xref: /openbmc/linux/arch/powerpc/kernel/udbg.c (revision 63dc02bd)
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_BOOTX_TEXT)
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_EHV_BC)
68 	udbg_init_ehv_bc();
69 #elif defined(CONFIG_PPC_EARLY_DEBUG_PS3GELIC)
70 	udbg_init_ps3gelic();
71 #elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_RAW)
72 	udbg_init_debug_opal_raw();
73 #elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI)
74 	udbg_init_debug_opal_hvsi();
75 #endif
76 
77 #ifdef CONFIG_PPC_EARLY_DEBUG
78 	console_loglevel = 10;
79 
80 	register_early_udbg_console();
81 #endif
82 }
83 
84 /* udbg library, used by xmon et al */
85 void udbg_puts(const char *s)
86 {
87 	if (udbg_putc) {
88 		char c;
89 
90 		if (s && *s != '\0') {
91 			while ((c = *s++) != '\0')
92 				udbg_putc(c);
93 		}
94 
95 		if (udbg_flush)
96 			udbg_flush();
97 	}
98 #if 0
99 	else {
100 		printk("%s", s);
101 	}
102 #endif
103 }
104 
105 int udbg_write(const char *s, int n)
106 {
107 	int remain = n;
108 	char c;
109 
110 	if (!udbg_putc)
111 		return 0;
112 
113 	if (s && *s != '\0') {
114 		while (((c = *s++) != '\0') && (remain-- > 0)) {
115 			udbg_putc(c);
116 		}
117 	}
118 
119 	if (udbg_flush)
120 		udbg_flush();
121 
122 	return n - remain;
123 }
124 
125 int udbg_read(char *buf, int buflen)
126 {
127 	char *p = buf;
128 	int i, c;
129 
130 	if (!udbg_getc)
131 		return 0;
132 
133 	for (i = 0; i < buflen; ++i) {
134 		do {
135 			c = udbg_getc();
136 			if (c == -1 && i == 0)
137 				return -1;
138 
139 		} while (c == 0x11 || c == 0x13);
140 		if (c == 0 || c == -1)
141 			break;
142 		*p++ = c;
143 	}
144 
145 	return i;
146 }
147 
148 #define UDBG_BUFSIZE 256
149 void udbg_printf(const char *fmt, ...)
150 {
151 	char buf[UDBG_BUFSIZE];
152 	va_list args;
153 
154 	va_start(args, fmt);
155 	vsnprintf(buf, UDBG_BUFSIZE, fmt, args);
156 	udbg_puts(buf);
157 	va_end(args);
158 }
159 
160 void __init udbg_progress(char *s, unsigned short hex)
161 {
162 	udbg_puts(s);
163 	udbg_puts("\n");
164 }
165 
166 /*
167  * Early boot console based on udbg
168  */
169 static void udbg_console_write(struct console *con, const char *s,
170 		unsigned int n)
171 {
172 	udbg_write(s, n);
173 }
174 
175 static struct console udbg_console = {
176 	.name	= "udbg",
177 	.write	= udbg_console_write,
178 	.flags	= CON_PRINTBUFFER | CON_ENABLED | CON_BOOT | CON_ANYTIME,
179 	.index	= 0,
180 };
181 
182 static int early_console_initialized;
183 
184 /*
185  * Called by setup_system after ppc_md->probe and ppc_md->early_init.
186  * Call it again after setting udbg_putc in ppc_md->setup_arch.
187  */
188 void __init register_early_udbg_console(void)
189 {
190 	if (early_console_initialized)
191 		return;
192 
193 	if (!udbg_putc)
194 		return;
195 
196 	if (strstr(boot_command_line, "udbg-immortal")) {
197 		printk(KERN_INFO "early console immortal !\n");
198 		udbg_console.flags &= ~CON_BOOT;
199 	}
200 	early_console_initialized = 1;
201 	register_console(&udbg_console);
202 }
203 
204 #if 0   /* if you want to use this as a regular output console */
205 console_initcall(register_udbg_console);
206 #endif
207