initial copy

git-svn-id: http://svn.asterisk.org/svn/dahdi/tools/trunk@4335 a0bf4364-ded3-4de4-8d8a-66a801d63aff

1 files changed, 1110 insertions, 0 deletions

diff --git a/fxotune.c b/fxotune.c
new file mode 100644
index 0000000..d7ee9ca
--- /dev/null
+++ b/fxotune.c
@@ -0,0 +1,1110 @@
+/* 
+ * This file and contents thereof are licensed under the terms and
+ * conditions of the GNU Public License version 2.  For more information
+ * (including terms and conditions) see http://www.gnu.org/
+ *
+ * fxotune.c -- A utility for tuning the various settings on the fxo
+ * 		modules for the TDM400 cards.
+ *
+ * by Matthew Fredrickson <creslin@digium.com>
+ * 
+ * (C) 2004-2005 Digium, Inc.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <math.h>
+#include <sys/time.h>
+
+#ifdef STANDALONE_ZAPATA
+#include "kernel/zaptel.h"
+#else
+#include <zaptel/zaptel.h>
+#endif
+#include "kernel/wctdm.h"
+#include "fxotune.h"
+
+#define TEST_DURATION 2000
+#define BUFFER_LENGTH (2 * TEST_DURATION)
+#define SKIP_SAMPLES 800
+
+static const float amplitude = 16384.0;
+
+static char *zappath = "/dev/zap";
+static char *configfile = "/etc/fxotune.conf";
+
+static int audio_dump_fd = -1;
+
+static char *usage =
+"Usage: fxotune [-v[vv] (-s | -i <options> | -d <options>)\n"
+"\n"
+"	-s : set previously calibrated echo settings\n"
+"	-i : calibrate echo settings\n"
+"		options : [<dialstring>] [-t <calibtype>]\n"
+"		[-b <startdev>][-e <stopdev>]\n"
+"		[-n <dialstring>][-l <delaytosilence>][-m <silencegoodfor>]\n"
+" 	-d : dump input and output waveforms to ./fxotune_dump.vals\n"
+"		options : [-b <device>][-w <waveform>]\n"
+"		   [-n <dialstring>][-l <delaytosilence>][-m <silencegoodfor>]\n"
+"	-v : more output (-vv, -vvv also)\n"
+"	-o <path> : Write the received raw 16-bit signed linear audio that is\n"
+"	            used in processing to the file specified by <path>\n"
+"	-c <config_file>\n"
+"\n"
+"		<calibtype>      - type of calibration\n"
+"		                   (default 2, old method 1)\n"
+"		<startdev>\n"
+"		<stopdev>        - defines a range of devices to test\n"
+"		                   (default: 1-252)\n"
+"		<dialstring>     - string to dial to clear the line\n"
+"		                   (default 5)\n"
+"		<delaytosilence> - seconds to wait for line to clear (default 0)\n"
+"		<silencegoodfor> - seconds before line will no longer be clear\n"
+"		                   (default 18)\n"
+"		<device>         - the device to perform waveform dump on\n"
+"		                   (default 1)\n"
+"		<waveform>       - -1 for multitone waveform, or frequency of\n"
+"		                   single tone (default -1)\n"
+"		<config_file>    - Alternative file to set from / calibrate to.\n"
+"				   (Default: /etc/fxotune.conf)\n"
+;
+
+
+#define OUT_OF_BOUNDS(x) ((x) < 0 || (x) > 255)
+
+struct silence_info{
+	char *dialstr;
+	/** fd of device we are working with */
+	int device; 
+	/** seconds we should wait after dialing the dialstring before we know for sure we'll have silence */
+	int initial_delay;
+	/** seconds after which a reset should occur */
+	int reset_after;
+	/** time of last reset */
+	struct timeval last_reset; 
+};
+
+static short outbuf[TEST_DURATION];
+static int debug = 0;
+
+static FILE *debugoutfile = NULL;
+
+static int fxotune_read(int fd, void *buffer, int len)
+{
+	int res;
+
+	res = read(fd, buffer, len);
+
+	if ((res > 0) && (audio_dump_fd != -1)) {
+		write(audio_dump_fd, buffer, len);
+	}
+
+	return res;
+}
+
+/**
+ * Makes sure that the line is clear.
+ * Right now, we do this by relying on the user to specify how long after dialing the
+ * dialstring we can rely on the line being silent (before the telco complains about
+ * the user not hitting the next digit).
+ * 
+ * A more robust way to do this would be to actually measure the sound levels on the line,
+ * but that's a lot more complicated, and this should work.
