ASoC: cs-amp-lib: Add KUnit test for calibration helpers

Add a KUnit test for the cs-amp-lib library. This has test cases
for cs_amp_get_efi_calibration_data() and cs_amp_write_cal_coeffs().

A KUNIT_STATIC_STUB_REDIRECT() has been added to
cs_amp_get_efi_variable() and cs_amp_write_cal_coeff() so that the
KUnit test can redirect these to test harness functions.

Much of the testing involves invoking the same function with different
parameters, i.e. the number of amps and the amp index within the array.
This uses parameterization rather than looping. The idea is to avoid
looping over configurations within one test case as that has a higher
chance of having a bug that doesn't actually test all the expected cases.
Having the test run exactly one configuration, and then tear-down, is less
prone to accidentally skipped configurations.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://msgid.link/r/20240304143705.26362-1-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

5 files changed, 754 insertions, 2 deletions

diff --git a/include/sound/cs-amp-lib.h b/include/sound/cs-amp-lib.h
index 077fe36885b5..f481148735e1 100644
--- a/include/sound/cs-amp-lib.h
+++ b/include/sound/cs-amp-lib.h
@@ -49,4 +49,18 @@ int cs_amp_write_cal_coeffs(struct cs_dsp *dsp,
 			    const struct cirrus_amp_cal_data *data);
 int cs_amp_get_efi_calibration_data(struct device *dev, u64 target_uid, int amp_index,
 				    struct cirrus_amp_cal_data *out_data);
+
+struct cs_amp_test_hooks {
+	efi_status_t (*get_efi_variable)(efi_char16_t *name,
+					 efi_guid_t *guid,
+					 unsigned long *size,
+					 void *buf);
+
+	int (*write_cal_coeff)(struct cs_dsp *dsp,
+			       const struct cirrus_amp_cal_controls *controls,
+			       const char *ctl_name, u32 val);
+};
+
+extern const struct cs_amp_test_hooks * const cs_amp_test_hooks;
+
 #endif /* CS_AMP_LIB_H */
diff --git a/sound/soc/codecs/Kconfig b/sound/soc/codecs/Kconfig
index 15f287784d8b..f78ea2f86fa6 100644
--- a/sound/soc/codecs/Kconfig
+++ b/sound/soc/codecs/Kconfig
@@ -732,6 +732,19 @@ config SND_SOC_CROS_EC_CODEC
 config SND_SOC_CS_AMP_LIB
 	tristate
 
+config SND_SOC_CS_AMP_LIB_TEST
+	tristate "KUnit test for Cirrus Logic cs-amp-lib"
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	select SND_SOC_CS_AMP_LIB
+	help
+	  This builds KUnit tests for the Cirrus Logic common
+	  amplifier library.
+	  For more information on KUnit and unit tests in general,
+	  please refer to the KUnit documentation in
+	  Documentation/dev-tools/kunit/.
+	  If in doubt, say "N".
+
 config SND_SOC_CS35L32
 	tristate "Cirrus Logic CS35L32 CODEC"
 	depends on I2C
diff --git a/sound/soc/codecs/Makefile b/sound/soc/codecs/Makefile
index 0fc40640e5d0..7c075539dc47 100644
--- a/sound/soc/codecs/Makefile
+++ b/sound/soc/codecs/Makefile
@@ -60,6 +60,7 @@ snd-soc-cpcap-objs := cpcap.o
 snd-soc-cq93vc-objs := cq93vc.o
 snd-soc-cros-ec-codec-objs := cros_ec_codec.o
 snd-soc-cs-amp-lib-objs := cs-amp-lib.o
+snd-soc-cs-amp-lib-test-objs := cs-amp-lib-test.o
 snd-soc-cs35l32-objs := cs35l32.o
 snd-soc-cs35l33-objs := cs35l33.o
 snd-soc-cs35l34-objs := cs35l34.o
@@ -454,6 +455,7 @@ obj-$(CONFIG_SND_SOC_CQ0093VC) += snd-soc-cq93vc.o
 obj-$(CONFIG_SND_SOC_CPCAP)	+= snd-soc-cpcap.o
 obj-$(CONFIG_SND_SOC_CROS_EC_CODEC)	+= snd-soc-cros-ec-codec.o
 obj-$(CONFIG_SND_SOC_CS_AMP_LIB)	+= snd-soc-cs-amp-lib.o
+obj-$(CONFIG_SND_SOC_CS_AMP_LIB_TEST)	+= snd-soc-cs-amp-lib-test.o
 obj-$(CONFIG_SND_SOC_CS35L32)	+= snd-soc-cs35l32.o
 obj-$(CONFIG_SND_SOC_CS35L33)	+= snd-soc-cs35l33.o
 obj-$(CONFIG_SND_SOC_CS35L34)	+= snd-soc-cs35l34.o
diff --git a/sound/soc/codecs/cs-amp-lib-test.c b/sound/soc/codecs/cs-amp-lib-test.c
new file mode 100644
index 000000000000..15f991b2e16e
--- /dev/null
+++ b/sound/soc/codecs/cs-amp-lib-test.c
@@ -0,0 +1,709 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// KUnit test for the Cirrus common amplifier library.
