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           = "V22RW-2X2",
  37                 .mach_type      = RAMIPS_MACH_V22RW_2X2,
  38         }, {
  39                 .name           = "WHR-G300N",
  40                 .mach_type      = RAMIPS_MACH_WHR_G300N,
  41         }
  42 };
  43
  44 static inline void *to_ram_addr(void *addr)
  45 {
  46         u32 base;
  47
  48         base = KSEG0ADDR(RALINK_SOC_SDRAM_BASE);
  49         if (((u32) addr > base) &&
  50             ((u32) addr < (base + RALINK_SOC_MEM_SIZE_MAX)))
  51                 return addr;
  52
  53         base = KSEG1ADDR(RALINK_SOC_SDRAM_BASE);
  54         if (((u32) addr > base) &&
  55             ((u32) addr < (base + RALINK_SOC_MEM_SIZE_MAX)))
  56                 return addr;
  57
  58         /* some U-Boot variants uses physical addresses */
  59         base = RALINK_SOC_SDRAM_BASE;
  60         if (((u32) addr > base) &&
  61             ((u32) addr < (base + RALINK_SOC_MEM_SIZE_MAX)))
  62                 return (void *)KSEG0ADDR(addr);
  63
  64         return NULL;
  65 }
  66
  67 static __init char *ramips_prom_getargv(const char *name)
  68 {
  69         int len = strlen(name);
  70         int i;
  71
  72         if (!ramips_prom_argv) {
  73                 printk(KERN_DEBUG "argv=%p is invalid, skipping\n",
  74                        ramips_prom_argv);
  75                 return NULL;
  76         }
  77
  78         for (i = 0; i < ramips_prom_argc; i++) {
  79                 char *argv = to_ram_addr(ramips_prom_argv[i]);
  80
  81                 if (!argv) {
  82                         printk(KERN_DEBUG
  83                                "argv[%d]=%p is invalid, skipping\n",
  84                                i, ramips_prom_argv[i]);
  85                         continue;
  86                 }
  87
  88                 printk(KERN_DEBUG "argv[%d]: %s\n", i, argv);
  89                 if (strncmp(name, argv, len) == 0 && (argv)[len] == '=')
  90                         return argv + len + 1;
  91         }
  92
  93         return NULL;
  94 }
  95
  96 static __init char *ramips_prom_getenv(const char *envname)
  97 {
  98 #define PROM_MAX_ENVS   256
  99         int len = strlen(envname);
 100         char **env;
 101         int i;
 102
 103         env = ramips_prom_envp;
 104         if (!env) {
 105                 printk(KERN_DEBUG "envp=%p is not in RAM, skipping\n",
 106                        ramips_prom_envp);
 107                 return NULL;
 108         }
 109
 110         for (i = 0; i < PROM_MAX_ENVS; i++) {
 111                 char *p = to_ram_addr(env[i]);
 112
 113                 if (!p)
 114                         break;
 115
 116                 printk(KERN_DEBUG "env[%d]: %s\n", i, p);
 117                 if (strncmp(envname, p, len) == 0 && p[len] == '=')
 118                         return p + len + 1;
 119         }
 120
 121         return NULL;
 122 #undef PROM_MAX_ENVS
 123 }
 124
 125 static __init void find_board_byname(char *name)
 126 {
 127         int i;
 128
 129         for (i = 0; i < ARRAY_SIZE(boards); i++)
 130                 if (strcmp(name, boards[i].name) == 0) {
 131                         ramips_mach = boards[i].mach_type;
 132                         break;
 133                 }
 134 }
 135
 136 void __init prom_init(void)
 137 {
 138         char *p;
 139
 140         printk(KERN_DEBUG
 141                "prom: fw_arg0=%08x, fw_arg1=%08x, fw_arg2=%08x, fw_arg3=%08x\n",
 142                (unsigned int)fw_arg0, (unsigned int)fw_arg1,
 143                (unsigned int)fw_arg2, (unsigned int)fw_arg3);
 144
 145         ramips_prom_argc = fw_arg0;
 146         ramips_prom_argv = to_ram_addr((void *)fw_arg1);
 147         ramips_prom_envp = to_ram_addr((void *)fw_arg2);
 148
 149         p = ramips_prom_getargv("board");
 150         if (!p)
 151                 p = ramips_prom_getenv("board");
 152         if (p)
 153                 find_board_byname(p);
 154 }
 155
 156 void __init prom_free_prom_memory(void)
 157 {
 158         /* We do not have to prom memory to free */
 159 }