arch/ppc/syslib/gen550_kgdb.c

   1 /*
   2  * Generic 16550 kgdb support intended to be useful on a variety
   3  * of platforms.  To enable this support, it is necessary to set
   4  * the CONFIG_GEN550 option.  Any virtual mapping of the serial
   5  * port(s) to be used can be accomplished by setting
   6  * ppc_md.early_serial_map to a platform-specific mapping function.
   7  *
   8  * Adapted from ppc4xx_kgdb.c.
   9  *
  10  * Author: Matt Porter <mporter@kernel.crashing.org>
  11  *
  12  * 2002-2004 (c) MontaVista Software, Inc.  This file is licensed under
  13  * the terms of the GNU General Public License version 2.  This program
  14  * is licensed "as is" without any warranty of any kind, whether express
  15  * or implied.
  16  */
  17
  18 #include <linux/config.h>
  19 #include <linux/types.h>
  20 #include <linux/kernel.h>
  21
  22 #include <asm/machdep.h>
  23
  24 extern unsigned long serial_init(int, void *);
  25 extern unsigned long serial_getc(unsigned long);
  26 extern unsigned long serial_putc(unsigned long, unsigned char);
  27
  28 #if defined(CONFIG_KGDB_TTYS0)
  29 #define KGDB_PORT 0
  30 #elif defined(CONFIG_KGDB_TTYS1)
  31 #define KGDB_PORT 1
  32 #elif defined(CONFIG_KGDB_TTYS2)
  33 #define KGDB_PORT 2
  34 #elif defined(CONFIG_KGDB_TTYS3)
  35 #define KGDB_PORT 3
  36 #else
  37 #error "invalid kgdb_tty port"
  38 #endif
  39
  40 static volatile unsigned int kgdb_debugport;
  41
  42 void putDebugChar(unsigned char c)
  43 {
  44         if (kgdb_debugport == 0)
  45                 kgdb_debugport = serial_init(KGDB_PORT, NULL);
  46
  47         serial_putc(kgdb_debugport, c);
  48 }
  49
  50 int getDebugChar(void)
  51 {
  52         if (kgdb_debugport == 0)
  53                 kgdb_debugport = serial_init(KGDB_PORT, NULL);
  54
  55         return(serial_getc(kgdb_debugport));
  56 }
  57
  58 void kgdb_interruptible(int enable)
  59 {
  60         return;
  61 }
  62
  63 void putDebugString(char* str)
  64 {
  65         while (*str != '\0') {
  66                 putDebugChar(*str);
  67                 str++;
  68         }
  69         putDebugChar('\r');
  70         return;
  71 }
  72
  73 /*
  74  * Note: gen550_init() must be called already on the port we are going
  75  * to use.
  76  */
  77 void
  78 gen550_kgdb_map_scc(void)
  79 {
  80         printk(KERN_DEBUG "kgdb init\n");
  81         if (ppc_md.early_serial_map)
  82                 ppc_md.early_serial_map();
  83         kgdb_debugport = serial_init(KGDB_PORT, NULL);
  84 }