+//
+// Copyright (C) 2024 Cirrus Logic, Inc. and
+//                    Cirrus Logic International Semiconductor Ltd.
+
+#include <kunit/test.h>
+#include <kunit/static_stub.h>
+#include <linux/firmware/cirrus/cs_dsp.h>
+#include <linux/firmware/cirrus/wmfw.h>
+#include <linux/gpio/driver.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/random.h>
+#include <sound/cs-amp-lib.h>
+
+struct cs_amp_lib_test_priv {
+	struct platform_device amp_pdev;
+
+	struct cirrus_amp_efi_data *cal_blob;
+	struct list_head ctl_write_list;
+};
+
+struct cs_amp_lib_test_ctl_write_entry {
+	struct list_head list;
+	unsigned int value;
+	char name[16];
+};
+
+struct cs_amp_lib_test_param {
+	int num_amps;
+	int amp_index;
+};
+
+static void cs_amp_lib_test_init_dummy_cal_blob(struct kunit *test, int num_amps)
+{
+	struct cs_amp_lib_test_priv *priv = test->priv;
+	unsigned int blob_size;
+
+	blob_size = offsetof(struct cirrus_amp_efi_data, data) +
+		    sizeof(struct cirrus_amp_cal_data) * num_amps;
+
+	priv->cal_blob = kunit_kzalloc(test, blob_size, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, priv->cal_blob);
+
+	priv->cal_blob->size = blob_size;
+	priv->cal_blob->count = num_amps;
+
+	get_random_bytes(priv->cal_blob->data, sizeof(struct cirrus_amp_cal_data) * num_amps);
+}
+
+static u64 cs_amp_lib_test_get_target_uid(struct kunit *test)
+{
+	struct cs_amp_lib_test_priv *priv = test->priv;
+	const struct cs_amp_lib_test_param *param = test->param_value;
+	u64 uid;
+
+	uid = priv->cal_blob->data[param->amp_index].calTarget[1];
+	uid <<= 32;
+	uid |= priv->cal_blob->data[param->amp_index].calTarget[0];
+
+	return uid;
+}
+
+/* Redirected get_efi_variable to simulate that the file is too short */
+static efi_status_t cs_amp_lib_test_get_efi_variable_nohead(efi_char16_t *name,
+							    efi_guid_t *guid,
+							    unsigned long *size,
+							    void *buf)
+{
+	if (!buf) {
+		*size = offsetof(struct cirrus_amp_efi_data, data) - 1;
+		return EFI_BUFFER_TOO_SMALL;
+	}
+
+	return EFI_NOT_FOUND;
+}
+
+/* Should return -EOVERFLOW if the header is larger than the EFI data */
+static void cs_amp_lib_test_cal_data_too_short_test(struct kunit *test)
+{
+	struct cs_amp_lib_test_priv *priv = test->priv;
+	struct cirrus_amp_cal_data result_data;
+	int ret;
+
+	/* Redirect calls to get EFI data */
+	kunit_activate_static_stub(test,
+				   cs_amp_test_hooks->get_efi_variable,
+				   cs_amp_lib_test_get_efi_variable_nohead);
+
+	ret = cs_amp_get_efi_calibration_data(&priv->amp_pdev.dev, 0, 0, &result_data);
+	KUNIT_EXPECT_EQ(test, ret, -EOVERFLOW);
+
+	kunit_deactivate_static_stub(test, cs_amp_test_hooks->get_efi_variable);
+}
+
+/* Redirected get_efi_variable to simulate that the count is larger than the file */
+static efi_status_t cs_amp_lib_test_get_efi_variable_bad_count(efi_char16_t *name,
+							       efi_guid_t *guid,
+							       unsigned long *size,
+							       void *buf)
+{
+	struct kunit *test = kunit_get_current_test();
+	struct cs_amp_lib_test_priv *priv = test->priv;
+
+	if (!buf) {
+		/*
+		 * Return a size that is shorter than required for the
+		 * declared number of entries.
