+/**
+ * Convert a numeric frequency value to the "natural" string representation
+ * of its voltage value.
+ *
+ * E.g. a value of 300000 would be converted to "300mV", 2 to "2V".
+ *
+ * @param voltage The voltage represented as a rational number, with the
+ * denominator a divisor of 1V.
+ *
+ * @return A g_try_malloc()ed string representation of the voltage value,
+ * or NULL upon errors. The caller is responsible to g_free() the
+ * memory.
+ */
+SR_API char *sr_voltage_string(struct sr_rational *voltage)
+{
+ char *o;
+ int r;
+
+ if (!(o = g_try_malloc0(30 + 1))) {
+ sr_err("strutil: %s: o malloc failed", __func__);
+ return NULL;
+ }
+
+ if (voltage->q == 1000)
+ r = snprintf(o, 30, "%" PRIu64 "mV", voltage->p);
+ else if (voltage->q == 1)
+ r = snprintf(o, 30, "%" PRIu64 "V", voltage->p);
+ else
+ r = -1;
+
+ if (r < 0) {
+ /* Something went wrong... */
+ g_free(o);
+ return NULL;
+ }
+
+ return o;
+}
+