output/analog: add revolutions per minute unit

libsigrok.h

@@ -216,6 +216,7 @@ enum {
 	 * represented as the fraction of number of particles of the substance.
 	 */
 	SR_UNIT_CONCENTRATION,
+	SR_UNIT_REVOLUTIONS_PER_MINUTE,
 };
 
 /** Values for sr_datafeed_analog.flags. */

output/analog.c

@@ -173,6 +173,9 @@ static void fancyprint(int unit, int mqflags, float value, GString *out)
 	case SR_UNIT_CONCENTRATION:
 		g_string_append_printf(out, "%f ppm", value * 1000000);
 		break;
+	case SR_UNIT_REVOLUTIONS_PER_MINUTE:
+		si_printf(value, out, "RPM");
+		break;
 	default:
 		si_printf(value, out, "");
 		break;