+ * 
+ * @return 0 if succesful (no errors), 1 if unsuccesful
+ */
+static int ensure_silence(struct silence_info *info)
+{
+	struct timeval tv;
+	long int elapsedms;
+	
+	gettimeofday(&tv, NULL);
+	
+	if (info->last_reset.tv_sec == 0) {
+		/* this is the first request, we will force it to run */
+		elapsedms = -1;
+	} else {
+		/* this is not the first request, we will compute elapsed time */
+		elapsedms = ((tv.tv_sec - info->last_reset.tv_sec) * 1000L + (tv.tv_usec - info->last_reset.tv_usec) / 1000L);
+	}
+	if (debug > 4) {
+		fprintf(stdout, "Reset line request received - elapsed ms = %li / reset after = %ld\n", elapsedms, info->reset_after * 1000L);
+	}
+
+	if (elapsedms > 0 && elapsedms < info->reset_after * 1000L)
+		return 0;
+	
+	if (debug > 1){
+		fprintf(stdout, "Resetting line\n");
+	}
+	
+	/* do a line reset */
+	/* prepare line for silence */
+	/* Do line hookstate reset */
+	int x = ZT_ONHOOK;
+
+	if (ioctl(info->device, ZT_HOOK, &x)) {
+		fprintf(stderr, "Unable to hang up fd %d\n", info->device);
+		return -1;
+	}
+
+	sleep(2);
+	x = ZT_OFFHOOK;
+	if (ioctl(info->device, ZT_HOOK, &x)) {
+		fprintf(stderr, "Cannot bring fd %d off hook\n", info->device);
+		return -1;
+	}
+	sleep(2); /* Added to ensure that dial can actually takes place */
+
+	struct zt_dialoperation dop;
+	memset(&dop, 0, sizeof(dop));
+	dop.op = ZT_DIAL_OP_REPLACE;
+	dop.dialstr[0] = 'T';
+	zap_copy_string(dop.dialstr + 1, info->dialstr, sizeof(dop.dialstr));
+
+
+	if (ioctl(info->device, ZT_DIAL, &dop)) {
+		fprintf(stderr, "Unable to dial!\n");
+		return -1;
+	}
+	sleep(1); 
+	sleep(info->initial_delay);  
+	
+	
+	gettimeofday(&info->last_reset, NULL);
+	
+	
+	return 0;
+}
+
+/**
+ * Generates a tone of specified frequency.
+ * 
+ * @param hz the frequency of the tone to be generated
+ * @param index the current sample
+ * 		to begenerated.  For a normal waveform you need to increment
+ * 		this every time you execute the function.
+ *
+ * @return 16bit slinear sample for the specified index
+ */
+static short inline gentone(int hz, int index)
+{
+	return amplitude * sin((index * 2.0 * M_PI * hz)/8000);
+}
+
+/* Using DTMF tones for now since they provide good mid band testing 
+ * while not being harmonics of each other */
+static int freqs[] = {697, 770, 941, 1209, 1336, 1633};
+static int freqcount = 6;
+
+/**
+ * Generates a waveform of several frequencies.
+ * 
+ * @param index the current sample
+ * 		to begenerated.  For a normal waveform you need to increment
+ * 		this every time you execute the function.
+ *
+ * @return 16bit slinear sample for the specified index
+ */
+static short inline genwaveform(int index)
+{
+	int i = 0;
+	float response = (float)0;
+	for (i = 0; i < freqcount; i++){
+		response += sin((index * 2.0 * M_PI * freqs[i])/8000);
+	}
+	
+
+	return amplitude * response / freqcount;
+}
+
+
+/**
+ *  Calculates the RMS of the waveform buffer of samples in 16bit slinear format.
+ *  prebuf the buffer of either shorts or floats
+ *  bufsize the number of elements in the prebuf buffer (not the number of bytes!)
+ *  short_format 1 if prebuf points to an array of shorts, 0 if it points to an array of floats
+ *  
+ *  Formula for RMS (http://en.wikipedia.org/wiki/Root_mean_square): 
+ *  
+ *  Xrms = sqrt(1/N Sum(x1^2, x2^2, ..., xn^2))
+ *  
+ *  Note:  this isn't really a power calculation - but it gives a good measure of the level of the response
+ *  
+ *  @param prebuf the buffer containing the values to compute
+ *  @param bufsize the size of the buffer
+ *  @param short_format 1 if prebuf contains short values, 0 if it contains float values
+ */
+static float power_of(void *prebuf, int bufsize, int short_format)
+{
+	float sum_of_squares = 0;
+	int numsamples = 0;
+	float finalanswer = 0;
+	short *sbuf = (short*)prebuf;
+	float *fbuf = (float*)prebuf;
+	int i = 0;
+
+	if (short_format) {
+		/* idiot proof checks */
+		if (bufsize <= 0)
+			return -1;
+
+		numsamples = bufsize; /* Got rid of divide by 2 - the bufsize parameter should give the number of samples (that's what it does for the float computation, and it should do it here as well) */
+
+		for (i = 0; i < numsamples; i++) {
+			sum_of_squares += ((float)sbuf[i] * (float)sbuf[i]);
+		}
+	} else {
+		/* Version for float inputs */
+		for (i = 0; i < bufsize; i++) {
+			sum_of_squares += (fbuf[i] * fbuf[i]);
+		}
+	}
+
+	finalanswer = sum_of_squares/(float)bufsize; /* need to divide by the number of elements in the sample for RMS calc */
+
+	if (finalanswer < 0) {
+		printf("Error: Final answer negative number %f\n", finalanswer);
+		return -3;
+	}
+
+	return sqrtf(finalanswer);
+}
+
+/* 
+ * In an effort to eliminate as much as possible the effect of outside noise, we use principles
+ * from the Fourier Transform to attempt to calculate the return loss of our signal for each setting.
+ *
+ * To begin, we send our output signal out on the line.  We then receive back the reflected
+ * response.  In the Fourier Transform, each evenly distributed frequency within the window
+ * is correlated (multiplied against, then the resulting samples are added together) with
+ * the real (cos) and imaginary (sin) portions of that frequency base to detect that frequency.
