ubb-patgen/ubb-patgen.c: accept SI suffixes and a unit for durations as well

ubb-patgen/README

@@ -77,6 +77,11 @@ while and clean up on exit, add the delay in seconds, e.g.:
 
 # ubb-patgen -f 500kHz -c 10
 
+The delay can be followed by "m", "u", or "n" for the respective
+multiplier. Furthermore, it can end with an optional "s". Note
+that the minimum time ubb-patgen actually spends generating a
+clock will typically be in the order of several milliseconds.
+
 To stop the MMC bus clock, run
 
 # ubb-patgen -c 0

ubb-patgen/ubb-patgen.c

@@ -465,6 +465,9 @@ static int frequency(const char *s, int *hz, int *rel)
 
 	f = strtod(s, &end);
 
+	if (end == s || f < 0)
+		return 0;
+
 	switch (*end) {
 	case 'M':
 	case 'm':
@@ -503,6 +506,49 @@ static int frequency(const char *s, int *hz, int *rel)
 }
 
 
+static int duration(const char *s, struct timespec *res)
+{
+	char *end;
+	double d;
+
+	d = strtod(s, &end);
+
+	if (end == s || d < 0)
+		return 0;
+
+	switch (*end) {
+	case 'M':
+	case 'm':
+		d /= 1e3;
+		end++;
+		break;
+	case 'U':
+	case 'u':
+		d /= 1e6;
+		end++;
+		break;
+	case 'N':
+	case 'n':
+		d /= 1e9;
+		end++;
+		break;
+	default:
+		break;
+	}
+
+	if (*end == 'S' || *end == 's')
+		end++;
+
+	if (*end)
+		return 0;
+
+	res->tv_sec = d;
+	res->tv_nsec = (d-res->tv_sec)*1e9;
+
+	return 1;
+}
+
+
 static void usage(const char *name)
 {
         fprintf(stderr,
@@ -523,10 +569,12 @@ static void usage(const char *name)
 "              (default: exit immediately but leave the clock on)\n"
 "  file        file containing the pattern\n"
 "  pattern     send the specified pattern on DAT0 through DAT3\n\n"
-"Frequency: the frequency in Hz, optionally followed by \"M\" or \"k\",\n"
+"Frequency: the frequency in hertz, optionally followed by \"M\" or \"k\",\n"
 "  optionally followed by \"Hz\", optionally followed by \"+\" or \"-\".\n"
 "  \"+\" selects a frequency >= the specified one, \"-\" one <=.\n"
 "  Without +/-, the closest available frequency is selected.\n"
+"Duration: the duration in seconds, optionally followed by \"m\", \"u\", or\n"
+"  \"n\", optionally followed by \"s\".\n"
 "Pattern: hex digits corresponding to 1 for DAT0, 2 for DAT1, etc.\n"
 "  {n} repeats the preceding digit n times, e.g., 1{3} is equivalent to 111.\n"
     , name, name, name, name);
@@ -540,7 +588,6 @@ int main(int argc, char **argv)
 	int bus_hz = 0, clk_only = 0, clkout = 0, bus_rel = 0;
 	const char *pattern = NULL;
 	int quiet = 0, force_pattern = 0;
-	double active_s = 0;
 	struct timespec active_ns;
 	int keep_clk = 1;
 	uint8_t mask = 0xf;
@@ -617,11 +664,8 @@ int main(int argc, char **argv)
 		if (clk_only) {
 			if (force_pattern)
 				usage(*argv);
-			active_s = strtod(argv[argc-1], &end);
+			if (!duration(argv[optind], &active_ns))
-			if (*end)
 				usage(*argv);
-			active_ns.tv_sec = (int) active_s;
-			active_ns.tv_nsec = (active_s-(int) active_s)*1e9;
 			keep_clk = 0;
 		} else {
 			pattern = argv[optind];
@@ -653,7 +697,7 @@ int main(int argc, char **argv)
 	if (pattern)
 		dma_pattern(&clk, pattern, mask << 10, trigger);
 
-	if (active_s)
+	if (!keep_clk)
 		if (nanosleep(&active_ns, NULL))
 			perror("nanosleep");
 	if (pattern) {