134 lines
2.9 KiB
C
134 lines
2.9 KiB
C
/* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 and
|
|
* only version 2 as published by the Free Software Foundation.
|
|
*
|
|
* 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., 51 Franklin Street, Fifth Floor, Boston, MA
|
|
* 02110-1301, 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 <asm/processor.h>
|
|
|
|
#include "hvc_console.h"
|
|
|
|
/* DCC Status Bits */
|
|
#define DCC_STATUS_RX (1 << 30)
|
|
#define DCC_STATUS_TX (1 << 29)
|
|
|
|
static inline u32 __dcc_getstatus(void)
|
|
{
|
|
u32 __ret;
|
|
|
|
asm("mrc p14, 0, %0, c0, c1, 0 @ read comms ctrl reg"
|
|
: "=r" (__ret) : : "cc");
|
|
|
|
return __ret;
|
|
}
|
|
|
|
|
|
#if defined(CONFIG_CPU_V7)
|
|
static inline char __dcc_getchar(void)
|
|
{
|
|
char __c;
|
|
|
|
asm("get_wait: mrc p14, 0, pc, c0, c1, 0 \n\
|
|
bne get_wait \n\
|
|
mrc p14, 0, %0, c0, c5, 0 @ read comms data reg"
|
|
: "=r" (__c) : : "cc");
|
|
|
|
return __c;
|
|
}
|
|
#else
|
|
static inline char __dcc_getchar(void)
|
|
{
|
|
char __c;
|
|
|
|
asm("mrc p14, 0, %0, c0, c5, 0 @ read comms data reg"
|
|
: "=r" (__c));
|
|
|
|
return __c;
|
|
}
|
|
#endif
|
|
|
|
#if defined(CONFIG_CPU_V7)
|
|
static inline void __dcc_putchar(char c)
|
|
{
|
|
asm("put_wait: mrc p14, 0, pc, c0, c1, 0 \n\
|
|
bcs put_wait \n\
|
|
mcr p14, 0, %0, c0, c5, 0 "
|
|
: : "r" (c) : "cc");
|
|
}
|
|
#else
|
|
static inline void __dcc_putchar(char c)
|
|
{
|
|
asm("mcr p14, 0, %0, c0, c5, 0 @ write a char"
|
|
: /* no output register */
|
|
: "r" (c));
|
|
}
|
|
#endif
|
|
|
|
static int hvc_dcc_put_chars(uint32_t vt, const char *buf, int count)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < count; i++) {
|
|
while (__dcc_getstatus() & DCC_STATUS_TX)
|
|
cpu_relax();
|
|
|
|
__dcc_putchar((char)(buf[i] & 0xFF));
|
|
}
|
|
|
|
return count;
|
|
}
|
|
|
|
static int hvc_dcc_get_chars(uint32_t vt, char *buf, int count)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < count; ++i) {
|
|
int c = -1;
|
|
|
|
if (__dcc_getstatus() & DCC_STATUS_RX)
|
|
c = __dcc_getchar();
|
|
if (c < 0)
|
|
break;
|
|
buf[i] = c;
|
|
}
|
|
|
|
return i;
|
|
}
|
|
|
|
static const struct hv_ops hvc_dcc_get_put_ops = {
|
|
.get_chars = hvc_dcc_get_chars,
|
|
.put_chars = hvc_dcc_put_chars,
|
|
};
|
|
|
|
static int __init hvc_dcc_console_init(void)
|
|
{
|
|
hvc_instantiate(0, 0, &hvc_dcc_get_put_ops);
|
|
return 0;
|
|
}
|
|
console_initcall(hvc_dcc_console_init);
|
|
|
|
static int __init hvc_dcc_init(void)
|
|
{
|
|
hvc_alloc(0, 0, &hvc_dcc_get_put_ops, 128);
|
|
return 0;
|
|
}
|
|
device_initcall(hvc_dcc_init);
|