1 files changed, 294 insertions, 0 deletions
diff --git a/src/examples/ad9361-iiostream.c b/src/examples/ad9361-iiostream.c
new file mode 100644
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+++ b/src/examples/ad9361-iiostream.c
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+/*
+ * libiio - AD9361 IIO streaming example
+ *
+ * Copyright (C) 2014 IABG mbH
+ * Author: Michael Feilen <feilen_at_iabg.de>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ **/
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
+#include <signal.h>
+#include <stdio.h>
+
+#ifdef __APPLE__
+#include <iio/iio.h>
+#else
+#include <iio.h>
+#endif
+
+/* helper macros */
+#define MHZ(x) ((long long)(x*1000000.0 + .5))
+#define GHZ(x) ((long long)(x*1000000000.0 + .5))
+
+#define ASSERT(expr) { \
+	if (!(expr)) { \
+		(void) fprintf(stderr, "assertion failed (%s:%d)\n", __FILE__, __LINE__); \
+		(void) abort(); \
+	} \
+}
+
+/* RX is input, TX is output */
+enum iodev { RX, TX };
+
+/* common RX and TX streaming params */
+struct stream_cfg {
+	long long bw_hz; // Analog banwidth in Hz
+	long long fs_hz; // Baseband sample rate in Hz
+	long long lo_hz; // Local oscillator frequency in Hz
+	const char* rfport; // Port name
+};
+
+/* static scratch mem for strings */
+static char tmpstr[64];
+
+/* IIO structs required for streaming */
+static struct iio_context *ctx   = NULL;
+static struct iio_channel *rx0_i = NULL;
+static struct iio_channel *rx0_q = NULL;
+static struct iio_channel *tx0_i = NULL;
+static struct iio_channel *tx0_q = NULL;
+static struct iio_buffer  *rxbuf = NULL;
+static struct iio_buffer  *txbuf = NULL;
+
+static bool stop;
+
+/* cleanup and exit */
+static void shutdown()
+{
+	printf("* Destroying buffers\n");
+	if (rxbuf) { iio_buffer_destroy(rxbuf); }
+	if (txbuf) { iio_buffer_destroy(txbuf); }
+
+	printf("* Disabling streaming channels\n");
+	if (rx0_i) { iio_channel_disable(rx0_i); }
+	if (rx0_q) { iio_channel_disable(rx0_q); }
+	if (tx0_i) { iio_channel_disable(tx0_i); }
+	if (tx0_q) { iio_channel_disable(tx0_q); }
+
+	printf("* Destroying context\n");
+	if (ctx) { iio_context_destroy(ctx); }
+	exit(0);
+}
+
+static void handle_sig(int sig)
+{
+	printf("Waiting for process to finish...\n");
+	stop = true;
+}
+
+/* check return value of attr_write function */
+static void errchk(int v, const char* what) {
+	 if (v < 0) { fprintf(stderr, "Error %d writing to channel \"%s\"\nvalue may not be supported.\n", v, what); shutdown(); }
+}
+
+/* write attribute: long long int */
+static void wr_ch_lli(struct iio_channel *chn, const char* what, long long val)
+{
+	errchk(iio_channel_attr_write_longlong(chn, what, val), what);
+}
+
+/* write attribute: string */
+static void wr_ch_str(struct iio_channel *chn, const char* what, const char* str)
+{
+	errchk(iio_channel_attr_write(chn, what, str), what);
+}
+
+/* helper function generating channel names */
+static char* get_ch_name(const char* type, int id)
+{
+	snprintf(tmpstr, sizeof(tmpstr), "%s%d", type, id);
+	return tmpstr;
+}
+
+/* returns ad9361 phy device */
+static struct iio_device* get_ad9361_phy(struct iio_context *ctx)
+{
+	struct iio_device *dev =  iio_context_find_device(ctx, "ad9361-phy");
+	ASSERT(dev && "No ad9361-phy found");
+	return dev;
+}
+
