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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - drivers/serial/kgdboc.c
2 * Based on the same principle as kgdboe using the NETPOLL api, this
3 * driver uses a console polling api to implement a gdb serial inteface
4 * which is multiplexed on a console port.
6 * Maintainer: Jason Wessel <jason.wessel@windriver.com>
8 * 2007-2008 (c) Jason Wessel - Wind River Systems, Inc.
10 * This file is licensed under the terms of the GNU General Public
11 * License version 2. This program is licensed "as is" without any
12 * warranty of any kind, whether express or implied.
14 #include <linux/kernel.h>
15 #include <linux/ctype.h>
16 #include <linux/kgdb.h>
17 #include <linux/tty.h>
19 #define MAX_CONFIG_LEN 40
21 static struct kgdb_io kgdboc_io_ops
;
23 /* -1 = init not run yet, 0 = unconfigured, 1 = configured. */
24 static int configured
= -1;
26 static char config
[MAX_CONFIG_LEN
];
27 static struct kparam_string kps
= {
29 .maxlen
= MAX_CONFIG_LEN
,
32 static struct tty_driver
*kgdb_tty_driver
;
33 static int kgdb_tty_line
;
35 static int kgdboc_option_setup(char *opt
)
37 if (strlen(opt
) > MAX_CONFIG_LEN
) {
38 printk(KERN_ERR
"kgdboc: config string too long\n");
46 __setup("kgdboc=", kgdboc_option_setup
);
48 static int configure_kgdboc(void)
54 err
= kgdboc_option_setup(config
);
55 if (err
|| !strlen(config
) || isspace(config
[0]))
60 p
= tty_find_polling_driver(config
, &tty_line
);
65 kgdb_tty_line
= tty_line
;
67 err
= kgdb_register_io_module(&kgdboc_io_ops
);
82 static int __init
init_kgdboc(void)
84 /* Already configured? */
88 return configure_kgdboc();
91 static void cleanup_kgdboc(void)
94 kgdb_unregister_io_module(&kgdboc_io_ops
);
97 static int kgdboc_get_char(void)
99 return kgdb_tty_driver
->ops
->poll_get_char(kgdb_tty_driver
,
103 static void kgdboc_put_char(u8 chr
)
105 kgdb_tty_driver
->ops
->poll_put_char(kgdb_tty_driver
,
109 static int param_set_kgdboc_var(const char *kmessage
, struct kernel_param
*kp
)
111 int len
= strlen(kmessage
);
113 if (len
>= MAX_CONFIG_LEN
) {
114 printk(KERN_ERR
"kgdboc: config string too long\n");
118 /* Only copy in the string if the init function has not run yet */
119 if (configured
< 0) {
120 strcpy(config
, kmessage
);
124 if (kgdb_connected
) {
126 "kgdboc: Cannot reconfigure while KGDB is connected.\n");
131 strcpy(config
, kmessage
);
132 /* Chop out \n char as a result of echo */
133 if (config
[len
- 1] == '\n')
134 config
[len
- 1] = '\0';
139 /* Go and configure with the new params. */
140 return configure_kgdboc();
143 static void kgdboc_pre_exp_handler(void)
145 /* Increment the module count when the debugger is active */
147 try_module_get(THIS_MODULE
);
150 static void kgdboc_post_exp_handler(void)
152 /* decrement the module count when the debugger detaches */
154 module_put(THIS_MODULE
);
157 static struct kgdb_io kgdboc_io_ops
= {
159 .read_char
= kgdboc_get_char
,
160 .write_char
= kgdboc_put_char
,
161 .pre_exception
= kgdboc_pre_exp_handler
,
162 .post_exception
= kgdboc_post_exp_handler
,
165 module_init(init_kgdboc
);
166 module_exit(cleanup_kgdboc
);
167 module_param_call(kgdboc
, param_set_kgdboc_var
, param_get_string
, &kps
, 0644);
168 MODULE_PARM_DESC(kgdboc
, "<serial_device>[,baud]");
169 MODULE_DESCRIPTION("KGDB Console TTY Driver");
170 MODULE_LICENSE("GPL");