mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-16 00:34:20 +08:00
d5e5491343
This adds a new backend for the hvc console based on the low-level udbg callbacks. This effectively implements a working runtime console in terms of the simple udbg primitives. This is kind of a hack - since udbg isn't something you really want to be using routinely - but it's really useful during bringup. This can be used to quickly implement a userspace-usable console while you're working on a proper driver for whatever console I/O device the hardware has. Or, it can be used to avoid writing a full blown tty/console driver entirely for quick-and-dirty I/O hardware that will later be replaced by something else. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
97 lines
2.0 KiB
C
97 lines
2.0 KiB
C
/*
|
|
* udbg interface to hvc_console.c
|
|
*
|
|
* (C) Copyright David Gibson, IBM Corporation 2008.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#include <linux/console.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/err.h>
|
|
#include <linux/init.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/types.h>
|
|
#include <linux/irq.h>
|
|
|
|
#include <asm/udbg.h>
|
|
|
|
#include "hvc_console.h"
|
|
|
|
struct hvc_struct *hvc_udbg_dev;
|
|
|
|
static int hvc_udbg_put(uint32_t vtermno, const char *buf, int count)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < count; i++)
|
|
udbg_putc(buf[i]);
|
|
|
|
return i;
|
|
}
|
|
|
|
static int hvc_udbg_get(uint32_t vtermno, char *buf, int count)
|
|
{
|
|
int i, c;
|
|
|
|
if (!udbg_getc_poll)
|
|
return 0;
|
|
|
|
for (i = 0; i < count; i++) {
|
|
if ((c = udbg_getc_poll()) == -1)
|
|
break;
|
|
buf[i] = c;
|
|
}
|
|
|
|
return i;
|
|
}
|
|
|
|
static struct hv_ops hvc_udbg_ops = {
|
|
.get_chars = hvc_udbg_get,
|
|
.put_chars = hvc_udbg_put,
|
|
};
|
|
|
|
static int __init hvc_udbg_init(void)
|
|
{
|
|
struct hvc_struct *hp;
|
|
|
|
BUG_ON(hvc_udbg_dev);
|
|
|
|
hp = hvc_alloc(0, NO_IRQ, &hvc_udbg_ops, 16);
|
|
if (IS_ERR(hp))
|
|
return PTR_ERR(hp);
|
|
|
|
hvc_udbg_dev = hp;
|
|
|
|
return 0;
|
|
}
|
|
module_init(hvc_udbg_init);
|
|
|
|
static void __exit hvc_udbg_exit(void)
|
|
{
|
|
if (hvc_udbg_dev)
|
|
hvc_remove(hvc_udbg_dev);
|
|
}
|
|
module_exit(hvc_udbg_exit);
|
|
|
|
static int __init hvc_udbg_console_init(void)
|
|
{
|
|
hvc_instantiate(0, 0, &hvc_udbg_ops);
|
|
add_preferred_console("hvc", 0, NULL);
|
|
|
|
return 0;
|
|
}
|
|
console_initcall(hvc_udbg_console_init);
|