Doxygen: Add @file items for the relevant files.

These short descriptions are shown in the "Files" section of the
Doxygen output.

backend.c

@@ -63,6 +63,12 @@
  * <a href="http://sigrok.org/wiki/Libsigrok">sigrok.org/wiki/Libsigrok</a>
  */
 
+/**
+ * @file
+ *
+ * Initializing and shutting down libsigrok.
+ */
+
 /**
  * @defgroup grp_init Initialization
  *

datastore.c

@@ -24,6 +24,12 @@
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 
+/**
+ * @file
+ *
+ * Creating, using, or destroying libsigrok datastores.
+ */
+
 /**
  * @defgroup grp_datastore Datastore
  *

device.c

@@ -22,6 +22,12 @@
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 
+/**
+ * @file
+ *
+ * Device handling in libsigrok.
+ */
+
 /**
  * @defgroup grp_devices Devices
  *

error.c

@@ -20,6 +20,12 @@
 
 #include "libsigrok.h"
 
+/**
+ * @file
+ *
+ * Error handling in libsigrok.
+ */
+
 /**
  * @defgroup grp_error Error handling
  *

filter.c

@@ -23,6 +23,12 @@
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 
+/**
+ * @file
+ *
+ * Helper functions to filter out unused probes from samples.
+ */
+
 /**
  * @defgroup grp_filter Probe filter
  *

hwdriver.c

@@ -26,6 +26,12 @@
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 
+/**
+ * @file
+ *
+ * Hardware driver handling in libsigrok.
+ */
+
 /**
  * @defgroup grp_driver Hardware drivers
  *

input/input.c

@@ -20,6 +20,12 @@
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 
+/**
+ * @file
+ *
+ * Input file/data format handling.
+ */
+
 /**
  * @defgroup grp_input Input formats
  *

libsigrok-internal.h

@@ -27,6 +27,12 @@
 #include <libusb.h>
 #endif
 
+/**
+ * @file
+ *
+ * libsigrok private header file, only to be used internally.
+ */
+
 /*--- Macros ----------------------------------------------------------------*/
 
 #ifndef ARRAY_SIZE

libsigrok.h

@@ -30,6 +30,12 @@
 extern "C" {
 #endif
 
+/**
+ * @file
+ *
+ * The public libsigrok header file to be used by frontends.
+ */
+
 /*
  * All possible return codes of libsigrok functions must be listed here.
  * Functions should never return hardcoded numbers as status, but rather

log.c

@@ -26,7 +26,7 @@
 /**
  * @file
  *
- * Logging support.
+ * Controlling the libsigrok message logging functionality.
  */
 
 /**

output/output.c

@@ -20,6 +20,12 @@
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 
+/**
+ * @file
+ *
+ * Output file/data format handling.
+ */
+
 /**
  * @defgroup grp_output Output formats
  *

proto.h

@@ -20,6 +20,12 @@
 #ifndef LIBSIGROK_SIGROK_PROTO_H
 #define LIBSIGROK_SIGROK_PROTO_H
 
+/**
+ * @file
+ *
+ * Header file containing API function prototypes.
+ */
+
 /*--- backend.c -------------------------------------------------------------*/
 
 SR_API int sr_init(struct sr_context **ctx);

session.c

@@ -25,6 +25,12 @@
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 
+/**
+ * @file
+ *
+ * Creating, using, or destroying libsigrok sessions.
+ */
+
 /**
  * @defgroup grp_session Session handling
  *

session_file.c

@@ -27,6 +27,12 @@
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 
+/**
+ * @file
+ *
+ * Loading and saving libsigrok session files.
+ */
+
 /**
  * @addtogroup grp_session
  *

strutil.c

@@ -24,6 +24,12 @@
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 
+/**
+ * @file
+ *
+ * Helper functions for handling or converting libsigrok-related strings.
+ */
+
 /**
  * @defgroup grp_strutil String utilities
  *

version.c

@@ -20,6 +20,12 @@
 
 #include "libsigrok.h"
 
+/**
+ * @file
+ *
+ * Version number querying functions.
+ */
+
 /**
  * @defgroup grp_versions Versions
  *