+ * 
+ * Instead of doing a complete Fourier Transform, we solve the transform for only our signal
+ * by multiplying the received signal by the real and imaginary portions of our reference
+ * signal.  This then gives us the real and imaginary values that we can use to calculate
+ * the return loss of the sinusoids that we sent out on the line.  This is done by finding
+ * the magnitude (think polar form) of the vector resulting from the real and imaginary
+ * portions calculated above.
+ *
+ * This essentially filters out any other noise which maybe present on the line which is outside
+ * the frequencies used in our test multi-tone.
+ */
+static float db_loss(float measured, float reference)
+{
+	return 20 * (logf(measured/reference)/logf(10));
+}
+
+static void one_point_dft(const short *inbuf, int len, int frequency, float *real, float *imaginary)
+{
+	float myreal = 0, myimag = 0;
+	int i;
+
+	for (i = 0; i < len; i++) {
+		myreal += (float) inbuf[i] * cos((i * 2.0 * M_PI * frequency)/8000);
+		myimag += (float) inbuf[i] * sin((i * 2.0 * M_PI * frequency)/8000);
+	}
+
+	myimag *= -1;
+
+	*real = myreal / (float) len;
+	*imaginary = myimag / (float) len;
+}
+
+static float calc_magnitude(short *inbuf, int insamps)
+{
+	float real, imaginary, magnitude;
+	float totalmagnitude = 0;
+	int i;
+
+	for (i = 0; i < freqcount; i++) {
+		one_point_dft(inbuf, insamps, freqs[i], &real, &imaginary);
+		magnitude = sqrtf((real * real) + (imaginary * imaginary));
+		totalmagnitude += magnitude;
+	}
+
+	return totalmagnitude;
+}
+
+/**
+ *  dumps input and output buffer contents for the echo test - used to see exactly what's going on
+ */
+static int maptone(int whichzap, int freq, char *dialstr, int delayuntilsilence)
+{
+	int i = 0;
+	int res = 0, x = 0;
+	struct zt_bufferinfo bi;
+	short inbuf[TEST_DURATION]; /* changed from BUFFER_LENGTH - this buffer is for short values, so it should be allocated using the length of the test */
+	FILE *outfile = NULL;
+
+	outfile = fopen("fxotune_dump.vals", "w");
+	if (!outfile) {
+		fprintf(stdout, "Cannot create fxotune_dump.vals\n");
+		return -1;
+	}
+
+	x = 1;
+	if (ioctl(whichzap, ZT_SETLINEAR, &x)) {
+		fprintf(stderr, "Unable to set channel to signed linear mode.\n");
+		return -1;
+	}
+
+	memset(&bi, 0, sizeof(bi));
+	if (ioctl(whichzap, ZT_GET_BUFINFO, &bi)) {
+		fprintf(stderr, "Unable to get buffer information!\n");
+		return -1;
+	}
+	bi.numbufs = 2;
+	bi.bufsize = TEST_DURATION; /* KD - changed from BUFFER_LENGTH; */
+	bi.txbufpolicy = ZT_POLICY_IMMEDIATE;
+	bi.rxbufpolicy = ZT_POLICY_IMMEDIATE;
+	if (ioctl(whichzap, ZT_SET_BUFINFO, &bi)) {
+		fprintf(stderr, "Unable to set buffer information!\n");
+		return -1;
+	}
+
+	/* Fill the output buffers */
+	int leadin = 50;
+	int trailout = 100;
+	for (i = 0; i < leadin; i++)
+		outbuf[i] = 0;
+	for (; i < TEST_DURATION - trailout; i++){
+		outbuf[i] = freq > 0 ? gentone(freq, i) : genwaveform(i); /* if frequency is negative, use a multi-part waveform instead of a single frequency */
+	}
+	for (; i < TEST_DURATION; i++)
+		outbuf[i] = 0;
+
+	/* Make sure the line is clear */
+	struct silence_info sinfo;
+	memset(&sinfo, 0, sizeof(sinfo));
+	sinfo.device = whichzap;
+	sinfo.dialstr = dialstr;
+	sinfo.initial_delay = delayuntilsilence;
+	sinfo.reset_after = 4; /* doesn't matter - we are only running one test */
+	
+	if (ensure_silence(&sinfo)){
+		fprintf(stderr, "Unable to get a clear outside line\n");
+		return -1;
+	}
+
+	/* Flush buffers */
+	x = ZT_FLUSH_READ | ZT_FLUSH_WRITE | ZT_FLUSH_EVENT;
+	if (ioctl(whichzap, ZT_FLUSH, &x)) {
+		fprintf(stderr, "Unable to flush I/O: %s\n", strerror(errno));
+		return -1;
+	}
+
+	/* send data out on line */
+	res = write(whichzap, outbuf, BUFFER_LENGTH); /* we are sending a TEST_DURATION length array of shorts (which are 2 bytes each) */
+	if (res != BUFFER_LENGTH) { 
+		fprintf(stderr, "Could not write all data to line\n");
+		return -1;
+	}
+
+retry:
+		/* read return response */
+	res = fxotune_read(whichzap, inbuf, BUFFER_LENGTH);
+	if (res != BUFFER_LENGTH) {
+		int x;
+
+		ioctl(whichzap, ZT_GETEVENT, &x);
+		goto retry;
+	}
+
+	/* write content of output buffer to debug file */
+	float power_result = power_of(inbuf, TEST_DURATION, 1); 
+	float power_waveform = power_of(outbuf, TEST_DURATION, 1); 
+	float echo = power_result/power_waveform;
+	
+	fprintf(outfile, "Buffers, freq=%d, outpower=%0.0f, echo=%0.4f\n", freq, power_result, echo);
+	fprintf(outfile, "Sample, Input (received from the line), Output (sent to the line)\n");
+	for (i = 0; i < TEST_DURATION; i++){
+		fprintf(outfile, "%d, %d, %d\n", 
+			i,
+			inbuf[i],
+			outbuf[i]
+		);
+	}
+
+	fclose(outfile);
+	
+	fprintf(stdout, "echo ratio = %0.4f (%0.1f / %0.1f)\n", echo, power_result, power_waveform);
+	
+	return 0;
+}
+
+
+
+/**
+ * Perform calibration type 2 on the specified device
+ * 
+ * Determine optimum echo coefficients for the specified device
+ * 
+ * New tuning strategy.  If we have a number that we can dial that will result in silence from the
+ * switch, the tune will be *much* faster (we don't have to keep hanging up and dialing a digit, etc...)
