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Chris Zankel7282bee2005-06-23 22:01:33 -07001/*
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>
Chris Zankel7282bee2005-06-23 22:01:33 -070013#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>
Chris Zankel7282bee2005-06-23 22:01:33 -070023
24#include <asm/uaccess.h>
25#include <asm/irq.h>
26
Chris Zankel173d6682006-12-10 02:18:48 -080027#include <asm/platform/simcall.h>
Chris Zankel7282bee2005-06-23 22:01:33 -070028
29#include <linux/tty.h>
30#include <linux/tty_flip.h>
31
Chris Zankel173d6682006-12-10 02:18:48 -080032#ifdef SERIAL_INLINE
33#define _INLINE_ inline
34#endif
35
Chris Zankel7282bee2005-06-23 22:01:33 -070036#define SERIAL_MAX_NUM_LINES 1
37#define SERIAL_TIMER_VALUE (20 * HZ)
38
39static struct tty_driver *serial_driver;
40static struct timer_list serial_timer;
41
42static DEFINE_SPINLOCK(timer_lock);
43
44int errno;
45
Marc Gauthierc8654152007-09-21 16:38:09 -070046static int __simc (int a, int b, int c, int d, int e, int f) __attribute__((__noinline__));
Chris Zankel7282bee2005-06-23 22:01:33 -070047static 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);
Alan Cox81459162006-02-03 03:04:08 -0800130 tty_insert_flip_char(tty, c, TTY_NORMAL);
Chris Zankel7282bee2005-06-23 22:01:33 -0700131 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
Chris Zankel173d6682006-12-10 02:18:48 -0800198static struct tty_operations serial_ops = {
Chris Zankel7282bee2005-06-23 22:01:33 -0700199 .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/* We use `late_initcall' instead of just `__initcall' as a workaround for
251 * the fact that (1) simcons_tty_init can't be called before tty_init,
252 * (2) tty_init is called via `module_init', (3) if statically linked,
253 * module_init == device_init, and (4) there's no ordering of init lists.
254 * We can do this easily because simcons is always statically linked, but
255 * other tty drivers that depend on tty_init and which must use
256 * `module_init' to declare their init routines are likely to be broken.
257 */
258
259late_initcall(rs_init);
260
261
262#ifdef CONFIG_SERIAL_CONSOLE
263
264static void iss_console_write(struct console *co, const char *s, unsigned count)
265{
266 int len = strlen(s);
267
268 if (s != 0 && *s != 0)
269 __simc (SYS_write, 1, (unsigned long)s,
270 count < len ? count : len,0,0);
271}
272
273static struct tty_driver* iss_console_device(struct console *c, int *index)
274{
275 *index = c->index;
276 return serial_driver;
277}
278
279
280static struct console sercons = {
281 .name = "ttyS",
282 .write = iss_console_write,
283 .device = iss_console_device,
284 .flags = CON_PRINTBUFFER,
285 .index = -1
286};
287
288static int __init iss_console_init(void)
289{
290 register_console(&sercons);
291 return 0;
292}
293
294console_initcall(iss_console_init);
295
296#endif /* CONFIG_SERIAL_CONSOLE */
297