documented all return codes in doxygen

git-svn-id: https://svn.code.sf.net/p/gphoto/code/trunk/libgphoto2@10343 67ed7778-7388-44ab-90cf-0a291f65f57c

libgphoto2_port/gphoto2/gphoto2-port-result.h

@@ -22,34 +22,101 @@
 #define __GPHOTO2_PORT_RESULT_H__
 
 /* Return values. gphoto2-port should only return values from 0 to -99 */
+/**
+ * \brief Everything is OK
+ * 
+ * Note that this is also the value 0, and every error is negative (lower).
+ */
 #define GP_OK                            0
+/**
+ * \brief Generic Error
+ */
 #define GP_ERROR                        -1
+/**
+ * \brief Bad parameters passed
+ */
 #define GP_ERROR_BAD_PARAMETERS		-2
+/**
+ * \brief Out of memory
+ */
 #define GP_ERROR_NO_MEMORY		-3
+/**
+ * \brief Error in the camera driver
+ */
 #define GP_ERROR_LIBRARY		-4
+/**
+ * \brief Unknown libgphoto2 port passed
+ */
 #define GP_ERROR_UNKNOWN_PORT		-5
+/**
+ * \brief Functionality not supported
+ */
 #define GP_ERROR_NOT_SUPPORTED		-6
+/**
+ * \brief Generic I/O error
+ */
 #define GP_ERROR_IO			-7
+/**
+ * \brief Buffer overflow of internal structure
+ */
 #define GP_ERROR_FIXED_LIMIT_EXCEEDED	-8
-
+/**
+ * \brief Operation timed out
+ */
 #define GP_ERROR_TIMEOUT                -10
 
+/**
+ * \brief Serial ports not supported
+ */
 #define GP_ERROR_IO_SUPPORTED_SERIAL    -20
+/**
+ * \brief USB ports not supported
+ */
 #define GP_ERROR_IO_SUPPORTED_USB       -21
 
+/**
+ * \brief Error initialising I/O
+ */
 #define GP_ERROR_IO_INIT                -31
+/**
+ * \brief I/O during read
+ */
 #define GP_ERROR_IO_READ                -34
+/**
+ * \brief I/O during write
+ */
 #define GP_ERROR_IO_WRITE               -35
+/**
+ * \brief I/O during update of settings
+ */
 #define GP_ERROR_IO_UPDATE              -37
 
+/**
+ * \brief Specified serial speed not possible.
+ */
 #define GP_ERROR_IO_SERIAL_SPEED        -41
 
+/**
+ * \brief Error during USB Clear HALT
+ */
 #define GP_ERROR_IO_USB_CLEAR_HALT      -51
+/**
+ * \brief Error when trying to find USB device
+ */
 #define GP_ERROR_IO_USB_FIND            -52
+/**
+ * \brief Error when trying to claim the USB device
+ */
 #define GP_ERROR_IO_USB_CLAIM           -53
 
+/**
+ * \brief Error when trying to lock the device
+ */
 #define GP_ERROR_IO_LOCK                -60
 
+/**
+ * \brief Unspecified error when talking to HAL
+ */
 #define GP_ERROR_HAL                    -70
 
 const char *gp_port_result_as_string (int result);