1 files changed, 301 insertions, 0 deletions
diff --git a/host/usrp_e_utils/usrp-e-loopback.c b/host/usrp_e_utils/usrp-e-loopback.c
new file mode 100644
index 000000000..762e55ac8
--- /dev/null
+++ b/host/usrp_e_utils/usrp-e-loopback.c
@@ -0,0 +1,301 @@
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stddef.h>
+#include <sys/mman.h>
+#include <sys/time.h>
+#include <poll.h>
+#include "linux/usrp_e.h"
+
+// max length #define PKT_DATA_LENGTH 1016
+static int packet_data_length;
+static int error;
+
+struct pkt {
+	int len;
+	int checksum;
+	int seq_num;
+	short data[1024-6];
+};
+
+struct ring_buffer_info (*rxi)[];
+struct ring_buffer_info (*txi)[];
+struct pkt (*rx_buf)[200];
+struct pkt (*tx_buf)[200];
+
+static int fp;
+static struct usrp_e_ring_buffer_size_t rb_size;
+
+static int calc_checksum(struct pkt *p)
+{
+	int i, sum;
+
+	i = 0;
+	sum = 0;
+
+	if (p->len < 1016) {
+		for (i=0; i < p->len; i++)
+			sum += p->data[i];
+	
+		sum += p->seq_num;
+		sum += p->len;
+	} else {	
+		printf("Bad packet length = %d received.\n", p->len);
+	}
+
+	return sum;
+}
+
+static struct timeval delta_time(struct timeval f, struct timeval s)
+{
+	struct timeval d;
+
+	if (f.tv_usec > s.tv_usec) {
+		d.tv_usec = f.tv_usec - s.tv_usec;
+		d.tv_sec = f.tv_sec - s.tv_sec;
+	} else {
+		d.tv_usec = f.tv_usec - s.tv_usec + 1e6;
+		d.tv_sec = f.tv_sec - s.tv_sec - 1;
+	}
+
+	return d;
+}
+
+static void *read_thread(void *threadid)
+{
+	int cnt, prev_seq_num, pkt_count, seq_num_failure;
+	struct pkt *p;
+	unsigned long bytes_transfered;
+	struct timeval start_time;
+	int rb_read;
+
+	printf("Greetings from the reading thread!\n");
+	printf("sizeof pkt = %d\n", sizeof(struct pkt));
+
+	rb_read = 0;
+
+	bytes_transfered = 0;
+	gettimeofday(&start_time, NULL);
+
+	prev_seq_num = 0;
+	pkt_count = 0;
+	seq_num_failure = 0;
+
+	while (1) {
+
+		if (!((*rxi)[rb_read].flags & RB_USER)) {
+//			printf("Waiting for data\n");
+			struct pollfd pfd;
+			pfd.fd = fp;
+			pfd.events = POLLIN;
+			poll(&pfd, 1, -1);
+		}
+
+		(*rxi)[rb_read].flags = RB_USER_PROCESS;
+
+//		printf("pkt received, rb_read = %d\n", rb_read);
+
+		cnt = (*rxi)[rb_read].len;
+		p = &(*rx_buf)[rb_read];
+
+//		cnt = read(fp, rx_data, 2048);
+//		if (cnt < 0)
+//			printf("Error returned from read: %d, sequence number = %d\n", cnt, p->seq_num);
+
+//		printf("p = %X, p->seq_num = %d p->len = %d\n", p, p->seq_num, p->len);
+
+
+		pkt_count++;
+
+		if (p->seq_num != prev_seq_num + 1) {
+			printf("Sequence number fail, current = %d, previous = %d, pkt_count = %d\n",
+				p->seq_num, prev_seq_num, pkt_count);
+			printf("pkt received, rb_read = %d\n", rb_read);
+			printf("p = %p, p->seq_num = %d p->len = %d\n", p, p->seq_num, p->len);
+
+			seq_num_failure ++;
+			if (seq_num_failure > 2)
+				error = 1;
+		}
+
+		prev_seq_num = p->seq_num;
+
+		if (calc_checksum(p) != p->checksum) {
+			printf("Checksum fail packet = %X, expected = %X, pkt_count = %d\n",
+				calc_checksum(p), p->checksum, pkt_count);
+			error = 1;
+		}
+
+		(*rxi)[rb_read].flags = RB_KERNEL;
+
+		rb_read++;
+		if (rb_read == rb_size.num_rx_frames)
+			rb_read = 0;
+
+		bytes_transfered += cnt;
+
+		if (bytes_transfered > (100 * 1000000)) {
+			struct timeval finish_time, d_time;
+			float elapsed_seconds;
+
+			gettimeofday(&finish_time, NULL);
+			d_time = delta_time(finish_time, start_time);
