samples: intel_s1000_crb: add DMIC sample app

Add a sample application to demonstrate usage of digital microphones
in an Intel S1000 CRB

Signed-off-by: Sathish Kuttan <sathish.k.kuttan@intel.com>

samples/boards/intel_s1000_crb/dmic/CMakeLists.txt

@@ -0,0 +1,5 @@
+cmake_minimum_required(VERSION 3.8.2)
+include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)
+project(NONE)
+
+target_sources(app PRIVATE src/dmic_sample.c)

samples/boards/intel_s1000_crb/dmic/prj.conf

@@ -0,0 +1,8 @@
+CONFIG_LOG=y
+
+CONFIG_DMA=y
+CONFIG_DCACHE_WRITEBACK=y
+
+CONFIG_USB=n
+CONFIG_I2C=y
+CONFIG_AUDIO=y

samples/boards/intel_s1000_crb/dmic/src/dmic_sample.c

@@ -0,0 +1,148 @@
+/*
+ * Copyright (c) 2019 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr.h>
+#include <audio/dmic.h>
+
+#define LOG_LEVEL LOG_LEVEL_INF
+#include <logging/log.h>
+LOG_MODULE_REGISTER(dmic_sample);
+
+#define AUDIO_SAMPLE_FREQ	48000
+#define AUDIO_SAMPLE_WIDTH	32
+#define SAMPLES_PER_FRAME	(64)
+
+#define NUM_MIC_CHANNELS	8
+#define MIC_FRAME_SAMPLES	(SAMPLES_PER_FRAME * NUM_MIC_CHANNELS)
+#define MIC_FRAME_BYTES		(MIC_FRAME_SAMPLES * AUDIO_SAMPLE_WIDTH / 8)
+
+#define LP_SRAM_BASE		0xBE800000
+#define LP_SRAM_BASE_UNCACHED	0x9E800000
+#define LP_SRAM_SIZE		(16 << 10)
+
+#define DMIC_DEV_NAME		"PDM"
+#define MIC_IN_BUF_COUNT	2
+
+#define FRAMES_PER_ITERATION	100
+#define NUM_ITERATIONS		4
+#define DELAY_BTW_ITERATIONS	K_MSEC(20)
+
+static struct k_mem_slab dmic_mem_slab;
+static char audio_buffers[MIC_FRAME_BYTES * MIC_IN_BUF_COUNT];
+static struct device *dmic_device;
+
+static void dmic_init(void)
+{
+	int ret;
+	struct pcm_stream_cfg stream = {
+		.pcm_rate		= AUDIO_SAMPLE_FREQ,
+		.pcm_width		= AUDIO_SAMPLE_WIDTH,
+		.block_size		= MIC_FRAME_BYTES,
+		.mem_slab		= &dmic_mem_slab,
+	};
+	struct dmic_cfg cfg = {
+		.io = {
+			.min_pdm_clk_freq	= 1024000,
+			.max_pdm_clk_freq	= 4800000,
+			.min_pdm_clk_dc		= 48,
+			.max_pdm_clk_dc		= 52,
+			.pdm_clk_pol		= 0,
+			.pdm_data_pol		= 0,
+		},
+		.streams			= &stream,
+		.channel = {
+			.req_chan_map_lo	=
+				dmic_build_channel_map(0, 0, PDM_CHAN_RIGHT) |
+				dmic_build_channel_map(1, 0, PDM_CHAN_LEFT) |
+				dmic_build_channel_map(2, 2, PDM_CHAN_RIGHT) |
+				dmic_build_channel_map(3, 2, PDM_CHAN_LEFT) |
+				dmic_build_channel_map(4, 1, PDM_CHAN_RIGHT) |
+				dmic_build_channel_map(5, 1, PDM_CHAN_LEFT) |
+				dmic_build_channel_map(6, 3, PDM_CHAN_RIGHT) |
+				dmic_build_channel_map(7, 3, PDM_CHAN_LEFT),
+			.req_num_chan		= NUM_MIC_CHANNELS,
+			.req_num_streams	= 1,
+		},
+	};
+
+	k_mem_slab_init(&dmic_mem_slab, audio_buffers, MIC_FRAME_BYTES,
+			MIC_IN_BUF_COUNT);
+	dmic_device = device_get_binding(DMIC_DEV_NAME);
+	if (!dmic_device) {
+		LOG_ERR("unable to find device %s", DMIC_DEV_NAME);
+		return;
+	}
+
+	ret = dmic_configure(dmic_device, &cfg);
+	if (ret != 0) {
+		LOG_ERR("dmic_configure failed with %d error", ret);
+	}
+}
+
+static void dmic_start(void)
+{
+	int ret;
+
+	LOG_DBG("starting dmic");
+	ret = dmic_trigger(dmic_device, DMIC_TRIGGER_START);
+	if (ret) {
+		LOG_ERR("dmic_trigger failed with code %d", ret);
+	}
+}
+
+static void dmic_receive(void)
+{
+	int frame_counter = 0;
+	s32_t *mic_in_buf;
+	size_t size;
+	int ret;
+
+	while (frame_counter++ < FRAMES_PER_ITERATION) {
+		ret = dmic_read(dmic_device, 0, (void **)&mic_in_buf, &size,
+				K_FOREVER);
+		if (ret) {
+			LOG_ERR("dmic_read failed %d", ret);
+		} else {
+			LOG_DBG("dmic_read buffer %p size %u frame %d",
+					mic_in_buf, size, frame_counter);
+			k_mem_slab_free(&dmic_mem_slab, (void **)&mic_in_buf);
+		}
+	}
+}
+
+static void dmic_stop(void)
+{
+	int ret;
+
+	ret = dmic_trigger(dmic_device, DMIC_TRIGGER_STOP);
+	if (ret) {
+		LOG_ERR("dmic_trigger failed with code %d", ret);
+	} else {
+		LOG_DBG("dmic stopped");
+	}
+}
+
+static void dmic_sample_app(void *p1, void *p2, void *p3)
+{
+	int loop_count = 0;
+
+	dmic_init();
+
+	LOG_INF("Starting DMIC sample app ...");
+	while (loop_count++ < NUM_ITERATIONS) {
+		dmic_start();
+		dmic_receive();
+		dmic_stop();
+		k_sleep(DELAY_BTW_ITERATIONS);
+		LOG_INF("Iteration %d/%d complete, %d audio frames received.",
+				loop_count, NUM_ITERATIONS,
+				FRAMES_PER_ITERATION);
+	}
+	LOG_INF("Exiting DMIC sample app ...");
+}
+
+K_THREAD_DEFINE(dmic_sample, 1024, dmic_sample_app, NULL, NULL, NULL, 10, 0,
+		K_NO_WAIT);