zephyr: test: Add tests for lis2dw12 driver

Add a single test for the lis2dw12 driver that checks the who-am-i
register.

BRANCH=none
BUG=b:200046770
TEST=zmake configure --test zephyr/test/drivers

Signed-off-by: Yuval Peress <peress@chromium.org>
Change-Id: I8dba62f941d74cca025645b81512b4e0c9e04908
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3168035
Tested-by: Yuval Peress <peress@google.com>
Reviewed-by: Jeremy Bettis <jbettis@chromium.org>
Commit-Queue: Yuval Peress <peress@google.com>

4 files changed, 115 insertions, 0 deletions

diff --git a/zephyr/emul/emul_lis2dw12.c b/zephyr/emul/emul_lis2dw12.c
index e775bdbb20..07d405bfc5 100644
--- a/zephyr/emul/emul_lis2dw12.c
+++ b/zephyr/emul/emul_lis2dw12.c
@@ -20,9 +20,15 @@
 #include <logging/log.h>
 LOG_MODULE_REGISTER(lis2dw12_emul, CONFIG_LIS2DW12_EMUL_LOG_LEVEL);
 
+#define LIS2DW12_DATA_FROM_I2C_EMUL(_emul)                                   \
+	CONTAINER_OF(CONTAINER_OF(_emul, struct i2c_common_emul_data, emul), \
+		     struct lis2dw12_emul_data, common)
+
 struct lis2dw12_emul_data {
 	/** Common I2C data */
 	struct i2c_common_emul_data common;
+	/** Emulated who-am-i register */
+	uint8_t who_am_i_reg;
 };
 
 struct lis2dw12_emul_cfg {
@@ -30,6 +36,50 @@ struct lis2dw12_emul_cfg {
 	struct i2c_common_emul_cfg common;
 };
 
+void lis2dw12_emul_reset(const struct emul *emul)
+{
+	struct lis2dw12_emul_data *data = emul->data;
+
+	data->who_am_i_reg = LIS2DW12_WHO_AM_I;
+}
+
+void lis2dw12_emul_set_who_am_i(const struct emul *emul, uint8_t who_am_i)
+{
+	struct lis2dw12_emul_data *data = emul->data;
+
+	data->who_am_i_reg = who_am_i;
+}
+
+static int lis2dw12_emul_read_byte(struct i2c_emul *emul, int reg, uint8_t *val,
+				   int bytes)
+{
+	struct lis2dw12_emul_data *data = LIS2DW12_DATA_FROM_I2C_EMUL(emul);
+
+	LOG_ERR("read_byte(reg=%d)", reg);
+	switch (reg) {
+	case LIS2DW12_WHO_AM_I_REG:
+		__ASSERT_NO_MSG(bytes == 0);
+		*val = data->who_am_i_reg;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int lis2dw12_emul_write_byte(struct i2c_emul *emul, int reg, uint8_t val,
+				    int bytes)
+{
+	switch (reg) {
+	case LIS2DW12_WHO_AM_I_REG:
+		LOG_ERR("Can't write to who-am-i register");
+		return -EINVAL;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
 static struct i2c_emul_api lis2dw12_emul_api_i2c = {
 	.transfer = i2c_common_emul_transfer,
 };
@@ -54,6 +104,8 @@ static int emul_lis2dw12_init(const struct emul *emul,
 #define INIT_LIS2DW12(n)                                                  \
 	static struct lis2dw12_emul_data lis2dw12_emul_data_##n = {       \
 		.common = {                                               \
+			.write_byte = lis2dw12_emul_write_byte,           \
+			.read_byte = lis2dw12_emul_read_byte,             \
 		},                                                        \
 	};                                                                \
 	static const struct lis2dw12_emul_cfg lis2dw12_emul_cfg_##n = {   \
diff --git a/zephyr/include/emul/emul_lis2dw12.h b/zephyr/include/emul/emul_lis2dw12.h
index ce34887da8..7433d27bfd 100644
--- a/zephyr/include/emul/emul_lis2dw12.h
+++ b/zephyr/include/emul/emul_lis2dw12.h
@@ -6,4 +6,24 @@
 #ifndef ZEPHYR_INCLUDE_EMUL_EMUL_LIS2DW12_H_
 #define ZEPHYR_INCLUDE_EMUL_EMUL_LIS2DW12_H_
 