+			elapsed_seconds = (float)d_time.tv_sec + ((float)d_time.tv_usec * 1e-6f);
+
+			printf("RX data transfer rate = %f K Samples/second\n",
+				(float) bytes_transfered / elapsed_seconds / 4000.0f);
+
+
+			start_time = finish_time;
+			bytes_transfered = 0;
+		}
+
+
+//		printf(".");
+//		fflush(stdout);
+//		printf("\n");
+	}
+	return NULL;
+}
+
+static void *write_thread(void *threadid)
+{
+	int seq_number, i, cnt, rb_write;
+	void *tx_data;
+	struct pkt *p;
+
+	printf("Greetings from the write thread!\n");
+
+	tx_data = malloc(2048);
+	p = (struct pkt *) ((void *)tx_data);
+
+	for (i=0; i < packet_data_length; i++)
+//		p->data[i] = random() >> 16;
+		p->data[i] = i;
+
+	seq_number = 1;
+	rb_write = 0;
+
+	while (1) {
+		p->seq_num = seq_number++;
+
+		if (packet_data_length > 0)
+			p->len = packet_data_length;
+		else
+			p->len = (random() & 0x1ff) + (1004 - 512);
+
+		p->checksum = calc_checksum(p);
+
+		if (!((*txi)[rb_write].flags & RB_KERNEL)) {
+//			printf("Waiting for space\n");
+			struct pollfd pfd;
+			pfd.fd = fp;
+			pfd.events = POLLOUT;
+			poll(&pfd, 1, -1);
+		}
+
+		memcpy(&(*tx_buf)[rb_write], tx_data, p->len * 2 + 12);
+
+		(*txi)[rb_write].len = p->len * 2 + 12;
+		(*txi)[rb_write].flags = RB_USER;
+
+		rb_write++;
+		if (rb_write == rb_size.num_tx_frames)
+			rb_write = 0;
+
+		cnt = write(fp, NULL, 0);
+//		if (cnt < 0)
+//			printf("Error returned from write: %d\n", cnt);
+//		sleep(1);
+	}
+	return NULL;
+}
+
+
+int main(int argc, char *argv[])
+{
+	pthread_t tx, rx;
+	long int t = 0;
+	struct sched_param s = {
+		.sched_priority = 1
+	};
+	int ret, map_size, page_size;
+	void *rb;
+	struct usrp_e_ctl16 d;
+
+	if (argc < 2) {
+		printf("%s data_size\n", argv[0]);
+		return -1;
+	}
+
+	packet_data_length = atoi(argv[1]);
+
+	if (packet_data_length > 1016) {
+		packet_data_length = 1016;
+		printf("Max data length = 1016, clamping.\n");
+	}
+
+	fp = open("/dev/usrp_e0", O_RDWR);
+	printf("fp = %d\n", fp);
+
+	d.offset = 14;
+	d.count = 1;
+	d.buf[0] = (1<<8) | (1<<9);
+	ioctl(fp, USRP_E_WRITE_CTL16, &d);
+
+	page_size = getpagesize();
+
+	ret = ioctl(fp, USRP_E_GET_RB_INFO, &rb_size);
+
+	map_size = (rb_size.num_pages_rx_flags + rb_size.num_pages_tx_flags) * page_size +
+		(rb_size.num_rx_frames + rb_size.num_tx_frames) * (page_size >> 1);
+
+	rb = mmap(0, map_size, PROT_READ|PROT_WRITE, MAP_SHARED, fp, 0);
+	if (rb == MAP_FAILED) {
+		perror("mmap failed");
+		return -1;
+	}
+
+	printf("rb = %p\n", rb);
+
+	rxi = rb;
+	rx_buf = rb + (rb_size.num_pages_rx_flags * page_size);
+	txi = rb +  (rb_size.num_pages_rx_flags * page_size) +
+		(rb_size.num_rx_frames * page_size >> 1);
+	tx_buf = rb +  (rb_size.num_pages_rx_flags * page_size) +
+		(rb_size.num_rx_frames * page_size >> 1) +
+		(rb_size.num_pages_tx_flags * page_size);
+
+	printf("rxi = %p, rx_buf = %p, txi = %p, tx_buf = %p\n", rxi, rx_buf, txi, tx_buf);
+
+	if ((ret = sched_setscheduler(0, SCHED_RR, &s)))
+		perror("sched_setscheduler");
+
+	error = 0;
+
+#if 1
+	if (pthread_create(&rx, NULL, read_thread, (void *) t)) {
+		printf("Failed to create rx thread\n");
+		exit(-1);
+	}
+
+	sleep(1);
+#endif
+
+	if (pthread_create(&tx, NULL, write_thread, (void *) t)) {
+		printf("Failed to create tx thread\n");
+		exit(-1);
+	}
+
+//	while (!error)
+		sleep(1000000000);
+
+	printf("Done sleeping\n");
+
+	return 0;
+}