set_reg(EMUL, ANX7452_TOP_STATUS_REG,
+			     ANX7452_TOP_REG_EN | ANX7452_TOP_DP_INFO);
+	zassert_equal(EC_SUCCESS,
+		      anx7452_usb_retimer_driver.get(
+			      usb_muxes[USBC_PORT_C1].mux, &mux_state));
+	zassert_equal(mux_state, USB_PD_MUX_DP_ENABLED);
+
+	anx7452_emul_set_reg(EMUL, ANX7452_TOP_STATUS_REG,
+			     ANX7452_TOP_REG_EN | ANX7452_TOP_TBT_INFO);
+	zassert_equal(EC_SUCCESS,
+		      anx7452_usb_retimer_driver.get(
+			      usb_muxes[USBC_PORT_C1].mux, &mux_state));
+	zassert_equal(mux_state, USB_PD_MUX_TBT_COMPAT_ENABLED);
+
+	anx7452_emul_set_reg(EMUL, ANX7452_TOP_STATUS_REG,
+			     ANX7452_TOP_REG_EN | ANX7452_TOP_USB3_INFO);
+	zassert_equal(EC_SUCCESS,
+		      anx7452_usb_retimer_driver.get(
+			      usb_muxes[USBC_PORT_C1].mux, &mux_state));
+	zassert_equal(mux_state, USB_PD_MUX_USB_ENABLED);
+
+	anx7452_emul_set_reg(EMUL, ANX7452_TOP_STATUS_REG,
+			     ANX7452_TOP_REG_EN | ANX7452_TOP_USB4_INFO);
+	zassert_equal(EC_SUCCESS,
+		      anx7452_usb_retimer_driver.get(
+			      usb_muxes[USBC_PORT_C1].mux, &mux_state));
+	zassert_equal(mux_state, USB_PD_MUX_USB4_ENABLED);
+
+	i2c_common_emul_set_read_fail_reg(COMMON_DATA(TOP_EMUL_PORT),
+					  ANX7452_TOP_STATUS_REG);
+	zassert_equal(EC_ERROR_INVAL,
+		      anx7452_usb_retimer_driver.get(
+			      usb_muxes[USBC_PORT_C1].mux, &mux_state));
+}
+
+ZTEST(anx7452, test_anx7452_set)
+{
+	mux_state_t mux_state = 0;
+	bool ack_required;
+
+	zassert_equal(EC_SUCCESS, anx7452_usb_retimer_driver.set(
+					  usb_muxes[USBC_PORT_C1].mux,
+					  mux_state, &ack_required));
+	zassert_equal(ack_required, false);
+
+	zassert_equal(anx7452_emul_get_reg(EMUL, ANX7452_CTLTOP_CFG0_REG), 0);
+	zassert_equal(EC_SUCCESS,
+		      anx7452_usb_retimer_driver.set(
+			      usb_muxes[USBC_PORT_C1].mux,
+			      USB_PD_MUX_POLARITY_INVERTED, &ack_required));
+	zassert_equal(anx7452_emul_get_reg(EMUL, ANX7452_CTLTOP_CFG0_REG),
+		      ANX7452_CTLTOP_CFG0_FLIP_EN);
+
+	zassert_equal(EC_SUCCESS,
+		      anx7452_usb_retimer_driver.set(
+			      usb_muxes[USBC_PORT_C1].mux,
+			      USB_PD_MUX_USB_ENABLED, &ack_required));
+	zassert_equal(anx7452_emul_get_reg(EMUL, ANX7452_CTLTOP_CFG0_REG),
+		      ANX7452_CTLTOP_CFG0_USB3_EN);
+
+	zassert_equal(anx7452_emul_get_reg(EMUL, ANX7452_CTLTOP_CFG1_REG), 0);
+	zassert_equal(EC_SUCCESS,
+		      anx7452_usb_retimer_driver.set(
+			      usb_muxes[USBC_PORT_C1].mux,
+			      USB_PD_MUX_DP_ENABLED, &ack_required));
+	zassert_equal(anx7452_emul_get_reg(EMUL, ANX7452_CTLTOP_CFG1_REG),
+		      ANX7452_CTLTOP_CFG1_DP_EN);
+
