sr: support for SR_HWCAP_COUPLING and SR_DI_COUPLING

hwdriver.c

@@ -44,6 +44,7 @@ SR_API struct sr_hwcap_option sr_hwcap_options[] = {
 	{SR_HWCAP_TIMEBASE, SR_T_RATIONAL_PERIOD, "Time base", "timebase"},
 	{SR_HWCAP_FILTER, SR_T_CHAR, "Filter targets", "filter"},
 	{SR_HWCAP_VDIV, SR_T_RATIONAL_VOLT, "Volts/div", "vdiv"},
+	{SR_HWCAP_COUPLING, SR_T_CHAR, "Coupling", "coupling"},
 	{0, 0, NULL, NULL},
 };
 

sigrok.h.in

@@ -323,6 +323,9 @@ enum {
 	/** Volts/div. */
 	SR_HWCAP_VDIV,
 
+	/** Coupling. */
+	SR_HWCAP_COUPLING,
+
 	/*--- Special stuff -------------------------------------------------*/
 
 	/* TODO: Better description. */
@@ -433,6 +436,8 @@ enum {
 	SR_DI_FILTERS,
 	/* Valid volts/div values */
 	SR_DI_VDIVS,
+	/* Coupling options */
+	SR_DI_COUPLING,
 };
 
 /*