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Subject: Re: [PATCH V12 2/2] mtd: spi-nor: Add driver for Cadence Quad SPI
 Flash Controller
To: Marek Vasut <marex@denx.de>, "linux-mtd@lists.infradead.org"
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From: Vignesh R <vigneshr@ti.com>
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Date: Fri, 17 Jun 2016 10:13:29 +0530
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On Thursday 16 June 2016 06:51 PM, Marek Vasut wrote:
> On 06/16/2016 08:43 AM, Vignesh R wrote:
[...]
>>> - I didn't find any way to find when all the data in the current 1 MiB
>>>   block were written and you can remap another 1 MiB block in place.
>>
>> I believe this constraint only applies if enahbremap bit is set in cfg
>> register, if not, then the entire memory map can be accessed.
> 
> And where is that memory window accessible then, at which address ?
> The SoCFPGA peripherals are stuffed in some 12 MiB of the address
> space, the rest is bootrom/sram/ram and the FPGA bridges, so I find
> it hard to believe you can place ie. 128 MiB SPI NOR mapping somewhere
> in there.
> 
> My impression is that in direct mode, the qspi will always overlay the
> address 0x0 on socfpga , but that might be configurable , I'm not sure.
> 

Ah, socfgpa provides just 1MB window to access QSPI_DATA area. So direct
mode may not be practical as it will require remapping.
But, on TI EVM, QSPI_DATA area is 64MB in size, so looks like direct
mode(when added) needs to be tied to TI specific compatible.

-- 
Regards
Vignesh