arch/mips/loongson1/common/prom.c

   1 /*
   2  * Copyright (c) 2011 Zhang, Keguang <keguang.zhang@gmail.com>
   3  *
   4  * Modified from arch/mips/pnx833x/common/prom.c.
   5  *
   6  * This program is free software; you can redistribute  it and/or modify it
   7  * under  the terms of  the GNU General  Public License as published by the
   8  * Free Software Foundation;  either version 2 of the  License, or (at your
   9  * option) any later version.
  10  */
  11
  12 #include <linux/serial_reg.h>
  13 #include <asm/bootinfo.h>
  14
  15 #include <loongson1.h>
  16 #include <prom.h>
  17
  18 int prom_argc;
  19 char **prom_argv, **prom_envp;
  20 unsigned long memsize, highmemsize;
  21
  22 char *prom_getenv(char *envname)
  23 {
  24         char **env = prom_envp;
  25         int i;
  26
  27         i = strlen(envname);
  28
  29         while (*env) {
  30                 if (strncmp(envname, *env, i) == 0 && *(*env+i) == '=')
  31                         return *env + i + 1;
  32                 env++;
  33         }
  34
  35         return 0;
  36 }
  37
  38 static inline unsigned long env_or_default(char *env, unsigned long dfl)
  39 {
  40         char *str = prom_getenv(env);
  41         return str ? simple_strtol(str, 0, 0) : dfl;
  42 }
  43
  44 void __init prom_init_cmdline(void)
  45 {
  46         char *c = &(arcs_cmdline[0]);
  47         int i;
  48
  49         for (i = 1; i < prom_argc; i++) {
  50                 strcpy(c, prom_argv[i]);
  51                 c += strlen(prom_argv[i]);
  52                 if (i < prom_argc-1)
  53                         *c++ = ' ';
  54         }
  55         *c = 0;
  56 }
  57
  58 void __init prom_init(void)
  59 {
  60         prom_argc = fw_arg0;
  61         prom_argv = (char **)fw_arg1;
  62         prom_envp = (char **)fw_arg2;
  63
  64         prom_init_cmdline();
  65
  66         memsize = env_or_default("memsize", DEFAULT_MEMSIZE);
  67         highmemsize = env_or_default("highmemsize", 0x0);
  68 }
  69
  70 void __init prom_free_prom_memory(void)
  71 {
  72 }
  73
  74 #define PORT(offset)    (u8 *)(KSEG1ADDR(LS1X_UART0_BASE + offset))
  75
  76 void prom_putchar(char c)
  77 {
  78         int timeout;
  79
  80         timeout = 1024;
  81
  82         while (((readb(PORT(UART_LSR)) & UART_LSR_THRE) == 0)
  83                         && (timeout-- > 0))
  84                 ;
  85
  86         writeb(c, PORT(UART_TX));
  87 }