diff options
Diffstat (limited to 'target/linux/adm5120/files-3.18/arch/mips/adm5120/common/memory.c')
| -rw-r--r-- | target/linux/adm5120/files-3.18/arch/mips/adm5120/common/memory.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/target/linux/adm5120/files-3.18/arch/mips/adm5120/common/memory.c b/target/linux/adm5120/files-3.18/arch/mips/adm5120/common/memory.c new file mode 100644 index 0000000..d07266f --- /dev/null +++ b/target/linux/adm5120/files-3.18/arch/mips/adm5120/common/memory.c @@ -0,0 +1,149 @@ +/* + * Copyright (C) 2007-2008 Gabor Juhos <juhosg@openwrt.org> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + * + */ + +#include <linux/init.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/io.h> + +#include <asm/bootinfo.h> +#include <asm/addrspace.h> + +#include <asm/mach-adm5120/adm5120_info.h> +#include <asm/mach-adm5120/adm5120_defs.h> +#include <asm/mach-adm5120/adm5120_switch.h> +#include <asm/mach-adm5120/adm5120_mpmc.h> + +#ifdef DEBUG +# define mem_dbg(f, a...) printk(KERN_INFO "mem_detect: " f, ## a) +#else +# define mem_dbg(f, a...) +#endif + +unsigned long adm5120_memsize; + +#define MEM_READL(a) __raw_readl((void __iomem *)(a)) +#define MEM_WRITEL(a, v) __raw_writel((v), (void __iomem *)(a)) + +static int __init mem_check_pattern(u8 *addr, unsigned long offs) +{ + u32 *p1 = (u32 *)addr; + u32 *p2 = (u32 *)(addr+offs); + u32 t, u, v; + + /* save original value */ + t = MEM_READL(p1); + + u = MEM_READL(p2); + if (t != u) + return 0; + + v = 0x55555555; + if (u == v) + v = 0xAAAAAAAA; + + mem_dbg("write 0x%08X to 0x%08lX\n", v, (unsigned long)p1); + + MEM_WRITEL(p1, v); + adm5120_ndelay(1000); + u = MEM_READL(p2); + + mem_dbg("pattern at 0x%08lX is 0x%08X\n", (unsigned long)p2, u); + + /* restore original value */ + MEM_WRITEL(p1, t); + + return (v == u); +} + +static void __init adm5120_detect_memsize(void) +{ + u32 memctrl; + u32 size, maxsize; + u8 *p; + + memctrl = SW_READ_REG(SWITCH_REG_MEMCTRL); + switch (memctrl & MEMCTRL_SDRS_MASK) { + case MEMCTRL_SDRS_4M: + maxsize = 4 << 20; + break; + case MEMCTRL_SDRS_8M: + maxsize = 8 << 20; + break; + case MEMCTRL_SDRS_16M: + maxsize = 16 << 20; + break; + default: + maxsize = 64 << 20; + break; + } + + mem_dbg("checking for %uMB chip in 1st bank\n", maxsize >> 20); + + /* detect size of the 1st SDRAM bank */ + p = (u8 *)KSEG1ADDR(0); + for (size = 2<<20; size <= (maxsize >> 1); size <<= 1) { + if (mem_check_pattern(p, size)) { + /* mirrored address */ + mem_dbg("mirrored data found at offset 0x%08X\n", size); + break; + } + } + + mem_dbg("chip size in 1st bank is %uMB\n", size >> 20); + adm5120_memsize = size; + + if (size != maxsize) + /* 2nd bank is not supported */ + goto out; + + if ((memctrl & MEMCTRL_SDR1_ENABLE) == 0) + /* 2nd bank is disabled */ + goto out; + + /* + * some bootloaders enable 2nd bank, even if the 2nd SDRAM chip + * are missing. + */ + mem_dbg("check presence of 2nd bank\n"); + + p = (u8 *)KSEG1ADDR(maxsize+size-4); + if (mem_check_pattern(p, 0)) + adm5120_memsize += size; + + if (maxsize != size) { + /* adjusting MECTRL register */ + memctrl &= ~(MEMCTRL_SDRS_MASK); + switch (size>>20) { + case 4: + memctrl |= MEMCTRL_SDRS_4M; + break; + case 8: + memctrl |= MEMCTRL_SDRS_8M; + break; + case 16: + memctrl |= MEMCTRL_SDRS_16M; + break; + default: + memctrl |= MEMCTRL_SDRS_64M; + break; + } + SW_WRITE_REG(SWITCH_REG_MEMCTRL, memctrl); + } + +out: + mem_dbg("%dx%uMB memory found\n", (adm5120_memsize == size) ? 1 : 2 , + size>>20); +} + +void __init adm5120_mem_init(void) +{ + adm5120_detect_memsize(); + add_memory_region(0, adm5120_memsize, BOOT_MEM_RAM); +} |