xref: /openbmc/linux/arch/m68k/emu/nfcon.c (revision 35267cea)
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 #include <linux/io.h>
19 
20 #include <asm/natfeat.h>
21 
22 static int stderr_id;
23 static struct tty_port nfcon_tty_port;
24 static struct tty_driver *nfcon_tty_driver;
25 
26 static void nfputs(const char *str, unsigned int count)
27 {
28 	char buf[68];
29 	unsigned long phys = virt_to_phys(buf);
30 
31 	buf[64] = 0;
32 	while (count > 64) {
33 		memcpy(buf, str, 64);
34 		nf_call(stderr_id, phys);
35 		str += 64;
36 		count -= 64;
37 	}
38 	memcpy(buf, str, count);
39 	buf[count] = 0;
40 	nf_call(stderr_id, phys);
41 }
42 
43 static void nfcon_write(struct console *con, const char *str,
44 			unsigned int count)
45 {
46 	nfputs(str, count);
47 }
48 
49 static struct tty_driver *nfcon_device(struct console *con, int *index)
50 {
51 	*index = 0;
52 	return (con->flags & CON_ENABLED) ? nfcon_tty_driver : NULL;
53 }
54 
55 static struct console nf_console = {
56 	.name	= "nfcon",
57 	.write	= nfcon_write,
58 	.device	= nfcon_device,
59 	.flags	= CON_PRINTBUFFER,
60 	.index	= -1,
61 };
62 
63 
64 static int nfcon_tty_open(struct tty_struct *tty, struct file *filp)
65 {
66 	return 0;
67 }
68 
69 static void nfcon_tty_close(struct tty_struct *tty, struct file *filp)
70 {
71 }
72 
73 static int nfcon_tty_write(struct tty_struct *tty, const unsigned char *buf,
74 			   int count)
75 {
76 	nfputs(buf, count);
77 	return count;
78 }
79 
80 static int nfcon_tty_put_char(struct tty_struct *tty, unsigned char ch)
81 {
82 	char temp[2] = { ch, 0 };
83 
84 	nf_call(stderr_id, virt_to_phys(temp));
85 	return 1;
86 }
87 
88 static unsigned int nfcon_tty_write_room(struct tty_struct *tty)
89 {
90 	return 64;
91 }
92 
93 static const struct tty_operations nfcon_tty_ops = {
94 	.open		= nfcon_tty_open,
95 	.close		= nfcon_tty_close,
96 	.write		= nfcon_tty_write,
97 	.put_char	= nfcon_tty_put_char,
98 	.write_room	= nfcon_tty_write_room,
99 };
100 
101 #ifndef MODULE
102 
103 static int __init nf_debug_setup(char *arg)
104 {
105 	if (strcmp(arg, "nfcon"))
106 		return 0;
107 
108 	stderr_id = nf_get_id("NF_STDERR");
109 	if (stderr_id) {
110 		nf_console.flags |= CON_ENABLED;
111 		register_console(&nf_console);
112 	}
113 
114 	return 0;
115 }
116 
117 early_param("debug", nf_debug_setup);
118 
119 #endif /* !MODULE */
120 
121 static int __init nfcon_init(void)
122 {
123 	int res;
124 
125 	stderr_id = nf_get_id("NF_STDERR");
126 	if (!stderr_id)
127 		return -ENODEV;
128 
129 	nfcon_tty_driver = alloc_tty_driver(1);
130 	if (!nfcon_tty_driver)
131 		return -ENOMEM;
132 
133 	tty_port_init(&nfcon_tty_port);
134 
135 	nfcon_tty_driver->driver_name = "nfcon";
136 	nfcon_tty_driver->name = "nfcon";
137 	nfcon_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM;
138 	nfcon_tty_driver->subtype = SYSTEM_TYPE_TTY;
139 	nfcon_tty_driver->init_termios = tty_std_termios;
140 	nfcon_tty_driver->flags = TTY_DRIVER_REAL_RAW;
141 
142 	tty_set_operations(nfcon_tty_driver, &nfcon_tty_ops);
143 	tty_port_link_device(&nfcon_tty_port, nfcon_tty_driver, 0);
144 	res = tty_register_driver(nfcon_tty_driver);
145 	if (res) {
146 		pr_err("failed to register nfcon tty driver\n");
147 		put_tty_driver(nfcon_tty_driver);
148 		tty_port_destroy(&nfcon_tty_port);
149 		return res;
150 	}
151 
152 	if (!(nf_console.flags & CON_ENABLED))
153 		register_console(&nf_console);
154 
155 	return 0;
156 }
157 
158 static void __exit nfcon_exit(void)
159 {
160 	unregister_console(&nf_console);
161 	tty_unregister_driver(nfcon_tty_driver);
162 	put_tty_driver(nfcon_tty_driver);
163 	tty_port_destroy(&nfcon_tty_port);
164 }
165 
166 module_init(nfcon_init);
167 module_exit(nfcon_exit);
168 
169 MODULE_LICENSE("GPL");
170