target/linux/ramips/files/arch/mips/ralink/rt305x/prom.c

   1 /*
   2  *  Ralink RT305x SoC specific prom routines
   3  *
   4  *  Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
   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 version 2 as published
   8  *  by the Free Software Foundation.
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13
  14 #include <asm/bootinfo.h>
  15
  16 #include <asm/mach-ralink/common.h>
  17 #include <asm/mach-ralink/rt305x.h>
  18 #include <asm/mach-ralink/rt305x_regs.h>
  19
  20 #include "machine.h"
  21
  22 struct board_rec {
  23         char                    *name;
  24         enum rt305x_mach_type   mach_type;
  25 };
  26
  27 static int rt305x_prom_argc __initdata;
  28 static char **rt305x_prom_argv __initdata;
  29 static char **rt305x_prom_envp __initdata;
  30
  31 static struct board_rec boards[] __initdata = {
  32         {
  33                 .name           = "WHR-G300N",
  34                 .mach_type      = RT305X_MACH_WHR_G300N,
  35         }
  36 };
  37
  38 static inline void *to_ram_addr(void *addr)
  39 {
  40         u32 base;
  41
  42         base = KSEG0ADDR(RT305X_SDRAM_BASE);
  43         if (((u32) addr > base) &&
  44             ((u32) addr < (base + RT305X_MEM_SIZE_MAX)))
  45                 return addr;
  46
  47         base = KSEG1ADDR(RT305X_SDRAM_BASE);
  48         if (((u32) addr > base) &&
  49             ((u32) addr < (base + RT305X_MEM_SIZE_MAX)))
  50                 return addr;
  51
  52         /* some U-Boot variants uses physical addresses */
  53         base = RT305X_SDRAM_BASE;
  54         if (((u32) addr > base) &&
  55             ((u32) addr < (base + RT305X_MEM_SIZE_MAX)))
  56                 return (void *)KSEG0ADDR(addr);
  57
  58         return NULL;
  59 }
  60
  61 static __init char *rt305x_prom_getargv(const char *name)
  62 {
  63         int len = strlen(name);
  64         int i;
  65
  66         if (!rt305x_prom_argv) {
  67                 printk(KERN_DEBUG "argv=%p is invalid, skipping\n",
  68                        rt305x_prom_argv);
  69                 return NULL;
  70         }
  71
  72         for (i = 0; i < rt305x_prom_argc; i++) {
  73                 char *argv = to_ram_addr(rt305x_prom_argv[i]);
  74
  75                 if (!argv) {
  76                         printk(KERN_DEBUG
  77                                "argv[%d]=%p is invalid, skipping\n",
  78                                i, rt305x_prom_argv[i]);
  79                         continue;
  80                 }
  81
  82                 printk(KERN_DEBUG "argv[i]: %s\n", argv);
  83                 if (strncmp(name, argv, len) == 0 && (argv)[len] == '=')
  84                         return argv + len + 1;
  85         }
  86
  87         return NULL;
  88 }
  89
  90 static __init char *rt305x_prom_getenv(const char *envname)
  91 {
  92         int len = strlen(envname);
  93         char **env;
  94         char *p;
  95
  96         env = rt305x_prom_envp;
  97         if (!env) {
  98                 printk(KERN_DEBUG "envp=%p is not in RAM, skipping\n",
  99                        rt305x_prom_envp);
 100                 return NULL;
 101         }
 102
 103         for (p = to_ram_addr(*env); p; env++) {
 104                 printk(KERN_DEBUG "env: %s\n", *env);
 105                 if (strncmp(envname, p, len) == 0 && (p)[len] == '=')
 106                         return p + len + 1;
 107         }
 108
 109         return NULL;
 110 }
 111
 112 static __init void find_board_byname(char *name)
 113 {
 114         int i;
 115
 116         rt305x_mach = RT305X_MACH_GENERIC;
 117
 118         for (i = 0; i < ARRAY_SIZE(boards); i++)
 119                 if (strcmp(name, boards[i].name) == 0) {
 120                         rt305x_mach = boards[i].mach_type;
 121                         break;
 122                 }
 123 }
 124
 125 void __init prom_init(void)
 126 {
 127         char *p;
 128
 129         printk(KERN_DEBUG
 130                "prom: fw_arg0=%08x, fw_arg1=%08x, fw_arg2=%08x, fw_arg3=%08x\n",
 131                (unsigned int)fw_arg0, (unsigned int)fw_arg1,
 132                (unsigned int)fw_arg2, (unsigned int)fw_arg3);
 133
 134         rt305x_prom_argc = fw_arg0;
 135         rt305x_prom_argv = to_ram_addr((void *)fw_arg1);
 136         rt305x_prom_envp = to_ram_addr((void *)fw_arg2);
 137
 138         p = rt305x_prom_getargv("board");
 139         if (!p)
 140                 p = rt305x_prom_getenv("board");
 141         if (p)
 142                 find_board_byname(p);
 143 }
 144
 145 void __init prom_free_prom_memory(void)
 146 {
 147         /* We do not have to prom memory to free */
 148 }