[PATCH V7 1/2] mtd: spi-nor: Bindings for Cadence Quad SPI Flash Controller driver.
Graham Moore
grmoore at opensource.altera.com
Tue Aug 18 12:03:57 PDT 2015
Hi all,
On 08/18/2015 12:48 AM, Vikas MANOCHA wrote:
[...]
>>>> +Required properties:
>>>> +- compatible : Should be "cdns,qspi-nor".
>>>> +- reg : Contains two entries, each of which is a tuple consisting of a
>>>> + physical address and length. The first entry is the address and
>>>> + length of the controller register set. The second entry is the
>>>> + address and length of the QSPI Controller data area.
>>>
>>> "Controller data area", i think it means mapped NOR Flash address ?
>>
>> Probably ; Graham ?
>>
>>> If yes, it would be more clear with "Physical base address & size of NOR
>>> Flash".
>>
>> This is the Direct mode thing, correct ? We don't support this, so I think
>> we should drop this bit altogether and keep only one single address in this
>> field.
>
> No it's not.
>
It's the location of the SRAM fifo. Also direct mode location I think,
if that were ever used.
The size is determined by a configuration parameter during system
design. On Altera Cyclone5 the size is really big compared to SRAM
fifo. I don't know why, maybe some hw engineer thought it would be
better to have a large size in case direct mode was used.
BR,
Graham
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