[v4,3/3] selftests: ALSA: Add test for the 'pcmtest' driver

diff --git a/tools/testing/selftests/alsa/Makefile b/tools/testing/selftests/alsa/Makefile
index 901949db80ad..5af9ba8a4645 100644
--- a/tools/testing/selftests/alsa/Makefile
+++ b/tools/testing/selftests/alsa/Makefile
@@ -12,7 +12,7 @@  LDLIBS+=-lpthread
 
 OVERRIDE_TARGETS = 1
 
-TEST_GEN_PROGS := mixer-test pcm-test
+TEST_GEN_PROGS := mixer-test pcm-test test-pcmtest-driver
 
 TEST_GEN_PROGS_EXTENDED := libatest.so
 
diff --git a/tools/testing/selftests/alsa/test-pcmtest-driver.c b/tools/testing/selftests/alsa/test-pcmtest-driver.c
new file mode 100644
index 000000000000..71931b240a83
--- /dev/null
+++ b/tools/testing/selftests/alsa/test-pcmtest-driver.c
@@ -0,0 +1,333 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This is the test which covers PCM middle layer data transferring using
+ * the virtual pcm test driver (snd-pcmtest).
+ *
+ * Copyright 2023 Ivan Orlov <ivan.orlov0322@gmail.com>
+ */
+#include <string.h>
+#include <alsa/asoundlib.h>
+#include "../kselftest_harness.h"
+
+#define CH_NUM 4
+
+struct pattern_buf {
+	char buf[1024];
+	int len;
+};
+
+struct pattern_buf patterns[CH_NUM];
+
+struct pcmtest_test_params {
+	unsigned long buffer_size;
+	unsigned long period_size;
+	unsigned long channels;
+	unsigned int rate;
+	snd_pcm_access_t access;
+	size_t sec_buf_len;
+	size_t sample_size;
+	int time;
+	snd_pcm_format_t format;
+};
+
+static int read_patterns(void)
+{
+	FILE *fp, *fpl;
+	int i;
+	char pf[64];
+	char plf[64];
+
+	for (i = 0; i < CH_NUM; i++) {
+		sprintf(plf, "/sys/kernel/debug/pcmtest/fill_pattern%d_len", i);
+		fpl = fopen(plf, "r");
+		if (!fpl)
+			return -1;
+		fscanf(fpl, "%u", &patterns[i].len);
+		fclose(fpl);
+
+		sprintf(pf, "/sys/kernel/debug/pcmtest/fill_pattern%d", i);
+		fp = fopen(pf, "r");
+		if (!fp) {
+			fclose(fpl);
+			return -1;
+		}
+		fread(patterns[i].buf, 1, patterns[i].len, fp);
+		fclose(fp);
+	}
+
+	return 0;
+}
+
+static int get_test_results(char *debug_name)
+{
+	int result;
+	FILE *f;
+	char fname[128];
+
+	sprintf(fname, "/sys/kernel/debug/pcmtest/%s", debug_name);
+
+	f = fopen(fname, "r");
+	if (!f) {
+		printf("Failed to open file\n");
+		return -1;
+	}
+	fscanf(f, "%d", &result);
+	fclose(f);
+
+	return result;
+}
+
+static size_t get_sec_buf_len(unsigned int rate, unsigned long channels, snd_pcm_format_t format)
+{
+	return rate * channels * snd_pcm_format_physical_width(format) / 8;
+}
+
+static int setup_handle(snd_pcm_t **handle, snd_pcm_sw_params_t *swparams,
+			snd_pcm_hw_params_t *hwparams, struct pcmtest_test_params *params,
+			int card, snd_pcm_stream_t stream)
+{
+	char pcm_name[32];
+	int err;
+
+	sprintf(pcm_name, "hw:%d,0,0", card);
+	err = snd_pcm_open(handle, pcm_name, stream, 0);
+	if (err < 0)
+		return err;
+	snd_pcm_hw_params_any(*handle, hwparams);
+	snd_pcm_hw_params_set_rate_resample(*handle, hwparams, 0);
+	snd_pcm_hw_params_set_access(*handle, hwparams, params->access);
+	snd_pcm_hw_params_set_format(*handle, hwparams, params->format);
+	snd_pcm_hw_params_set_channels(*handle, hwparams, params->channels);
+	snd_pcm_hw_params_set_rate_near(*handle, hwparams, &params->rate, 0);
+	snd_pcm_hw_params_set_period_size_near(*handle, hwparams, &params->period_size, 0);
+	snd_pcm_hw_params_set_buffer_size_near(*handle, hwparams, &params->buffer_size);
+	snd_pcm_hw_params(*handle, hwparams);
+	snd_pcm_sw_params_current(*handle, swparams);
+
+	snd_pcm_hw_params_set_rate_resample(*handle, hwparams, 0);
+	snd_pcm_sw_params_set_avail_min(*handle, swparams, params->period_size);
