xref: /openbmc/linux/arch/powerpc/kernel/udbg.c (revision 7b6d864b)
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_BEAT)
50 	udbg_init_debug_beat();
51 #elif defined(CONFIG_PPC_EARLY_DEBUG_PAS_REALMODE)
52 	udbg_init_pas_realmode();
53 #elif defined(CONFIG_PPC_EARLY_DEBUG_BOOTX)
54 	udbg_init_btext();
55 #elif defined(CONFIG_PPC_EARLY_DEBUG_44x)
56 	/* PPC44x debug */
57 	udbg_init_44x_as1();
58 #elif defined(CONFIG_PPC_EARLY_DEBUG_40x)
59 	/* PPC40x debug */
60 	udbg_init_40x_realmode();
61 #elif defined(CONFIG_PPC_EARLY_DEBUG_CPM)
62 	udbg_init_cpm();
63 #elif defined(CONFIG_PPC_EARLY_DEBUG_USBGECKO)
64 	udbg_init_usbgecko();
65 #elif defined(CONFIG_PPC_EARLY_DEBUG_WSP)
66 	udbg_init_wsp();
67 #elif defined(CONFIG_PPC_EARLY_DEBUG_MEMCONS)
68 	/* In memory console */
69 	udbg_init_memcons();
70 #elif defined(CONFIG_PPC_EARLY_DEBUG_EHV_BC)
71 	udbg_init_ehv_bc();
72 #elif defined(CONFIG_PPC_EARLY_DEBUG_PS3GELIC)
73 	udbg_init_ps3gelic();
74 #elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_RAW)
75 	udbg_init_debug_opal_raw();
76 #elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI)
77 	udbg_init_debug_opal_hvsi();
78 #endif
79 
80 #ifdef CONFIG_PPC_EARLY_DEBUG
81 	console_loglevel = 10;
82 
83 	register_early_udbg_console();
84 #endif
85 }
86 
87 /* udbg library, used by xmon et al */
88 void udbg_puts(const char *s)
89 {
90 	if (udbg_putc) {
91 		char c;
92 
93 		if (s && *s != '\0') {
94 			while ((c = *s++) != '\0')
95 				udbg_putc(c);
96 		}
97 
98 		if (udbg_flush)
99 			udbg_flush();
100 	}
101 #if 0
102 	else {
103 		printk("%s", s);
104 	}
105 #endif
106 }
107 
108 int udbg_write(const char *s, int n)
109 {
110 	int remain = n;
111 	char c;
112 
113 	if (!udbg_putc)
114 		return 0;
115 
116 	if (s && *s != '\0') {
117 		while (((c = *s++) != '\0') && (remain-- > 0)) {
118 			udbg_putc(c);
119 		}
120 	}
121 
122 	if (udbg_flush)
123 		udbg_flush();
124 
125 	return n - remain;
126 }
127 
128 #define UDBG_BUFSIZE 256
129 void udbg_printf(const char *fmt, ...)
130 {
131 	char buf[UDBG_BUFSIZE];
132 	va_list args;
133 
134 	va_start(args, fmt);
135 	vsnprintf(buf, UDBG_BUFSIZE, fmt, args);
136 	udbg_puts(buf);
137 	va_end(args);
138 }
139 
140 void __init udbg_progress(char *s, unsigned short hex)
141 {
142 	udbg_puts(s);
143 	udbg_puts("\n");
144 }
145 
146 /*
147  * Early boot console based on udbg
148  */
149 static void udbg_console_write(struct console *con, const char *s,
150 		unsigned int n)
151 {
152 	udbg_write(s, n);
153 }
154 
155 static struct console udbg_console = {
156 	.name	= "udbg",
157 	.write	= udbg_console_write,
158 	.flags	= CON_PRINTBUFFER | CON_ENABLED | CON_BOOT | CON_ANYTIME,
159 	.index	= 0,
160 };
161 
162 /*
163  * Called by setup_system after ppc_md->probe and ppc_md->early_init.
164  * Call it again after setting udbg_putc in ppc_md->setup_arch.
165  */
166 void __init register_early_udbg_console(void)
167 {
168 	if (early_console)
169 		return;
170 
171 	if (!udbg_putc)
172 		return;
173 
174 	if (strstr(boot_command_line, "udbg-immortal")) {
175 		printk(KERN_INFO "early console immortal !\n");
176 		udbg_console.flags &= ~CON_BOOT;
177 	}
178 	early_console = &udbg_console;
179 	register_console(&udbg_console);
180 }
181 
182 #if 0   /* if you want to use this as a regular output console */
183 console_initcall(register_udbg_console);
184 #endif
185