+/* finds AD9361 streaming IIO devices */
+static bool get_ad9361_stream_dev(struct iio_context *ctx, enum iodev d, struct iio_device **dev)
+{
+	switch (d) {
+	case TX: *dev = iio_context_find_device(ctx, "cf-ad9361-dds-core-lpc"); return *dev != NULL;
+	case RX: *dev = iio_context_find_device(ctx, "cf-ad9361-lpc");  return *dev != NULL;
+	default: ASSERT(0); return false;
+	}
+}
+
+/* finds AD9361 streaming IIO channels */
+static bool get_ad9361_stream_ch(struct iio_context *ctx, enum iodev d, struct iio_device *dev, int chid, struct iio_channel **chn)
+{
+	*chn = iio_device_find_channel(dev, get_ch_name("voltage", chid), d == TX);
+	if (!*chn)
+		*chn = iio_device_find_channel(dev, get_ch_name("altvoltage", chid), d == TX);
+	return *chn != NULL;
+}
+
+/* finds AD9361 phy IIO configuration channel with id chid */
+static bool get_phy_chan(struct iio_context *ctx, enum iodev d, int chid, struct iio_channel **chn)
+{
+	switch (d) {
+	case RX: *chn = iio_device_find_channel(get_ad9361_phy(ctx), get_ch_name("voltage", chid), false); return *chn != NULL;
+	case TX: *chn = iio_device_find_channel(get_ad9361_phy(ctx), get_ch_name("voltage", chid), true);  return *chn != NULL;
+	default: ASSERT(0); return false;
+	}
+}
+
+/* finds AD9361 local oscillator IIO configuration channels */
+static bool get_lo_chan(struct iio_context *ctx, enum iodev d, struct iio_channel **chn)
+{
+	switch (d) {
+	 // LO chan is always output, i.e. true
+	case RX: *chn = iio_device_find_channel(get_ad9361_phy(ctx), get_ch_name("altvoltage", 0), true); return *chn != NULL;
+	case TX: *chn = iio_device_find_channel(get_ad9361_phy(ctx), get_ch_name("altvoltage", 1), true); return *chn != NULL;
+	default: ASSERT(0); return false;
+	}
+}
+
+/* applies streaming configuration through IIO */
+bool cfg_ad9361_streaming_ch(struct iio_context *ctx, struct stream_cfg *cfg, enum iodev type, int chid)
+{
+	struct iio_channel *chn = NULL;
+
+	// Configure phy and lo channels
+	printf("* Acquiring AD9361 phy channel %d\n", chid);
+	if (!get_phy_chan(ctx, type, chid, &chn)) {	return false; }
+	wr_ch_str(chn, "rf_port_select",     cfg->rfport);
+	wr_ch_lli(chn, "rf_bandwidth",       cfg->bw_hz);
+	wr_ch_lli(chn, "sampling_frequency", cfg->fs_hz);
+
+	// Configure LO channel
+	printf("* Acquiring AD9361 %s lo channel\n", type == TX ? "TX" : "RX");
+	if (!get_lo_chan(ctx, type, &chn)) { return false; }
+	wr_ch_lli(chn, "frequency", cfg->lo_hz);
+	return true;
+}
+
+/* simple configuration and streaming */
+int main (int argc, char **argv)
+{
+	// Streaming devices
+	struct iio_device *tx;
+	struct iio_device *rx;
+
+	// RX and TX sample counters
+	size_t nrx = 0;
+	size_t ntx = 0;
+
+	// Stream configurations
+	struct stream_cfg rxcfg;
+	struct stream_cfg txcfg;
+
+	// Listen to ctrl+c and ASSERT
+	signal(SIGINT, handle_sig);
+
+	// RX stream config
+	rxcfg.bw_hz = MHZ(2);   // 2 MHz rf bandwidth
+	rxcfg.fs_hz = MHZ(2.5);   // 2.5 MS/s rx sample rate
+	rxcfg.lo_hz = GHZ(2.5); // 2.5 GHz rf frequency
+	rxcfg.rfport = "A_BALANCED"; // port A (select for rf freq.)
+
+	// TX stream config
+	txcfg.bw_hz = MHZ(1.5); // 1.5 MHz rf bandwidth
+	txcfg.fs_hz = MHZ(2.5);   // 2.5 MS/s tx sample rate
+	txcfg.lo_hz = GHZ(2.5); // 2.5 GHz rf frequency
+	txcfg.rfport = "A"; // port A (select for rf freq.)
