| 1 | /* |
| 2 | * Copyright (C) 2007-2008 Gabor Juhos <juhosg@openwrt.org> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU General Public License version 2 as published |
| 6 | * by the Free Software Foundation. |
| 7 | * |
| 8 | */ |
| 9 | |
| 10 | #include <linux/init.h> |
| 11 | #include <linux/types.h> |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/io.h> |
| 14 | |
| 15 | #include <asm/bootinfo.h> |
| 16 | #include <asm/addrspace.h> |
| 17 | |
| 18 | #include <asm/mach-adm5120/adm5120_info.h> |
| 19 | #include <asm/mach-adm5120/adm5120_defs.h> |
| 20 | #include <asm/mach-adm5120/adm5120_switch.h> |
| 21 | #include <asm/mach-adm5120/adm5120_mpmc.h> |
| 22 | |
| 23 | #ifdef DEBUG |
| 24 | # define mem_dbg(f, a...) printk(KERN_INFO "mem_detect: " f, ## a) |
| 25 | #else |
| 26 | # define mem_dbg(f, a...) |
| 27 | #endif |
| 28 | |
| 29 | unsigned long adm5120_memsize; |
| 30 | |
| 31 | #define MEM_READL(a) __raw_readl((void __iomem *)(a)) |
| 32 | #define MEM_WRITEL(a, v) __raw_writel((v), (void __iomem *)(a)) |
| 33 | |
| 34 | static int __init mem_check_pattern(u8 *addr, unsigned long offs) |
| 35 | { |
| 36 | u32 *p1 = (u32 *)addr; |
| 37 | u32 *p2 = (u32 *)(addr+offs); |
| 38 | u32 t, u, v; |
| 39 | |
| 40 | /* save original value */ |
| 41 | t = MEM_READL(p1); |
| 42 | |
| 43 | u = MEM_READL(p2); |
| 44 | if (t != u) |
| 45 | return 0; |
| 46 | |
| 47 | v = 0x55555555; |
| 48 | if (u == v) |
| 49 | v = 0xAAAAAAAA; |
| 50 | |
| 51 | mem_dbg("write 0x%08X to 0x%08lX\n", v, (unsigned long)p1); |
| 52 | |
| 53 | MEM_WRITEL(p1, v); |
| 54 | adm5120_ndelay(1000); |
| 55 | u = MEM_READL(p2); |
| 56 | |
| 57 | mem_dbg("pattern at 0x%08lX is 0x%08X\n", (unsigned long)p2, u); |
| 58 | |
| 59 | /* restore original value */ |
| 60 | MEM_WRITEL(p1, t); |
| 61 | |
| 62 | return (v == u); |
| 63 | } |
| 64 | |
| 65 | static void __init adm5120_detect_memsize(void) |
| 66 | { |
| 67 | u32 memctrl; |
| 68 | u32 size, maxsize; |
| 69 | u8 *p; |
| 70 | |
| 71 | memctrl = SW_READ_REG(SWITCH_REG_MEMCTRL); |
| 72 | switch (memctrl & MEMCTRL_SDRS_MASK) { |
| 73 | case MEMCTRL_SDRS_4M: |
| 74 | maxsize = 4 << 20; |
| 75 | break; |
| 76 | case MEMCTRL_SDRS_8M: |
| 77 | maxsize = 8 << 20; |
| 78 | break; |
| 79 | case MEMCTRL_SDRS_16M: |
| 80 | maxsize = 16 << 20; |
| 81 | break; |
| 82 | default: |
| 83 | maxsize = 64 << 20; |
| 84 | break; |
| 85 | } |
| 86 | |
| 87 | mem_dbg("checking for %uMB chip in 1st bank\n", maxsize >> 20); |
| 88 | |
| 89 | /* detect size of the 1st SDRAM bank */ |
| 90 | p = (u8 *)KSEG1ADDR(0); |
| 91 | for (size = 2<<20; size <= (maxsize >> 1); size <<= 1) { |
| 92 | if (mem_check_pattern(p, size)) { |
| 93 | /* mirrored address */ |
| 94 | mem_dbg("mirrored data found at offset 0x%08X\n", size); |
| 95 | break; |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | mem_dbg("chip size in 1st bank is %uMB\n", size >> 20); |
| 100 | adm5120_memsize = size; |
| 101 | |
| 102 | if (size != maxsize) |
| 103 | /* 2nd bank is not supported */ |
| 104 | goto out; |
| 105 | |
| 106 | if ((memctrl & MEMCTRL_SDR1_ENABLE) == 0) |
| 107 | /* 2nd bank is disabled */ |
| 108 | goto out; |
| 109 | |
| 110 | /* |
| 111 | * some bootloaders enable 2nd bank, even if the 2nd SDRAM chip |
| 112 | * are missing. |
| 113 | */ |
| 114 | mem_dbg("check presence of 2nd bank\n"); |
| 115 | |
| 116 | p = (u8 *)KSEG1ADDR(maxsize+size-4); |
| 117 | if (mem_check_pattern(p, 0)) |
| 118 | adm5120_memsize += size; |
| 119 | |
| 120 | if (maxsize != size) { |
| 121 | /* adjusting MECTRL register */ |
| 122 | memctrl &= ~(MEMCTRL_SDRS_MASK); |
| 123 | switch (size>>20) { |
| 124 | case 4: |
| 125 | memctrl |= MEMCTRL_SDRS_4M; |
| 126 | break; |
| 127 | case 8: |
| 128 | memctrl |= MEMCTRL_SDRS_8M; |
| 129 | break; |
| 130 | case 16: |
| 131 | memctrl |= MEMCTRL_SDRS_16M; |
| 132 | break; |
| 133 | default: |
| 134 | memctrl |= MEMCTRL_SDRS_64M; |
| 135 | break; |
| 136 | } |
| 137 | SW_WRITE_REG(SWITCH_REG_MEMCTRL, memctrl); |
| 138 | } |
| 139 | |
| 140 | out: |
| 141 | mem_dbg("%dx%uMB memory found\n", (adm5120_memsize == size) ? 1 : 2 , |
| 142 | size>>20); |
| 143 | } |
| 144 | |
| 145 | void __init adm5120_mem_init(void) |
| 146 | { |
| 147 | adm5120_detect_memsize(); |
| 148 | add_memory_region(0, adm5120_memsize, BOOT_MEM_RAM); |
| 149 | } |
| 150 | |
