On 10 April 2013 13:47, John Crispin <blogic@xxxxxxxxxxx> wrote:
> This allows us to add a device_node called "memorydetect" to the DT with
> information about the memory windoe of the SoC. Based on this the memory is
> detected ar runtime.
>
> Signed-off-by: John Crispin <blogic@xxxxxxxxxxx>
> ---
> arch/mips/ralink/Makefile | 2 +-
> arch/mips/ralink/common.h | 3 ++
> arch/mips/ralink/memory.c | 119 +++++++++++++++++++++++++++++++++++++++++++++
> arch/mips/ralink/of.c | 3 ++
> 4 files changed, 126 insertions(+), 1 deletion(-)
> create mode 100644 arch/mips/ralink/memory.c
(snip)
> diff --git a/arch/mips/ralink/memory.c b/arch/mips/ralink/memory.c
> new file mode 100644
> index 0000000..57f3b83
> --- /dev/null
> +++ b/arch/mips/ralink/memory.c
> @@ -0,0 +1,119 @@
> +/*
> + * 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.
> + *
> + * Copyright (C) 2009 Gabor Juhos <juhosg@xxxxxxxxxxx>
> + * Copyright (C) 2013 John Crispin <blogic@xxxxxxxxxxx>
> + */
> +
> +#include <linux/string.h>
> +#include <linux/of_fdt.h>
> +#include <linux/of_platform.h>
> +
> +#include <asm/bootinfo.h>
> +#include <asm/addrspace.h>
> +
> +#include "common.h"
> +
> +#define MB (1024 * 1024)
There's <linux/sizes.h>, which has macros like SZ_1M, SZ_2M, SZ_8M,
SZ_16M ... ;-)
> +
> +unsigned long ramips_mem_base;
> +unsigned long ramips_mem_size_min;
> +unsigned long ramips_mem_size_max;
> +
> +#ifdef CONFIG_SOC_RT305X
> +
> +#include <asm/mach-ralink/rt305x.h>
> +
> +static unsigned long rt5350_get_mem_size(void)
> +{
> + void __iomem *sysc = (void __iomem *) KSEG1ADDR(RT305X_SYSC_BASE);
> + unsigned long ret;
> + u32 t;
> +
> + t = __raw_readl(sysc + SYSC_REG_SYSTEM_CONFIG);
> + t = (t >> RT5350_SYSCFG0_DRAM_SIZE_SHIFT) &
> + RT5350_SYSCFG0_DRAM_SIZE_MASK;
> +
> + switch (t) {
> + case RT5350_SYSCFG0_DRAM_SIZE_2M:
> + ret = 2 * 1024 * 1024;
> + break;
> + case RT5350_SYSCFG0_DRAM_SIZE_8M:
> + ret = 8 * 1024 * 1024;
> + break;
> + case RT5350_SYSCFG0_DRAM_SIZE_16M:
> + ret = 16 * 1024 * 1024;
> + break;
> + case RT5350_SYSCFG0_DRAM_SIZE_32M:
> + ret = 32 * 1024 * 1024;
> + break;
> + case RT5350_SYSCFG0_DRAM_SIZE_64M:
> + ret = 64 * 1024 * 1024;
> + break;
> + default:
> + panic("rt5350: invalid DRAM size: %u", t);
> + break;
> + }
> +
> + return ret;
> +}
> +
> +#endif
> +
> +static void __init detect_mem_size(void)
> +{
> + unsigned long size;
> +
> +#ifdef CONFIG_SOC_RT305X
> + if (soc_is_rt5350()) {
> + size = rt5350_get_mem_size();
> + } else
> +#endif
> + {
> + void *base;
> +
> + base = (void *) KSEG1ADDR(detect_mem_size);
> + for (size = ramips_mem_size_min;
> + size < ramips_mem_size_max; size <<= 1) {
> + if (!memcmp(base, base + size, 1024))
> + break;
> + }
> + }
> +
> + pr_info("memory detected: %uMB\n", (unsigned int) size / MB);
> +
> + add_memory_region(ramips_mem_base, size, BOOT_MEM_RAM);
> +}
> +
> +int __init early_init_dt_detect_memory(unsigned long node, const char *uname,
> + int depth, void *data)
> +{
> + unsigned long l;
> + __be32 *mem;
> +
> + /* We are scanning "memorydetect" nodes only */
> + if (depth != 1 || strcmp(uname, "memorydetect") != 0)
> + return 0;
> +
> + mem = of_get_flat_dt_prop(node, "ralink,memory", &l);
> + if (mem == NULL)
> + return 0;
> +
> + if ((l / sizeof(__be32)) != 3)
> + panic("invalid memorydetect node\n");
> +
> + ramips_mem_base = dt_mem_next_cell(dt_root_addr_cells, &mem);
> + ramips_mem_size_min = dt_mem_next_cell(dt_root_size_cells, &mem);
> + ramips_mem_size_max = dt_mem_next_cell(dt_root_size_cells, &mem);
> +
> + pr_info("memory window: 0x%llx, min: %uMB, max: %uMB\n",
> + (unsigned long long) ramips_mem_base,
> + (unsigned int) ramips_mem_size_min / MB,
> + (unsigned int) ramips_mem_size_max / MB);
Is there a reason for those casts instead of just using the right
printk %-thingies?
> +
> + detect_mem_size();
> +
> + return 0;
> +}
Jonas
