LXR linux/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 */
  41int 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
  51EXPORT_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 */
  62int 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
  81EXPORT_SYMBOL(hvc_put_chars);
  82