[U-Boot] [PATCH] ARMV7: OMAP4: Calculate SDRAM size

[Nishanth Menon]

On 09/23/2010 04:12 PM, Steve Sakoman wrote:
> From: Aneesh V<aneesh at ti.com>
>
> Calculate the SDRAM size from DMM configuration registers instead of using
> hard-coded values. This gives correct values for all different boards.
>
> It's assumed that DMM sections do not overlap memory areas.

How do we handle NOR boot? is it assumed that the configuration will be 
done way befor the sdram_init?

>
> Signed-off-by: Aneesh V<aneesh at ti.com>
> Tested-by: Steve Sakoman<steve at sakoman.com>
> ---
>   arch/arm/cpu/armv7/omap4/board.c        |   30 +++++++++++++++++++++++++++++-
>   arch/arm/include/asm/arch-omap4/omap4.h |   10 ++++++++++
>   2 files changed, 39 insertions(+), 1 deletions(-)
>
> diff --git a/arch/arm/cpu/armv7/omap4/board.c b/arch/arm/cpu/armv7/omap4/board.c
> index 195be6e..8c1f395 100644
> --- a/arch/arm/cpu/armv7/omap4/board.c
> +++ b/arch/arm/cpu/armv7/omap4/board.c
> @@ -30,6 +30,7 @@
>   #include<common.h>
>   #include<asm/arch/cpu.h>
>   #include<asm/arch/sys_proto.h>
> +#include<asm/sizes.h>
>
>   /*
>    * Routine: s_init
> @@ -66,6 +67,33 @@ void watchdog_init(void)
>   	writel(WD_UNLOCK2,&wd2_base->wspr);
>   }
>
> +
> +/*
> + * This function finds the SDRAM size available in the system
> + * based on DMM section configurations
> + * This is needed because the size of memory installed may be
> + * different on different versions of the board
> + */
> +u32 sdram_size(void)
> +{
> +	u32 section, i, total_size = 0, size, addr;
> +	for (i = 0; i<  4; i++) {
> +		section	= __raw_readl(DMM_LISA_MAP_BASE + i*4);
> +		addr = section&  DMM_LISA_MAP_SYS_ADDR_MASK;
> +		/* See if the address is valid */
> +		if ((addr>= OMAP44XX_DRAM_ADDR_SPACE_START)&&
> +		    (addr<  OMAP44XX_DRAM_ADDR_SPACE_END)) {
> +			size	= ((section&  DMM_LISA_MAP_SYS_SIZE_MASK)>>
> +				    DMM_LISA_MAP_SYS_SIZE_SHIFT);
> +			size	= 1<<  size;
> +			size	*= SZ_16M;
> +			total_size += size;
> +		}
> +	}
> +	return total_size;
> +}
> +
> +
>   /*
>    * Routine: dram_init
>    * Description: sets uboots idea of sdram size
> @@ -75,7 +103,7 @@ int dram_init(void)
>   	DECLARE_GLOBAL_DATA_PTR;
>
>   	gd->bd->bi_dram[0].start = 0x80000000;
> -	gd->bd->bi_dram[0].size = 512<<  20;
> +	gd->bd->bi_dram[0].size = sdram_size();
>   	return 0;
>   }
>
> diff --git a/arch/arm/include/asm/arch-omap4/omap4.h b/arch/arm/include/asm/arch-omap4/omap4.h
> index d0c808d..a30bb33 100644
> --- a/arch/arm/include/asm/arch-omap4/omap4.h
> +++ b/arch/arm/include/asm/arch-omap4/omap4.h
> @@ -42,6 +42,10 @@
>   #define OMAP44XX_L4_WKUP_BASE	0x4A300000
>   #define OMAP44XX_L4_PER_BASE	0x48000000
>
> +#define OMAP44XX_DRAM_ADDR_SPACE_START	0x80000000
> +#define OMAP44XX_DRAM_ADDR_SPACE_END	0xD0000000
> +
> +
>   /* CONTROL */
>   #define CTRL_BASE		(OMAP44XX_L4_CORE_BASE + 0x2000)
>   #define CONTROL_PADCONF_CORE	(OMAP44XX_L4_CORE_BASE + 0x100000)
> @@ -66,6 +70,12 @@
>   /* GPMC */
>   #define OMAP44XX_GPMC_BASE	0x50000000
>
> +/* DMM */
> +#define OMAP44XX_DMM_BASE		0x4E000000
> +#define DMM_LISA_MAP_BASE		(OMAP44XX_DMM_BASE + 0x40)
> +#define DMM_LISA_MAP_SYS_SIZE_MASK	(7<<  20)
> +#define DMM_LISA_MAP_SYS_SIZE_SHIFT	20
> +#define DMM_LISA_MAP_SYS_ADDR_MASK	(0xFF<<  24)
>   /*
>    * Hardware Register Details
>    */