+		 */
+		*size = priv->cal_blob->size - 1;
+		return EFI_BUFFER_TOO_SMALL;
+	}
+
+	memcpy(buf, priv->cal_blob, priv->cal_blob->size - 1);
+
+	return EFI_SUCCESS;
+}
+
+/* Should return -EOVERFLOW if the entry count is larger than the EFI data */
+static void cs_amp_lib_test_cal_count_too_big_test(struct kunit *test)
+{
+	struct cs_amp_lib_test_priv *priv = test->priv;
+	struct cirrus_amp_cal_data result_data;
+	int ret;
+
+	cs_amp_lib_test_init_dummy_cal_blob(test, 8);
+
+	/* Redirect calls to get EFI data */
+	kunit_activate_static_stub(test,
+				   cs_amp_test_hooks->get_efi_variable,
+				   cs_amp_lib_test_get_efi_variable_bad_count);
+
+	ret = cs_amp_get_efi_calibration_data(&priv->amp_pdev.dev, 0, 0, &result_data);
+	KUNIT_EXPECT_EQ(test, ret, -EOVERFLOW);
+
+	kunit_deactivate_static_stub(test, cs_amp_test_hooks->get_efi_variable);
+}
+
+/* Redirected get_efi_variable to simulate that the variable not found */
+static efi_status_t cs_amp_lib_test_get_efi_variable_none(efi_char16_t *name,
+							  efi_guid_t *guid,
+							  unsigned long *size,
+							  void *buf)
+{
+	return EFI_NOT_FOUND;
+}
+
+/* If EFI doesn't contain a cal data variable the result should be -ENOENT */
+static void cs_amp_lib_test_no_cal_data_test(struct kunit *test)
+{
+	struct cs_amp_lib_test_priv *priv = test->priv;
+	struct cirrus_amp_cal_data result_data;
+	int ret;
+
+	/* Redirect calls to get EFI data */
+	kunit_activate_static_stub(test,
+				   cs_amp_test_hooks->get_efi_variable,
+				   cs_amp_lib_test_get_efi_variable_none);
+
+	ret = cs_amp_get_efi_calibration_data(&priv->amp_pdev.dev, 0, 0, &result_data);
+	KUNIT_EXPECT_EQ(test, ret, -ENOENT);
+
+	kunit_deactivate_static_stub(test, cs_amp_test_hooks->get_efi_variable);
+}
+
+/* Redirected get_efi_variable to simulate reading a cal data blob */
+static efi_status_t cs_amp_lib_test_get_efi_variable(efi_char16_t *name,
+						     efi_guid_t *guid,
+						     unsigned long *size,
+						     void *buf)
+{
+	static const efi_char16_t expected_name[] = L"CirrusSmartAmpCalibrationData";
+	static const efi_guid_t expected_guid =
+		EFI_GUID(0x02f9af02, 0x7734, 0x4233, 0xb4, 0x3d, 0x93, 0xfe, 0x5a, 0xa3, 0x5d, 0xb3);
+	struct kunit *test = kunit_get_current_test();
+	struct cs_amp_lib_test_priv *priv = test->priv;
+
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, name);
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, guid);
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, size);
+
+	KUNIT_EXPECT_MEMEQ(test, name, expected_name, sizeof(expected_name));
+	KUNIT_EXPECT_MEMEQ(test, guid, &expected_guid, sizeof(expected_guid));
+
+	if (!buf) {
+		*size = priv->cal_blob->size;
+		return EFI_BUFFER_TOO_SMALL;
+	}
+
+	KUNIT_ASSERT_GE_MSG(test, ksize(buf), priv->cal_blob->size, "Buffer to small");
+
+	memcpy(buf, priv->cal_blob, priv->cal_blob->size);
+
+	return EFI_SUCCESS;
+}
+
+/* Get cal data block for a given amp, matched by target UID. */
+static void cs_amp_lib_test_get_efi_cal_by_uid_test(struct kunit *test)
+{
+	struct cs_amp_lib_test_priv *priv = test->priv;
+	const struct cs_amp_lib_test_param *param = test->param_value;
+	struct cirrus_amp_cal_data result_data;
+	u64 target_uid;
+	int ret;
+
+	cs_amp_lib_test_init_dummy_cal_blob(test, param->num_amps);
+
+	/* Redirect calls to get EFI data */
+	kunit_activate_static_stub(test,
+				   cs_amp_test_hooks->get_efi_variable,
+				   cs_amp_lib_test_get_efi_variable);
+
+	target_uid = cs_amp_lib_test_get_target_uid(test);
+	ret = cs_amp_get_efi_calibration_data(&priv->amp_pdev.dev, target_uid, -1, &result_data);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	kunit_deactivate_static_stub(test, cs_amp_test_hooks->get_efi_variable);
+
+	KUNIT_EXPECT_EQ(test, result_data.calTarget[0], target_uid & 0xFFFFFFFFULL);
+	KUNIT_EXPECT_EQ(test, result_data.calTarget[1], target_uid >> 32);
+	KUNIT_EXPECT_EQ(test, result_data.calTime[0],
+			      priv->cal_blob->data[param->amp_index].calTime[0]);
+	KUNIT_EXPECT_EQ(test, result_data.calTime[1],
+			      priv->cal_blob->data[param->amp_index].calTime[1]);
+	KUNIT_EXPECT_EQ(test, result_data.calAmbient,
+			      priv->cal_blob->data[param->amp_index].calAmbient);
+	KUNIT_EXPECT_EQ(test, result_data.calStatus,
+			      priv->cal_blob->data[param->amp_index].calStatus);
+	KUNIT_EXPECT_EQ(test, result_data.calR,
+			      priv->cal_blob->data[param->amp_index].calR);
+}
+
+/* Get cal data block for a given amp index without checking target UID. */
+static void cs_amp_lib_test_get_efi_cal_by_index_unchecked_test(struct kunit *test)
+{
+	struct cs_amp_lib_test_priv *priv = test->priv;
+	const struct cs_amp_lib_test_param *param = test->param_value;
+	struct cirrus_amp_cal_data result_data;
+	int ret;
+
+	cs_amp_lib_test_init_dummy_cal_blob(test, param->num_amps);
+
+	/* Redirect calls to get EFI data */
+	kunit_activate_static_stub(test,
+				   cs_amp_test_hooks->get_efi_variable,
+				   cs_amp_lib_test_get_efi_variable);
+
