tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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(&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(&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 struct timeval tv = { .tv_sec = 0, .tv_usec = 0 };
103 int i = 0;
104 unsigned char c;
105
106 spin_lock(&timer_lock);
107
108 while (__simc(SYS_select_one, 0, XTISS_SELECT_ONE_READ, (int)&tv,0,0)){
109 __simc (SYS_read, 0, (unsigned long)&c, 1, 0, 0);
110 tty_insert_flip_char(port, c, TTY_NORMAL);
111 i++;
112 }
113
114 if (i)
115 tty_flip_buffer_push(port);
116
117
118 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
119 spin_unlock(&timer_lock);
120}
121
122
123static int rs_put_char(struct tty_struct *tty, unsigned char ch)
124{
125 return rs_write(tty, &ch, 1);
126}
127
128static void rs_flush_chars(struct tty_struct *tty)
129{
130}
131
132static int rs_write_room(struct tty_struct *tty)
133{
134 /* Let's say iss can always accept 2K characters.. */
135 return 2 * 1024;
136}
137
138static int rs_chars_in_buffer(struct tty_struct *tty)
139{
140 /* the iss doesn't buffer characters */
141 return 0;
142}
143
144static void rs_hangup(struct tty_struct *tty)
145{
146 /* Stub, once again.. */
147}
148
149static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
150{
151 /* Stub, once again.. */
152}
153
154static int rs_proc_show(struct seq_file *m, void *v)
155{
156 seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version);
157 return 0;
158}
159
160static int rs_proc_open(struct inode *inode, struct file *file)
161{
162 return single_open(file, rs_proc_show, NULL);
163}
164
165static const struct file_operations rs_proc_fops = {
166 .owner = THIS_MODULE,
167 .open = rs_proc_open,
168 .read = seq_read,
169 .llseek = seq_lseek,
170 .release = single_release,
171};
172
173static const struct tty_operations serial_ops = {
174 .open = rs_open,
175 .close = rs_close,
176 .write = rs_write,
177 .put_char = rs_put_char,
178 .flush_chars = rs_flush_chars,
179 .write_room = rs_write_room,
180 .chars_in_buffer = rs_chars_in_buffer,
181 .hangup = rs_hangup,
182 .wait_until_sent = rs_wait_until_sent,
183 .proc_fops = &rs_proc_fops,
184};
185
186int __init rs_init(void)
187{
188 tty_port_init(&serial_port);
189
190 serial_driver = alloc_tty_driver(SERIAL_MAX_NUM_LINES);
191
192 printk ("%s %s\n", serial_name, serial_version);
193
194 /* Initialize the tty_driver structure */
195
196 serial_driver->driver_name = "iss_serial";
197 serial_driver->name = "ttyS";
198 serial_driver->major = TTY_MAJOR;
199 serial_driver->minor_start = 64;
200 serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
201 serial_driver->subtype = SERIAL_TYPE_NORMAL;
202 serial_driver->init_termios = tty_std_termios;
203 serial_driver->init_termios.c_cflag =
204 B9600 | CS8 | CREAD | HUPCL | CLOCAL;
205 serial_driver->flags = TTY_DRIVER_REAL_RAW;
206
207 tty_set_operations(serial_driver, &serial_ops);
208 tty_port_link_device(&serial_port, serial_driver, 0);
209
210 if (tty_register_driver(serial_driver))
211 panic("Couldn't register serial driver\n");
212 return 0;
213}
214
215
216static __exit void rs_exit(void)
217{
218 int error;
219
220 if ((error = tty_unregister_driver(serial_driver)))
221 printk("ISS_SERIAL: failed to unregister serial driver (%d)\n",
222 error);
223 put_tty_driver(serial_driver);
224 tty_port_destroy(&serial_port);
225}
226
227
228/* We use `late_initcall' instead of just `__initcall' as a workaround for
229 * the fact that (1) simcons_tty_init can't be called before tty_init,
230 * (2) tty_init is called via `module_init', (3) if statically linked,
231 * module_init == device_init, and (4) there's no ordering of init lists.
232 * We can do this easily because simcons is always statically linked, but
233 * other tty drivers that depend on tty_init and which must use
234 * `module_init' to declare their init routines are likely to be broken.
235 */
236
237late_initcall(rs_init);
238
239
240#ifdef CONFIG_SERIAL_CONSOLE
241
242static void iss_console_write(struct console *co, const char *s, unsigned count)
243{
244 int len = strlen(s);
245
246 if (s != 0 && *s != 0)
247 __simc (SYS_write, 1, (unsigned long)s,
248 count < len ? count : len,0,0);
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