2 * arch/xtensa/platforms/iss/console.c
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
8 * Copyright (C) 2001-2005 Tensilica Inc.
9 * Authors Christian Zankel, Joe Taylor
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>
18 #include <linux/major.h>
19 #include <linux/param.h>
20 #include <linux/seq_file.h>
21 #include <linux/serial.h>
23 #include <linux/uaccess.h>
26 #include <platform/simcall.h>
28 #include <linux/tty.h>
29 #include <linux/tty_flip.h>
31 #define SERIAL_MAX_NUM_LINES 1
32 #define SERIAL_TIMER_VALUE (HZ / 10)
34 static struct tty_driver *serial_driver;
35 static struct tty_port serial_port;
36 static struct timer_list serial_timer;
38 static DEFINE_SPINLOCK(timer_lock);
40 static char *serial_version = "0.1";
41 static char *serial_name = "ISS serial driver";
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.
50 static void rs_poll(struct timer_list *);
52 static int rs_open(struct tty_struct *tty, struct file * filp)
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);
60 spin_unlock_bh(&timer_lock);
67 * ------------------------------------------------------------
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 * ------------------------------------------------------------
76 static void rs_close(struct tty_struct *tty, struct file * filp)
78 spin_lock_bh(&timer_lock);
80 del_timer_sync(&serial_timer);
81 spin_unlock_bh(&timer_lock);
85 static int rs_write(struct tty_struct * tty,
86 const unsigned char *buf, int count)
88 /* see drivers/char/serialX.c to reference original version */
90 simc_write(1, buf, count);
94 static void rs_poll(struct timer_list *unused)
96 struct tty_port *port = &serial_port;
101 spin_lock(&timer_lock);
103 while (simc_poll(0)) {
104 rd = simc_read(0, &c, 1);
107 tty_insert_flip_char(port, c, TTY_NORMAL);
112 tty_flip_buffer_push(port);
114 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
115 spin_unlock(&timer_lock);
119 static int rs_put_char(struct tty_struct *tty, unsigned char ch)
121 return rs_write(tty, &ch, 1);
124 static void rs_flush_chars(struct tty_struct *tty)
128 static int rs_write_room(struct tty_struct *tty)
130 /* Let's say iss can always accept 2K characters.. */
134 static int rs_chars_in_buffer(struct tty_struct *tty)
136 /* the iss doesn't buffer characters */
140 static void rs_hangup(struct tty_struct *tty)
142 /* Stub, once again.. */
145 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
147 /* Stub, once again.. */
150 static int rs_proc_show(struct seq_file *m, void *v)
152 seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version);
156 static const struct tty_operations serial_ops = {
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,
165 .wait_until_sent = rs_wait_until_sent,
166 .proc_show = rs_proc_show,
169 int __init rs_init(void)
173 serial_driver = alloc_tty_driver(SERIAL_MAX_NUM_LINES);
177 tty_port_init(&serial_port);
179 pr_info("%s %s\n", serial_name, serial_version);
181 /* Initialize the tty_driver structure */
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;
194 tty_set_operations(serial_driver, &serial_ops);
195 tty_port_link_device(&serial_port, serial_driver, 0);
197 ret = tty_register_driver(serial_driver);
199 pr_err("Couldn't register serial driver\n");
200 tty_driver_kref_put(serial_driver);
201 tty_port_destroy(&serial_port);
210 static __exit void rs_exit(void)
214 if ((error = tty_unregister_driver(serial_driver)))
215 pr_err("ISS_SERIAL: failed to unregister serial driver (%d)\n",
217 put_tty_driver(serial_driver);
218 tty_port_destroy(&serial_port);
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.
231 late_initcall(rs_init);
234 #ifdef CONFIG_SERIAL_CONSOLE
236 static void iss_console_write(struct console *co, const char *s, unsigned count)
240 if (s != 0 && *s != 0)
241 simc_write(1, s, count < len ? count : len);
244 static struct tty_driver* iss_console_device(struct console *c, int *index)
247 return serial_driver;
251 static struct console sercons = {
253 .write = iss_console_write,
254 .device = iss_console_device,
255 .flags = CON_PRINTBUFFER,
259 static int __init iss_console_init(void)
261 register_console(&sercons);
265 console_initcall(iss_console_init);
267 #endif /* CONFIG_SERIAL_CONSOLE */