+	ret = cs_amp_get_efi_calibration_data(&priv->amp_pdev.dev, 0,
+					      param->amp_index, &result_data);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	kunit_deactivate_static_stub(test, cs_amp_test_hooks->get_efi_variable);
+
+	KUNIT_EXPECT_EQ(test, result_data.calTime[0],
+			      priv->cal_blob->data[param->amp_index].calTime[0]);
+	KUNIT_EXPECT_EQ(test, result_data.calTime[1],
+			      priv->cal_blob->data[param->amp_index].calTime[1]);
+	KUNIT_EXPECT_EQ(test, result_data.calAmbient,
+			      priv->cal_blob->data[param->amp_index].calAmbient);
+	KUNIT_EXPECT_EQ(test, result_data.calStatus,
+			      priv->cal_blob->data[param->amp_index].calStatus);
+	KUNIT_EXPECT_EQ(test, result_data.calR,
+			      priv->cal_blob->data[param->amp_index].calR);
+}
+
+/* Get cal data block for a given amp index with checked target UID. */
+static void cs_amp_lib_test_get_efi_cal_by_index_checked_test(struct kunit *test)
+{
+	struct cs_amp_lib_test_priv *priv = test->priv;
+	const struct cs_amp_lib_test_param *param = test->param_value;
+	struct cirrus_amp_cal_data result_data;
+	u64 target_uid;
+	int ret;
+
+	cs_amp_lib_test_init_dummy_cal_blob(test, param->num_amps);
+
+	/* Redirect calls to get EFI data */
+	kunit_activate_static_stub(test,
+				   cs_amp_test_hooks->get_efi_variable,
+				   cs_amp_lib_test_get_efi_variable);
+
+	target_uid = cs_amp_lib_test_get_target_uid(test);
+	ret = cs_amp_get_efi_calibration_data(&priv->amp_pdev.dev, target_uid,
+					      param->amp_index, &result_data);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	kunit_deactivate_static_stub(test, cs_amp_test_hooks->get_efi_variable);
+
+	KUNIT_EXPECT_EQ(test, result_data.calTime[0],
+			      priv->cal_blob->data[param->amp_index].calTime[0]);
+	KUNIT_EXPECT_EQ(test, result_data.calTime[1],
+			      priv->cal_blob->data[param->amp_index].calTime[1]);
+	KUNIT_EXPECT_EQ(test, result_data.calAmbient,
+			      priv->cal_blob->data[param->amp_index].calAmbient);
+	KUNIT_EXPECT_EQ(test, result_data.calStatus,
+			      priv->cal_blob->data[param->amp_index].calStatus);
+	KUNIT_EXPECT_EQ(test, result_data.calR,
+			      priv->cal_blob->data[param->amp_index].calR);
+}
+
+/*
+ * Get cal data block for a given amp index with checked target UID.
+ * The UID does not match so the result should be -ENOENT.
+ */
+static void cs_amp_lib_test_get_efi_cal_by_index_uid_mismatch_test(struct kunit *test)
+{
+	struct cs_amp_lib_test_priv *priv = test->priv;
+	const struct cs_amp_lib_test_param *param = test->param_value;
+	struct cirrus_amp_cal_data result_data;
+	u64 target_uid;
+	int ret;
+
+	cs_amp_lib_test_init_dummy_cal_blob(test, param->num_amps);
+
+	/* Redirect calls to get EFI data */
+	kunit_activate_static_stub(test,
+				   cs_amp_test_hooks->get_efi_variable,
+				   cs_amp_lib_test_get_efi_variable);
+
+	/* Get a target UID that won't match the entry */
+	target_uid = ~cs_amp_lib_test_get_target_uid(test);
+	ret = cs_amp_get_efi_calibration_data(&priv->amp_pdev.dev, target_uid,
+					      param->amp_index, &result_data);
+	KUNIT_EXPECT_EQ(test, ret, -ENOENT);
+
+	kunit_deactivate_static_stub(test, cs_amp_test_hooks->get_efi_variable);
+}
+
+/*
+ * Get cal data block for a given amp, where the cal data does not
+ * specify calTarget so the lookup falls back to using the index
+ */
+static void cs_amp_lib_test_get_efi_cal_by_index_fallback_test(struct kunit *test)
+{
+	struct cs_amp_lib_test_priv *priv = test->priv;
+	const struct cs_amp_lib_test_param *param = test->param_value;
+	struct cirrus_amp_cal_data result_data;
+	static const u64 bad_target_uid = 0xBADCA100BABABABAULL;
+	int i, ret;
+
+	cs_amp_lib_test_init_dummy_cal_blob(test, param->num_amps);
+
+	/* Make all the target values zero so they are ignored */
+	for (i = 0; i < priv->cal_blob->count; ++i) {
+		priv->cal_blob->data[i].calTarget[0] = 0;
+		priv->cal_blob->data[i].calTarget[1] = 0;
+	}
+
+	/* Redirect calls to get EFI data */
+	kunit_activate_static_stub(test,
+				   cs_amp_test_hooks->get_efi_variable,
+				   cs_amp_lib_test_get_efi_variable);
+
+	ret = cs_amp_get_efi_calibration_data(&priv->amp_pdev.dev, bad_target_uid,
+					      param->amp_index, &result_data);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	kunit_deactivate_static_stub(test, cs_amp_test_hooks->get_efi_variable);
+
+	KUNIT_EXPECT_EQ(test, result_data.calTime[0],
+			      priv->cal_blob->data[param->amp_index].calTime[0]);
+	KUNIT_EXPECT_EQ(test, result_data.calTime[1],
+			      priv->cal_blob->data[param->amp_index].calTime[1]);
+	KUNIT_EXPECT_EQ(test, result_data.calAmbient,
+			      priv->cal_blob->data[param->amp_index].calAmbient);
+	KUNIT_EXPECT_EQ(test, result_data.calStatus,
+			      priv->cal_blob->data[param->amp_index].calStatus);
+	KUNIT_EXPECT_EQ(test, result_data.calR,
+			      priv->cal_blob->data[param->amp_index].calR);
+}
+
+/*
+ * If the target UID isn't present in the cal data, and there isn't an
+ * index to fall back do, the result should be -ENOENT.
