xref: /openbmc/linux/arch/m68k/emu/nfcon.c (revision e9e8bcb8)
1 /*
2  * ARAnyM console driver
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 
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/console.h>
12 #include <linux/tty.h>
13 #include <linux/tty_driver.h>
14 #include <linux/tty_flip.h>
15 #include <linux/slab.h>
16 #include <linux/err.h>
17 #include <linux/uaccess.h>
18 
19 #include <asm/natfeat.h>
20 
21 static int stderr_id;
22 static struct tty_driver *nfcon_tty_driver;
23 
24 static void nfputs(const char *str, unsigned int count)
25 {
26 	char buf[68];
27 
28 	buf[64] = 0;
29 	while (count > 64) {
30 		memcpy(buf, str, 64);
31 		nf_call(stderr_id, buf);
32 		str += 64;
33 		count -= 64;
34 	}
35 	memcpy(buf, str, count);
36 	buf[count] = 0;
37 	nf_call(stderr_id, buf);
38 }
39 
40 static void nfcon_write(struct console *con, const char *str,
41 			unsigned int count)
42 {
43 	nfputs(str, count);
44 }
45 
46 static struct tty_driver *nfcon_device(struct console *con, int *index)
47 {
48 	*index = 0;
49 	return (con->flags & CON_ENABLED) ? nfcon_tty_driver : NULL;
50 }
51 
52 static struct console nf_console = {
53 	.name	= "nfcon",
54 	.write	= nfcon_write,
55 	.device	= nfcon_device,
56 	.flags	= CON_PRINTBUFFER,
57 	.index	= -1,
58 };
59 
60 
61 static int nfcon_tty_open(struct tty_struct *tty, struct file *filp)
62 {
63 	return 0;
64 }
65 
66 static void nfcon_tty_close(struct tty_struct *tty, struct file *filp)
67 {
68 }
69 
70 static int nfcon_tty_write(struct tty_struct *tty, const unsigned char *buf,
71 			   int count)
72 {
73 	nfputs(buf, count);
74 	return count;
75 }
76 
77 static int nfcon_tty_put_char(struct tty_struct *tty, unsigned char ch)
78 {
79 	char temp[2] = { ch, 0 };
80 
81 	nf_call(stderr_id, temp);
82 	return 1;
83 }
84 
85 static int nfcon_tty_write_room(struct tty_struct *tty)
86 {
87 	return 64;
88 }
89 
90 static const struct tty_operations nfcon_tty_ops = {
91 	.open		= nfcon_tty_open,
92 	.close		= nfcon_tty_close,
93 	.write		= nfcon_tty_write,
94 	.put_char	= nfcon_tty_put_char,
95 	.write_room	= nfcon_tty_write_room,
96 };
97 
98 #ifndef MODULE
99 
100 static int __init nf_debug_setup(char *arg)
101 {
102 	if (strcmp(arg, "nfcon"))
103 		return 0;
104 
105 	stderr_id = nf_get_id("NF_STDERR");
106 	if (stderr_id) {
107 		nf_console.flags |= CON_ENABLED;
108 		register_console(&nf_console);
109 	}
110 
111 	return 0;
112 }
113 
114 early_param("debug", nf_debug_setup);
115 
116 #endif /* !MODULE */
117 
118 static int __init nfcon_init(void)
119 {
120 	int res;
121 
122 	stderr_id = nf_get_id("NF_STDERR");
123 	if (!stderr_id)
124 		return -ENODEV;
125 
126 	nfcon_tty_driver = alloc_tty_driver(1);
127 	if (!nfcon_tty_driver)
128 		return -ENOMEM;
129 
130 	nfcon_tty_driver->owner = THIS_MODULE;
131 	nfcon_tty_driver->driver_name = "nfcon";
132 	nfcon_tty_driver->name = "nfcon";
133 	nfcon_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM;
134 	nfcon_tty_driver->subtype = SYSTEM_TYPE_TTY;
135 	nfcon_tty_driver->init_termios = tty_std_termios;
136 	nfcon_tty_driver->flags = TTY_DRIVER_REAL_RAW;
137 
138 	tty_set_operations(nfcon_tty_driver, &nfcon_tty_ops);
139 	res = tty_register_driver(nfcon_tty_driver);
140 	if (res) {
141 		pr_err("failed to register nfcon tty driver\n");
142 		put_tty_driver(nfcon_tty_driver);
143 		return res;
144 	}
145 
146 	if (!(nf_console.flags & CON_ENABLED))
147 		register_console(&nf_console);
148 
149 	return 0;
150 }
151 
152 static void __exit nfcon_exit(void)
153 {
154 	unregister_console(&nf_console);
155 	tty_unregister_driver(nfcon_tty_driver);
156 	put_tty_driver(nfcon_tty_driver);
157 }
158 
159 module_init(nfcon_init);
160 module_exit(nfcon_exit);
161 
162 MODULE_LICENSE("GPL");
163