SR_API char *sr_si_string_u64(uint64_t x, const char *unit);
SR_API char *sr_samplerate_string(uint64_t samplerate);
SR_API char *sr_period_string(uint64_t frequency);
-SR_API char *sr_voltage_string(struct sr_rational *voltage);
+SR_API char *sr_voltage_string(uint64_t v_p, uint64_t v_q);
SR_API char **sr_parse_triggerstring(const struct sr_dev_inst *sdi,
const char *triggerstring);
SR_API int sr_parse_sizestring(const char *sizestring, uint64_t *size);