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

   1 /*
   2  *  Ralink 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 #include <linux/string.h>
  14
  15 #include <asm/bootinfo.h>
  16 #include <asm/addrspace.h>
  17
  18 #include <asm/mach-ralink/common.h>
  19 #include <asm/mach-ralink/machine.h>
  20 #include <ralink_soc.h>
  21
  22 struct board_rec {
  23         char                    *name;
  24         enum ramips_mach_type   mach_type;
  25 };
  26
  27 static int ramips_prom_argc __initdata;
  28 static char **ramips_prom_argv __initdata;
  29 static char **ramips_prom_envp __initdata;
  30
  31 static struct board_rec boards[] __initdata = {
  32         {
  33                 .name           = "RT-N15",
  34                 .mach_type      = RAMIPS_MACH_RT_N15,
  35         }, {
  36                 .name           = "WHR-G300N",
  37                 .mach_type      = RAMIPS_MACH_WHR_G300N,
  38         }
  39 };
  40
  41 static inline void *to_ram_addr(void *addr)
  42 {
  43         u32 base;
  44
  45         base = KSEG0ADDR(RALINK_SOC_SDRAM_BASE);
  46         if (((u32) addr > base) &&
  47             ((u32) addr < (base + RALINK_SOC_MEM_SIZE_MAX)))
  48                 return addr;
  49
  50         base = KSEG1ADDR(RALINK_SOC_SDRAM_BASE);
  51         if (((u32) addr > base) &&
  52             ((u32) addr < (base + RALINK_SOC_MEM_SIZE_MAX)))
  53                 return addr;
  54
  55         /* some U-Boot variants uses physical addresses */
  56         base = RALINK_SOC_SDRAM_BASE;
  57         if (((u32) addr > base) &&
  58             ((u32) addr < (base + RALINK_SOC_MEM_SIZE_MAX)))
  59                 return (void *)KSEG0ADDR(addr);
  60
  61         return NULL;
  62 }
  63
  64 static __init char *ramips_prom_getargv(const char *name)
  65 {
  66         int len = strlen(name);
  67         int i;
  68
  69         if (!ramips_prom_argv) {
  70                 printk(KERN_DEBUG "argv=%p is invalid, skipping\n",
  71                        ramips_prom_argv);
  72                 return NULL;
  73         }
  74
  75         for (i = 0; i < ramips_prom_argc; i++) {
  76                 char *argv = to_ram_addr(ramips_prom_argv[i]);
  77
  78                 if (!argv) {
  79                         printk(KERN_DEBUG
  80                                "argv[%d]=%p is invalid, skipping\n",
  81                                i, ramips_prom_argv[i]);
  82                         continue;
  83                 }
  84
  85                 printk(KERN_DEBUG "argv[%d]: %s\n", i, argv);
  86                 if (strncmp(name, argv, len) == 0 && (argv)[len] == '=')
  87                         return argv + len + 1;
  88         }
  89
  90         return NULL;
  91 }
  92
  93 static __init char *ramips_prom_getenv(const char *envname)
  94 {
  95 #define PROM_MAX_ENVS   256
  96         int len = strlen(envname);
  97         char **env;
  98         int i;
  99
 100         env = ramips_prom_envp;
 101         if (!env) {
 102                 printk(KERN_DEBUG "envp=%p is not in RAM, skipping\n",
 103                        ramips_prom_envp);
 104                 return NULL;
 105         }
 106
 107         for (i = 0; i < PROM_MAX_ENVS; i++) {
 108                 char *p = to_ram_addr(env[i]);
 109
 110                 if (!p)
 111                         break;
 112
 113                 printk(KERN_DEBUG "env[%d]: %s\n", i, p);
 114                 if (strncmp(envname, p, len) == 0 && p[len] == '=')
 115                         return p + len + 1;
 116         }
 117
 118         return NULL;
 119 #undef PROM_MAX_ENVS
 120 }
 121
 122 static __init void find_board_byname(char *name)
 123 {
 124         int i;
 125
 126         for (i = 0; i < ARRAY_SIZE(boards); i++)
 127                 if (strcmp(name, boards[i].name) == 0) {
 128                         ramips_mach = boards[i].mach_type;
 129                         break;
 130                 }
 131 }
 132
 133 void __init prom_init(void)
 134 {
 135         char *p;
 136
 137         printk(KERN_DEBUG
 138                "prom: fw_arg0=%08x, fw_arg1=%08x, fw_arg2=%08x, fw_arg3=%08x\n",
 139                (unsigned int)fw_arg0, (unsigned int)fw_arg1,
 140                (unsigned int)fw_arg2, (unsigned int)fw_arg3);
 141
 142         ramips_prom_argc = fw_arg0;
 143         ramips_prom_argv = to_ram_addr((void *)fw_arg1);
 144         ramips_prom_envp = to_ram_addr((void *)fw_arg2);
 145
 146         p = ramips_prom_getargv("board");
 147         if (!p)
 148                 p = ramips_prom_getenv("board");
 149         if (p)
 150                 find_board_byname(p);
 151 }
 152
 153 void __init prom_free_prom_memory(void)
 154 {
 155         /* We do not have to prom memory to free */
 156 }