+	zassert_equal(anx7452_emul_get_reg(EMUL, ANX7452_CTLTOP_CFG2_REG), 0);
+	zassert_equal(EC_SUCCESS,
+		      anx7452_usb_retimer_driver.set(
+			      usb_muxes[USBC_PORT_C1].mux,
+			      USB_PD_MUX_USB4_ENABLED, &ack_required));
+	zassert_equal(anx7452_emul_get_reg(EMUL, ANX7452_CTLTOP_CFG2_REG),
+		      ANX7452_CTLTOP_CFG2_USB4_EN);
+
+	zassert_equal(EC_SUCCESS,
+		      anx7452_usb_retimer_driver.set(
+			      usb_muxes[USBC_PORT_C1].mux,
+			      USB_PD_MUX_TBT_COMPAT_ENABLED, &ack_required));
+	zassert_equal(anx7452_emul_get_reg(EMUL, ANX7452_CTLTOP_CFG2_REG),
+		      ANX7452_CTLTOP_CFG2_TBT_EN);
+
+	i2c_common_emul_set_read_fail_reg(COMMON_DATA(CTLTOP_EMUL_PORT),
+					  I2C_COMMON_EMUL_NO_FAIL_REG);
+	i2c_common_emul_set_read_fail_reg(COMMON_DATA(CTLTOP_EMUL_PORT),
+					  ANX7452_CTLTOP_CFG0_REG);
+	zassert_equal(EC_ERROR_INVAL, anx7452_usb_retimer_driver.set(
+					      usb_muxes[USBC_PORT_C1].mux,
+					      mux_state, &ack_required));
+
+	i2c_common_emul_set_read_fail_reg(COMMON_DATA(CTLTOP_EMUL_PORT),
+					  I2C_COMMON_EMUL_NO_FAIL_REG);
+	i2c_common_emul_set_read_fail_reg(COMMON_DATA(CTLTOP_EMUL_PORT),
+					  ANX7452_CTLTOP_CFG1_REG);
+	zassert_equal(EC_ERROR_INVAL, anx7452_usb_retimer_driver.set(
+					      usb_muxes[USBC_PORT_C1].mux,
+					      mux_state, &ack_required));
+
+	i2c_common_emul_set_read_fail_reg(COMMON_DATA(CTLTOP_EMUL_PORT),
+					  I2C_COMMON_EMUL_NO_FAIL_REG);
+	i2c_common_emul_set_read_fail_reg(COMMON_DATA(CTLTOP_EMUL_PORT),
+					  ANX7452_CTLTOP_CFG2_REG);
+	zassert_equal(EC_ERROR_INVAL, anx7452_usb_retimer_driver.set(
+					      usb_muxes[USBC_PORT_C1].mux,
+					      mux_state, &ack_required));
+
+	i2c_common_emul_set_read_fail_reg(COMMON_DATA(CTLTOP_EMUL_PORT),
+					  I2C_COMMON_EMUL_NO_FAIL_REG);
+	i2c_common_emul_set_write_fail_reg(COMMON_DATA(CTLTOP_EMUL_PORT),
+					   ANX7452_CTLTOP_CFG0_REG);
+	zassert_equal(EC_ERROR_TIMEOUT, anx7452_usb_retimer_driver.set(
+						usb_muxes[USBC_PORT_C1].mux,
+						mux_state, &ack_required));
+
+	i2c_common_emul_set_write_fail_reg(COMMON_DATA(CTLTOP_EMUL_PORT),
+					   I2C_COMMON_EMUL_NO_FAIL_REG);
+	i2c_common_emul_set_write_fail_reg(COMMON_DATA(CTLTOP_EMUL_PORT),
+					   ANX7452_CTLTOP_CFG1_REG);
+	zassert_equal(EC_ERROR_TIMEOUT, anx7452_usb_retimer_driver.set(
+						usb_muxes[USBC_PORT_C1].mux,
+						mux_state, &ack_required));
+
+	i2c_common_emul_set_write_fail_reg(COMMON_DATA(CTLTOP_EMUL_PORT),
+					   I2C_COMMON_EMUL_NO_FAIL_REG);
+	i2c_common_emul_set_write_fail_reg(COMMON_DATA(CTLTOP_EMUL_PORT),
+					   ANX7452_CTLTOP_CFG2_REG);
+	zassert_equal(EC_ERROR_TIMEOUT, anx7452_usb_retimer_driver.set(