+ * The downside is that the user needs to actually find a 'no tone' phone number at their CO's switch - but for
+ * really fixing echo problems, this is what it takes.
+ *
+ * Also, for the purposes of optimizing settings, if we pick a single frequency and test with that,
+ * we can try a whole bunch of impedence/echo coefficients.  This should give better results than trying
+ * a bunch of frequencies, and we can always do a a frequency sweep to pick between the best 3 or 4
+ * impedence/coefficients configurations.
+ *   
+ * Note:  It may be possible to take this even further and do some pertubation analysis on the echo coefficients
+ * 		 themselves (maybe use the 72 entry sweep to find some settings that are close to working well, then
+ * 		 deviate the coefficients a bit to see if we can improve things).  A better way to do this would be to
+ * 		 use the optimization strategy from silabs.  For reference, here is an application note that describes
+ * 		 the echo coefficients (and acim values):
+ * 		 
+ * 		 http://www.silabs.com/public/documents/tpub_doc/anote/Wireline/Silicon_DAA/en/an84.pdf
+ * 		 
+ */
+static int acim_tune2(int whichzap, int freq, char *dialstr, int delayuntilsilence, int silencegoodfor, struct wctdm_echo_coefs *coefs_out)
+{
+	int i = 0;
+	int res = 0, x = 0;
+	int lowesttry = -1;
+	float lowesttryresult = 999999999999.0;
+	float lowestecho = 999999999999.0;;
+	struct zt_bufferinfo bi;
+
+	short inbuf[TEST_DURATION * 2];
+
+	if (debug && !debugoutfile) {
+		if (!(debugoutfile = fopen("fxotune.vals", "w"))) {
+			fprintf(stdout, "Cannot create fxotune.vals\n");
+			return -1;
+		}
+	}
+
+	/* Set echo settings */
+	if (ioctl(whichzap, WCTDM_SET_ECHOTUNE, &echo_trys[0])) {
+		fprintf(stderr, "Unable to set impedance on fd %d\n", whichzap);
+		return -1;
+	}
+
+	x = 1;
+	if (ioctl(whichzap, ZT_SETLINEAR, &x)) {
+		fprintf(stderr, "Unable to set channel to signed linear mode.\n");
+		return -1;
+	}
+
+	memset(&bi, 0, sizeof(bi));
+	if (ioctl(whichzap, ZT_GET_BUFINFO, &bi)) {
+		fprintf(stderr, "Unable to get buffer information!\n");
+		return -1;
+	}
+	bi.numbufs = 2;
+	bi.bufsize = BUFFER_LENGTH;
+	bi.txbufpolicy = ZT_POLICY_IMMEDIATE;
+	bi.rxbufpolicy = ZT_POLICY_IMMEDIATE;
+	if (ioctl(whichzap, ZT_SET_BUFINFO, &bi)) {
+		fprintf(stderr, "Unable to set buffer information!\n");
+		return -1;
+	}
+	x = ZT_OFFHOOK;
+	if (ioctl(whichzap, ZT_HOOK, &x)) {
+		fprintf(stderr, "Cannot bring fd %d off hook", whichzap);
+		return -1;
+	}
+
+
+	/* Set up silence settings */
+	struct silence_info sinfo;
+	memset(&sinfo, 0, sizeof(sinfo));
+	sinfo.device = whichzap;
+	sinfo.dialstr = dialstr;
+	sinfo.initial_delay = delayuntilsilence;
+	sinfo.reset_after = silencegoodfor;
+
+	/* Fill the output buffers */
+	for (i = 0; i < TEST_DURATION; i++)
+		outbuf[i] = freq > 0 ? gentone(freq, i) : genwaveform(i); /* if freq is negative, use a multi-frequency waveform */
+	
+	/* compute power of input (so we can later compute echo levels relative to input) */
+	float waveform_power = calc_magnitude(outbuf, TEST_DURATION);
+	
+
+	/* sweep through the various coefficient settings and see how our responses look */
+
+	int echo_trys_size = 72;
+	int trys = 0;
+	for (trys = 0; trys < echo_trys_size; trys++){
+		
+		/* ensure silence on the line */
+		if (ensure_silence(&sinfo)){
+			fprintf(stderr, "Unable to get a clear outside line\n");
+			return -1;
+		}
+		
+		if (ioctl(whichzap, WCTDM_SET_ECHOTUNE, &echo_trys[trys])) {
+			fprintf(stderr, "Unable to set echo coefficients on fd %d\n", whichzap);
+			return -1;
+		}
+
+		/* Flush buffers */
+		x = ZT_FLUSH_READ | ZT_FLUSH_WRITE | ZT_FLUSH_EVENT;
+		if (ioctl(whichzap, ZT_FLUSH, &x)) {
+			fprintf(stderr, "Unable to flush I/O: %s\n", strerror(errno));
+			return -1;
+		}
+
+		/* send data out on line */
+		res = write(whichzap, outbuf, BUFFER_LENGTH);
+		if (res != BUFFER_LENGTH) {
+			fprintf(stderr, "Could not write all data to line\n");
