Update platform.h

Minor documentation improvements:
*Standardized file brief description.
*Reordered tags within documentation blocks so that params and returns are last in block.
*Some minor rephrasing.

include/mbedtls/platform.h

@@ -1,7 +1,8 @@
 /**
  * \file platform.h
  *
- * \brief The Mbed TLS platform abstraction layer.
+ * \brief This file contains the definitions and functions of the
+ *        Mbed TLS platform abstraction layer.
  */
 /*
  *  Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved
@@ -102,7 +103,7 @@ extern "C" {
 /* \} name SECTION: Module settings */
 
 /*
- * The function pointers for calloc and free
+ * The function pointers for calloc and free.
  */
 #if defined(MBEDTLS_PLATFORM_MEMORY)
 #if defined(MBEDTLS_PLATFORM_FREE_MACRO) && \
@@ -116,7 +117,8 @@ extern void * (*mbedtls_calloc)( size_t n, size_t size );
 extern void (*mbedtls_free)( void *ptr );
 
 /**
- * \brief   This function allows configuring custom memory-management functions.
+ * \brief               This function allows configuring custom
+ *                      memory-management functions.
  *
  * \param calloc_func   The \c calloc function implementation.
  * \param free_func     The \c free function implementation.
@@ -140,7 +142,8 @@ int mbedtls_platform_set_calloc_free( void * (*calloc_func)( size_t, size_t ),
 extern int (*mbedtls_fprintf)( FILE *stream, const char *format, ... );
 
 /**
- * \brief   This function allows configuring a custom \p fprintf function pointer.
+ * \brief                This function allows configuring a custom
+ *                       \p fprintf function pointer.
  *
  * \param fprintf_func   The \c fprintf function implementation.
  *
@@ -163,8 +166,8 @@ int mbedtls_platform_set_fprintf( int (*fprintf_func)( FILE *stream, const char
 extern int (*mbedtls_printf)( const char *format, ... );
 
 /**
- * \brief    This function allows configuring a custom \c printf function
+ * \brief               This function allows configuring a custom \c printf
- *           pointer.
+ *                      function pointer.
  *
  * \param printf_func   The \c printf function implementation.
  *
@@ -197,12 +200,12 @@ int mbedtls_platform_win32_snprintf( char *s, size_t n, const char *fmt, ... );
 extern int (*mbedtls_snprintf)( char * s, size_t n, const char * format, ... );
 
 /**
- * \brief   This function allows configuring a custom \c snprintf function
+ * \brief                 This function allows configuring a custom
- *          pointer.
+ *                        \c snprintf function pointer.
  *
  * \param snprintf_func   The \c snprintf function implementation.
  *
- * \return    \c 0 on success.
+ * \return                \c 0 on success.
  */
 int mbedtls_platform_set_snprintf( int (*snprintf_func)( char * s, size_t n,
                                                  const char * format, ... ) );
@@ -221,12 +224,12 @@ int mbedtls_platform_set_snprintf( int (*snprintf_func)( char * s, size_t n,
 extern void (*mbedtls_exit)( int status );
 
 /**
- * \brief   This function allows configuring a custom \c exit function
+ * \brief             This function allows configuring a custom
- *          pointer.
+ *                    \c exit function pointer.
  *
  * \param exit_func   The \c exit function implementation.
  *
- * \return  \c 0 on success.
+ * \return            \c 0 on success.
  */
 int mbedtls_platform_set_exit( void (*exit_func)( int status ) );
 #else
@@ -302,7 +305,7 @@ int mbedtls_platform_set_nv_seed(
  *          setup or teardown operations.
  */
 typedef struct {
-    char dummy; /**< Placeholder member, as empty structs are not portable. */
+    char dummy; /**< A placeholder member, as empty structs are not portable. */
 }
 mbedtls_platform_context;
 
@@ -311,33 +314,33 @@ mbedtls_platform_context;
 #endif /* !MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT */
 
 /**
- * \brief   This function performs any platform initialization operations.
+ * \brief   This function performs any platform-specific initialization operations.
+ *
+ * \note    This function should be called before any other library functions.
+ *
+ *          Its implementation is platform-specific, and unless
+ *          platform-specific code is provided, it does nothing. 
+ *
+ * \note    The usage and necessity of this function is dependent on the platform.
  *
  * \param   ctx     The Mbed TLS context.
  *
  * \return  \c 0 on success.
- *
- * \note    This function is intended to allow platform-specific initialization,
- *          and should be called before any other library functions. Its
- *          implementation is platform-specific, and unless
- *          platform-specific code is provided, it does nothing.
- *
- *          Its use and whether it is necessary to call it is dependent on the
- *          platform.
  */
 int mbedtls_platform_setup( mbedtls_platform_context *ctx );
 /**
  * \brief   This function performs any platform teardown operations.
  *
- * \param   ctx     The Mbed TLS context.
- *
  * \note    This function should be called after every other Mbed TLS module
  *          has been correctly freed using the appropriate free function.
+ *
  *          Its implementation is platform-specific, and unless
  *          platform-specific code is provided, it does nothing.
  *
- *          Its use and whether it is necessary to call it is dependent on the
+ * \note    The usage and necessity of this function is dependent on the platform.
- *          platform.
+ *
+ * \param   ctx     The Mbed TLS context.
+ *
  */
 void mbedtls_platform_teardown( mbedtls_platform_context *ctx );