X-Git-Url: http://sigrok.org/gitweb/?a=blobdiff_plain;f=libsigrok.h;h=f371c944fd6ff85ac6b699ec1cba06f40f272836;hb=17dfb2c32c6686630fd95b2f25e554fa01f8ebd1;hp=ee1e9e1037fe377bf01022f944b2c1f0045a0bf7;hpb=ef4344e7f44fe8b67fdbf1cebf2b1a6d7edbfe77;p=libsigrok.git

diff --git a/libsigrok.h b/libsigrok.h
index ee1e9e10..f371c944 100644
--- a/libsigrok.h
+++ b/libsigrok.h
@@ -210,6 +210,11 @@ enum {
 	SR_UNIT_UNITLESS,
 	/** Sound pressure level relative so 20 micropascals. */
 	SR_UNIT_DECIBEL_SPL,
+	/**
+	 * Normalized (0 to 1) concentration of a substance or compound with 0
+	 * representing a concentration of 0%, and 1 being 100%. This is
+	 * represented as the fraction of number of particles of the substance.
+	 */
 	SR_UNIT_CONCENTRATION,
 };
 
@@ -263,7 +268,7 @@ struct sr_context;
 
 struct sr_datafeed_packet {
 	uint16_t type;
-	void *payload;
+	const void *payload;
 };
 
 struct sr_datafeed_header {
@@ -331,7 +336,7 @@ struct sr_output_format {
 	int (*event) (struct sr_output *o, int event_type, uint8_t **data_out,
 		      uint64_t *length_out);
 	GString *(*recv) (struct sr_output *o, const struct sr_dev_inst *sdi,
-			struct sr_datafeed_packet *packet);
+			const struct sr_datafeed_packet *packet);
 	int (*cleanup) (struct sr_output *o);
 };