1 /* Simple console for lguest.
3 * Copyright (C) 2006 Rusty Russell, IBM Corporation
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 #include <linux/err.h>
20 #include <linux/init.h>
21 #include <linux/lguest_bus.h>
22 #include "hvc_console.h"
24 static char inbuf
[256];
25 static struct lguest_dma cons_input
= { .used_len
= 0,
26 .addr
[0] = __pa(inbuf
),
27 .len
[0] = sizeof(inbuf
),
30 static int put_chars(u32 vtermno
, const char *buf
, int count
)
32 struct lguest_dma dma
;
34 /* FIXME: what if it's over a page boundary? */
37 dma
.addr
[0] = __pa(buf
);
39 lguest_send_dma(LGUEST_CONSOLE_DMA_KEY
, &dma
);
43 static int get_chars(u32 vtermno
, char *buf
, int count
)
45 static int cons_offset
;
47 if (!cons_input
.used_len
)
50 if (cons_input
.used_len
- cons_offset
< count
)
51 count
= cons_input
.used_len
- cons_offset
;
53 memcpy(buf
, inbuf
+ cons_offset
, count
);
55 if (cons_offset
== cons_input
.used_len
) {
57 cons_input
.used_len
= 0;
62 static struct hv_ops lguest_cons
= {
63 .get_chars
= get_chars
,
64 .put_chars
= put_chars
,
67 static int __init
cons_init(void)
69 if (strcmp(paravirt_ops
.name
, "lguest") != 0)
72 return hvc_instantiate(0, 0, &lguest_cons
);
74 console_initcall(cons_init
);
76 static int lguestcons_probe(struct lguest_device
*lgdev
)
80 lgdev
->private = hvc_alloc(0, lgdev_irq(lgdev
), &lguest_cons
, 256);
81 if (IS_ERR(lgdev
->private))
82 return PTR_ERR(lgdev
->private);
84 err
= lguest_bind_dma(LGUEST_CONSOLE_DMA_KEY
, &cons_input
, 1,
87 printk("lguest console: failed to bind buffer.\n");
91 static struct lguest_driver lguestcons_drv
= {
94 .device_type
= LGUEST_DEVICE_T_CONSOLE
,
95 .probe
= lguestcons_probe
,
98 static int __init
hvc_lguest_init(void)
100 return register_lguest_driver(&lguestcons_drv
);
102 module_init(hvc_lguest_init
);