+	snd_pcm_hw_params_set_buffer_size_near(*handle, hwparams, &params->buffer_size);
+	snd_pcm_hw_params_set_period_size_near(*handle, hwparams, &params->period_size, 0);
+	snd_pcm_sw_params(*handle, swparams);
+	snd_pcm_hw_params(*handle, hwparams);
+
+	return 0;
+}
+
+FIXTURE(pcmtest) {
+	int card;
+	snd_pcm_sw_params_t *swparams;
+	snd_pcm_hw_params_t *hwparams;
+	struct pcmtest_test_params params;
+};
+
+FIXTURE_TEARDOWN(pcmtest) {
+}
+
+FIXTURE_SETUP(pcmtest) {
+	char *card_name;
+	int err;
+
+	if (geteuid())
+		SKIP(exit(-1), "This test needs root to run!");
+
+	err = read_patterns();
+	if (err)
+		SKIP(exit(-1), "Can't read patterns. Probably, module isn't loaded");
+
+	card_name = malloc(127);
+	ASSERT_NE(card_name, NULL);
+	self->params.buffer_size = 16384;
+	self->params.period_size = 4096;
+	self->params.channels = CH_NUM;
+	self->params.rate = 8000;
+	self->params.access = SND_PCM_ACCESS_RW_INTERLEAVED;
+	self->params.format = SND_PCM_FORMAT_S16_LE;
+	self->card = -1;
+	self->params.sample_size = snd_pcm_format_physical_width(self->params.format) / 8;
+
+	self->params.sec_buf_len = get_sec_buf_len(self->params.rate, self->params.channels,
+						   self->params.format);
+	self->params.time = 4;
+
+	while (snd_card_next(&self->card) >= 0) {
+		if (self->card == -1)
+			break;
+		snd_card_get_name(self->card, &card_name);
+		if (!strcmp(card_name, "PCM-Test"))
+			break;
+	}
+	free(card_name);
+	ASSERT_NE(self->card, -1);
+}
+
+/*
+ * Here we are trying to send the looped monotonically increasing sequence of bytes to the driver.
+ * If our data isn't corrupted, the driver will set the content of 'pc_test' debugfs file to '1'
+ */
+TEST_F(pcmtest, playback) {
+	snd_pcm_t *handle;
+	unsigned char *it;
+	size_t write_res;
+	int test_results;
+	int i, cur_ch, pos_in_ch;
+	void *samples;
+	struct pcmtest_test_params *params = &self->params;
+
+	samples = calloc(self->params.sec_buf_len * self->params.time, 1);
+	ASSERT_NE(samples, NULL);
+
+	snd_pcm_sw_params_alloca(&self->swparams);
+	snd_pcm_hw_params_alloca(&self->hwparams);
+
+	ASSERT_EQ(setup_handle(&handle, self->swparams, self->hwparams, params,
+			       self->card, SND_PCM_STREAM_PLAYBACK), 0);
+	snd_pcm_format_set_silence(params->format, samples,
+				   params->rate * params->channels * params->time);
+	it = samples;
+	for (i = 0; i < self->params.sec_buf_len * params->time; i++) {
+		cur_ch = (i / params->sample_size) % CH_NUM;
+		pos_in_ch = i / params->sample_size / CH_NUM * params->sample_size
+			    + (i % params->sample_size);
+		it[i] = patterns[cur_ch].buf[pos_in_ch % patterns[cur_ch].len];
+	}
+	write_res = snd_pcm_writei(handle, samples, params->rate * params->time);
+	ASSERT_GE(write_res, 0);
+
+	snd_pcm_close(handle);
+	free(samples);
+	test_results = get_test_results("pc_test");
+	ASSERT_EQ(test_results, 1);
+}
+
+/*
+ * Here we test that the virtual alsa driver returns looped and monotonically increasing sequence
+ * of bytes. In the interleaved mode the buffer will contain samples in the following order:
+ * C0, C1, C2, C3, C0, C1, ...
+ */
+TEST_F(pcmtest, capture) {
+	snd_pcm_t *handle;
+	unsigned char *it;
+	size_t read_res;
+	int i, cur_ch, pos_in_ch;
+	void *samples;
+	struct pcmtest_test_params *params = &self->params;
+
+	samples = calloc(self->params.sec_buf_len * self->params.time, 1);
+	ASSERT_NE(samples, NULL);
+
+	snd_pcm_sw_params_alloca(&self->swparams);
+	snd_pcm_hw_params_alloca(&self->hwparams);
+
+	ASSERT_EQ(setup_handle(&handle, self->swparams, self->hwparams,
