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