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>

1 files changed, 16 insertions, 2 deletions

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");