+			return -1;
+		}
+
+retry:
+		/* read return response */
+		res = fxotune_read(whichzap, inbuf, BUFFER_LENGTH * 2);
+		if (res != BUFFER_LENGTH * 2) {
+			int x;
+
+			ioctl(whichzap, ZT_GETEVENT, &x);
+			goto retry;
+		}
+
+		float freq_result = calc_magnitude(inbuf, TEST_DURATION * 2);
+		float echo = db_loss(freq_result, waveform_power);
+		
+#if 0
+		if (debug > 0)
+			fprintf(stdout, "%3d,%d,%d,%d,%d,%d,%d,%d,%d: magnitude = %0.0f, echo = %0.4f dB\n", 
+					echo_trys[trys].acim, echo_trys[trys].coef1, echo_trys[trys].coef2,
+					echo_trys[trys].coef3, echo_trys[trys].coef4, echo_trys[trys].coef5,
+					echo_trys[trys].coef6, echo_trys[trys].coef7, echo_trys[trys].coef8,
+					freq_result, echo);
+#endif
+
+		if (freq_result < lowesttryresult){
+			lowesttry = trys;
+			lowesttryresult = freq_result;
+			lowestecho = echo;
+		}
+		if (debug) {
+			char result[256];
+			snprintf(result, sizeof(result), "%3d,%3d,%3d,%3d,%3d,%3d,%3d,%3d,%3d,%f,%f", 
+						echo_trys[trys].acim, 
+						echo_trys[trys].coef1, 
+						echo_trys[trys].coef2, 
+						echo_trys[trys].coef3, 
+						echo_trys[trys].coef4, 
+						echo_trys[trys].coef5, 
+						echo_trys[trys].coef6, 
+						echo_trys[trys].coef7, 
+						echo_trys[trys].coef8, 
+						freq_result,
+						echo
+					);
+			
+			fprintf(debugoutfile, "%s\n", result);
+			fprintf(stdout, "%3d,%3d,%3d,%3d,%3d,%3d,%3d,%3d,%3d: magnitude = %0.0f, echo = %0.4f dB\n", 
+					echo_trys[trys].acim, echo_trys[trys].coef1, echo_trys[trys].coef2,
+					echo_trys[trys].coef3, echo_trys[trys].coef4, echo_trys[trys].coef5,
+					echo_trys[trys].coef6, echo_trys[trys].coef7, echo_trys[trys].coef8,
+					freq_result, echo);
+		}
+	}
+
+	if (debug > 0)
+		fprintf(stdout, "Config with lowest response = %d, magnitude = %0.0f, echo = %0.4f dB\n", lowesttry, lowesttryresult, lowestecho);
+
+	memcpy(coefs_out, &echo_trys[lowesttry], sizeof(struct wctdm_echo_coefs));
+
+	return 0;
+}
+
+/**
+ *  Perform calibration type 1 on the specified device.  Only tunes the line impedance.  Look for best response range 
+ */
+static int acim_tune(int whichzap, char *dialstr, int delayuntilsilence, int silencegoodfor, struct wctdm_echo_coefs *coefs_out)
+{
+	int i = 0, freq = 0, acim = 0;
+	int res = 0, x = 0;
+	struct zt_bufferinfo bi;
+	struct wctdm_echo_coefs coefs;
+	short inbuf[TEST_DURATION]; /* changed from BUFFER_LENGTH - this buffer is for short values, so it should be allocated using the length of the test */
+	int lowest = 0;
+	FILE *outfile = NULL;
+	float acim_results[16];
+
+
+	if (debug) {
+		outfile = fopen("fxotune.vals", "w");
+		if (!outfile) {
+			fprintf(stdout, "Cannot create fxotune.vals\n");
+			return -1;
+		}
+	}
+
+	/* Set up silence settings */
+	struct silence_info sinfo;
+	memset(&sinfo, 0, sizeof(sinfo));
+	sinfo.device = whichzap;
+	sinfo.dialstr = dialstr;
+	sinfo.initial_delay = delayuntilsilence;
+	sinfo.reset_after = silencegoodfor;
+	
+	/* Set echo settings */
+	memset(&coefs, 0, sizeof(coefs));
+	if (ioctl(whichzap, WCTDM_SET_ECHOTUNE, &coefs)) {
+		fprintf(stdout, "Skipping non-TDM / non-FXO\n");
+		return -1;
+	}
+
+	x = 1;
+	if (ioctl(whichzap, ZT_SETLINEAR, &x)) {
+		fprintf(stderr, "Unable to set channel to signed linear mode.\n");
+		return -1;
+	}
+
+	memset(&bi, 0, sizeof(bi));
+	if (ioctl(whichzap, ZT_GET_BUFINFO, &bi)) {
+		fprintf(stderr, "Unable to get buffer information!\n");
+		return -1;
+	}
+	bi.numbufs = 2;
+	bi.bufsize = BUFFER_LENGTH;
+	bi.txbufpolicy = ZT_POLICY_IMMEDIATE;
+	bi.rxbufpolicy = ZT_POLICY_IMMEDIATE;
+	if (ioctl(whichzap, ZT_SET_BUFINFO, &bi)) {
+		fprintf(stderr, "Unable to set buffer information!\n");
+		return -1;
+	}
+
+	for (acim = 0; acim < 16; acim++) {
+		float freq_results[15];
+
+		coefs.acim = acim;
+		if (ioctl(whichzap, WCTDM_SET_ECHOTUNE, &coefs)) {
+			fprintf(stderr, "Unable to set impedance on fd %d\n", whichzap);
+			return -1;
+		}
+
+		for (freq = 200; freq <=3000; freq+=200) {
