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/module.h>
  28 #include <asm/hvcall.h>
  29 #include <asm/hvconsole.h>
  30 #include "plpar_wrappers.h"
  31
  32 /**
  33  * hvc_get_chars - retrieve characters from firmware for denoted vterm adatper
  34  * @vtermno: The vtermno or unit_address of the adapter from which to fetch the
  35  *      data.
  36  * @buf: The character buffer into which to put the character data fetched from
  37  *      firmware.
  38  * @count: not used?
  39  */
  40 int hvc_get_chars(uint32_t vtermno, char *buf, int count)
  41 {
  42         unsigned long got;
  43
  44         if (plpar_get_term_char(vtermno, &got, buf) == H_SUCCESS)
  45                 return got;
  46
  47         return 0;
  48 }
  49
  50 EXPORT_SYMBOL(hvc_get_chars);
  51
  52
  53 /**
  54  * hvc_put_chars: send characters to firmware for denoted vterm adapter
  55  * @vtermno: The vtermno or unit_address of the adapter from which the data
  56  *      originated.
  57  * @buf: The character buffer that contains the character data to send to
  58  *      firmware.
  59  * @count: Send this number of characters.
  60  */
  61 int hvc_put_chars(uint32_t vtermno, const char *buf, int count)
  62 {
  63         unsigned long *lbuf = (unsigned long *) buf;
  64         long ret;
  65
  66
  67         /* hcall will ret H_PARAMETER if 'count' exceeds firmware max.*/
  68         if (count > MAX_VIO_PUT_CHARS)
  69                 count = MAX_VIO_PUT_CHARS;
  70
  71         ret = plpar_hcall_norets(H_PUT_TERM_CHAR, vtermno, count, lbuf[0],
  72                                  lbuf[1]);
  73         if (ret == H_SUCCESS)
  74                 return count;
  75         if (ret == H_BUSY)
  76                 return 0;
  77         return -EIO;
  78 }
  79
  80 EXPORT_SYMBOL(hvc_put_chars);