+ * @param dev The device for which the trigger specification is intended.
+ * @param triggerstring The string containing the trigger specification for
+ * one or more probes of this device. Entries for multiple probes are
+ * comma-separated. Triggers are specified in the form key=value,
+ * where the key is a probe number (or probe name) and the value is
+ * the requested trigger type. Valid trigger types currently
+ * include 'r' (rising edge), 'f' (falling edge), 'c' (any pin value
+ * change), '0' (low value), or '1' (high value).
+ * Example: "1=r,sck=f,miso=0,7=c"