+ */
+static void cs_amp_lib_test_get_efi_cal_uid_not_found_noindex_test(struct kunit *test)
+{
+	struct cs_amp_lib_test_priv *priv = test->priv;
+	struct cirrus_amp_cal_data result_data;
+	static const u64 bad_target_uid = 0xBADCA100BABABABAULL;
+	int i, ret;
+
+	cs_amp_lib_test_init_dummy_cal_blob(test, 8);
+
+	/* Make all the target values != bad_target_uid */
+	for (i = 0; i < priv->cal_blob->count; ++i) {
+		priv->cal_blob->data[i].calTarget[0] &= ~(bad_target_uid & 0xFFFFFFFFULL);
+		priv->cal_blob->data[i].calTarget[1] &= ~(bad_target_uid >> 32);
+	}
+
+	/* Redirect calls to get EFI data */
+	kunit_activate_static_stub(test,
+				   cs_amp_test_hooks->get_efi_variable,
+				   cs_amp_lib_test_get_efi_variable);
+
+	ret = cs_amp_get_efi_calibration_data(&priv->amp_pdev.dev, bad_target_uid, -1,
+					      &result_data);
+	KUNIT_EXPECT_EQ(test, ret, -ENOENT);
+
+	kunit_deactivate_static_stub(test, cs_amp_test_hooks->get_efi_variable);
+}
+
+/*
+ * If the target UID isn't present in the cal data, and the index is
+ * out of range, the result should be -ENOENT.
+ */
+static void cs_amp_lib_test_get_efi_cal_uid_not_found_index_not_found_test(struct kunit *test)
+{
+	struct cs_amp_lib_test_priv *priv = test->priv;
+	struct cirrus_amp_cal_data result_data;
+	static const u64 bad_target_uid = 0xBADCA100BABABABAULL;
+	int i, ret;
+
+	cs_amp_lib_test_init_dummy_cal_blob(test, 8);
+
+	/* Make all the target values != bad_target_uid */
+	for (i = 0; i < priv->cal_blob->count; ++i) {
+		priv->cal_blob->data[i].calTarget[0] &= ~(bad_target_uid & 0xFFFFFFFFULL);
+		priv->cal_blob->data[i].calTarget[1] &= ~(bad_target_uid >> 32);
+	}
+
+	/* Redirect calls to get EFI data */
+	kunit_activate_static_stub(test,
+				   cs_amp_test_hooks->get_efi_variable,
+				   cs_amp_lib_test_get_efi_variable);
+
+	ret = cs_amp_get_efi_calibration_data(&priv->amp_pdev.dev, bad_target_uid, 99,
+					      &result_data);
+	KUNIT_EXPECT_EQ(test, ret, -ENOENT);
+
+	kunit_deactivate_static_stub(test, cs_amp_test_hooks->get_efi_variable);
+}
+
+/*
+ * If the target UID isn't given, and the index is out of range, the
+ * result should be -ENOENT.
