[U-Boot] [RFC PATCH] sf: New SF-NOR framework

[Jagan Teki]

On 12 November 2014 04:26, Marek Vasut <marex at denx.de> wrote:
> On Tuesday, November 11, 2014 at 10:37:33 PM, Jagan Teki wrote:
>> On 12 November 2014 02:52, Marek Vasut <marex at denx.de> wrote:
>> > On Tuesday, November 11, 2014 at 09:50:35 PM, Jagannadha Sutradharudu
>> > Teki
>> >
>> > wrote:
>> >> This is long lasting work that I did last few months back,
>> >> I'm sure it's where much need now.
>> >>
>> >> - spi driver: drivers/spi/fsl_qspi.c
>> >> - flash attributes in spi_slave {} and
>> >> - etc ...
>> >> making spi subsystem becomes more flash specific rather operating
>> >> as a generic spi bus. So SF-NOR divides normal spi flash operations
>> >> through generic SPI API's(sf_spi.c) and more spi flash(sf) specific
>> >> operations through SF NOR API's.
>> >>
>> >> So the controllers those are operating more on flash needs to
>> >> write a driver on drivers/mtd/spi/ example fsl_qspi.c
>> >>
>> >> I have not tested more accuratly as of now, will come back again
>> >> with new feature additions/removal, zynq_qspi additions and more...
>> >>
>> >> Note: dm-spi ops can gets effected with this new framework
>> >> { .ops            = &spi_flash_std_ops, } and will fix that in next
>> >> version patches.
>> >>
>> >> Signed-off-by: Jagannadha Sutradharudu Teki <jagannadh.teki at gmail.com>
>> >
>> > I have but a general question -- why did you not just import the spi-nor
>> > framework from Linux ?
>>
>> Well, importing spi-nor from Linux is may not be a good idea as we
>> have a working stuff
>> at our end along with different dependencies and I'm sure this will
>> becomes similar way as
>> spi-nor at some point of time.
>
> What you said doesn't add up to me -- you introduced a completely new framework
> in this patch, right ? So what exact "working stuff" do we have if this is a
> completely new code ?

Yes - this is a new framework with exiting working code by maintain sf_nor {} to
common for spi_sf drivers and flash based drivers.

Not completely new code, It's a re-arranged proven/working existing
code, please understand this.
re-arranged as we have an issue with spi is handling more flash stuff.

>
> Compared to that, the SPI NOR framework in Linux is being actively maintained
> and actively used for a while now, so it's actually a proven code already. Also,
> we just recently resynced MTD subsystem with Linux, adding the SPI NOR framework
> which is based on that same MTD framework would probably be pretty
> straighforward.

Even sf stuff in u-boot is actively maintained and code in sf and
Linux are almost similar
except Linux specific stuff. I don't see any point to import the Linux
stuff as we have working
and actively maintained stuff. By addition of this I'm sure something
proved will not effect.

thanks!
-- 
Jagan.