Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
[linux-2.6] / arch / blackfin / kernel / early_printk.c
1 /*
2  * File:         arch/blackfin/kernel/early_printk.c
3  * Based on:     arch/x86_64/kernel/early_printk.c
4  * Author:       Robin Getz <rgetz@blackfin.uclinux.org
5  *
6  * Created:      14Aug2007
7  * Description:  allow a console to be used for early printk
8  *
9  * Modified:
10  *               Copyright 2004-2007 Analog Devices Inc.
11  *
12  * Bugs:         Enter bugs at http://blackfin.uclinux.org/
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2 of the License, or
17  * (at your option) any later version.
18  *
19  * This program is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22  * GNU General Public License for more details.
23  */
24
25 #include <linux/kernel.h>
26 #include <linux/init.h>
27 #include <linux/serial_core.h>
28 #include <linux/console.h>
29 #include <linux/string.h>
30 #include <asm/blackfin.h>
31 #include <asm/irq_handler.h>
32 #include <asm/early_printk.h>
33
34 #ifdef CONFIG_SERIAL_BFIN
35 extern struct console *bfin_earlyserial_init(unsigned int port,
36                                                 unsigned int cflag);
37 #endif
38 #ifdef CONFIG_BFIN_JTAG_COMM
39 extern struct console *bfin_jc_early_init(void);
40 #endif
41
42 static struct console *early_console;
43
44 /* Default console */
45 #define DEFAULT_PORT 0
46 #define DEFAULT_CFLAG CS8|B57600
47
48 /* Default console for early crashes */
49 #define DEFAULT_EARLY_PORT "serial,uart0,57600"
50
51 #ifdef CONFIG_SERIAL_CORE
52 /* What should get here is "0,57600" */
53 static struct console * __init earlyserial_init(char *buf)
54 {
55         int baud, bit;
56         char parity;
57         unsigned int serial_port = DEFAULT_PORT;
58         unsigned int cflag = DEFAULT_CFLAG;
59
60         serial_port = simple_strtoul(buf, &buf, 10);
61         buf++;
62
63         cflag = 0;
64         baud = simple_strtoul(buf, &buf, 10);
65         switch (baud) {
66         case 1200:
67                 cflag |= B1200;
68                 break;
69         case 2400:
70                 cflag |= B2400;
71                 break;
72         case 4800:
73                 cflag |= B4800;
74                 break;
75         case 9600:
76                 cflag |= B9600;
77                 break;
78         case 19200:
79                 cflag |= B19200;
80                 break;
81         case 38400:
82                 cflag |= B38400;
83                 break;
84         case 115200:
85                 cflag |= B115200;
86                 break;
87         default:
88                 cflag |= B57600;
89         }
90
91         parity = buf[0];
92         buf++;
93         switch (parity) {
94         case 'e':
95                 cflag |= PARENB;
96                 break;
97         case 'o':
98                 cflag |= PARODD;
99                 break;
100         }
101
102         bit = simple_strtoul(buf, &buf, 10);
103         switch (bit) {
104         case 5:
105                 cflag |= CS5;
106                 break;
107         case 6:
108                 cflag |= CS6;
109                 break;
110         case 7:
111                 cflag |= CS7;
112                 break;
113         default:
114                 cflag |= CS8;
115         }
116
117 #ifdef CONFIG_SERIAL_BFIN
118         return bfin_earlyserial_init(serial_port, cflag);
119 #else
120         return NULL;
121 #endif
122
123 }
124 #endif
125
126 int __init setup_early_printk(char *buf)
127 {
128
129         /* Crashing in here would be really bad, so check both the var
130            and the pointer before we start using it
131          */
132         if (!buf)
133                 return 0;
134
135         if (!*buf)
136                 return 0;
137
138         if (early_console != NULL)
139                 return 0;
140
141 #ifdef CONFIG_SERIAL_BFIN
142         /* Check for Blackfin Serial */
143         if (!strncmp(buf, "serial,uart", 11)) {
144                 buf += 11;
145                 early_console = earlyserial_init(buf);
146         }
147 #endif
148
149 #ifdef CONFIG_BFIN_JTAG_COMM
150         /* Check for Blackfin JTAG */
151         if (!strncmp(buf, "jtag", 4)) {
152                 buf += 4;
153                 early_console = bfin_jc_early_init();
154         }
155 #endif
156
157 #ifdef CONFIG_FB
158                 /* TODO: add framebuffer console support */
159 #endif
160
161         if (likely(early_console)) {
162                 early_console->flags |= CON_BOOT;
163
164                 register_console(early_console);
165                 printk(KERN_INFO "early printk enabled on %s%d\n",
166                         early_console->name,
167                         early_console->index);
168         }
169
170         return 0;
171 }
172
173 /*
174  * Set up a temporary Event Vector Table, so if something bad happens before
175  * the kernel is fully started, it doesn't vector off into somewhere we don't
176  * know
177  */
178
179 asmlinkage void __init init_early_exception_vectors(void)
180 {
181         SSYNC();
182
183         /* cannot program in software:
184          * evt0 - emulation (jtag)
185          * evt1 - reset
186          */
187         bfin_write_EVT2(early_trap);
188         bfin_write_EVT3(early_trap);
189         bfin_write_EVT5(early_trap);
190         bfin_write_EVT6(early_trap);
191         bfin_write_EVT7(early_trap);
192         bfin_write_EVT8(early_trap);
193         bfin_write_EVT9(early_trap);
194         bfin_write_EVT10(early_trap);
195         bfin_write_EVT11(early_trap);
196         bfin_write_EVT12(early_trap);
197         bfin_write_EVT13(early_trap);
198         bfin_write_EVT14(early_trap);
199         bfin_write_EVT15(early_trap);
200         CSYNC();
201
202         /* Set all the return from interrupt, exception, NMI to a known place
203          * so if we do a RETI, RETX or RETN by mistake - we go somewhere known
204          * Note - don't change RETS - we are in a subroutine, or
205          * RETE - since it might screw up if emulator is attached
206          */
207         asm("\tRETI = %0; RETX = %0; RETN = %0;\n"
208                 : : "p"(early_trap));
209
210 }
211
212 asmlinkage void __init early_trap_c(struct pt_regs *fp, void *retaddr)
213 {
214         /* This can happen before the uart is initialized, so initialize
215          * the UART now
216          */
217         if (likely(early_console == NULL))
218                 setup_early_printk(DEFAULT_EARLY_PORT);
219
220         dump_bfin_mem(fp);
221         show_regs(fp);
222         dump_bfin_trace_buffer();
223
224         panic("Died early");
225 }
226
227 early_param("earlyprintk", setup_early_printk);