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/kdb.h>
18 #include <linux/tty.h>
20 #define MAX_CONFIG_LEN 40
22 static struct kgdb_io kgdboc_io_ops;
24 /* -1 = init not run yet, 0 = unconfigured, 1 = configured. */
25 static int configured = -1;
27 static char config[MAX_CONFIG_LEN];
28 static struct kparam_string kps = {
30 .maxlen = MAX_CONFIG_LEN,
33 static struct tty_driver *kgdb_tty_driver;
34 static int kgdb_tty_line;
36 #ifdef CONFIG_KDB_KEYBOARD
37 static int kgdboc_register_kbd(char **cptr)
39 if (strncmp(*cptr, "kbd", 3) == 0) {
40 if (kdb_poll_idx < KDB_POLL_FUNC_MAX) {
41 kdb_poll_funcs[kdb_poll_idx] = kdb_get_kbd_char;
43 if (cptr[0][3] == ',')
52 static void kgdboc_unregister_kbd(void)
56 for (i = 0; i < kdb_poll_idx; i++) {
57 if (kdb_poll_funcs[i] == kdb_get_kbd_char) {
59 kdb_poll_funcs[i] = kdb_poll_funcs[kdb_poll_idx];
60 kdb_poll_funcs[kdb_poll_idx] = NULL;
65 #else /* ! CONFIG_KDB_KEYBOARD */
66 #define kgdboc_register_kbd(x) 0
67 #define kgdboc_unregister_kbd()
68 #endif /* ! CONFIG_KDB_KEYBOARD */
70 static int kgdboc_option_setup(char *opt)
72 if (strlen(opt) > MAX_CONFIG_LEN) {
73 printk(KERN_ERR "kgdboc: config string too long\n");
81 __setup("kgdboc=", kgdboc_option_setup);
83 static void cleanup_kgdboc(void)
85 kgdboc_unregister_kbd();
87 kgdb_unregister_io_module(&kgdboc_io_ops);
90 static int configure_kgdboc(void)
97 err = kgdboc_option_setup(config);
98 if (err || !strlen(config) || isspace(config[0]))
102 kgdb_tty_driver = NULL;
104 if (kgdboc_register_kbd(&cptr))
107 p = tty_find_polling_driver(cptr, &tty_line);
112 kgdb_tty_line = tty_line;
115 err = kgdb_register_io_module(&kgdboc_io_ops);
131 static int __init init_kgdboc(void)
133 /* Already configured? */
137 return configure_kgdboc();
140 static int kgdboc_get_char(void)
142 if (!kgdb_tty_driver)
144 return kgdb_tty_driver->ops->poll_get_char(kgdb_tty_driver,
148 static void kgdboc_put_char(u8 chr)
150 if (!kgdb_tty_driver)
152 kgdb_tty_driver->ops->poll_put_char(kgdb_tty_driver,
156 static int param_set_kgdboc_var(const char *kmessage, struct kernel_param *kp)
158 int len = strlen(kmessage);
160 if (len >= MAX_CONFIG_LEN) {
161 printk(KERN_ERR "kgdboc: config string too long\n");
165 /* Only copy in the string if the init function has not run yet */
166 if (configured < 0) {
167 strcpy(config, kmessage);
171 if (kgdb_connected) {
173 "kgdboc: Cannot reconfigure while KGDB is connected.\n");
178 strcpy(config, kmessage);
179 /* Chop out \n char as a result of echo */
180 if (config[len - 1] == '\n')
181 config[len - 1] = '\0';
186 /* Go and configure with the new params. */
187 return configure_kgdboc();
190 static void kgdboc_pre_exp_handler(void)
192 /* Increment the module count when the debugger is active */
194 try_module_get(THIS_MODULE);
197 static void kgdboc_post_exp_handler(void)
199 /* decrement the module count when the debugger detaches */
201 module_put(THIS_MODULE);
204 static struct kgdb_io kgdboc_io_ops = {
206 .read_char = kgdboc_get_char,
207 .write_char = kgdboc_put_char,
208 .pre_exception = kgdboc_pre_exp_handler,
209 .post_exception = kgdboc_post_exp_handler,
212 module_init(init_kgdboc);
213 module_exit(cleanup_kgdboc);
214 module_param_call(kgdboc, param_set_kgdboc_var, param_get_string, &kps, 0644);
215 MODULE_PARM_DESC(kgdboc, "<serial_device>[,baud]");
216 MODULE_DESCRIPTION("KGDB Console TTY Driver");
217 MODULE_LICENSE("GPL");