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

Lokesh Vutla lokeshvutla at ti.com
Wed Nov 14 17:44:27 CET 2012


On Wednesday 14 November 2012 07:02 PM, R Sricharan wrote:
> 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.
Yes you are right. Ill do this post it.

Thanks
Lokesh
>
> Regards,
>   Sricharan



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