+
+	printf("* Acquiring IIO context\n");
+	ASSERT((ctx = iio_create_default_context()) && "No context");
+	ASSERT(iio_context_get_devices_count(ctx) > 0 && "No devices");
+
+	printf("* Acquiring AD9361 streaming devices\n");
+	ASSERT(get_ad9361_stream_dev(ctx, TX, &tx) && "No tx dev found");
+	ASSERT(get_ad9361_stream_dev(ctx, RX, &rx) && "No rx dev found");
+
+	printf("* Configuring AD9361 for streaming\n");
+	ASSERT(cfg_ad9361_streaming_ch(ctx, &rxcfg, RX, 0) && "RX port 0 not found");
+	ASSERT(cfg_ad9361_streaming_ch(ctx, &txcfg, TX, 0) && "TX port 0 not found");
+
+	printf("* Initializing AD9361 IIO streaming channels\n");
+	ASSERT(get_ad9361_stream_ch(ctx, RX, rx, 0, &rx0_i) && "RX chan i not found");
+	ASSERT(get_ad9361_stream_ch(ctx, RX, rx, 1, &rx0_q) && "RX chan q not found");
+	ASSERT(get_ad9361_stream_ch(ctx, TX, tx, 0, &tx0_i) && "TX chan i not found");
+	ASSERT(get_ad9361_stream_ch(ctx, TX, tx, 1, &tx0_q) && "TX chan q not found");
+
+	printf("* Enabling IIO streaming channels\n");
+	iio_channel_enable(rx0_i);
+	iio_channel_enable(rx0_q);
+	iio_channel_enable(tx0_i);
+	iio_channel_enable(tx0_q);
+
+	printf("* Creating non-cyclic IIO buffers with 1 MiS\n");
+	rxbuf = iio_device_create_buffer(rx, 1024*1024, false);
+	if (!rxbuf) {
+		perror("Could not create RX buffer");
+		shutdown();
+	}
+	txbuf = iio_device_create_buffer(tx, 1024*1024, false);
+	if (!txbuf) {
+		perror("Could not create TX buffer");
+		shutdown();
+	}
+
+	printf("* Starting IO streaming (press CTRL+C to cancel)\n");
+	while (!stop)
+	{
+		ssize_t nbytes_rx, nbytes_tx;
+		char *p_dat, *p_end;
+		ptrdiff_t p_inc;
+
+		// Schedule TX buffer
+		nbytes_tx = iio_buffer_push(txbuf);
+		if (nbytes_tx < 0) { printf("Error pushing buf %d\n", (int) nbytes_tx); shutdown(); }
+
+		// Refill RX buffer
+		nbytes_rx = iio_buffer_refill(rxbuf);
+		if (nbytes_rx < 0) { printf("Error refilling buf %d\n",(int) nbytes_rx); shutdown(); }
+
+		// READ: Get pointers to RX buf and read IQ from RX buf port 0
+		p_inc = iio_buffer_step(rxbuf);
+		p_end = iio_buffer_end(rxbuf);
+		for (p_dat = (char *)iio_buffer_first(rxbuf, rx0_i); p_dat < p_end; p_dat += p_inc) {
+			// Example: swap I and Q
+			const int16_t i = ((int16_t*)p_dat)[0]; // Real (I)
+			const int16_t q = ((int16_t*)p_dat)[1]; // Imag (Q)
+			((int16_t*)p_dat)[0] = q;
+			((int16_t*)p_dat)[1] = i;
+		}
+
+		// WRITE: Get pointers to TX buf and write IQ to TX buf port 0
+		p_inc = iio_buffer_step(txbuf);
+		p_end = iio_buffer_end(txbuf);
+		for (p_dat = (char *)iio_buffer_first(txbuf, tx0_i); p_dat < p_end; p_dat += p_inc) {
+			// Example: fill with zeros
+			// 12-bit sample needs to be MSB alligned so shift by 4
+			// https://wiki.analog.com/resources/eval/user-guides/ad-fmcomms2-ebz/software/basic_iq_datafiles#binary_format
+			((int16_t*)p_dat)[0] = 0 << 4; // Real (I)
+			((int16_t*)p_dat)[1] = 0 << 4; // Imag (Q)
+		}
+
+		// Sample counter increment and status output
+		nrx += nbytes_rx / iio_device_get_sample_size(rx);
+		ntx += nbytes_tx / iio_device_get_sample_size(tx);
+		printf("\tRX %8.2f MSmp, TX %8.2f MSmp\n", nrx/1e6, ntx/1e6);
+	}
+
+	shutdown();
+
+	return 0;
+}