specification

mpc8xx driver(led), based on tqm8

/***********************************************************************
 *
 * (C) Copyright 2000
 * Jean-Jacques Germond, Fr閐閞ic Soulier, Christian Batt; Alcatel
 * C/O [e-mail]
 *
 * All rights reserved.
 *
 * This code is free software; you can redistribute it and/or
 * modify it under the terms of the GNU *Library* General Public License
 * as published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This code is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * *Library* General Public License for more details.
 *
 * You should have received a copy of the GNU *Library* General Public
 * License along with this program (see file COPYING.LIB); if not,
 * write to the Free Software Foundation, Inc., 675 Mass Ave,
 * Cambridge, MA 02139, USA.
 *
 ***********************************************************************/

Trivial driver spec


On writing, The files look like files with a "physical" content of at
most TRV_MAX_CHARS at head, followed by a /dev/nill like device.


     +---------------------------+  <---   begining of file
     |                           |
     |                           |
     |                           |
     |                           |
     |      Physical area        |
     |                           |
     |                           |
     |                           |
     |                           |
     |                           |
     +---------------------------+  <--- TRV_MAX_CHARS
     .                           .
     .                           .
     .                           .
     .                           .
     .                           .
     .                           .
     . Infinite unrecorded area  .
     .                           .
     .                           .
     .                           .
     .                           .
     .                           .







On reading, files look like files with a max length of TRV_MAX_CHARS.


open      standard AR open

write     write at most TRV_MAX_CHARS in the driver's static buffer.
          If the buffer becomes full, then switch to the /dev/null mode,
          that is accept and silently drop any incomming bytes.

read      returns:

               "TRV_EMPTY"  if no write was done.
                The string (or max size) if write was done (and update the
                file position)
                EOF as appropriate.

close     standard AR close


seek      standard seek



Note that inod & ivol as statically allocated because dynamic
allocation such as (AR pg 45) (Alesssandro Rubini) requests tools
such as mknod and awk that I do not want to put in the webphone
ramdisk. (ie too costly for embedded application).