sr: support for SR_HWCAP_FILTER and SR_DI_FILTERS

hwdriver.c

@@ -42,6 +42,7 @@ SR_API struct sr_hwcap_option sr_hwcap_options[] = {
 			"horiz_triggerpos"},
 	{SR_HWCAP_BUFFERSIZE, SR_T_UINT64, "Buffer size", "buffersize"},
 	{SR_HWCAP_TIMEBASE, SR_T_RATIONAL, "Time base", "timebase"},
+	{SR_HWCAP_FILTER, SR_T_CHAR, "Filter targets", "filter"},
 	{0, 0, NULL, NULL},
 };
 

sigrok.h.in

@@ -316,6 +316,9 @@ enum {
 	/** Time base. */
 	SR_HWCAP_TIMEBASE,
 
+	/** Filter. */
+	SR_HWCAP_FILTER,
+
 	/*--- Special stuff -------------------------------------------------*/
 
 	/* TODO: Better description. */
@@ -422,6 +425,8 @@ enum {
 	SR_DI_TIMEBASES,
 	/* Supported trigger sources */
 	SR_DI_TRIGGER_SOURCES,
+	/* Supported filter targets */
+	SR_DI_FILTERS,
 };
 
 /*