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
34 static void rs_poll(struct timer_list *);
35
36 static struct tty_driver *serial_driver;
37 static struct tty_port serial_port;
38 static DEFINE_TIMER(serial_timer, rs_poll);
39
rs_open(struct tty_struct * tty,struct file * filp)40 static int rs_open(struct tty_struct *tty, struct file * filp)
41 {
42 if (tty->count == 1)
43 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
44
45 return 0;
46 }
47
rs_close(struct tty_struct * tty,struct file * filp)48 static void rs_close(struct tty_struct *tty, struct file * filp)
49 {
50 if (tty->count == 1)
51 del_timer_sync(&serial_timer);
52 }
53
54
rs_write(struct tty_struct * tty,const u8 * buf,size_t count)55 static ssize_t rs_write(struct tty_struct * tty, const u8 *buf, size_t count)
56 {
57 /* see drivers/char/serialX.c to reference original version */
58
59 simc_write(1, buf, count);
60 return count;
61 }
62
rs_poll(struct timer_list * unused)63 static void rs_poll(struct timer_list *unused)
64 {
65 struct tty_port *port = &serial_port;
66 int i = 0;
67 int rd = 1;
68 u8 c;
69
70 while (simc_poll(0)) {
71 rd = simc_read(0, &c, 1);
72 if (rd <= 0)
73 break;
74 tty_insert_flip_char(port, c, TTY_NORMAL);
75 i++;
76 }
77
78 if (i)
79 tty_flip_buffer_push(port);
80 if (rd)
81 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
82 }
83
rs_write_room(struct tty_struct * tty)84 static unsigned int rs_write_room(struct tty_struct *tty)
85 {
86 /* Let's say iss can always accept 2K characters.. */
87 return 2 * 1024;
88 }
89
rs_proc_show(struct seq_file * m,void * v)90 static int rs_proc_show(struct seq_file *m, void *v)
91 {
92 seq_printf(m, "serinfo:1.0 driver:0.1\n");
93 return 0;
94 }
95
96 static const struct tty_operations serial_ops = {
97 .open = rs_open,
98 .close = rs_close,
99 .write = rs_write,
100 .write_room = rs_write_room,
101 .proc_show = rs_proc_show,
102 };
103
rs_init(void)104 static int __init rs_init(void)
105 {
106 struct tty_driver *driver;
107 int ret;
108
109 driver = tty_alloc_driver(SERIAL_MAX_NUM_LINES, TTY_DRIVER_REAL_RAW);
110 if (IS_ERR(driver))
111 return PTR_ERR(driver);
112
113 tty_port_init(&serial_port);
114
115 /* Initialize the tty_driver structure */
116
117 driver->driver_name = "iss_serial";
118 driver->name = "ttyS";
119 driver->major = TTY_MAJOR;
120 driver->minor_start = 64;
121 driver->type = TTY_DRIVER_TYPE_SERIAL;
122 driver->subtype = SERIAL_TYPE_NORMAL;
123 driver->init_termios = tty_std_termios;
124 driver->init_termios.c_cflag =
125 B9600 | CS8 | CREAD | HUPCL | CLOCAL;
126
127 tty_set_operations(driver, &serial_ops);
128 tty_port_link_device(&serial_port, driver, 0);
129
130 ret = tty_register_driver(driver);
131 if (ret) {
132 pr_err("Couldn't register serial driver\n");
133 tty_driver_kref_put(driver);
134 tty_port_destroy(&serial_port);
135
136 return ret;
137 }
138
139 serial_driver = driver;
140
141 return 0;
142 }
143
144
rs_exit(void)145 static __exit void rs_exit(void)
146 {
147 tty_unregister_driver(serial_driver);
148 tty_driver_kref_put(serial_driver);
149 tty_port_destroy(&serial_port);
150 }
151
152
153 /* We use `late_initcall' instead of just `__initcall' as a workaround for
154 * the fact that (1) simcons_tty_init can't be called before tty_init,
155 * (2) tty_init is called via `module_init', (3) if statically linked,
156 * module_init == device_init, and (4) there's no ordering of init lists.
157 * We can do this easily because simcons is always statically linked, but
158 * other tty drivers that depend on tty_init and which must use
159 * `module_init' to declare their init routines are likely to be broken.
160 */
161
162 late_initcall(rs_init);
163
164
165 #ifdef CONFIG_SERIAL_CONSOLE
166
iss_console_write(struct console * co,const char * s,unsigned count)167 static void iss_console_write(struct console *co, const char *s, unsigned count)
168 {
169 if (s && *s != 0)
170 simc_write(1, s, min(count, strlen(s)));
171 }
172
iss_console_device(struct console * c,int * index)173 static struct tty_driver* iss_console_device(struct console *c, int *index)
174 {
175 *index = c->index;
176 return serial_driver;
177 }
178
179
180 static struct console sercons = {
181 .name = "ttyS",
182 .write = iss_console_write,
183 .device = iss_console_device,
184 .flags = CON_PRINTBUFFER,
185 .index = -1
186 };
187
iss_console_init(void)188 static int __init iss_console_init(void)
189 {
190 register_console(&sercons);
191 return 0;
192 }
193
194 console_initcall(iss_console_init);
195
196 #endif /* CONFIG_SERIAL_CONSOLE */
197
198