drivers/char/hvc_tile.c

   1 /*
   2  * Copyright 2010 Tilera Corporation. All Rights Reserved.
   3  *
   4  *   This program is free software; you can redistribute it and/or
   5  *   modify it under the terms of the GNU General Public License
   6  *   as published by the Free Software Foundation, version 2.
   7  *
   8  *   This program is distributed in the hope that it will be useful, but
   9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11  *   NON INFRINGEMENT.  See the GNU General Public License for
  12  *   more details.
  13  *
  14  * Tilera TILE Processor hypervisor console
  15  */
  16
  17 #include <linux/console.h>
  18 #include <linux/delay.h>
  19 #include <linux/err.h>
  20 #include <linux/init.h>
  21 #include <linux/moduleparam.h>
  22 #include <linux/types.h>
  23
  24 #include <hv/hypervisor.h>
  25
  26 #include "hvc_console.h"
  27
  28 static int hvc_tile_put_chars(uint32_t vt, const char *buf, int count)
  29 {
  30         return hv_console_write((HV_VirtAddr)buf, count);
  31 }
  32
  33 static int hvc_tile_get_chars(uint32_t vt, char *buf, int count)
  34 {
  35         int i, c;
  36
  37         for (i = 0; i < count; ++i) {
  38                 c = hv_console_read_if_ready();
  39                 if (c < 0)
  40                         break;
  41                 buf[i] = c;
  42         }
  43
  44         return i;
  45 }
  46
  47 static const struct hv_ops hvc_tile_get_put_ops = {
  48         .get_chars = hvc_tile_get_chars,
  49         .put_chars = hvc_tile_put_chars,
  50 };
  51
  52 static int __init hvc_tile_console_init(void)
  53 {
  54         extern void disable_early_printk(void);
  55         hvc_instantiate(0, 0, &hvc_tile_get_put_ops);
  56         add_preferred_console("hvc", 0, NULL);
  57         disable_early_printk();
  58         return 0;
  59 }
  60 console_initcall(hvc_tile_console_init);
  61
  62 static int __init hvc_tile_init(void)
  63 {
  64         struct hvc_struct *s;
  65         s = hvc_alloc(0, 0, &hvc_tile_get_put_ops, 128);
  66         return IS_ERR(s) ? PTR_ERR(s) : 0;
  67 }
  68 device_initcall(hvc_tile_init);