X-Git-Url: https://sigrok.org/gitweb/?p=sigrok-cli.git;a=blobdiff_plain;f=device.c;h=141e3cfd2c9edb35887c02a0a2ff3acb891c4f2c;hp=a159ff003c7f07f7b2669885e87fdbb44d5730b7;hb=cfad6a304754649dbd8841af8a15ddba16a69cc6;hpb=d486cbddfe380de95a98646f7626426955e563ee

diff --git a/device.c b/device.c
index a159ff0..141e3cf 100644
--- a/device.c
+++ b/device.c
@@ -35,12 +35,16 @@ GSList *device_scan(void)
 	int i;
 
 	if (opt_drv) {
+		/* Caller specified driver. Use it. Only this one. */
 		if (!parse_driver(opt_drv, &driver, &drvopts))
 			return NULL;
 		devices = sr_driver_scan(driver, drvopts);
 		g_slist_free_full(drvopts, (GDestroyNotify)free_drvopts);
+	} else if (opt_dont_scan) {
+		/* No -d choice, and -D "don't scan" requested. Do nothing. */
+		devices = NULL;
 	} else {
-		/* No driver specified, let them all scan on their own. */
+		/* No driver specified. Scan all available drivers. */
 		devices = NULL;
 		drivers = sr_driver_list(sr_ctx);
 		for (i = 0; drivers[i]; i++) {
@@ -59,7 +63,20 @@ GSList *device_scan(void)
 	return devices;
 }
 
-struct sr_channel_group *select_channel_group(struct sr_dev_inst *sdi)
+/**
+ * Lookup a channel group from its name.
+ *
+ * Uses the previously stored option value to lookup a channel group.
+ * Returns a reference to the channel group when the lookup succeeded,
+ * or #NULL after lookup failure, or #NULL for the global channel group
+ * (the device's global parameters). Emits an error message when the
+ * lookup failed while a channel group's name was specified.
+ *
+ * @param[in] sdi Device instance.
+ *
+ * @returns The channel group, or #NULL for failed lookup.
+ */
+struct sr_channel_group *lookup_channel_group(struct sr_dev_inst *sdi)
 {
 	struct sr_channel_group *cg;
 	GSList *l, *channel_groups;
@@ -68,7 +85,6 @@ struct sr_channel_group *select_channel_group(struct sr_dev_inst *sdi)
 		return NULL;
 
 	channel_groups = sr_dev_inst_channel_groups_get(sdi);
-
 	if (!channel_groups) {
 		g_critical("This device does not have any channel groups.");
 		return NULL;
@@ -76,9 +92,9 @@ struct sr_channel_group *select_channel_group(struct sr_dev_inst *sdi)
 
 	for (l = channel_groups; l; l = l->next) {
 		cg = l->data;
-		if (!g_ascii_strcasecmp(opt_channel_group, cg->name)) {
-			return cg;
-		}
+		if (g_ascii_strcasecmp(opt_channel_group, cg->name) != 0)
+			continue;
+		return cg;
 	}
 	g_critical("Invalid channel group '%s'", opt_channel_group);