+			       params, self->card, SND_PCM_STREAM_CAPTURE), 0);
+	snd_pcm_format_set_silence(params->format, samples,
+				   params->rate * params->channels * params->time);
+	read_res = snd_pcm_readi(handle, samples, params->rate * params->time);
+	ASSERT_GE(read_res, 0);
+	snd_pcm_close(handle);
+	it = (unsigned char *)samples;
+	for (i = 0; i < self->params.sec_buf_len * self->params.time; i++) {
+		cur_ch = (i / params->sample_size) % CH_NUM;
+		pos_in_ch = i / params->sample_size / CH_NUM * params->sample_size
+			    + (i % params->sample_size);
+		ASSERT_EQ(it[i], patterns[cur_ch].buf[pos_in_ch % patterns[cur_ch].len]);
+	}
+	free(samples);
+}
+
+// Test capture in the non-interleaved access mode. The are buffers for each recorded channel
+TEST_F(pcmtest, ni_capture) {
+	snd_pcm_t *handle;
+	struct pcmtest_test_params params = self->params;
+	char **chan_samples;
+	size_t i, j, read_res;
+
+	chan_samples = calloc(CH_NUM, sizeof(*chan_samples));
+	ASSERT_NE(chan_samples, NULL);
+
+	snd_pcm_sw_params_alloca(&self->swparams);
+	snd_pcm_hw_params_alloca(&self->hwparams);
+
+	params.access = SND_PCM_ACCESS_RW_NONINTERLEAVED;
+
+	ASSERT_EQ(setup_handle(&handle, self->swparams, self->hwparams,
+			       &params, self->card, SND_PCM_STREAM_CAPTURE), 0);
+
+	for (i = 0; i < CH_NUM; i++)
+		chan_samples[i] = calloc(params.sec_buf_len * params.time, 1);
+
+	for (i = 0; i < 1; i++) {
+		read_res = snd_pcm_readn(handle, (void **)chan_samples, params.rate * params.time);
+		ASSERT_GE(read_res, 0);
+	}
+	snd_pcm_close(handle);
+
+	for (i = 0; i < CH_NUM; i++) {
+		for (j = 0; j < params.rate * params.time; j++)
+			ASSERT_EQ(chan_samples[i][j], patterns[i].buf[j % patterns[i].len]);
+		free(chan_samples[i]);
+	}
+	free(chan_samples);
+}
+
+TEST_F(pcmtest, ni_playback) {
+	snd_pcm_t *handle;
+	struct pcmtest_test_params params = self->params;
+	char **chan_samples;
+	size_t i, j, read_res;
+	int test_res;
+
+	chan_samples = calloc(CH_NUM, sizeof(*chan_samples));
+	ASSERT_NE(chan_samples, NULL);
+
+	snd_pcm_sw_params_alloca(&self->swparams);
+	snd_pcm_hw_params_alloca(&self->hwparams);
+
+	params.access = SND_PCM_ACCESS_RW_NONINTERLEAVED;
+
+	ASSERT_EQ(setup_handle(&handle, self->swparams, self->hwparams,
+			       &params, self->card, SND_PCM_STREAM_PLAYBACK), 0);
+
+	for (i = 0; i < CH_NUM; i++) {
+		chan_samples[i] = calloc(params.sec_buf_len * params.time, 1);
+		for (j = 0; j < params.sec_buf_len * params.time; j++)
+			chan_samples[i][j] = patterns[i].buf[j % patterns[i].len];
+	}
+
+	for (i = 0; i < 1; i++) {
+		read_res = snd_pcm_writen(handle, (void **)chan_samples, params.rate * params.time);
+		ASSERT_GE(read_res, 0);
+	}
+
+	snd_pcm_close(handle);
+	test_res = get_test_results("pc_test");
+	ASSERT_EQ(test_res, 1);
+
+	for (i = 0; i < CH_NUM; i++)
+		free(chan_samples[i]);
+	free(chan_samples);
+}
+
+/*
+ * Here we are testing the custom ioctl definition inside the virtual driver. If it triggers
+ * successfully, the driver sets the content of 'ioctl_test' debugfs file to '1'.
+ */
+TEST_F(pcmtest, reset_ioctl) {
+	snd_pcm_t *handle;
+	unsigned char *it;
+	int test_res;
+	struct pcmtest_test_params *params = &self->params;
+
+	snd_pcm_sw_params_alloca(&self->swparams);
+	snd_pcm_hw_params_alloca(&self->hwparams);
+
+	ASSERT_EQ(setup_handle(&handle, self->swparams, self->hwparams, params,
+			       self->card, SND_PCM_STREAM_CAPTURE), 0);
+	snd_pcm_reset(handle);
+	test_res = get_test_results("ioctl_test");
+	ASSERT_EQ(test_res, 1);
+	snd_pcm_close(handle);
+}
+
+TEST_HARNESS_MAIN