[U-Boot] [UBOOT PATCH 1/2] spi: zynqmp_qspi: Add support for ZynqMP qspi driver

[Siva Durga Prasad Paladugu]

Hi Jagan,

> -----Original Message-----
> From: Jagan Teki [mailto:jagannadh.teki at gmail.com]
> Sent: Tuesday, October 31, 2017 3:01 PM
> To: Siva Durga Prasad Paladugu <sivadur at xilinx.com>
> Cc: u-boot at lists.denx.de; Liam Beguin <liambeguin at gmail.com>
> Subject: Re: [UBOOT PATCH 1/2] spi: zynqmp_qspi: Add support for
> ZynqMP qspi driver
> 
> On Tue, Oct 31, 2017 at 2:50 PM, Siva Durga Prasad Paladugu
> <sivadur at xilinx.com> wrote:
> > Hi Jagan,
> >
> >> -----Original Message-----
> >> From: Jagan Teki [mailto:jagannadh.teki at gmail.com]
> >> Sent: Tuesday, October 31, 2017 2:40 PM
> >> To: Siva Durga Prasad Paladugu <sivadur at xilinx.com>
> >> Cc: u-boot at lists.denx.de; Liam Beguin <liambeguin at gmail.com>; Siva
> >> Durga Prasad Paladugu <sivadur at xilinx.com>
> >> Subject: Re: [UBOOT PATCH 1/2] spi: zynqmp_qspi: Add support for
> >> ZynqMP qspi driver
> >>
> >> On Tue, Oct 24, 2017 at 3:33 PM, Siva Durga Prasad Paladugu
> >> <siva.durga.paladugu at xilinx.com> wrote:
> >> > This patch adds qspi driver support for ZynqMP SoC. This driver is
> >> > responsible for communicating with qspi flash devices.
> >>
> >> Legacy question, what is your approach for dual memory setup? Did you
> >> write another flash driver?
> > No
> >
> >>
> >> I see this driver use dual flash slave 'option' which doesn't live on
> >> spi side anymore. better to have a discussion on approach and will
> review further.
> >
> > I can see that spi_flash.c(driver/mtd/spi/spi_flash.c) has the option for
> dual flash under CONFIG_SF_DUAL_FLASH.
> > I thought of using the same. Isn't it takes care of dual flash case?
> > Please let me know if you any further thoughts on how it has to be
> handled.
> 
> Dual flash case should take for generic spi drivers, if you strictly want your
> controller to handle flash device rather !flashes then we need to write the
> driver at flash side. ie why I asked as first question.

Does this mean that drivers that are present in drivers/spi/ should work for both flashes and !flashes. And the
drivers that only targets flash devices should be in different place and doesn’t use Dual flash functionality under
CONFIG_SF_DUAL_FLASH? Or it can still use this.


Thanks,
DP


> 
> thanks!
> --
> Jagan Teki
> Free Software Engineer | www.openedev.com U-Boot, Linux | Upstream
> Maintainer Hyderabad, India.