1/*
2 * arch/xtensa/platforms/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/mm.h>
18#include <linux/major.h>
19#include <linux/param.h>
20#include <linux/seq_file.h>
21#include <linux/serial.h>
22
23#include <asm/uaccess.h>
24#include <asm/irq.h>
25
26#include <platform/simcall.h>
27
28#include <linux/tty.h>
29#include <linux/tty_flip.h>
30
31#ifdef SERIAL_INLINE
32#define _INLINE_ inline
33#endif
34
35#define SERIAL_MAX_NUM_LINES 1
36#define SERIAL_TIMER_VALUE (HZ / 10)
37
38static struct tty_driver *serial_driver;
39static struct tty_port serial_port;
40static struct timer_list serial_timer;
41
42static DEFINE_SPINLOCK(timer_lock);
43
44static char *serial_version = "0.1";
45static char *serial_name = "ISS serial driver";
46
47/*
48 * This routine is called whenever a serial port is opened.  It
49 * enables interrupts for a serial port, linking in its async structure into
50 * the IRQ chain.   It also performs the serial-specific
51 * initialization for the tty structure.
52 */
53
54static void rs_poll(unsigned long);
55
56static int rs_open(struct tty_struct *tty, struct file * filp)
57{
58	tty->port = &serial_port;
59	spin_lock_bh(&timer_lock);
60	if (tty->count == 1) {
61		setup_timer(&serial_timer, rs_poll,
62				(unsigned long)&serial_port);
63		mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
64	}
65	spin_unlock_bh(&timer_lock);
66
67	return 0;
68}
69
70
71/*
72 * ------------------------------------------------------------
73 * iss_serial_close()
74 *
75 * This routine is called when the serial port gets closed.  First, we
76 * wait for the last remaining data to be sent.  Then, we unlink its
77 * async structure from the interrupt chain if necessary, and we free
78 * that IRQ if nothing is left in the chain.
79 * ------------------------------------------------------------
80 */
81static void rs_close(struct tty_struct *tty, struct file * filp)
82{
83	spin_lock_bh(&timer_lock);
84	if (tty->count == 1)
85		del_timer_sync(&serial_timer);
86	spin_unlock_bh(&timer_lock);
87}
88
89
90static int rs_write(struct tty_struct * tty,
91		    const unsigned char *buf, int count)
92{
93	/* see drivers/char/serialX.c to reference original version */
94
95	simc_write(1, buf, count);
96	return count;
97}
98
99static void rs_poll(unsigned long priv)
100{
101	struct tty_port *port = (struct tty_port *)priv;
102	int i = 0;
103	int rd = 1;
104	unsigned char c;
105
106	spin_lock(&timer_lock);
107
108	while (simc_poll(0)) {
109		rd = simc_read(0, &c, 1);
110		if (rd <= 0)
111			break;
112		tty_insert_flip_char(port, c, TTY_NORMAL);
113		i++;
114	}
115
116	if (i)
117		tty_flip_buffer_push(port);
118	if (rd)
119		mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
120	spin_unlock(&timer_lock);
121}
122
123
124static int rs_put_char(struct tty_struct *tty, unsigned char ch)
125{
126	return rs_write(tty, &ch, 1);
127}
128
129static void rs_flush_chars(struct tty_struct *tty)
130{
131}
132
133static int rs_write_room(struct tty_struct *tty)
134{
135	/* Let's say iss can always accept 2K characters.. */
136	return 2 * 1024;
137}
138
139static int rs_chars_in_buffer(struct tty_struct *tty)
140{
141	/* the iss doesn't buffer characters */
142	return 0;
143}
144
145static void rs_hangup(struct tty_struct *tty)
146{
147	/* Stub, once again.. */
148}
149
150static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
151{
152	/* Stub, once again.. */
153}
154
155static int rs_proc_show(struct seq_file *m, void *v)
156{
157	seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version);
158	return 0;
159}
160
161static int rs_proc_open(struct inode *inode, struct file *file)
162{
163	return single_open(file, rs_proc_show, NULL);
164}
165
166static const struct file_operations rs_proc_fops = {
167	.owner		= THIS_MODULE,
168	.open		= rs_proc_open,
169	.read		= seq_read,
170	.llseek		= seq_lseek,
171	.release	= single_release,
172};
173
174static const struct tty_operations serial_ops = {
175	.open = rs_open,
176	.close = rs_close,
177	.write = rs_write,
178	.put_char = rs_put_char,
179	.flush_chars = rs_flush_chars,
180	.write_room = rs_write_room,
181	.chars_in_buffer = rs_chars_in_buffer,
182	.hangup = rs_hangup,
183	.wait_until_sent = rs_wait_until_sent,
184	.proc_fops = &rs_proc_fops,
185};
186
187int __init rs_init(void)
188{
189	tty_port_init(&serial_port);
190
191	serial_driver = alloc_tty_driver(SERIAL_MAX_NUM_LINES);
192
193	printk ("%s %s\n", serial_name, serial_version);
194
195	/* Initialize the tty_driver structure */
196
197	serial_driver->driver_name = "iss_serial";
198	serial_driver->name = "ttyS";
199	serial_driver->major = TTY_MAJOR;
200	serial_driver->minor_start = 64;
201	serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
202	serial_driver->subtype = SERIAL_TYPE_NORMAL;
203	serial_driver->init_termios = tty_std_termios;
204	serial_driver->init_termios.c_cflag =
205		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
206	serial_driver->flags = TTY_DRIVER_REAL_RAW;
207
208	tty_set_operations(serial_driver, &serial_ops);
209	tty_port_link_device(&serial_port, serial_driver, 0);
210
211	if (tty_register_driver(serial_driver))
212		panic("Couldn't register serial driver\n");
213	return 0;
214}
215
216
217static __exit void rs_exit(void)
218{
219	int error;
220
221	if ((error = tty_unregister_driver(serial_driver)))
222		printk("ISS_SERIAL: failed to unregister serial driver (%d)\n",
223		       error);
224	put_tty_driver(serial_driver);
225	tty_port_destroy(&serial_port);
226}
227
228
229/* We use `late_initcall' instead of just `__initcall' as a workaround for
230 * the fact that (1) simcons_tty_init can't be called before tty_init,
231 * (2) tty_init is called via `module_init', (3) if statically linked,
232 * module_init == device_init, and (4) there's no ordering of init lists.
233 * We can do this easily because simcons is always statically linked, but
234 * other tty drivers that depend on tty_init and which must use
235 * `module_init' to declare their init routines are likely to be broken.
236 */
237
238late_initcall(rs_init);
239
240
241#ifdef CONFIG_SERIAL_CONSOLE
242
243static void iss_console_write(struct console *co, const char *s, unsigned count)
244{
245	int len = strlen(s);
246
247	if (s != 0 && *s != 0)
248		simc_write(1, s, count < len ? count : len);
249}
250
251static struct tty_driver* iss_console_device(struct console *c, int *index)
252{
253	*index = c->index;
254	return serial_driver;
255}
256
257
258static struct console sercons = {
259	.name = "ttyS",
260	.write = iss_console_write,
261	.device = iss_console_device,
262	.flags = CON_PRINTBUFFER,
263	.index = -1
264};
265
266static int __init iss_console_init(void)
267{
268	register_console(&sercons);
269	return 0;
270}
271
272console_initcall(iss_console_init);
273
274#endif /* CONFIG_SERIAL_CONSOLE */
275
276