summaryrefslogtreecommitdiffstats
path: root/arch/v850/kernel/simcons.c
blob: 7f0efaa025c9ba99fe2e130ac502824ae70ffcc5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
/*
 * arch/v850/kernel/simcons.c -- Console I/O for GDB v850e simulator
 *
 *  Copyright (C) 2001,02,03  NEC Electronics Corporation
 *  Copyright (C) 2001,02,03  Miles Bader <miles@gnu.org>
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License.  See the file COPYING in the main directory of this
 * archive for more details.
 *
 * Written by Miles Bader <miles@gnu.org>
 */

#include <linux/kernel.h>
#include <linux/console.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/tty_driver.h>
#include <linux/init.h>

#include <asm/poll.h>
#include <asm/string.h>
#include <asm/simsyscall.h>


/*  Low-level console. */

static void simcons_write (struct console *co, const char *buf, unsigned len)
{
	V850_SIM_SYSCALL (write, 1, buf, len);
}

static int simcons_read (struct console *co, char *buf, unsigned len)
{
	return V850_SIM_SYSCALL (read, 0, buf, len);
}

static struct tty_driver *tty_driver;
static struct tty_driver *simcons_device (struct console *c, int *index)
{
	*index = c->index;
	return tty_driver;
}

static struct console simcons =
{
    .name	= "simcons",
    .write	= simcons_write,
    .read	= simcons_read,
    .device	= simcons_device,
    .flags	= CON_PRINTBUFFER,
    .index	= -1,
};

/* Higher level TTY interface.  */

int simcons_tty_open (struct tty_struct *tty, struct file *filp)
{
	return 0;
}

int simcons_tty_write (struct tty_struct *tty,
		       const unsigned char *buf, int count)
{
	return V850_SIM_SYSCALL (write, 1, buf, count);
}

int simcons_tty_write_room (struct tty_struct *tty)
{
	/* Completely arbitrary.  */
	return 0x100000;
}

int simcons_tty_chars_in_buffer (struct tty_struct *tty)
{
	/* We have no buffer.  */
	return 0;
}

static struct tty_operations ops = {
	.open = simcons_tty_open,
	.write = simcons_tty_write,
	.write_room = simcons_tty_write_room,
	.chars_in_buffer = simcons_tty_chars_in_buffer,
};

int __init simcons_tty_init (void)
{
	struct tty_driver *driver = alloc_tty_driver(1);
	int err;
	if (!driver)
		return -ENOMEM;
	driver->name = "simcons";
	driver->major = TTY_MAJOR;
	driver->minor_start = 64;
	driver->type = TTY_DRIVER_TYPE_SYSCONS;
	driver->init_termios = tty_std_termios;
	tty_set_operations(driver, &ops);
	err = tty_register_driver(driver);
	if (err) {
		put_tty_driver(driver);
		return err;
	}
	tty_driver = driver;
	return 0;
}
/* We use `late_initcall' instead of just `__initcall' as a workaround for
   the fact that (1) simcons_tty_init can't be called before tty_init,
   (2) tty_init is called via `module_init', (3) if statically linked,
   module_init == device_init, and (4) there's no ordering of init lists.
   We can do this easily because simcons is always statically linked, but
   other tty drivers that depend on tty_init and which must use
   `module_init' to declare their init routines are likely to be broken.  */
late_initcall(simcons_tty_init);

/* Poll for input on the console, and if there's any, deliver it to the
   tty driver.  */
void simcons_poll_tty (struct tty_struct *tty)
{
	int flip = 0, send_break = 0;
	struct pollfd pfd;
	pfd.fd = 0;
	pfd.events = POLLIN;

	if (V850_SIM_SYSCALL (poll, &pfd, 1, 0) > 0) {
		if (pfd.revents & POLLIN) {
			int left = TTY_FLIPBUF_SIZE - tty->flip.count;

			if (left > 0) {
				unsigned char *buf = tty->flip.char_buf_ptr;
				int rd = V850_SIM_SYSCALL (read, 0, buf, left);

				if (rd > 0) {
					tty->flip.count += rd;
					tty->flip.char_buf_ptr += rd;
					memset (tty->flip.flag_buf_ptr, 0, rd);
					tty->flip.flag_buf_ptr += rd;
					flip = 1;
				} else
					send_break = 1;
			}
		} else if (pfd.revents & POLLERR)
			send_break = 1;
	}

	if (send_break) {
		tty_insert_flip_char (tty, 0, TTY_BREAK);		
		flip = 1;
	}

	if (flip)
		tty_schedule_flip (tty);
}

void simcons_poll_ttys (void)
{
	if (tty_driver && tty_driver->ttys[0])
		simcons_poll_tty (tty_driver->ttys[0]);
}

void simcons_setup (void)
{
	V850_SIM_SYSCALL (make_raw, 0);
	register_console (&simcons);
	printk (KERN_INFO "Console: GDB V850E simulator stdio\n");
}