xref: /openbmc/linux/arch/powerpc/kernel/udbg.c (revision 9b93eb47)
1 /*
2  * polling mode stateless debugging stuff, originally for NS16550 Serial Ports
3  *
4  * c 2001 PPC 64 Team, IBM Corp
5  *
6  *      This program is free software; you can redistribute it and/or
7  *      modify it under the terms of the GNU General Public License
8  *      as published by the Free Software Foundation; either version
9  *      2 of the License, or (at your option) any later version.
10  */
11 
12 #include <stdarg.h>
13 #include <linux/types.h>
14 #include <linux/sched.h>
15 #include <linux/console.h>
16 #include <linux/init.h>
17 #include <asm/processor.h>
18 #include <asm/udbg.h>
19 
20 void (*udbg_putc)(char c);
21 void (*udbg_flush)(void);
22 int (*udbg_getc)(void);
23 int (*udbg_getc_poll)(void);
24 
25 /*
26  * Early debugging facilities. You can enable _one_ of these via .config,
27  * if you do so your kernel _will not boot_ on anything else. Be careful.
28  */
29 void __init udbg_early_init(void)
30 {
31 #if defined(CONFIG_PPC_EARLY_DEBUG_LPAR)
32 	/* For LPAR machines that have an HVC console on vterm 0 */
33 	udbg_init_debug_lpar();
34 #elif defined(CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI)
35 	/* For LPAR machines that have an HVSI console on vterm 0 */
36 	udbg_init_debug_lpar_hvsi();
37 #elif defined(CONFIG_PPC_EARLY_DEBUG_G5)
38 	/* For use on Apple G5 machines */
39 	udbg_init_pmac_realmode();
40 #elif defined(CONFIG_PPC_EARLY_DEBUG_RTAS_PANEL)
41 	/* RTAS panel debug */
42 	udbg_init_rtas_panel();
43 #elif defined(CONFIG_PPC_EARLY_DEBUG_RTAS_CONSOLE)
44 	/* RTAS console debug */
45 	udbg_init_rtas_console();
46 #elif defined(CONFIG_PPC_EARLY_DEBUG_MAPLE)
47 	/* Maple real mode debug */
48 	udbg_init_maple_realmode();
49 #elif defined(CONFIG_PPC_EARLY_DEBUG_PAS_REALMODE)
50 	udbg_init_pas_realmode();
51 #elif defined(CONFIG_PPC_EARLY_DEBUG_BOOTX)
52 	udbg_init_btext();
53 #elif defined(CONFIG_PPC_EARLY_DEBUG_44x)
54 	/* PPC44x debug */
55 	udbg_init_44x_as1();
56 #elif defined(CONFIG_PPC_EARLY_DEBUG_40x)
57 	/* PPC40x debug */
58 	udbg_init_40x_realmode();
59 #elif defined(CONFIG_PPC_EARLY_DEBUG_CPM)
60 	udbg_init_cpm();
61 #elif defined(CONFIG_PPC_EARLY_DEBUG_USBGECKO)
62 	udbg_init_usbgecko();
63 #elif defined(CONFIG_PPC_EARLY_DEBUG_MEMCONS)
64 	/* In memory console */
65 	udbg_init_memcons();
66 #elif defined(CONFIG_PPC_EARLY_DEBUG_EHV_BC)
67 	udbg_init_ehv_bc();
68 #elif defined(CONFIG_PPC_EARLY_DEBUG_PS3GELIC)
69 	udbg_init_ps3gelic();
70 #elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_RAW)
71 	udbg_init_debug_opal_raw();
72 #elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI)
73 	udbg_init_debug_opal_hvsi();
74 #endif
75 
76 #ifdef CONFIG_PPC_EARLY_DEBUG
77 	console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
78 
79 	register_early_udbg_console();
80 #endif
81 }
82 
83 /* udbg library, used by xmon et al */
84 void udbg_puts(const char *s)
85 {
86 	if (udbg_putc) {
87 		char c;
88 
89 		if (s && *s != '\0') {
90 			while ((c = *s++) != '\0')
91 				udbg_putc(c);
92 		}
93 
94 		if (udbg_flush)
95 			udbg_flush();
96 	}
97 #if 0
98 	else {
99 		printk("%s", s);
100 	}
101 #endif
102 }
103 
104 int udbg_write(const char *s, int n)
105 {
106 	int remain = n;
107 	char c;
108 
109 	if (!udbg_putc)
110 		return 0;
111 
112 	if (s && *s != '\0') {
113 		while (((c = *s++) != '\0') && (remain-- > 0)) {
114 			udbg_putc(c);
115 		}
116 	}
117 
118 	if (udbg_flush)
119 		udbg_flush();
120 
121 	return n - remain;
122 }
123 
124 #define UDBG_BUFSIZE 256
125 void udbg_printf(const char *fmt, ...)
126 {
127 	char buf[UDBG_BUFSIZE];
128 	va_list args;
129 
130 	va_start(args, fmt);
131 	vsnprintf(buf, UDBG_BUFSIZE, fmt, args);
132 	udbg_puts(buf);
133 	va_end(args);
134 }
135 
136 void __init udbg_progress(char *s, unsigned short hex)
137 {
138 	udbg_puts(s);
139 	udbg_puts("\n");
140 }
141 
142 /*
143  * Early boot console based on udbg
144  */
145 static void udbg_console_write(struct console *con, const char *s,
146 		unsigned int n)
147 {
148 	udbg_write(s, n);
149 }
150 
151 static struct console udbg_console = {
152 	.name	= "udbg",
153 	.write	= udbg_console_write,
154 	.flags	= CON_PRINTBUFFER | CON_ENABLED | CON_BOOT | CON_ANYTIME,
155 	.index	= 0,
156 };
157 
158 /*
159  * Called by setup_system after ppc_md->probe and ppc_md->early_init.
160  * Call it again after setting udbg_putc in ppc_md->setup_arch.
161  */
162 void __init register_early_udbg_console(void)
163 {
164 	if (early_console)
165 		return;
166 
167 	if (!udbg_putc)
168 		return;
169 
170 	if (strstr(boot_command_line, "udbg-immortal")) {
171 		printk(KERN_INFO "early console immortal !\n");
172 		udbg_console.flags &= ~CON_BOOT;
173 	}
174 	early_console = &udbg_console;
175 	register_console(&udbg_console);
176 }
177 
178 #if 0   /* if you want to use this as a regular output console */
179 console_initcall(register_udbg_console);
180 #endif
181