summaryrefslogtreecommitdiff
path: root/arch/xtensa/platforms/iss/console.c
blob: 7d1f8b398a464d8909a3cb3af8920d494c7cf044 (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
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
/*
 * arch/xtensa/platforms/iss/console.c
 *
 * 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.
 *
 * Copyright (C) 2001-2005 Tensilica Inc.
 *   Authors	Christian Zankel, Joe Taylor
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/console.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/major.h>
#include <linux/param.h>
#include <linux/seq_file.h>
#include <linux/serial.h>

#include <linux/uaccess.h>
#include <asm/irq.h>

#include <platform/simcall.h>

#include <linux/tty.h>
#include <linux/tty_flip.h>

#define SERIAL_MAX_NUM_LINES 1
#define SERIAL_TIMER_VALUE (HZ / 10)

static void rs_poll(struct timer_list *);

static struct tty_driver *serial_driver;
static struct tty_port serial_port;
static DEFINE_TIMER(serial_timer, rs_poll);

static int rs_open(struct tty_struct *tty, struct file * filp)
{
	if (tty->count == 1)
		mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);

	return 0;
}

static void rs_close(struct tty_struct *tty, struct file * filp)
{
	if (tty->count == 1)
		del_timer_sync(&serial_timer);
}


static ssize_t rs_write(struct tty_struct * tty, const u8 *buf, size_t count)
{
	/* see drivers/char/serialX.c to reference original version */

	simc_write(1, buf, count);
	return count;
}

static void rs_poll(struct timer_list *unused)
{
	struct tty_port *port = &serial_port;
	int i = 0;
	int rd = 1;
	unsigned char c;

	while (simc_poll(0)) {
		rd = simc_read(0, &c, 1);
		if (rd <= 0)
			break;
		tty_insert_flip_char(port, c, TTY_NORMAL);
		i++;
	}

	if (i)
		tty_flip_buffer_push(port);
	if (rd)
		mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
}

static unsigned int rs_write_room(struct tty_struct *tty)
{
	/* Let's say iss can always accept 2K characters.. */
	return 2 * 1024;
}

static int rs_proc_show(struct seq_file *m, void *v)
{
	seq_printf(m, "serinfo:1.0 driver:0.1\n");
	return 0;
}

static const struct tty_operations serial_ops = {
	.open = rs_open,
	.close = rs_close,
	.write = rs_write,
	.write_room = rs_write_room,
	.proc_show = rs_proc_show,
};

static int __init rs_init(void)
{
	struct tty_driver *driver;
	int ret;

	driver = tty_alloc_driver(SERIAL_MAX_NUM_LINES, TTY_DRIVER_REAL_RAW);
	if (IS_ERR(driver))
		return PTR_ERR(driver);

	tty_port_init(&serial_port);

	/* Initialize the tty_driver structure */

	driver->driver_name = "iss_serial";
	driver->name = "ttyS";
	driver->major = TTY_MAJOR;
	driver->minor_start = 64;
	driver->type = TTY_DRIVER_TYPE_SERIAL;
	driver->subtype = SERIAL_TYPE_NORMAL;
	driver->init_termios = tty_std_termios;
	driver->init_termios.c_cflag =
		B9600 | CS8 | CREAD | HUPCL | CLOCAL;

	tty_set_operations(driver, &serial_ops);
	tty_port_link_device(&serial_port, driver, 0);

	ret = tty_register_driver(driver);
	if (ret) {
		pr_err("Couldn't register serial driver\n");
		tty_driver_kref_put(driver);
		tty_port_destroy(&serial_port);

		return ret;
	}

	serial_driver = driver;

	return 0;
}


static __exit void rs_exit(void)
{
	tty_unregister_driver(serial_driver);
	tty_driver_kref_put(serial_driver);
	tty_port_destroy(&serial_port);
}


/* 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(rs_init);


#ifdef CONFIG_SERIAL_CONSOLE

static void iss_console_write(struct console *co, const char *s, unsigned count)
{
	if (s && *s != 0) {
		int len = strlen(s);
		simc_write(1, s, count < len ? count : len);
	}
}

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


static struct console sercons = {
	.name = "ttyS",
	.write = iss_console_write,
	.device = iss_console_device,
	.flags = CON_PRINTBUFFER,
	.index = -1
};

static int __init iss_console_init(void)
{
	register_console(&sercons);
	return 0;
}

console_initcall(iss_console_init);

#endif /* CONFIG_SERIAL_CONSOLE */