examples: Add ad57xx dac example

examples/CMakeLists.txt

@@ -5,6 +5,7 @@ project(ad9371-iiostream C)
 project(adrv9009-iiostream C)
 project(dummy-iiostream C)
 project(adrv9002-iiostream C)
+project(ad57xx-iiostream C)
 
 add_library(iiostream_helper STATIC iiostream-common.c)
 target_link_libraries(iiostream_helper PUBLIC iio)
@@ -45,15 +46,19 @@ add_executable(
     adrv9002-iiostream adrv9002-iiostream.c ${GETOPT_C_FILE} ${LIBIIO_RC}
 )
 add_executable(dummy-iiostream dummy-iiostream.c ${GETOPT_C_FILE} ${LIBIIO_RC})
+add_executable(
+    ad57xx-iiostream ad57xx-iiostream.c ${GETOPT_C_FILE} ${LIBIIO_RC}
+)
 
 target_link_libraries(ad9361-iiostream iiostream_helper)
 target_link_libraries(ad9371-iiostream iiostream_helper)
 target_link_libraries(adrv9009-iiostream iiostream_helper)
 target_link_libraries(dummy-iiostream iiostream_helper)
 target_link_libraries(adrv9002-iiostream iiostream_helper)
+target_link_libraries(ad57xx-iiostream iiostream_helper)
 
 set(IIO_EXAMPLES_TARGETS ad9361-iiostream ad9371-iiostream adrv9009-iiostream
-                         dummy-iiostream adrv9002-iiostream
+                         dummy-iiostream adrv9002-iiostream ad57xx-iiostream
 )
 
 find_library(PTHREAD_LIBRARIES pthread)

examples/ad57xx-iiostream.c

@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * libiio - AD5791 IIO streaming example
+ *
+ * Copyright 2024 BayLibre, SAS
+ * Author: Axel Haslam <[email protected]>
+ **/
+
+#include "iiostream-common.h"
+
+#include <iio/iio.h>
+#include <iio/iio-debug.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
+#include <signal.h>
+#include <stdio.h>
+#include <errno.h>
+
+
+#define MAX_SAMPLE_VAL		((1 << 18) - 1)
+#define BLOCK_SIZE		(1024 * 4)
+bool stop = false;
+
+static void handle_sig(int sig)
+{
+	printf("Waiting for process to finish... Got signal %d\n", sig);
+	stop = true;
+}
+
+int get_step_size(struct iio_device *dev, long long freq)
+{
+	const struct iio_attr *attr;
+	long long ratio;
+	int ret;
+
+	attr = iio_device_find_attr(dev, "sampling_frequency");
+	if (!attr) {
+		printf("could not find sampling_frequency  attr\n");
+		return -1;
+	}
+
+	ret = iio_attr_read_longlong(attr, &ratio);
+	if (ret)
+		return -1;
+
+	ratio /= freq;
+
+	return (MAX_SAMPLE_VAL / ratio) * 2;
+}
+
+
+int main (int argc, char **argv)
+{
+	struct iio_context *ctx;
+	struct iio_channel *chn;
+	struct iio_buffer *buf;
+	struct iio_stream *txstream;
+	struct iio_device *dev;
+	struct iio_channels_mask *mask;
+	const struct iio_attr *attr;
+	const struct iio_block *block;
+	size_t sample_size;
+	bool up = true;
+	int ret;
+	int i;
+	int step;
+
+	signal(SIGINT, handle_sig);
+
+	ctx = iio_create_context(NULL, NULL);
+	if (!ctx) {
+		printf("create context error\n");
+		goto out;
+	}
+
+	dev = iio_context_find_device(ctx, "ad5791");
+	if (!dev) {
+		printf("find device error\n");
+		goto out;
+	}
+
+	chn = iio_device_find_channel(dev, "voltage0", true);
+	if (!ctx) {
+		printf("find channel error\n");
+		goto out;
+	}
+
+	attr = iio_channel_find_attr(chn, "powerdown");
+	if (!attr) {
+		printf("a could not find power down attr\n");
+		goto out;
+	}
+
+	ret = iio_attr_write_bool(attr, false);
+	if (ret) {
+		printf("Power up fail: %d\n", ret);
+		goto out;
+	}
+
+	mask = iio_create_channels_mask(iio_device_get_channels_count(dev));
+	if (!mask) {
+		printf("channel mask error\n");
+		goto out;
+	}
+
+	iio_channel_enable(chn, mask);
+
+	sample_size = iio_device_get_sample_size(dev, mask);
+
+	buf = iio_device_create_buffer(dev, 0, mask);
+	if (!ctx) {
+		printf("create buffer error\n");
+		goto out;
+	}
+
+	txstream = iio_buffer_create_stream(buf, 4, BLOCK_SIZE);
+	if (!txstream) {
+		printf("create stream error\n");
+		goto out;
+	}
+
+	step = get_step_size(dev, 1000);
+	if (step < 0) {
+		printf("Fail to get step size\n");
+		goto out;
+	}
+
+	while (!stop) {
+		int32_t *p_dat, *p_end;
+		ptrdiff_t p_inc = sample_size;
+
+		block = iio_stream_get_next_block(txstream);
+		if (!block) {
+			printf("get block error\n");
+			goto out;
+		}
+
+		p_dat = iio_block_first(block, chn);
+		p_end= iio_block_end(block);
+		for (;p_dat < p_end; p_dat += 1) {
+			if (up)
+				i += step;
+			else
+				i -= step;
+
+			*p_dat = (1 << 20) | i;
+			if (i >= 0x3FFFF)
+				up = false;
+			if (i == 0)
+				up = true;
+		}
+	}
+
+
+out:
+	if (txstream)
+		iio_stream_destroy(txstream);
+
+	if (buf)
+		iio_buffer_destroy(buf);
+
+	ret = iio_attr_write_bool(attr, true);
+	if (ret)
+		printf("Power down fail: %d\n", ret);
+
+	if (mask)
+		iio_channels_mask_destroy(mask);
+
+	if (ctx)
+		iio_context_destroy(ctx);
+
+	return 0;
+}