+#include <emul.h>
+
+/**
+ * @brief Reset the state of the lis2dw12 emulator.
+ *
+ * @param emul The emulator to reset.
+ */
+void lis2dw12_emul_reset(const struct emul *emul);
+
+/**
+ * @brief Set the who-am-i register value.
+ *
+ * By default the who-am-i register holds LIS2DW12_WHO_AM_I, this function
+ * enables overriding that value in order to drive testing.
+ *
+ * @param emul The emulator to modify.
+ * @param who_am_i The new who-am-i register value.
+ */
+void lis2dw12_emul_set_who_am_i(const struct emul *emul, uint8_t who_am_i);
+
 #endif /* ZEPHYR_INCLUDE_EMUL_EMUL_LIS2DW12_H_ */
diff --git a/zephyr/test/drivers/src/lis2dw12.c b/zephyr/test/drivers/src/lis2dw12.c
new file mode 100644
index 0000000000..204c259bdc
--- /dev/null
+++ b/zephyr/test/drivers/src/lis2dw12.c
@@ -0,0 +1,41 @@
+/* Copyright 2021 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <ztest.h>
+#include <drivers/emul.h>
+#include "driver/accel_lis2dw12.h"
+#include "emul/emul_lis2dw12.h"
+
+#define LIS2DW12_NODELABEL DT_NODELABEL(ms_lis2dw12_accel)
+#define LIS2DW12_SENSOR_ID SENSOR_ID(LIS2DW12_NODELABEL)
+#define EMUL_LABEL DT_LABEL(DT_NODELABEL(lis2dw12_emul))
+
+#include <stdio.h>
+static void lis2dw12_setup(void)
+{
+	lis2dw12_emul_reset(emul_get_binding(EMUL_LABEL));
+}
+
+static void test_lis2dw12_init__fail_who_am_i(void)
+{
+	const struct emul *emul = emul_get_binding(EMUL_LABEL);
+	struct motion_sensor_t *ms = &motion_sensors[LIS2DW12_SENSOR_ID];
+	int rv;
+
+	lis2dw12_emul_set_who_am_i(emul, ~LIS2DW12_WHO_AM_I);
+
+	rv = ms->drv->init(ms);
+	zassert_equal(EC_ERROR_ACCESS_DENIED, rv,
+		      "init returned %d but was expecting %d", rv,
+		      EC_ERROR_ACCESS_DENIED);
+}
+
+void test_suite_lis2dw12(void)
+{
+	ztest_test_suite(lis2dw12, ztest_unit_test_setup_teardown(
+					   test_lis2dw12_init__fail_who_am_i,
+					   lis2dw12_setup, unit_test_noop));
+	ztest_run_test_suite(lis2dw12);
+}
diff --git a/zephyr/test/drivers/src/main.c b/zephyr/test/drivers/src/main.c
index 5237f74c2f..dd5ad79d0a 100644
--- a/zephyr/test/drivers/src/main.c
+++ b/zephyr/test/drivers/src/main.c
@@ -21,6 +21,7 @@ extern void test_suite_tcs3400(void);
 extern void test_suite_espi(void);
 extern void test_suite_bb_retimer(void);
 extern void test_suite_ln9310(void);
+extern void test_suite_lis2dw12(void);
 
 void test_main(void)
 {
@@ -43,4 +44,5 @@ void test_main(void)
 	test_suite_espi();
 	test_suite_bb_retimer();
 	test_suite_ln9310();
+	test_suite_lis2dw12();
 }