+			/* Fill the output buffers */
+			for (i = 0; i < TEST_DURATION; i++)
+				outbuf[i] = gentone(freq, i);
+
+			/* Make sure line is ready for next test iteration */
+			if (ensure_silence(&sinfo)){
+				fprintf(stderr, "Unable to get a clear line\n");
+				return -1;
+			}
+			
+
+			/* Flush buffers */
+			x = ZT_FLUSH_READ | ZT_FLUSH_WRITE | ZT_FLUSH_EVENT;
+			if (ioctl(whichzap, ZT_FLUSH, &x)) {
+				fprintf(stderr, "Unable to flush I/O: %s\n", strerror(errno));
+				return -1;
+			}
+	
+			/* send data out on line */
+			res = write(whichzap, outbuf, BUFFER_LENGTH);
+			if (res != BUFFER_LENGTH) {
+				fprintf(stderr, "Could not write all data to line\n");
+				return -1;
+			}
+
+			/* read return response */
+retry:
+			/* read return response */
+			res = fxotune_read(whichzap, inbuf, BUFFER_LENGTH);
+			if (res != BUFFER_LENGTH) {
+				int x;
+	
+				ioctl(whichzap, ZT_GETEVENT, &x);
+				goto retry;
+			}
+
+			/* calculate power of response */
+			
+			freq_results[(freq/200)-1] = power_of(inbuf+SKIP_SAMPLES, TEST_DURATION-SKIP_SAMPLES, 1); /* changed from inbuf+SKIP_BYTES, BUFFER_LENGTH-SKIP_BYTES, 1 */
+			if (debug) fprintf(outfile, "%d,%d,%f\n", acim, freq, freq_results[(freq/200)-1]);
+		}
+		acim_results[acim] = power_of(freq_results, 15, 0);
+	}
+
+	if (debug) {
+		for (i = 0; i < 16; i++)
+			fprintf(outfile, "acim_results[%d] = %f\n", i, acim_results[i]);
+	}
+	/* Find out what the "best" impedance is for the line */
+	lowest = 0;
+	for (i = 0; i < 16; i++) {
+		if (acim_results[i] < acim_results[lowest]) {
+			lowest = i;
+		}
+	}
+
+	coefs_out->acim = lowest;
+	coefs_out->coef1 = 0;
+	coefs_out->coef2 = 0;
+	coefs_out->coef3 = 0;
+	coefs_out->coef4 = 0;
+	coefs_out->coef5 = 0;
+	coefs_out->coef6 = 0;
+	coefs_out->coef7 = 0;
+	coefs_out->coef8 = 0;
+	
+	return 0;
+}
+
+/**
+ * Reads echo register settings from the configuration file and pushes them into
+ * the appropriate devices
+ * 
+ * @param configfilename the path of the file that the calibration results should be written to
+ * 
+ * @return 0 if successful, !0 otherwise
+ */	
+static int do_set(char *configfilename)
+{
+	FILE *fp = NULL;
+	int res = 0;
+	int fd = 0;
+		
+	fp = fopen(configfile, "r");
+	
+    if (!fp) {
+            fprintf(stdout, "Cannot open %s!\n",configfile);
+            return -1;
+    }
+
+	
+	while (res != EOF) {
+		struct wctdm_echo_coefs mycoefs;
+		char completezappath[56] = "";
+		int myzap,myacim,mycoef1,mycoef2,mycoef3,mycoef4,mycoef5,mycoef6,mycoef7,mycoef8;
+
+
+		res = fscanf(fp, "%d=%d,%d,%d,%d,%d,%d,%d,%d,%d",&myzap,&myacim,&mycoef1,
+				&mycoef2,&mycoef3,&mycoef4,&mycoef5,&mycoef6,&mycoef7,
+				&mycoef8);
+
+		if (res == EOF) {
+			break;
+		}
+
+		/* Check to be sure conversion is done correctly */
+		if (OUT_OF_BOUNDS(myacim) || OUT_OF_BOUNDS(mycoef1)||
+			OUT_OF_BOUNDS(mycoef2)|| OUT_OF_BOUNDS(mycoef3)||
+			OUT_OF_BOUNDS(mycoef4)|| OUT_OF_BOUNDS(mycoef5)||
+			OUT_OF_BOUNDS(mycoef6)|| OUT_OF_BOUNDS(mycoef7)|| OUT_OF_BOUNDS(mycoef8)) {
+
+			fprintf(stdout, "Bounds check error on inputs from %s:%d\n", configfile, myzap);
+			return -1;
+		}
+
+		mycoefs.acim = myacim;
+		mycoefs.coef1 = mycoef1;
+		mycoefs.coef2 = mycoef2;
+		mycoefs.coef3 = mycoef3;
+		mycoefs.coef4 = mycoef4;
+		mycoefs.coef5 = mycoef5;
+		mycoefs.coef6 = mycoef6;
+		mycoefs.coef7 = mycoef7;
+		mycoefs.coef8 = mycoef8;
+	
+		snprintf(completezappath, sizeof(completezappath), "%s/%d", zappath, myzap);
+		fd = open(completezappath, O_RDWR);
+
+		if (fd < 0) {
+			fprintf(stdout, "open error on %s: %s\n", completezappath, strerror(errno));
+			return -1;
+		}
+
+		if (ioctl(fd, WCTDM_SET_ECHOTUNE, &mycoefs)) {
+			fprintf(stdout, "%s: %s\n", completezappath, strerror(errno));
+			return -1;
+		}
+
+		close(fd);
+	}
+
+	fclose(fp);
+
+	if (debug)
+		fprintf(stdout, "fxotune: successfully set echo coeffecients on FXO modules\n");
+	return 0;	
+}
+
+/**
+ * Output waveform information from a single test
+ * 
