app/arm/armtest_clk/sys_dev.c

   1 /**************************** sys_dev.c *********************************/
   2 /* Copyright 2003/12/27 Aeolus Development                              */
   3 /* All rights reserved.                                                 */
   4 /*                                                                      */
   5 /* Redistribution and use in source and binary forms, with or without   */
   6 /* modification, are permitted provided that the following conditions   */
   7 /* are met:                                                             */
   8 /* 1. Redistributions of source code must retain the above copyright    */
   9 /*   notice, this list of conditions and the following disclaimer.      */
  10 /* 2. Redistributions in binary form must reproduce the above copyright */
  11 /*   notice, this list of conditions and the following disclaimer in the*/
  12 /*   documentation and/or other materials provided with the             */
  13 /*   distribution.                                                      */
  14 /* 3. The name of the Aeolus Development or its contributors may not be */
  15 /* used to endorse or promote products derived from this software       */
  16 /* without specific prior written permission.                           */
  17 /*                                                                      */
  18 /* THIS SOFTWARE IS PROVIDED BY THE AEOULUS DEVELOPMENT "AS IS" AND ANY */
  19 /* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE    */
  20 /* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR   */
  21 /* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AEOLUS DEVELOPMENT BE  */
  22 /* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR  */
  23 /* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF */
  24 /* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR      */
  25 /* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,*/
  26 /* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE */
  27 /* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,    */
  28 /* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.                   */
  29 /*                                                                      */
  30 /*  System device.  Right now mostly a place holder.                    */
  31 /* Provides hooks needed to work as a device driver.                    */
  32 /* Note:  All the actual routines are private to this module.  The only */
  33 /* element publically visible is the device table entry structure.      */
  34 /************************************************************************/
  35 /*
  36 *   TLIB revision history:
  37 *   1 sys_dev.c 30-Dec-2003,10:34:12,`RADSETT' First archival version.
  38 *   TLIB revision history ends.
  39 */
  40 #include <errno.h>
  41 #include <limits.h>
  42 //#include "lpc210x.h"
  43 #include "dev_cntrl.h"
  44 #include <stdio.h>
  45
  46         /**** Local Prototypes ****/
  47 static _ssize_t sys_read ( struct _reent *r, int file, void *ptr, size_t len);
  48 static _ssize_t sys_write ( struct _reent *r, int file, const void *ptr, size_t len);
  49 static int sys_open( struct _reent *r, const char *name, int o_flags, int o_mode);
  50 static int sys_close( struct _reent *r, int file);
  51
  52 /************************** sys_read ************************************/
  53 /*  Reads from 'sys'.                                                   */
  54 /*  struct _reent *r    -- re-entrancy structure, used by newlib to     */
  55 /*                      support multiple threads of operation.          */
  56 /*  int file            -- number referring to the open file. Generally */
  57 /*                      obtained from a corresponding call to open.     */
  58 /*                      Only one file number (0) is supported.          */
  59 /*  void *ptr           -- memory area to place read bytes into.        */
  60 /*  size_t len          -- maximum number of bytes to read.             */
  61 /*  Note:  will only return a single byte on every call.  That byte is  */
  62 /* just a dummy.                                                        */
  63 /*  Returns number of bytes read. (_ssize_t)-1 on error.                */
  64 /*lint -e{715} multiple arguments not referenced since this is          */
  65 /* basically a placeholder.                                             */
  66 static _ssize_t sys_read (
  67     struct _reent *r,           /*  Re-entrancy structure, used to make */
  68                                 /* thread safe.                         */
  69     int file,                   /*  File handle.  Used to distinguish   */
  70                                 /* multiple instances.                  */
  71     void *ptr,                  /*  Where to place data.                */
  72     size_t len)                 /*  Max data to read.                   */
  73 {
  74 unsigned char *p;
  75
  76  if( file != 0) {               /* Only one device.                     */
  77     r->_errno = EBADF;          /* Bad file number.                     */
  78     return (_ssize_t)-1;
  79     }
  80
  81  p = ptr;
  82  *p = (unsigned char)'a';       /* Dummy operation for now.             */
  83  return (_ssize_t)1;
  84 }
  85
  86 /************************** sys_write ***********************************/
  87 /*  Writes to 'sys'.                                                    */
  88 /*  struct _reent *r    -- re-entrancy structure, used by newlib to     */
  89 /*                      support multiple threads of operation.          */
  90 /*  int file            -- number referring to the open file. Generally */
  91 /*                      obtained from a corresponding call to open.     */
