[U-Boot] [PATCH v2 2/2] mtd: add altera quadspi driver

Jagan Teki
2015-11-05T14:57:01Z

Hi Thomas,

On 5 November 2015 at 20:15, Thomas Chou <thomas@wytron.com.tw> wrote:
> Hi Jagan,
>
> On 2015?11?05? 22:25, Jagan Teki wrote:
>>
>> On 5 November 2015 at 14:17, Thomas Chou <thomas@wytron.com.tw> wrote:
>>>
>>> Add Altera Generic Quad SPI Controller support. The controller
>>> converts SPI NOR flash to parallel flash interface. So it is
>>> not like other SPI flash, but rather like CFI flash.
>>
>>
>> Can you wait till spi-nor ready? it doesn't make sense to have Serial
>> NOR to created as parallel NOR.
>
>
> The altera quad spi core is very special that the hardware handle the
> spi-nor protocol. The core is designed to replace the CFI flash interface.
> So there is nothing to do with SPI from the parallel flash interface. It is
> memory mapped. There is no SPI interface. There is nothing related to SPI
> programming. So please don't worry about the progress on spi-nor. The core
> should belong to parallel flash, but not serial flash.

Agreed that this is not doing any generic spi things, but it's a
spi-nor controller all spi-nor controller should be part of spi-nor
subsystem Linux agreed and have a framework for that.

drivers/mtd/spi-nor/fsl-quadspi.c
drivers/mtd/spi-nor/nxp-spifi.c

all these are spi-nor controller which doesn't do any generic spi
things but should be in spi-nor subsystem. Even Marek send altera_qspi
as spi-nor controller [1]

Since I'm working on similar spi-nor subsystem what Linux have +
driver model little worried about this because once we have spi-nor
again it should be a re-work.

[1] http://lists.infradead.org/pipermail/linux-mtd/2015-April/058650.html

--
Jagan | openedev