1/*
2 * arch/xtensa/platform-iss/console.c
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License.  See the file "COPYING" in the main directory of this archive
6 * for more details.
7 *
8 * Copyright (C) 2001-2005 Tensilica Inc.
9 *   Authors	Christian Zankel, Joe Taylor
10 */
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/sched.h>
15#include <linux/console.h>
16#include <linux/init.h>
17#include <linux/slab.h>
18#include <linux/mm.h>
19#include <linux/major.h>
20#include <linux/param.h>
21#include <linux/serial.h>
22#include <linux/serialP.h>
23#include <linux/console.h>
24
25#include <asm/uaccess.h>
26#include <asm/irq.h>
27
28#include <asm/platform/simcall.h>
29
30#include <linux/tty.h>
31#include <linux/tty_flip.h>
32
33#ifdef SERIAL_INLINE
34#define _INLINE_ inline
35#endif
36
37#define SERIAL_MAX_NUM_LINES 1
38#define SERIAL_TIMER_VALUE (20 * HZ)
39
40static struct tty_driver *serial_driver;
41static struct timer_list serial_timer;
42
43static DEFINE_SPINLOCK(timer_lock);
44
45int errno;
46
47static int __simc (int a, int b, int c, int d, int e, int f)
48{
49	int ret;
50	__asm__ __volatile__ ("simcall\n"
51			"mov %0, a2\n"
52			"mov %1, a3\n" : "=a" (ret), "=a" (errno)
53			: : "a2", "a3");
54	return ret;
55}
56
57static char *serial_version = "0.1";
58static char *serial_name = "ISS serial driver";
59
60/*
61 * This routine is called whenever a serial port is opened.  It
62 * enables interrupts for a serial port, linking in its async structure into
63 * the IRQ chain.   It also performs the serial-specific
64 * initialization for the tty structure.
65 */
66
67static void rs_poll(unsigned long);
68
69static int rs_open(struct tty_struct *tty, struct file * filp)
70{
71	int line = tty->index;
72
73	if ((line < 0) || (line >= SERIAL_MAX_NUM_LINES))
74		return -ENODEV;
75
76	spin_lock(&timer_lock);
77
78	if (tty->count == 1) {
79		init_timer(&serial_timer);
80		serial_timer.data = (unsigned long) tty;
81		serial_timer.function = rs_poll;
82		mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
83	}
84	spin_unlock(&timer_lock);
85
86	return 0;
87}
88
89
90/*
91 * ------------------------------------------------------------
92 * iss_serial_close()
93 *
94 * This routine is called when the serial port gets closed.  First, we
95 * wait for the last remaining data to be sent.  Then, we unlink its
96 * async structure from the interrupt chain if necessary, and we free
97 * that IRQ if nothing is left in the chain.
98 * ------------------------------------------------------------
99 */
100static void rs_close(struct tty_struct *tty, struct file * filp)
101{
102	spin_lock(&timer_lock);
103	if (tty->count == 1)
104		del_timer_sync(&serial_timer);
105	spin_unlock(&timer_lock);
106}
107
108
109static int rs_write(struct tty_struct * tty,
110		    const unsigned char *buf, int count)
111{
112	/* see drivers/char/serialX.c to reference original version */
113
114	__simc (SYS_write, 1, (unsigned long)buf, count, 0, 0);
115	return count;
116}
117
118static void rs_poll(unsigned long priv)
119{
120	struct tty_struct* tty = (struct tty_struct*) priv;
121
122	struct timeval tv = { .tv_sec = 0, .tv_usec = 0 };
123	int i = 0;
124	unsigned char c;
125
126	spin_lock(&timer_lock);
127
128	while (__simc(SYS_select_one, 0, XTISS_SELECT_ONE_READ, (int)&tv,0,0)){
129		__simc (SYS_read, 0, (unsigned long)&c, 1, 0, 0);
130		tty_insert_flip_char(tty, c, TTY_NORMAL);
131		i++;
132	}
133
134	if (i)
135		tty_flip_buffer_push(tty);
136
137
138	mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
