[U-Boot] [PATCH 0/4] sf: Accessing > 16MBytes flashes in existing 3-byte addr mode.

[U-Boot] [PATCH 0/4] sf: Accessing > 16MBytes flashes in existing 3-byte addr mode.

[Jagannadha Sutradharudu Teki]

The current implementation in spi_flash supports 3-byte address mode
due to this up to 16MB amount of flash is able to access for those
flashes which has an actual size of > 16MB.

List of flashes:
S25FL256S
N25Q256
N25Q256A
W25Q256(not yet mainlined)

extended/bank address register contains an information to access the
4th byte addressing hence the flashes which has > 16MB can be accessible.

extended/bank address read/write commands in spansion & winbond/stmicro
are different, currently I have added support for spansion.

if the user is giving an offset > 0x1000000 for read/write/erase commands
the implementation will subtract the offset from 0x1000000 and then enable the
extended/bank address register.

[pseudo]
if (offset > 0x1000000) {
        offset -= 0x1000000;
        enable the ext/bank addr register
} else
        disable the ext/bank addr register


Thanks,
Jagan.

Jagannadha Sutradharudu Teki (4):
  sf: Add extended address register writing support
  sf: Add extended address register reading support
  sf: Add extended address access support
  sf: winbond: Add support for W25Q256

 drivers/mtd/spi/spi_flash.c          |  145 ++++++++++++++++++++++++++++++++++
 drivers/mtd/spi/spi_flash_internal.h |   18 ++++
 drivers/mtd/spi/winbond.c            |    5 +
 3 files changed, 168 insertions(+), 0 deletions(-)

-- 
1.7.4

[U-Boot] [PATCH 0/4] sf: Accessing > 16MBytes flashes in existing 3-byte addr mode.

[Jagan Teki]

On Sat, Feb 23, 2013 at 5:08 PM, Jagannadha Sutradharudu Teki
<jagannadha.sutradharudu-teki@xilinx.com> wrote:
> The current implementation in spi_flash supports 3-byte address mode
> due to this up to 16MB amount of flash is able to access for those
> flashes which has an actual size of > 16MB.
>
> List of flashes:
> S25FL256S
> N25Q256
> N25Q256A
> W25Q256(not yet mainlined)
>
> extended/bank address register contains an information to access the
> 4th byte addressing hence the flashes which has > 16MB can be accessible.
>
> extended/bank address read/write commands in spansion & winbond/stmicro
> are different, currently I have added support for spansion.
>
> if the user is giving an offset > 0x1000000 for read/write/erase commands
> the implementation will subtract the offset from 0x1000000 and then enable the
> extended/bank address register.
>
> [pseudo]
> if (offset > 0x1000000) {
>         offset -= 0x1000000;
>         enable the ext/bank addr register
> } else
>         disable the ext/bank addr register
>
>
> Thanks,
> Jagan.
>
> Jagannadha Sutradharudu Teki (4):
>   sf: Add extended address register writing support
>   sf: Add extended address register reading support
>   sf: Add extended address access support
>   sf: winbond: Add support for W25Q256
>
>  drivers/mtd/spi/spi_flash.c          |  145 ++++++++++++++++++++++++++++++++++
>  drivers/mtd/spi/spi_flash_internal.h |   18 ++++
>  drivers/mtd/spi/winbond.c            |    5 +
>  3 files changed, 168 insertions(+), 0 deletions(-)
>
> --
> 1.7.4

Thanks for your contribution for new feature setup.
Could you please send the v2 for these > 16MB flash support patch set.

--
Thanks,
Jagan.

[U-Boot] [PATCH 0/4] sf: Accessing > 16MBytes flashes in existing 3-byte addr mode.

[Jagannadha Sutradharudu Teki]

Hi Thomas,

> -----Original Message-----
> From: Langer Thomas (LQDE RD ST PON SW)
> [mailto:thomas.langer at lantiq.com]
> Sent: 24 February 2013 21:21
> To: Jagannadha Sutradharudu Teki; u-boot at lists.denx.de
> Cc: Michal at theia.denx.de; Jagannadha Sutradharudu Teki
> Subject: AW: [U-Boot] [PATCH 0/4] sf: Accessing > 16MBytes flashes in
> existing 3-byte addr mode.
>
> Hello Jagan,
>
> thanks for your contribution.
>
> As there is currently no explicit custodian for sf, I would like to give some
> comments to your code.
>
> Am 23.02.2013 12:38, schrieb Jagannadha Sutradharudu Teki:
> > The current implementation in spi_flash supports 3-byte address mode
> > due to this up to 16MB amount of flash is able to access for those
> > flashes which has an actual size of > 16MB.
> >
> > List of flashes:
> > S25FL256S
> > N25Q256
> > N25Q256A
> > W25Q256(not yet mainlined)
> >
> > extended/bank address register contains an information to access the
> > 4th byte addressing hence the flashes which has > 16MB can be accessible.
> >
>
> I don't see a config option described here (and also don't find it in the
> patches).
> Please keep in mind that the code size for existing boards should not
> increase!
> See http://www.denx.de/wiki/U-Boot/DesignPrinciples , points 1 and 5
>
> The code might fit for your use-case, but has influence on other
> boards/systems, and this is not acceptable.
> Please add a config option for this new code and also use the existing
> options, like CONFIG_SPI_FLASH_SPANSION, in your code.

The main reason for not adding CONFIG macro is like this entire support requires
spansion, winbond and numonyx flashes.  I

As I have added support for spansion, I will send few more patches
for winbond and numonyx support as well.

Can I send all the patches again including winbond and numonyx support
with RESEND as prefix?

Is still a config macro required if the code opt for these 3 flashes?

Thanks,
Jagan.



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[U-Boot] [PATCH 0/4] sf: Accessing > 16MBytes flashes in existing 3-byte addr mode.

[Langer Thomas]

Hello Jagan,

thanks for your contribution.

As there is currently no explicit custodian for sf, I would like to give some comments to your code.

Am 23.02.2013 12:38, schrieb Jagannadha Sutradharudu Teki:
> The current implementation in spi_flash supports 3-byte address mode
> due to this up to 16MB amount of flash is able to access for those
> flashes which has an actual size of > 16MB.
> 
> List of flashes:
> S25FL256S
> N25Q256
> N25Q256A
> W25Q256(not yet mainlined)
> 
> extended/bank address register contains an information to access the
> 4th byte addressing hence the flashes which has > 16MB can be accessible.
> 

I don't see a config option described here (and also don't find it in the patches).
Please keep in mind that the code size for existing boards should not increase!
See http://www.denx.de/wiki/U-Boot/DesignPrinciples , points 1 and 5

The code might fit for your use-case, but has influence on other boards/systems,
and this is not acceptable.
Please add a config option for this new code and also use the existing options,
like CONFIG_SPI_FLASH_SPANSION, in your code.

> 
> Thanks,
> Jagan.
> 

Best Regards,
Thomas