aboutsummaryrefslogtreecommitdiffstats
path: root/arch/xtensa/platforms/iss/console.c
blob: 2c723e8b30da4f7b08b9bb7418735356d69639fb (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
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
/*
 * 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/serialP.h>

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

#include <platform/simcall.h>

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

#ifdef SERIAL_INLINE
#define _INLINE_ inline
#endif

#define SERIAL_MAX_NUM_LINES 1
#define SERIAL_TIMER_VALUE (20 * HZ)

static struct tty_driver *serial_driver;
static struct timer_list serial_timer;

static DEFINE_SPINLOCK(timer_lock);

int errno;

static int __simc (int a, int b, int c, int d, int e, int f) __attribute__((__noinline__));
static int __simc (int a, int b, int c, int d, int e, int f)
{
	int ret;
	__asm__ __volatile__ ("simcall\n"
			"mov %0, a2\n"
			"mov %1, a3\n" : "=a" (ret), "=a" (errno)
			: : "a2", "a3");
	return ret;
}

static char *serial_version = "0.1";
static char *serial_name = "ISS serial driver";

/*
 * This routine is called whenever a serial port is opened.  It
 * enables interrupts for a serial port, linking in its async structure into
 * the IRQ chain.   It also performs the serial-specific
 * initialization for the tty structure.
 */

static void rs_poll(unsigned long);

static int rs_open(struct tty_struct *tty, struct file * filp)
{
	int line = tty->index;

	if ((line < 0) || (line >= SERIAL_MAX_NUM_LINES))
		return -ENODEV;

	spin_lock(&timer_lock);

	if (tty->count == 1) {
		init_timer(&serial_timer);
		serial_timer.data = (unsigned long) tty;
		serial_timer.function = rs_poll;
		mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
	}
	spin_unlock(&timer_lock);

	return 0;
}


/*
 * ------------------------------------------------------------
 * iss_serial_close()
 *
 * This routine is called when the serial port gets closed.  First, we
 * wait for the last remaining data to be sent.  Then, we unlink its
 * async structure from the interrupt chain if necessary, and we free
 * that IRQ if nothing is left in the chain.
 * ------------------------------------------------------------
 */
static void rs_close(struct tty_struct *tty, struct file * filp)
{
	spin_lock(&timer_lock);
	if (tty->count == 1)
		del_timer_sync(&serial_timer);
	spin_unlock(&timer_lock);
}


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

	__simc (SYS_write, 1, (unsigned long)buf, count, 0, 0);
	return count;
}

static void rs_poll(unsigned long priv)
{
	struct tty_struct* tty = (struct tty_struct*) priv;

	struct timeval tv = { .tv_sec = 0, .tv_usec = 0 };
	int i = 0;
	unsigned char c;

	spin_lock(&timer_lock);

	while (__simc(SYS_select_one, 0, XTISS_SELECT_ONE_READ, (int)&tv,0,0)){
		__simc (SYS_read, 0, (unsigned long)&c, 1, 0, 0);
		tty_insert_flip_char(tty, c, TTY_NORMAL);
		i++;
	}

	if (i)
		tty_flip_buffer_push(tty);


	mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
	spin_unlock(&timer_lock);
}


static int rs_put_char(struct tty_struct *tty, unsigned char ch)
{
	char buf[2];

	buf[0] = ch;
	buf[1] = '\0';		/* Is this NULL necessary? */
	__simc (SYS_write, 1, (unsigned long) buf, 1, 0, 0);
	return 1;
}

static void rs_flush_chars(struct tty_struct *tty)
{
}

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

static int rs_chars_in_buffer(struct tty_struct *tty)
{
	/* the iss doesn't buffer characters */
	return 0;
}

static void rs_hangup(struct tty_struct *tty)
{
	/* Stub, once again.. */
}

static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
{
	/* Stub, once again.. */
}

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

static int rs_proc_open(struct inode *inode, struct file *file)
{
	return single_open(file, rs_proc_show, NULL);
}

static const struct file_operations rs_proc_fops = {
	.owner		= THIS_MODULE,
	.open		= rs_proc_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static const struct tty_operations serial_ops = {
	.open = rs_open,
	.close = rs_close,
	.write = rs_write,
	.put_char = rs_put_char,
	.flush_chars = rs_flush_chars,
	.write_room = rs_write_room,
	.chars_in_buffer = rs_chars_in_buffer,
	.hangup = rs_hangup,
	.wait_until_sent = rs_wait_until_sent,
	.proc_fops = &rs_proc_fops,
};

int __init rs_init(void)
{
	serial_driver = alloc_tty_driver(1);

	printk ("%s %s\n", serial_name, serial_version);

	/* Initialize the tty_driver structure */

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

	tty_set_operations(serial_driver, &serial_ops);

	if (tty_register_driver(serial_driver))
		panic("Couldn't register serial driver\n");
	return 0;
}


static __exit void rs_exit(void)
{
	int error;

	if ((error = tty_unregister_driver(serial_driver)))
		printk("ISS_SERIAL: failed to unregister serial driver (%d)\n",
		       error);
	put_tty_driver(serial_driver);
}


/* 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)
{
	int len = strlen(s);

	if (s != 0 && *s != 0)
		__simc (SYS_write, 1, (unsigned long)s,
			count < len ? count : len,0,0);
}

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 */

Privacy Policy