arch/mips/basler/excite/excite_prom.c

   1 /*
   2  *  Copyright (C) 2004, 2005 by Thomas Koeller (thomas.koeller@baslerweb.com)
   3  *  Based on the PMC-Sierra Yosemite board support by Ralf Baechle and
   4  *  Manish Lachwani.
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include <linux/init.h>
  22 #include <linux/sched.h>
  23 #include <linux/mm.h>
  24 #include <linux/delay.h>
  25 #include <linux/smp.h>
  26 #include <linux/module.h>
  27 #include <asm/io.h>
  28 #include <asm/pgtable.h>
  29 #include <asm/processor.h>
  30 #include <asm/reboot.h>
  31 #include <asm/system.h>
  32 #include <asm/bootinfo.h>
  33 #include <asm/string.h>
  34
  35 #include <excite.h>
  36
  37 /* This struct is used by Redboot to pass arguments to the kernel */
  38 typedef struct
  39 {
  40         char *name;
  41         char *val;
  42 } t_env_var;
  43
  44 struct parmblock {
  45         t_env_var memsize;
  46         t_env_var modetty0;
  47         t_env_var ethaddr;
  48         t_env_var env_end;
  49         char *argv[2];
  50         char text[0];
  51 };
  52
  53 static unsigned int prom_argc;
  54 static const char ** prom_argv;
  55 static const t_env_var * prom_env;
  56
  57 static void prom_halt(void) __attribute__((noreturn));
  58 static void prom_exit(void) __attribute__((noreturn));
  59
  60
  61
  62 const char *get_system_type(void)
  63 {
  64         return "Basler eXcite";
  65 }
  66
  67 /*
  68  * Halt the system
  69  */
  70 static void prom_halt(void)
  71 {
  72         printk(KERN_NOTICE "\n** System halted.\n");
  73         while (1)
  74                 asm volatile (
  75                         "\t.set\tmips3\n"
  76                         "\twait\n"
  77                         "\t.set\tmips0\n"
  78                 );
  79 }
  80
  81 /*
  82  * Reset the CPU and re-enter Redboot
  83  */
  84 static void prom_exit(void)
  85 {
  86         unsigned int i;
  87         volatile unsigned char * const flg =
  88                 (volatile unsigned char *) (EXCITE_ADDR_FPGA + EXCITE_FPGA_DPR);
  89
  90         /* Clear the watchdog reset flag, set the reboot flag */
  91         *flg &= ~0x01;
  92         *flg |= 0x80;
  93
  94         for (i = 0; i < 10; i++) {
  95                 *(volatile unsigned char *)  (EXCITE_ADDR_FPGA + EXCITE_FPGA_SYSCTL) = 0x02;
  96                 iob();
  97                 mdelay(1000);
  98         }
  99
 100         printk(KERN_NOTICE "Reset failed\n");
 101         prom_halt();
 102 }
 103
 104 static const char __init *prom_getenv(char *name)
 105 {
 106         const t_env_var * p;
 107         for (p = prom_env; p->name != NULL; p++)
 108                 if(strcmp(name, p->name) == 0)
 109                         break;
 110         return p->val;
 111 }
 112
 113 /*
 114  * Init routine which accepts the variables from Redboot
 115  */
 116 void __init prom_init(void)
 117 {
 118         const struct parmblock * const pb = (struct parmblock *) fw_arg2;
 119
 120         prom_argc = fw_arg0;
 121         prom_argv = (const char **) fw_arg1;
 122         prom_env = &pb->memsize;
 123
 124         /* Callbacks for halt, restart */
 125         _machine_restart = (void (*)(char *)) prom_exit;
 126         _machine_halt = prom_halt;
 127
 128 #ifdef CONFIG_32BIT
 129         /* copy command line */
 130         strcpy(arcs_cmdline, prom_argv[1]);
 131         memsize = simple_strtol(prom_getenv("memsize"), NULL, 16);
 132         strcpy(modetty, prom_getenv("modetty0"));
 133 #endif /* CONFIG_32BIT */
 134
 135 #ifdef CONFIG_64BIT
 136 #       error 64 bit support not implemented
 137 #endif /* CONFIG_64BIT */
 138 }
 139
 140 /* This is called from free_initmem(), so we need to provide it */
 141 void __init prom_free_prom_memory(void)
 142 {
 143         /* Nothing to do */
 144 }