+ * Clears the line, then sends a single waveform (multi-tone, or single tone), and listens
+ * for the response on the line.  Output is written to fxotune_dump.vals
+ * 
+ * @param startdev the device to test
+ * @param dialstr the string that should be dialed to clear the dialtone from the line
+ * @param delayuntilsilence the number of seconds to wait after dialing dialstr before starting the test
+ * @param silencegoodfor the number of seconds that the test can run before having to reset the line again
+ * 			(this is basically the amount of time it takes before the 'if you'd like to make a call...' message
+ * 			kicks in after you dial dialstr.  This test is so short that the value is pretty much ignored.
+ * @param waveformtype the type of waveform to use - -1 = multi-tone waveform, otherwise the specified value
+ * 			is used as the frequency of a single tone.  A value of 0 will output silence.
+ */
+static int do_dump(int startdev, char* dialstr, int delayuntilsilence, int silencegoodfor, int waveformtype)
+{
+	int res = 0;
+	int fd;
+	char zapdev[80] = "";
+	
+	int zapmodule = startdev;
+	snprintf(zapdev, sizeof(zapdev), "%s/%d", zappath, zapmodule);
+
+	fd = open(zapdev, O_RDWR);
+	if (fd < 0) {
+		fprintf(stdout, "%s absent: %s\n", zapdev, strerror(errno));
+		return -1;
+	}
+
+	fprintf(stdout, "Dumping module %s\n", zapdev);
+	res = maptone(fd, waveformtype, dialstr, delayuntilsilence); 
+
+	close(fd);
+
+	if (res) {
+		fprintf(stdout, "Failure!\n");
+		return res;
+	} else {
+		fprintf(stdout, "Done!\n");
+		return 0;
+	}
+
+}	
+
+/**
+ * Performs calibration on all specified devices
+ * 
+ * @param startdev the first device to check
+ * @param enddev the last device to check
+ * @param calibtype the type of calibration to perform.  1=old style (loops through individual frequencies
+ * 			doesn't optimize echo coefficients.  2=new style (uses multi-tone and optimizes echo coefficients
+ * 			and acim setting)
+ * @param configfilename the path of the file that the calibration results should be written to
+ * @param dialstr the string that should be dialed to clear the dialtone from the line
+ * @param delayuntilsilence the number of seconds to wait after dialing dialstr before starting the test
+ * @param silencegoodfor the number of seconds that the test can run before having to reset the line again
+ * 			(this is basically the amount of time it takes before the 'if you'd like to make a call...' message
+ * 			kicks in after you dial dialstr
+ * 
+ * @return 0 if successful, !0 otherwise
+ */	
+static int do_calibrate(int startdev, int enddev, int calibtype, char* configfilename, char* dialstr, int delayuntilsilence, int silencegoodfor)
+{
+	int problems = 0;
+	int res = 0;
+	int configfd, fd;
+	int devno = 0;
+	char zapdev[80] = "";
+	struct wctdm_echo_coefs coefs;
+	
+	configfd = open(configfile, O_CREAT|O_TRUNC|O_WRONLY, 0666);
+
+	if (configfd < 0) {
+		fprintf(stderr, "Cannot generate config file %s: open: %s\n", configfile, strerror(errno));
+		return -1;
+	}
+
+	for (devno = startdev; devno <= enddev; devno++) {
+		snprintf(zapdev, sizeof(zapdev), "%s/%d", zappath, devno);
+
+		fd = open(zapdev, O_RDWR);
+		if (fd < 0) {
+			fprintf(stdout, "%s absent: %s\n", zapdev, strerror(errno));
+			continue;
+		}
+
+		fprintf(stdout, "Tuning module %s\n", zapdev);
+		
+		if (1 == calibtype)
+			res = acim_tune(fd, dialstr, delayuntilsilence, silencegoodfor, &coefs);
+		else
+			res = acim_tune2(fd, -1, dialstr, delayuntilsilence, silencegoodfor, &coefs);
+
+		close(fd);
+		
+		if (res) {
+			fprintf(stdout, "Failure!\n");
+			problems++;
+		} else {
+			fprintf(stdout, "Done!\n");
+		}
+
+		if (res == 0) {
+			
+		/* Do output to file */
+			int len = 0;
+			static char output[255] = "";
+
+			snprintf(output, sizeof(output), "%d=%d,%d,%d,%d,%d,%d,%d,%d,%d\n", 
+				devno,
+				coefs.acim, 
+				coefs.coef1, 
+				coefs.coef2, 
+				coefs.coef3, 
+				coefs.coef4, 
+				coefs.coef5, 