139	spin_unlock(&timer_lock);
140}
141
142
143static void rs_put_char(struct tty_struct *tty, unsigned char ch)
144{
145	char buf[2];
146
147	if (!tty)
148		return;
149
150	buf[0] = ch;
151	buf[1] = '\0';		/* Is this NULL necessary? */
152	__simc (SYS_write, 1, (unsigned long) buf, 1, 0, 0);
153}
154
155static void rs_flush_chars(struct tty_struct *tty)
156{
157}
158
159static int rs_write_room(struct tty_struct *tty)
160{
161	/* Let's say iss can always accept 2K characters.. */
162	return 2 * 1024;
163}
164
165static int rs_chars_in_buffer(struct tty_struct *tty)
166{
167	/* the iss doesn't buffer characters */
168	return 0;
169}
170
171static void rs_hangup(struct tty_struct *tty)
172{
173	/* Stub, once again.. */
174}
175
176static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
177{
178	/* Stub, once again.. */
179}
180
181static int rs_read_proc(char *page, char **start, off_t off, int count,
182			int *eof, void *data)
183{
184	int len = 0;
185	off_t begin = 0;
186
187	len += sprintf(page, "serinfo:1.0 driver:%s\n", serial_version);
188	*eof = 1;
189
190	if (off >= len + begin)
191		return 0;
192
193	*start = page + (off - begin);
194	return ((count < begin + len - off) ? count : begin + len - off);
195}
196
197
198static struct tty_operations serial_ops = {
199	.open = rs_open,
200	.close = rs_close,
201	.write = rs_write,
202	.put_char = rs_put_char,
203	.flush_chars = rs_flush_chars,
204	.write_room = rs_write_room,
205	.chars_in_buffer = rs_chars_in_buffer,
206	.hangup = rs_hangup,
207	.wait_until_sent = rs_wait_until_sent,
208	.read_proc = rs_read_proc
209};
210
211int __init rs_init(void)
212{
213	serial_driver = alloc_tty_driver(1);
214
215	printk ("%s %s\n", serial_name, serial_version);
216
217	/* Initialize the tty_driver structure */
218
219	serial_driver->owner = THIS_MODULE;
220	serial_driver->driver_name = "iss_serial";
221	serial_driver->name = "ttyS";
222	serial_driver->major = TTY_MAJOR;
223	serial_driver->minor_start = 64;
224	serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
225	serial_driver->subtype = SERIAL_TYPE_NORMAL;
226	serial_driver->init_termios = tty_std_termios;
227	serial_driver->init_termios.c_cflag =
228		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
229	serial_driver->flags = TTY_DRIVER_REAL_RAW;
230
231	tty_set_operations(serial_driver, &serial_ops);
232
233	if (tty_register_driver(serial_driver))
234		panic("Couldn't register serial driver\n");
235	return 0;
236}
237
238
239static __exit void rs_exit(void)
240{
241	int error;
242
243	if ((error = tty_unregister_driver(serial_driver)))
244		printk("ISS_SERIAL: failed to unregister serial driver (%d)\n",
245		       error);
246	put_tty_driver(serial_driver);
247}
248
249
250
251late_initcall(rs_init);
252
253
254#ifdef CONFIG_SERIAL_CONSOLE
255
256static void iss_console_write(struct console *co, const char *s, unsigned count)
257{
258	int len = strlen(s);
259
260	if (s != 0 && *s != 0)
261		__simc (SYS_write, 1, (unsigned long)s,
262			count < len ? count : len,0,0);
263}
264
265static struct tty_driver* iss_console_device(struct console *c, int *index)
266{
267	*index = c->index;
268	return serial_driver;
269}
270
271
272static struct console sercons = {
273	.name = "ttyS",
274	.write = iss_console_write,
275	.device = iss_console_device,
276	.flags = CON_PRINTBUFFER,
277	.index = -1
278};
279
280static int __init iss_console_init(void)
281{
282	register_console(&sercons);
283	return 0;
284}
285
286console_initcall(iss_console_init);
287
288#endif /* CONFIG_SERIAL_CONSOLE */
289