Doxygen fixes: Hide private stuff, document some structs.

backend.c

@@ -98,7 +98,7 @@ extern struct sr_session *session;
  *   	struct sr_context *sr_ctx;
  *
  *   	if ((ret = sr_init(&sr_ctx)) != SR_OK) {
- *   		printf("Error initializing libsigrok (%s): %s.",
+ *   		printf("Error initializing libsigrok (%s): %s.\n",
  *   		       sr_strerror_name(ret), sr_strerror(ret));
  *   		return 1;
  *   	}
@@ -106,7 +106,7 @@ extern struct sr_session *session;
  *   	// Use libsigrok functions here...
  *
  *   	if ((ret = sr_exit(sr_ctx)) != SR_OK) {
- *   		printf("Error shutting down libsigrok (%s): %s.",
+ *   		printf("Error shutting down libsigrok (%s): %s.\n",
  *   		       sr_strerror_name(ret), sr_strerror(ret));
  *   		return 1;
  *   	}

device.c

@@ -380,6 +380,7 @@ SR_PRIV void sr_serial_dev_inst_free(struct sr_serial_dev_inst *serial)
 }
 #endif
 
+/** @private */
 SR_PRIV struct sr_usbtmc_dev_inst *sr_usbtmc_dev_inst_new(const char *device)
 {
 	struct sr_usbtmc_dev_inst *usbtmc;
@@ -400,6 +401,7 @@ SR_PRIV struct sr_usbtmc_dev_inst *sr_usbtmc_dev_inst_new(const char *device)
 	return usbtmc;
 }
 
+/** @private */
 SR_PRIV void sr_usbtmc_dev_inst_free(struct sr_usbtmc_dev_inst *usbtmc)
 {
 	g_free(usbtmc->device);

libsigrok.h

@@ -303,7 +303,14 @@ enum {
 	SR_MQFLAG_AVG = 0x40000,
 };
 
-/** sigrok context (opaque). @see sr_init(), sr_exit(). */
+/**
+ * @struct sr_context
+ * Opaque structure representing a libsigrok context.
+ *
+ * None of the fields of this structure are meant to be accessed directly.
+ *
+ * @see sr_init(), sr_exit().
+ */
 struct sr_context;
 
 /** Packet in a sigrok data feed. */
@@ -948,6 +955,8 @@ struct sr_dev_driver {
 };
 
 /**
+ * @struct sr_session
+ *
  * Opaque data structure representing a libsigrok session. None of the fields
  * of this structure are meant to be accessed directly.
  */

strutil.c

@@ -42,6 +42,8 @@
  */
 
 /**
+ * @private
+ *
  * Convert a string representation of a numeric value to a long integer. The
  * conversion is strict and will fail if the complete string does not represent
  * a valid long integer. The function sets errno according to the details of the
@@ -73,6 +75,8 @@ SR_PRIV int sr_atol(const char *str, long *ret)
 }
 
 /**
+ * @private
+ *
  * Convert a string representation of a numeric value to an integer. The
  * conversion is strict and will fail if the complete string does not represent
  * a valid integer. The function sets errno according to the details of the
@@ -102,6 +106,8 @@ SR_PRIV int sr_atoi(const char *str, int *ret)
 }
 
 /**
+ * @private
+ *
  * Convert a string representation of a numeric value to a double. The
  * conversion is strict and will fail if the complete string does not represent
  * a valid double. The function sets errno according to the details of the
@@ -133,6 +139,8 @@ SR_PRIV int sr_atod(const char *str, double *ret)
 }
 
 /**
+ * @private
+ *
  * Convert a string representation of a numeric value to a float. The
  * conversion is strict and will fail if the complete string does not represent
  * a valid float. The function sets errno according to the details of the