[U-Boot] [PATCH] omap: emif: configure emif only when required

[R Sricharan]

On Wednesday 14 November 2012 02:19 PM, Lokesh Vutla wrote:
> DMM_LISA_MAP registers program whether memory is mapped
> on particular EMIF or not. Irrespective of these registers
> EMIF is getting configured. Correcting the same.
>
> Signed-off-by: Lokesh Vutla <lokeshvutla at ti.com>
> ---
>   arch/arm/cpu/armv7/omap-common/emif-common.c |   39 ++++++++++++++++++++++----
>   1 file changed, 34 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm/cpu/armv7/omap-common/emif-common.c b/arch/arm/cpu/armv7/omap-common/emif-common.c
> index 30dcf1b..179525f 100644
> --- a/arch/arm/cpu/armv7/omap-common/emif-common.c
> +++ b/arch/arm/cpu/armv7/omap-common/emif-common.c
> @@ -33,6 +33,8 @@
>   #include <asm/utils.h>
>   #include <linux/compiler.h>
>
> +static int emif1_enabled = -1, emif2_enabled = -1;
> +
>   void set_lpmode_selfrefresh(u32 base)
>   {
>   	struct emif_reg_struct *emif = (struct emif_reg_struct *)base;
> @@ -1218,6 +1220,27 @@ void dmm_init(u32 base)
>   	}
>   }
>
> +static void enable_emifs(void)
> +{
> +	u32 i, section, valid;
> +
> +	emif1_enabled = 0;
> +	emif2_enabled = 0;
> +	for (i = 0; i < 4; i++) {
> +		section	= __raw_readl(DMM_BASE + i*4);
> +		valid = (section & EMIF_SDRC_MAP_MASK) >>
> +			(EMIF_SDRC_MAP_SHIFT);
> +		if (valid == 1) {
> +			emif1_enabled = 1;
> +		} else if (valid == 2) {
> +			emif2_enabled = 1;
> +		} else if (valid == 3) {
> +			emif1_enabled = 1;
> +			emif2_enabled = 1;
> +			return;
> +		}
> +	}
> +}
>   /*
>    * SDRAM initialization:
>    * SDRAM initialization has two parts:
> @@ -1255,15 +1278,21 @@ void sdram_init(void)
>   			writel(CM_DLL_CTRL_NO_OVERRIDE, &prcm->cm_dll_ctrl);
>   	}
>
> -	do_sdram_init(EMIF1_BASE);
> -	do_sdram_init(EMIF2_BASE);
> -
>   	if (!in_sdram)
>   		dmm_init(DMM_BASE);
>
> +	enable_emifs();
  The function name is odd. It has got nothing to do with enabling 
EMIF's. It just identifies which is enabled ?. How about
set_enabled_emifs ?

Also this can done just when you are configuring the LISA registers.
That way a extra function is avoided.

Regards,
  Sricharan