+						usb_muxes[USBC_PORT_C1].mux,
+						mux_state, &ack_required));
+}
+
+static inline void reset_anx7452_state(void)
+{
+	i2c_common_emul_set_write_func(COMMON_DATA(TOP_EMUL_PORT), NULL, NULL);
+	i2c_common_emul_set_read_func(COMMON_DATA(TOP_EMUL_PORT), NULL, NULL);
+	i2c_common_emul_set_write_fail_reg(COMMON_DATA(TOP_EMUL_PORT),
+					   I2C_COMMON_EMUL_NO_FAIL_REG);
+	i2c_common_emul_set_read_fail_reg(COMMON_DATA(TOP_EMUL_PORT),
+					  I2C_COMMON_EMUL_NO_FAIL_REG);
+
+	i2c_common_emul_set_write_func(COMMON_DATA(CTLTOP_EMUL_PORT), NULL,
+				       NULL);
+	i2c_common_emul_set_read_func(COMMON_DATA(CTLTOP_EMUL_PORT), NULL,
+				      NULL);
+	i2c_common_emul_set_write_fail_reg(COMMON_DATA(CTLTOP_EMUL_PORT),
+					   I2C_COMMON_EMUL_NO_FAIL_REG);
+	i2c_common_emul_set_read_fail_reg(COMMON_DATA(CTLTOP_EMUL_PORT),
+					  I2C_COMMON_EMUL_NO_FAIL_REG);
+
+	anx7452_emul_reset(EMUL);
+}
+
+static void anx7452_before(void *state)
+{
+	ARG_UNUSED(state);
+	reset_anx7452_state();
+}
+
+static void anx7452_after(void *state)
+{
+	ARG_UNUSED(state);
+	reset_anx7452_state();
+}
+
+ZTEST_SUITE(anx7452, drivers_predicate_post_main, NULL, anx7452_before,
+	    anx7452_after, NULL);
diff --git a/zephyr/test/drivers/anx7452/usbc.dts b/zephyr/test/drivers/anx7452/usbc.dts
new file mode 100644
index 0000000000..3441cf842f
--- /dev/null
+++ b/zephyr/test/drivers/anx7452/usbc.dts
@@ -0,0 +1,32 @@
+/* Copyright 2023 The ChromiumOS Authors
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <dt-bindings/usb_pd_tcpm.h>
+
+/ {
+	usbc {
+		port1@1 {
+			compatible = "named-usbc-port";
+			reg = <1>;
+			usb-mux-chain-1 {
+				compatible = "cros-ec,usb-mux-chain";
+				usb-muxes = <&usb_c1_anx7452_emul>;
+			};
+		};
+	};
+
+};
+&i2c3 {
+	status = "okay";
+
+	/delete-node/ bbretimer@42;
+
+	usb_c1_anx7452_emul: anx7452@10 {
+		compatible = "analogix,anx7452";
+		reg = <0x10>;
+		usb-en-pin = <&usb_c1_ls_en>;
+		dp-en-pin = <&usb_c1_rt_rst_odl>;
+	};
+};
diff --git a/zephyr/test/drivers/testcase.yaml b/zephyr/test/drivers/testcase.yaml
index d4c6fc7e75..dbae8be1e2 100644
--- a/zephyr/test/drivers/testcase.yaml
+++ b/zephyr/test/drivers/testcase.yaml
@@ -462,3 +462,12 @@ tests:
     - CONFIG_LINK_TEST_SUITE_HOST_COMMAND_MEMORY_DUMP=y
     - CONFIG_PLATFORM_EC_HOST_COMMAND_MEMORY_DUMP=y
     - CONFIG_PLATFORM_EC_KEYBOARD_PROTOCOL_8042=y
+  drivers.anx7452:
+    extra_conf_files:
+    - prj.conf
+    - anx7452/prj.conf
+    extra_dtc_overlay_files:
+    - boards/native_posix.overlay
+    - anx7452/usbc.dts
+    extra_configs:
+    - CONFIG_LINK_TEST_SUITE_ANX7452=y