+ */
+static void cs_amp_lib_test_get_efi_cal_no_uid_index_not_found_test(struct kunit *test)
+{
+	struct cs_amp_lib_test_priv *priv = test->priv;
+	struct cirrus_amp_cal_data result_data;
+	int ret;
+
+	cs_amp_lib_test_init_dummy_cal_blob(test, 8);
+
+	/* Redirect calls to get EFI data */
+	kunit_activate_static_stub(test,
+				   cs_amp_test_hooks->get_efi_variable,
+				   cs_amp_lib_test_get_efi_variable);
+
+	ret = cs_amp_get_efi_calibration_data(&priv->amp_pdev.dev, 0, 99, &result_data);
+	KUNIT_EXPECT_EQ(test, ret, -ENOENT);
+
+	kunit_deactivate_static_stub(test, cs_amp_test_hooks->get_efi_variable);
+}
+
+/* If neither the target UID or the index is given the result should be -ENOENT. */
+static void cs_amp_lib_test_get_efi_cal_no_uid_no_index_test(struct kunit *test)
+{
+	struct cs_amp_lib_test_priv *priv = test->priv;
+	struct cirrus_amp_cal_data result_data;
+	int ret;
+
+	cs_amp_lib_test_init_dummy_cal_blob(test, 8);
+
+	/* Redirect calls to get EFI data */
+	kunit_activate_static_stub(test,
+				   cs_amp_test_hooks->get_efi_variable,
+				   cs_amp_lib_test_get_efi_variable);
+
+	ret = cs_amp_get_efi_calibration_data(&priv->amp_pdev.dev, 0, -1, &result_data);
+	KUNIT_EXPECT_EQ(test, ret, -ENOENT);
+
+	kunit_deactivate_static_stub(test, cs_amp_test_hooks->get_efi_variable);
+}
+
+/*
+ * If the UID is passed as 0 this must not match an entry with an
+ * unpopulated calTarget
+ */
+static void cs_amp_lib_test_get_efi_cal_zero_not_matched_test(struct kunit *test)
+{
+	struct cs_amp_lib_test_priv *priv = test->priv;
+	struct cirrus_amp_cal_data result_data;
+	int i, ret;
+
+	cs_amp_lib_test_init_dummy_cal_blob(test, 8);
+
+	/* Make all the target values zero so they are ignored */
+	for (i = 0; i < priv->cal_blob->count; ++i) {
+		priv->cal_blob->data[i].calTarget[0] = 0;
+		priv->cal_blob->data[i].calTarget[1] = 0;
+	}
+
+	/* Redirect calls to get EFI data */
+	kunit_activate_static_stub(test,
+				   cs_amp_test_hooks->get_efi_variable,
+				   cs_amp_lib_test_get_efi_variable);
+
+	ret = cs_amp_get_efi_calibration_data(&priv->amp_pdev.dev, 0, -1, &result_data);
+	KUNIT_EXPECT_EQ(test, ret, -ENOENT);
+
+	kunit_deactivate_static_stub(test, cs_amp_test_hooks->get_efi_variable);
+}
+
+static const struct cirrus_amp_cal_controls cs_amp_lib_test_calibration_controls = {
+	.alg_id =	0x9f210,
+	.mem_region =	WMFW_ADSP2_YM,
+	.ambient =	"CAL_AMBIENT",
+	.calr =		"CAL_R",
+	.status =	"CAL_STATUS",
+	.checksum =	"CAL_CHECKSUM",
+};
+
+static int cs_amp_lib_test_write_cal_coeff(struct cs_dsp *dsp,
+					   const struct cirrus_amp_cal_controls *controls,
+					   const char *ctl_name, u32 val)
+{
+	struct kunit *test = kunit_get_current_test();
+	struct cs_amp_lib_test_priv *priv = test->priv;
+	struct cs_amp_lib_test_ctl_write_entry *entry;
+
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctl_name);
+	KUNIT_EXPECT_PTR_EQ(test, controls, &cs_amp_lib_test_calibration_controls);
+
+	entry = kunit_kzalloc(test, sizeof(*entry), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, entry);
+
+	INIT_LIST_HEAD(&entry->list);
+	strscpy(entry->name, ctl_name, sizeof(entry->name));
+	entry->value = val;
+
+	list_add_tail(&entry->list, &priv->ctl_write_list);
+
+	return 0;
+}
+
+static void cs_amp_lib_test_write_cal_data_test(struct kunit *test)
+{
+	struct cs_amp_lib_test_priv *priv = test->priv;
+	struct cs_amp_lib_test_ctl_write_entry *entry;
+	struct cirrus_amp_cal_data data;
+	struct cs_dsp *dsp;
+	int ret;
+
+	dsp = kunit_kzalloc(test, sizeof(*dsp), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dsp);
+	dsp->dev = &priv->amp_pdev.dev;
+
+	get_random_bytes(&data, sizeof(data));
+
+	/* Redirect calls to write firmware controls */
+	kunit_activate_static_stub(test,
+				   cs_amp_test_hooks->write_cal_coeff,
+				   cs_amp_lib_test_write_cal_coeff);
+
