[U-Boot-Users] [PATCH] CFI: synchronize command offsets with Linux CFI driver
Bartlomiej Sieka
tur at semihalf.com
Tue Dec 11 15:25:25 CET 2007
Stefan Roese wrote:
[...]
>> diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
>> index 66754cd..b748a9f 100644
>> --- a/drivers/mtd/cfi_flash.c
>> +++ b/drivers/mtd/cfi_flash.c
>> @@ -1231,9 +1231,26 @@ static int flash_detect_cfi (flash_info_t * info)
>> debug ("port %d bits chip %d bits\n",
>> info->portwidth << CFI_FLASH_SHIFT_WIDTH,
>> info->chipwidth << CFI_FLASH_SHIFT_WIDTH);
>> - /* this probably only works if info->interface == FLASH_CFI_X8X16 */
>> - info->addr_unlock1 = (info->portwidth == FLASH_CFI_8BIT) ? 0xAAA :
>> 0x555; - info->addr_unlock2 = (info->portwidth == FLASH_CFI_8BIT) ?
>> 0x555 : 0x2AA; +
>> + /* calculate command offsets as in the Linux driver */
>> + info->addr_unlock1 = 0x555;
>> + info->addr_unlock2 = 0x2aa;
>> +
>> + /*
>> + * modify the unlock address if we are
>> + * in compatibility mode
>> + */
>> + if ( /* x8/x16 in x8 mode */
>> + ((info->chipwidth == FLASH_CFI_BY8) &&
>> + (info->interface == FLASH_CFI_X8X16)) ||
>> + /* x16/x32 in x16 mode */
>> + ((info->chipwidth == FLASH_CFI_BY16) &&
>> + (info->interface == FLASH_CFI_X16X32)))
>> + {
>> + info->addr_unlock1 = 0xaaa;
>> + info->addr_unlock2 = 0x555;
>> + }
>> +
>
> Why not like this:
>
> if (((info->chipwidth == FLASH_CFI_BY8) &&
> (info->interface == FLASH_CFI_X8X16)) ||
> ((info->chipwidth == FLASH_CFI_BY16) &&
> (info->interface == FLASH_CFI_X16X32))) {
> /*
> * Compatibility mode:
> * x8/x16 in x8 mode or
> * x16/x32 in x16 mode
> */
> info->addr_unlock1 = 0xaaa;
> info->addr_unlock2 = 0x555;
> } else {
> /* default */
> info->addr_unlock1 = 0x555;
> info->addr_unlock2 = 0x2aa;
> }
I copied the code from Linux CFI driver and kept it as is (modulo
#define names). I'm fine with either of the two forms, although I think
that there is some benefit in keeping borrowed code as intact as possible.
Regards,
Bartlomiej
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