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

[Marek Vasut]

On Wednesday, November 04, 2015 at 03:36:08 AM, Thomas Chou wrote:
> Hi Marek,

Hi!

> On 2015年11月04日 01:44, Marek Vasut wrote:
> > On Tuesday, November 03, 2015 at 02:22:12 PM, Thomas Chou 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.
> >> 
> >> Signed-off-by: Thomas Chou <thomas at wytron.com.tw>
> >> ---
> > 
> > You might want to look at https://lwn.net/Articles/636882/ , it is the
> > driver for the same hardware, but for Linux. But keep in mind that the
> > driver had some difficulties getting in, you might want to check the
> > discussions in linux-mtd .
> 
> I did check and follow the threads for a while since you pointed me
> about it in earlier communication. It is v5 last month. But the author
> decided to wait for hardware fix on rdid.

I think I had a stake there as well ;-)

> Yet I have a different point as I stated in the patch message. It is NOT
> a spi-nor since the hardware converted it to parallel interface. It
> should be treated more like cfi flash. I think it might be a mistake to
> take it as spi-nor. And this might be the hidden cause to prevent the
> linux driver getting in.  So I wrote it my way.

Let me just put an idea here, it might be wrong -- but doesn't this seem
like some sort of NVMEM device? See for example:

https://lkml.org/lkml/2015/5/21/643

Best regards,
Marek Vasut