+				coefs.coef6, 
+				coefs.coef7, 
+				coefs.coef8
+			);
+
+			if (debug)
+				fprintf(stdout, "Found best echo coefficients: %s\n", output);
+
+			len = strlen(output);
+			res = write(configfd, output, strlen(output));
+			if (res != len) {
+				fprintf(stdout, "Unable to write line \"%s\" to file.\n", output);
+				return -1;
+			}
+		}
+	}
+
+	close(configfd);
+	
+	if (problems)
+		fprintf(stdout, "Unable to tune %d devices, even though those devices are present\n", problems);
+	
+	return problems;
+}	
+	
+int main(int argc , char **argv)
+{
+	int startdev = 1; /* -b */
+	int stopdev = 252; /* -e */
+	int calibtype = 2; /* -t */
+	int waveformtype = -1; /* -w multi-tone by default.  If > 0, single tone of specified frequency */
+	int delaytosilence = 0; /* -l */
+	int silencegoodfor = 18; /* -m */
+	
+	char* dialstr = "5"; /* -n */
+	
+	int res = 0;
+
+	int doset = 0; /* -s */
+	int docalibrate = 0; /* -i <dialstr> */
+	int dodump = 0; /* -d */
+
+	int i = 0;
+	
+	for (i = 1; i < argc; i++){
+		if (!(argv[i][0] == '-' || argv[i][0] == '/') || (strlen(argv[i]) <= 1)){
+			fprintf(stdout, "Unknown option : %s\n", argv[i]);
+			/* Show usage */
+			fputs(usage, stdout);
+			return -1;
+		}
+		int moreargs = (i < argc - 1);
+		
+		switch(argv[i][1]){
+			case 's':
+				doset=1;
+				continue;
+			case 'i':
+				docalibrate = 1;
+				if (moreargs){ /* we need to check for a value after 'i' for backwards compatability with command line options of old fxotune */
+					if (argv[i+1][0] != '-' && argv[i+1][0] != '/')
+						dialstr = argv[++i];
+				}
+				continue;
+			case 'c':
+				configfile = moreargs ? argv[++i] : configfile;
+				continue;
+			case 'd':
+				dodump = 1;
+				continue;
+			case 'b':
+				startdev = moreargs ? atoi(argv[++i]) : startdev;
+				break;
+			case 'e':
+				stopdev = moreargs ? atoi(argv[++i]) : stopdev;
+				break;
+			case 't':
+				calibtype = moreargs ? atoi(argv[++i]) : calibtype;
+				break;
+			case 'w':
+				waveformtype = moreargs ? atoi(argv[++i]) : waveformtype;
+				break;
+			case 'l':
+				delaytosilence = moreargs ? atoi(argv[++i]) : delaytosilence;
+				break;
+			case 'm':
+				silencegoodfor = moreargs ? atoi(argv[++i]) : silencegoodfor;
+				break;
+			case 'n':
+				dialstr = moreargs ? argv[++i] : dialstr;
+				break;
+			case 'v':
+				debug = strlen(argv[i])-1;
+				break;
+			case 'o':
+				if (moreargs) {
+					audio_dump_fd = open(argv[++i], O_WRONLY|O_CREAT|O_TRUNC, 0666);
+					if (audio_dump_fd == -1) {
+						fprintf(stdout, "Unable to open file %s: %s\n", argv[i], strerror(errno));
+						return -1;
+					}
+					break;
+				} else {
+					fprintf(stdout, "No path supplied to -o option!\n");
+					return -1;
+				}
+			default:
+				fprintf(stdout, "Unknown option : %s\n", argv[i]);
+				/* Show usage */
+				fputs(usage, stdout);
+				return -1;
+				
+		}
+	}
+	
+	if (debug > 3){
+		fprintf(stdout, "Running with parameters:\n");
+		fprintf(stdout, "\tdoset=%d\n", doset);	
+		fprintf(stdout, "\tdocalibrate=%d\n", docalibrate);	
+		fprintf(stdout, "\tdodump=%d\n", dodump);	
+		fprintf(stdout, "\tstartdev=%d\n", startdev);	
+		fprintf(stdout, "\tstopdev=%d\n", stopdev);	
+		fprintf(stdout, "\tcalibtype=%d\n", calibtype);	
+		fprintf(stdout, "\twaveformtype=%d\n", waveformtype);	
+		fprintf(stdout, "\tdelaytosilence=%d\n", delaytosilence);	
+		fprintf(stdout, "\tsilencegoodfor=%d\n", silencegoodfor);	
+		fprintf(stdout, "\tdialstr=%s\n", dialstr);	
+		fprintf(stdout, "\tdebug=%d\n", debug);	
+	}
+
+	if (docalibrate){
+		res = do_calibrate(startdev, stopdev, calibtype, configfile, dialstr, delaytosilence, silencegoodfor);
+		if (!res)
+			return do_set(configfile);	
+		else
+			return -1;
+	}
+
+	if (doset)
+		return do_set(configfile);
+				
+	if (dodump){
+		res = do_dump(startdev, dialstr, delaytosilence, silencegoodfor, waveformtype);
+		if (!res)
+			return 0;
+		else
+			return -1;
+	}
+
+	fputs(usage, stdout);
+	return -1;
+}