+	ret = cs_amp_write_cal_coeffs(dsp, &cs_amp_lib_test_calibration_controls, &data);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	kunit_deactivate_static_stub(test, cs_amp_test_hooks->write_cal_coeff);
+
+	KUNIT_EXPECT_EQ(test, list_count_nodes(&priv->ctl_write_list), 4);
+
+	/* Checksum control must be written last */
+	entry = list_last_entry(&priv->ctl_write_list, typeof(*entry), list);
+	KUNIT_EXPECT_STREQ(test, entry->name, cs_amp_lib_test_calibration_controls.checksum);
+	KUNIT_EXPECT_EQ(test, entry->value, data.calR + 1);
+	list_del(&entry->list);
+
+	entry = list_first_entry(&priv->ctl_write_list, typeof(*entry), list);
+	KUNIT_EXPECT_STREQ(test, entry->name, cs_amp_lib_test_calibration_controls.ambient);
+	KUNIT_EXPECT_EQ(test, entry->value, data.calAmbient);
+	list_del(&entry->list);
+
+	entry = list_first_entry(&priv->ctl_write_list, typeof(*entry), list);
+	KUNIT_EXPECT_STREQ(test, entry->name, cs_amp_lib_test_calibration_controls.calr);
+	KUNIT_EXPECT_EQ(test, entry->value, data.calR);
+	list_del(&entry->list);
+
+	entry = list_first_entry(&priv->ctl_write_list, typeof(*entry), list);
+	KUNIT_EXPECT_STREQ(test, entry->name, cs_amp_lib_test_calibration_controls.status);
+	KUNIT_EXPECT_EQ(test, entry->value, data.calStatus);
+}
+
+static void cs_amp_lib_test_dev_release(struct device *dev)
+{
+}
+
+static int cs_amp_lib_test_case_init(struct kunit *test)
+{
+	struct cs_amp_lib_test_priv *priv;
+	int ret;
+
+	KUNIT_ASSERT_NOT_NULL(test, cs_amp_test_hooks);
+
+	priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	test->priv = priv;
+	INIT_LIST_HEAD(&priv->ctl_write_list);
+
+	/* Create dummy amp driver dev */
+	priv->amp_pdev.name = "cs_amp_lib_test_drv";
+	priv->amp_pdev.id = -1;
+	priv->amp_pdev.dev.release = cs_amp_lib_test_dev_release;
+	ret = platform_device_register(&priv->amp_pdev);
+	KUNIT_ASSERT_GE_MSG(test, ret, 0, "Failed to register amp platform device\n");
+
+	return 0;
+}
+
+static void cs_amp_lib_test_case_exit(struct kunit *test)
+{
+	struct cs_amp_lib_test_priv *priv = test->priv;
+
+	if (priv->amp_pdev.name)
+		platform_device_unregister(&priv->amp_pdev);
+}
+
+static const struct cs_amp_lib_test_param cs_amp_lib_test_get_cal_param_cases[] = {
+	{ .num_amps = 2, .amp_index = 0 },
+	{ .num_amps = 2, .amp_index = 1 },
+
+	{ .num_amps = 3, .amp_index = 0 },
+	{ .num_amps = 3, .amp_index = 1 },
+	{ .num_amps = 3, .amp_index = 2 },
+
+	{ .num_amps = 4, .amp_index = 0 },
+	{ .num_amps = 4, .amp_index = 1 },
+	{ .num_amps = 4, .amp_index = 2 },
+	{ .num_amps = 4, .amp_index = 3 },
+
+	{ .num_amps = 5, .amp_index = 0 },
+	{ .num_amps = 5, .amp_index = 1 },
+	{ .num_amps = 5, .amp_index = 2 },
+	{ .num_amps = 5, .amp_index = 3 },
+	{ .num_amps = 5, .amp_index = 4 },
+
+	{ .num_amps = 6, .amp_index = 0 },
+	{ .num_amps = 6, .amp_index = 1 },
+	{ .num_amps = 6, .amp_index = 2 },
+	{ .num_amps = 6, .amp_index = 3 },
+	{ .num_amps = 6, .amp_index = 4 },
+	{ .num_amps = 6, .amp_index = 5 },
+
+	{ .num_amps = 8, .amp_index = 0 },
+	{ .num_amps = 8, .amp_index = 1 },
+	{ .num_amps = 8, .amp_index = 2 },
+	{ .num_amps = 8, .amp_index = 3 },
+	{ .num_amps = 8, .amp_index = 4 },
+	{ .num_amps = 8, .amp_index = 5 },
+	{ .num_amps = 8, .amp_index = 6 },
+	{ .num_amps = 8, .amp_index = 7 },
+};
+
+static void cs_amp_lib_test_get_cal_param_desc(const struct cs_amp_lib_test_param *param,
+					       char *desc)
+{
+	snprintf(desc, KUNIT_PARAM_DESC_SIZE, "num_amps:%d amp_index:%d",
+		 param->num_amps, param->amp_index);
+}
+
+KUNIT_ARRAY_PARAM(cs_amp_lib_test_get_cal, cs_amp_lib_test_get_cal_param_cases,
+		  cs_amp_lib_test_get_cal_param_desc);
+
+static struct kunit_case cs_amp_lib_test_cases[] = {
+	/* Tests for getting calibration data from EFI */
+	KUNIT_CASE(cs_amp_lib_test_cal_data_too_short_test),
+	KUNIT_CASE(cs_amp_lib_test_cal_count_too_big_test),
+	KUNIT_CASE(cs_amp_lib_test_no_cal_data_test),
+	KUNIT_CASE(cs_amp_lib_test_get_efi_cal_uid_not_found_noindex_test),
