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/machine.h>
  18 #include <asm/mach-ralink/rt305x.h>
  19 #include <asm/mach-ralink/rt305x_regs.h>
  20
  21 struct board_rec {
  22         char                    *name;
  23         enum ramips_mach_type   mach_type;
  24 };
  25
  26 static int rt305x_prom_argc __initdata;
  27 static char **rt305x_prom_argv __initdata;
  28 static char **rt305x_prom_envp __initdata;
  29
  30 static struct board_rec boards[] __initdata = {
  31         {
  32                 .name           = "WHR-G300N",
  33                 .mach_type      = RAMIPS_MACH_WHR_G300N,
  34         }
  35 };
  36
  37 static inline void *to_ram_addr(void *addr)
  38 {
  39         u32 base;
  40
  41         base = KSEG0ADDR(RT305X_SDRAM_BASE);
  42         if (((u32) addr > base) &&
  43             ((u32) addr < (base + RT305X_MEM_SIZE_MAX)))
  44                 return addr;
  45
  46         base = KSEG1ADDR(RT305X_SDRAM_BASE);
  47         if (((u32) addr > base) &&
  48             ((u32) addr < (base + RT305X_MEM_SIZE_MAX)))
  49                 return addr;
  50
  51         /* some U-Boot variants uses physical addresses */
  52         base = RT305X_SDRAM_BASE;
  53         if (((u32) addr > base) &&
  54             ((u32) addr < (base + RT305X_MEM_SIZE_MAX)))
  55                 return (void *)KSEG0ADDR(addr);
  56
  57         return NULL;
  58 }
  59
  60 static __init char *rt305x_prom_getargv(const char *name)
  61 {
  62         int len = strlen(name);
  63         int i;
  64
  65         if (!rt305x_prom_argv) {
  66                 printk(KERN_DEBUG "argv=%p is invalid, skipping\n",
  67                        rt305x_prom_argv);
  68                 return NULL;
  69         }
  70
  71         for (i = 0; i < rt305x_prom_argc; i++) {
  72                 char *argv = to_ram_addr(rt305x_prom_argv[i]);
  73
  74                 if (!argv) {
  75                         printk(KERN_DEBUG
  76                                "argv[%d]=%p is invalid, skipping\n",
  77                                i, rt305x_prom_argv[i]);
  78                         continue;
  79                 }
  80
  81                 printk(KERN_DEBUG "argv[i]: %s\n", argv);
  82                 if (strncmp(name, argv, len) == 0 && (argv)[len] == '=')
  83                         return argv + len + 1;
  84         }
  85
  86         return NULL;
  87 }
  88
  89 static __init char *rt305x_prom_getenv(const char *envname)
  90 {
  91         int len = strlen(envname);
  92         char **env;
  93         char *p;
  94
  95         env = rt305x_prom_envp;
  96         if (!env) {
  97                 printk(KERN_DEBUG "envp=%p is not in RAM, skipping\n",
  98                        rt305x_prom_envp);
  99                 return NULL;
 100         }
 101
 102         for (p = to_ram_addr(*env); p; env++) {
 103                 printk(KERN_DEBUG "env: %s\n", *env);
 104                 if (strncmp(envname, p, len) == 0 && (p)[len] == '=')
 105                         return p + len + 1;
 106         }
 107
 108         return NULL;
 109 }
 110
 111 static __init void find_board_byname(char *name)
 112 {
 113         int i;
 114
 115         for (i = 0; i < ARRAY_SIZE(boards); i++)
 116                 if (strcmp(name, boards[i].name) == 0) {
 117                         ramips_mach = boards[i].mach_type;
 118                         break;
 119                 }
 120 }
 121
 122 void __init prom_init(void)
 123 {
 124         char *p;
 125
 126         printk(KERN_DEBUG
 127                "prom: fw_arg0=%08x, fw_arg1=%08x, fw_arg2=%08x, fw_arg3=%08x\n",
 128                (unsigned int)fw_arg0, (unsigned int)fw_arg1,
 129                (unsigned int)fw_arg2, (unsigned int)fw_arg3);
 130
 131         rt305x_prom_argc = fw_arg0;
 132         rt305x_prom_argv = to_ram_addr((void *)fw_arg1);
 133         rt305x_prom_envp = to_ram_addr((void *)fw_arg2);
 134
 135         p = rt305x_prom_getargv("board");
 136         if (!p)
 137                 p = rt305x_prom_getenv("board");
 138         if (p)
 139                 find_board_byname(p);
 140 }
 141
 142 void __init prom_free_prom_memory(void)
 143 {
 144         /* We do not have to prom memory to free */
 145 }