aboutsummaryrefslogtreecommitdiffstats
path: root/arch/blackfin/kernel/early_printk.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/blackfin/kernel/early_printk.c')
-rw-r--r--arch/blackfin/kernel/early_printk.c214
1 files changed, 214 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/early_printk.c b/arch/blackfin/kernel/early_printk.c
new file mode 100644
index 000000000000..6ec518a81113
--- /dev/null
+++ b/arch/blackfin/kernel/early_printk.c
@@ -0,0 +1,214 @@
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
35extern struct console *bfin_earlyserial_init(unsigned int port,
36 unsigned int cflag);
37#endif
38
39static struct console *early_console;
40
41/* Default console */
42#define DEFAULT_PORT 0
43#define DEFAULT_CFLAG CS8|B57600
44
45/* Default console for early crashes */
46#define DEFAULT_EARLY_PORT "serial,uart0,57600"
47
48#ifdef CONFIG_SERIAL_CORE
49/* What should get here is "0,57600" */
50static struct console * __init earlyserial_init(char *buf)
51{
52 int baud, bit;
53 char parity;
54 unsigned int serial_port = DEFAULT_PORT;
55 unsigned int cflag = DEFAULT_CFLAG;
56
57 serial_port = simple_strtoul(buf, &buf, 10);
58 buf++;
59
60 cflag = 0;
61 baud = simple_strtoul(buf, &buf, 10);
62 switch (baud) {
63 case 1200:
64 cflag |= B1200;
65 break;
66 case 2400:
67 cflag |= B2400;
68 break;
69 case 4800:
70 cflag |= B4800;
71 break;
72 case 9600:
73 cflag |= B9600;
74 break;
75 case 19200:
76 cflag |= B19200;
77 break;
78 case 38400:
79 cflag |= B38400;
80 break;
81 case 115200:
82 cflag |= B115200;
83 break;
84 default:
85 cflag |= B57600;
86 }
87
88 parity = buf[0];
89 buf++;
90 switch (parity) {
91 case 'e':
92 cflag |= PARENB;
93 break;
94 case 'o':
95 cflag |= PARODD;
96 break;
97 }
98
99 bit = simple_strtoul(buf, &buf, 10);
100 switch (bit) {
101 case 5:
102 cflag |= CS5;
103 break;
104 case 6:
105 cflag |= CS5;
106 break;
107 case 7:
108 cflag |= CS5;
109 break;
110 default:
111 cflag |= CS8;
112 }
113
114#ifdef CONFIG_SERIAL_BFIN
115 return bfin_earlyserial_init(serial_port, cflag);
116#else
117 return NULL;
118#endif
119
120}
121#endif
122
123int __init setup_early_printk(char *buf)
124{
125
126 /* Crashing in here would be really bad, so check both the var
127 and the pointer before we start using it
128 */
129 if (!buf)
130 return 0;
131
132 if (!*buf)
133 return 0;
134
135 if (early_console != NULL)
136 return 0;
137
138#ifdef CONFIG_SERIAL_BFIN
139 /* Check for Blackfin Serial */
140 if (!strncmp(buf, "serial,uart", 11)) {
141 buf += 11;
142 early_console = earlyserial_init(buf);
143 }
144#endif
145#ifdef CONFIG_FB
146 /* TODO: add framebuffer console support */
147#endif
148
149 if (likely(early_console)) {
150 early_console->flags |= CON_BOOT;
151
152 register_console(early_console);
153 printk(KERN_INFO "early printk enabled on %s%d\n",
154 early_console->name,
155 early_console->index);
156 }
157
158 return 0;
159}
160
161/*
162 * Set up a temporary Event Vector Table, so if something bad happens before
163 * the kernel is fully started, it doesn't vector off into somewhere we don't
164 * know
165 */
166
167asmlinkage void __init init_early_exception_vectors(void)
168{
169 SSYNC();
170
171 /* cannot program in software:
172 * evt0 - emulation (jtag)
173 * evt1 - reset
174 */
175 bfin_write_EVT2(early_trap);
176 bfin_write_EVT3(early_trap);
177 bfin_write_EVT5(early_trap);
178 bfin_write_EVT6(early_trap);
179 bfin_write_EVT7(early_trap);
180 bfin_write_EVT8(early_trap);
181 bfin_write_EVT9(early_trap);
182 bfin_write_EVT10(early_trap);
183 bfin_write_EVT11(early_trap);
184 bfin_write_EVT12(early_trap);
185 bfin_write_EVT13(early_trap);
186 bfin_write_EVT14(early_trap);
187 bfin_write_EVT15(early_trap);
188 CSYNC();
189
190 /* Set all the return from interupt, exception, NMI to a known place
191 * so if we do a RETI, RETX or RETN by mistake - we go somewhere known
192 * Note - don't change RETS - we are in a subroutine, or
193 * RETE - since it might screw up if emulator is attached
194 */
195 asm("\tRETI = %0; RETX = %0; RETN = %0;\n"
196 : : "p"(early_trap));
197
198}
199
200asmlinkage void __init early_trap_c(struct pt_regs *fp, void *retaddr)
201{
202 /* This can happen before the uart is initialized, so initialize
203 * the UART now
204 */
205 if (likely(early_console == NULL))
206 setup_early_printk(DEFAULT_EARLY_PORT);
207
208 dump_bfin_regs(fp, retaddr);
209 dump_bfin_trace_buffer();
210
211 panic("Died early");
212}
213
214early_param("earlyprintk", setup_early_printk);
generated by cgit v1.2.2 (git 2.25.0) at 2025-02-23 13:08:40 -0500