+	KUNIT_CASE(cs_amp_lib_test_get_efi_cal_uid_not_found_index_not_found_test),
+	KUNIT_CASE(cs_amp_lib_test_get_efi_cal_no_uid_index_not_found_test),
+	KUNIT_CASE(cs_amp_lib_test_get_efi_cal_no_uid_no_index_test),
+	KUNIT_CASE(cs_amp_lib_test_get_efi_cal_zero_not_matched_test),
+	KUNIT_CASE_PARAM(cs_amp_lib_test_get_efi_cal_by_uid_test,
+			 cs_amp_lib_test_get_cal_gen_params),
+	KUNIT_CASE_PARAM(cs_amp_lib_test_get_efi_cal_by_index_unchecked_test,
+			 cs_amp_lib_test_get_cal_gen_params),
+	KUNIT_CASE_PARAM(cs_amp_lib_test_get_efi_cal_by_index_checked_test,
+			 cs_amp_lib_test_get_cal_gen_params),
+	KUNIT_CASE_PARAM(cs_amp_lib_test_get_efi_cal_by_index_uid_mismatch_test,
+			 cs_amp_lib_test_get_cal_gen_params),
+	KUNIT_CASE_PARAM(cs_amp_lib_test_get_efi_cal_by_index_fallback_test,
+			 cs_amp_lib_test_get_cal_gen_params),
+
+	/* Tests for writing calibration data */
+	KUNIT_CASE(cs_amp_lib_test_write_cal_data_test),
+
+	{ } /* terminator */
+};
+
+static struct kunit_suite cs_amp_lib_test_suite = {
+	.name = "snd-soc-cs-amp-lib-test",
+	.init = cs_amp_lib_test_case_init,
+	.exit = cs_amp_lib_test_case_exit,
+	.test_cases = cs_amp_lib_test_cases,
+};
+
+kunit_test_suite(cs_amp_lib_test_suite);
+
+MODULE_IMPORT_NS(SND_SOC_CS_AMP_LIB);
+MODULE_DESCRIPTION("KUnit test for Cirrus Logic amplifier library");
+MODULE_AUTHOR("Richard Fitzgerald <rf@opensource.cirrus.com>");
+MODULE_LICENSE("GPL");
diff --git a/sound/soc/codecs/cs-amp-lib.c b/sound/soc/codecs/cs-amp-lib.c
index 4e2e5157a73f..01ef4db5407d 100644
--- a/sound/soc/codecs/cs-amp-lib.c
+++ b/sound/soc/codecs/cs-amp-lib.c
@@ -6,6 +6,7 @@
 //               Cirrus Logic International Semiconductor Ltd.
 
 #include <asm/byteorder.h>
+#include <kunit/static_stub.h>
 #include <linux/dev_printk.h>
 #include <linux/efi.h>
 #include <linux/firmware/cirrus/cs_dsp.h>
@@ -27,6 +28,8 @@ static int cs_amp_write_cal_coeff(struct cs_dsp *dsp,
 	__be32 beval = cpu_to_be32(val);
 	int ret;
 
+	KUNIT_STATIC_STUB_REDIRECT(cs_amp_write_cal_coeff, dsp, controls, ctl_name, val);
+
 	if (IS_REACHABLE(CONFIG_FW_CS_DSP)) {
 		mutex_lock(&dsp->pwr_lock);
 		cs_ctl = cs_dsp_get_ctl(dsp, ctl_name, controls->mem_region, controls->alg_id);
@@ -84,7 +87,7 @@ int cs_amp_write_cal_coeffs(struct cs_dsp *dsp,
 			    const struct cirrus_amp_cal_controls *controls,
 			    const struct cirrus_amp_cal_data *data)
 {
-	if (IS_REACHABLE(CONFIG_FW_CS_DSP))
+	if (IS_REACHABLE(CONFIG_FW_CS_DSP) || IS_ENABLED(CONFIG_SND_SOC_CS_AMP_LIB_TEST))
 		return _cs_amp_write_cal_coeffs(dsp, controls, data);
 	else
 		return -ENODEV;
@@ -98,6 +101,8 @@ static efi_status_t cs_amp_get_efi_variable(efi_char16_t *name,
 {
 	u32 attr;
 
+	KUNIT_STATIC_STUB_REDIRECT(cs_amp_get_efi_variable, name, guid, size, buf);
+
 	if (IS_ENABLED(CONFIG_EFI))
 		return efi.get_variable(name, guid, &attr, size, buf);
 
@@ -250,13 +255,22 @@ static int _cs_amp_get_efi_calibration_data(struct device *dev, u64 target_uid,
 int cs_amp_get_efi_calibration_data(struct device *dev, u64 target_uid, int amp_index,
 				    struct cirrus_amp_cal_data *out_data)
 {
-	if (IS_ENABLED(CONFIG_EFI))
+	if (IS_ENABLED(CONFIG_EFI) || IS_ENABLED(CONFIG_SND_SOC_CS_AMP_LIB_TEST))
 		return _cs_amp_get_efi_calibration_data(dev, target_uid, amp_index, out_data);
 	else
 		return -ENOENT;
 }
 EXPORT_SYMBOL_NS_GPL(cs_amp_get_efi_calibration_data, SND_SOC_CS_AMP_LIB);
 
+static const struct cs_amp_test_hooks cs_amp_test_hook_ptrs = {
+	.get_efi_variable = cs_amp_get_efi_variable,
+	.write_cal_coeff = cs_amp_write_cal_coeff,
+};
+
+const struct cs_amp_test_hooks * const cs_amp_test_hooks =
+	PTR_IF(IS_ENABLED(CONFIG_SND_SOC_CS_AMP_LIB_TEST), &cs_amp_test_hook_ptrs);
+EXPORT_SYMBOL_NS_GPL(cs_amp_test_hooks, SND_SOC_CS_AMP_LIB);
+
 MODULE_DESCRIPTION("Cirrus Logic amplifier library");
 MODULE_AUTHOR("Richard Fitzgerald <rf@opensource.cirrus.com>");
 MODULE_LICENSE("GPL");