  92 /*                      Only one file number (0) is supported.          */
  93 /*  const void *ptr     -- memory area to place read bytes from.        */
  94 /*  size_t len          -- maximum number of bytes to write.            */
  95 /*  Returns number of bytes written. (_ssize_t)-1 on error.             */
  96 /*  Note:  simply returns indicating it wrote everything requested. IE  */
  97 /*lint -e{715} multiple arguments not referenced since this is          */
  98 /* basically a placeholder.                                             */
  99 static _ssize_t sys_write (
 100     struct _reent *r,           /*  Re-entrancy structure, used to make */
 101                                 /* thread safe.                         */
 102     int file,                   /*  File handle.  Used to distinguish   */
 103                                 /* multiple instances.                  */
 104     const void *ptr,            /*  Pointer to data to write.           */
 105     size_t len)                 /*  Amount of data to write.            */
 106  {
 107
 108  if( file != 0) {               /* Only one device.                     */
 109     r->_errno = EBADF;          /* Bad file number.                     */
 110     return (_ssize_t)-1;
 111     }
 112
 113  return (_ssize_t)len;
 114 }
 115
 116 /************************** sys_open ************************************/
 117 /*  Opens 'sys'                                                         */
 118 /*  struct _reent *r    -- re-entrancy structure, used by newlib to     */
 119 /*                      support multiple threads of operation.          */
 120 /*  const char *name    -- name of file/device to open. Since sys       */
 121 /*                      supports no sub devices this should be an empty */
 122 /*                      string.                                         */
 123 /*  int flags           -- Flags to control open.  Not used at the      */
 124 /*                      moment.                                         */
 125 /*  int mode            -- Mode to open in.  Not used at the moment.    */
 126 /*  Returns file number >= 0 if successful.  Otherwise the error code   */
 127 /* may be found in errno.                                               */
 128 /*lint -e{715} multiple arguments not referenced since this is          */
 129 /* basically a placeholder.                                             */
 130 static int sys_open(
 131     struct _reent *r,           /*  Re-entrancy structure, used to make */
 132                                 /* thread safe.                         */
 133     const char *name,           /*  Name to open.                       */
 134     int o_flags,                /*  Flags to control open.              */
 135                                 /* Read, write binary etc...            */
 136                                 /* See flags.c for values generated by  */
 137                                 /* newlib.                              */
 138     int o_mode)                 /*  Mode to open in.  This is a         */
 139                                 /* security or permissions value.       */
 140                                 /* Newlib uses the classic 0666 for all */
 141                                 /* fopens.  See fopen.c                 */
 142 {
 143
 144         /*  Check against null pointer.  Also no sub-devices available  */
 145         /* so make sure we aren't asked to open one.                    */
 146  if( (name == 0) || (*name != '\0')) {
 147     r->_errno = ENOENT;         /* No such file or directory.           */
 148     return( -1);
 149     }
 150  return( 0);                    /*  Always sub-handle 0.  Note we never */
 151                                 /* fail on this open.                   */
 152 }
 153
 154 /************************** sys_close ***********************************/
 155 /*  Close sys.                                                          */
 156 /*  struct _reent *r    -- re-entrancy structure, used by newlib to     */
 157 /*                      support multiple threads of operation.          */
 158 /*  int file            -- number referring to the open file. Generally */
 159 /*                      obtained from a corresponding call to open.     */
 160 /*                      Only one file number (0) is supported.          */
 161 /*  Returns 0 if successful.  Otherwise the error code may be found in  */
 162 /* errno.                                                               */
 163 static int sys_close(
 164     struct _reent *r,           /*  Re-entrancy structure, used to make */
 165                                 /* thread safe.                         */
 166     int file)                   /*  File/device sub handle.             */
 167 {
 168
 169  if( file != 0) {               /* Only one device.                     */
 170     r->_errno = EBADF;          /* Bad file number.                     */
 171     return -1;
 172     }
 173  return( 0);                    /* Always succeeds.                     */
 174 }
 175
 176 /************************** sys *****************************************/
 177 /*  Device table entry used to add this device.                         */
 178 const struct device_table_entry sys = {
 179         "sys",                          /*  Device name.                */
 180         sys_open,                       /*  Open method.                */
 181         sys_close,                      /*  Close method.               */
 182         sys_read,                       /*  Read method.                */
 183         sys_write,                      /*  Write method.               */
 184         0 };                            /*  ioctl not supported.        */