[U-Boot] [PATCH 0/3] Read SFDP parameters and access flash above 16MB

[Rajat Srivastava]

> -----Original Message-----
> From: Simon Goldschmidt <simon.k.r.goldschmidt at gmail.com>
> Sent: Wednesday, October 31, 2018 1:09 PM
> To: Rajat Srivastava <rajat.srivastava at nxp.com>; U-Boot Mailing List <u-
> boot at lists.denx.de>
> Cc: Jagan Teki <jagan at openedev.com>
> Subject: Re: [U-Boot] [PATCH 0/3] Read SFDP parameters and access flash
> above 16MB
> 
> On Tue, Oct 30, 2018 at 9:35 PM Simon Goldschmidt
> <simon.k.r.goldschmidt at gmail.com> wrote:
> >
> > On 17.10.2018 13:27, Rajat Srivastava wrote:
> > > Add functionality to read and parse SFDP parameters to auto-detect
> > > flash size, page size and address width of flash. This enables
> > > flash access above 16MB using 4-byte addressing mode.
> > >
> > > Add driver support to get SFDP information of flash and use it to
> > > access flash above 16MB.
> > >
> > > Enable reading and parsing of SFDP parameters for Spansion's
> > > s25fs512 flash to auto-detect its size, its page size and the
> > > addressing mode it supports.
> >
> > Why do you need driver-specific code to read the sfdp parameters?
> > Wouldn't it be much cleaner to solve this from spi_flash.c only?
> >
> > If so, just adding the 'spi_flash_parse_sfdp()' function on top of
> > Stefan's patch should work?
> >
> > I tried testing this patch, but just like for Stefan, but it just didn't
> > work for me and I failed to see some simple steps to adjust my spi
> > driver to make it work.
> 
> And taking this further, would it make sense to add a config option
> that dumps the whole flash chip table and only uses SFDP? Then we
> could save a lot of space in SPL for boards where reading SFDP is
> enough.

Does the whole flash chip table mean the table that consists CFI information 
as well as SFDP information? If that's so, could you please elaborate where 
would we dump and save this table? And how will this help in saving space in SPL?

Rajat

> 
> Simon
> 
> >
> > Simon
> >
> > >
> > > Rajat Srivastava (3):
> > >    mtd/spi: Add JEDEC SFDP support in SPI framework
> > >    fsl_qspi: Access flash above 16MB using SFDP
> > >    spi_flash_ids: Enable SFDP parsing for s25fs512 flash
> > >
> > >   drivers/mtd/spi/sf_internal.h   |   4 +
> > >   drivers/mtd/spi/spi_flash.c     | 297
> +++++++++++++++++++++++++++++++++++++---
> > >   drivers/mtd/spi/spi_flash_ids.c |   3 +-
> > >   drivers/spi/fsl_qspi.c          | 103 +++++++++++++-
> > >   include/spi.h                   |   2 +
> > >   include/spi_flash.h             | 120 ++++++++++++++++
> > >   6 files changed, 501 insertions(+), 28 deletions(-)
> > >
> >