arch/powerpc/platforms/pseries/hvconsole.c

   1 /*
   2  * hvconsole.c
   3  * Copyright (C) 2004 Hollis Blanchard, IBM Corporation
   4  * Copyright (C) 2004 IBM Corporation
   5  *
   6  * Additional Author(s):
   7  *  Ryan S. Arnold <rsa@us.ibm.com>
   8  *
   9  * LPAR console support.
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/export.h>
  28 #include <linux/errno.h>
  29 #include <asm/hvcall.h>
  30 #include <asm/hvconsole.h>
  31 #include "plpar_wrappers.h"
  32
  33 /**
  34  * hvc_get_chars - retrieve characters from firmware for denoted vterm adatper
  35  * @vtermno: The vtermno or unit_address of the adapter from which to fetch the
  36  *      data.
  37  * @buf: The character buffer into which to put the character data fetched from
  38  *      firmware.
  39  * @count: not used?
  40  */
  41 int hvc_get_chars(uint32_t vtermno, char *buf, int count)
  42 {
  43         unsigned long got;
  44
  45         if (plpar_get_term_char(vtermno, &got, buf) == H_SUCCESS)
  46                 return got;
  47
  48         return 0;
  49 }
  50
  51 EXPORT_SYMBOL(hvc_get_chars);
  52
  53
  54 /**
  55  * hvc_put_chars: send characters to firmware for denoted vterm adapter
  56  * @vtermno: The vtermno or unit_address of the adapter from which the data
  57  *      originated.
  58  * @buf: The character buffer that contains the character data to send to
  59  *      firmware.
  60  * @count: Send this number of characters.
  61  */
  62 int hvc_put_chars(uint32_t vtermno, const char *buf, int count)
  63 {
  64         unsigned long *lbuf = (unsigned long *) buf;
  65         long ret;
  66
  67
  68         /* hcall will ret H_PARAMETER if 'count' exceeds firmware max.*/
  69         if (count > MAX_VIO_PUT_CHARS)
  70                 count = MAX_VIO_PUT_CHARS;
  71
  72         ret = plpar_hcall_norets(H_PUT_TERM_CHAR, vtermno, count, lbuf[0],
  73                                  lbuf[1]);
  74         if (ret == H_SUCCESS)
  75                 return count;
  76         if (ret == H_BUSY)
  77                 return -EAGAIN;
  78         return -EIO;
  79 }
  80
  81 EXPORT_SYMBOL(hvc_put_chars);