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[v2,0/3] omap-gpmc wait pin additions

Message ID 20220902091028.1346952-1-benedikt.niedermayr@siemens.com (mailing list archive)
Headers show
Series omap-gpmc wait pin additions | expand

Message

Benedikt Niedermayr Sept. 2, 2022, 9:10 a.m. UTC
From: Benedikt Niedermayr <benedikt.niedermayr@siemens.com>

There is currently no possibility for the gpmc to set either the
waitp-pin polarity or use the same wait-pin for different cs-regions.

While the current implementation may fullfill most usecases, it may not
be sufficient for more complex setups (e.g. FPGA/ASIC interfaces), where
more complex interfacing options where possible.

For example interfacing an ASIC which offers multiple cs-regions but
only one waitpin the current driver and dt-bindings are not sufficient.

While using the same waitpin for different cs-regions worked for older
kernels (4.14) the omap-gpmc.c driver refused to probe (-EBUSY) with
newer kernels (>5.10).

Changes since v1: 
  * Rebase against recent 6.0.0-rc3 kernel, but the maintainers list
    stays the same!

  ./scripts/get_maintainer.pl drivers/memory/omap-gpmc.c
  Roger Quadros <rogerq@kernel.org> (maintainer:OMAP GENERAL PURPOSE MEMORY CONTROLLER SUPPORT)
  Tony Lindgren <tony@atomide.com> (maintainer:OMAP GENERAL PURPOSE MEMORY CONTROLLER SUPPORT)
  Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> (maintainer:MEMORY CONTROLLER DRIVERS)
  linux-omap@vger.kernel.org (open list:OMAP GENERAL PURPOSE MEMORY CONTROLLER SUPPORT)
  linux-kernel@vger.kernel.org (open list:MEMORY CONTROLLER DRIVERS)
  
  ./scripts/get_maintainer.pl Documentation/devicetree/bindings/memory-controllers/ti,gpmc-child.yaml 
  Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> (maintainer:MEMORY CONTROLLER DRIVERS)
  Rob Herring <robh+dt@kernel.org> (maintainer:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS)
  Tony Lindgren <tony@atomide.com> (in file)
  Roger Quadros <rogerq@kernel.org> (in file)
  linux-kernel@vger.kernel.org (open list:MEMORY CONTROLLER DRIVERS)
  devicetree@vger.kernel.org (open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS)



Benedikt Niedermayr (3):
  memory: omap-gpmc: allow shared wait pins
  memory: omap-gpmc: add support for wait pin polarity
  dt-bindings: memory-controllers: gpmc-child: Add binding for
    wait-pin-polarity

 .../memory-controllers/ti,gpmc-child.yaml     |  7 ++++
 drivers/memory/omap-gpmc.c                    | 38 +++++++++++++++----
 include/linux/platform_data/gpmc-omap.h       |  1 +
 3 files changed, 39 insertions(+), 7 deletions(-)

Comments

Krzysztof Kozlowski Sept. 5, 2022, 6:44 a.m. UTC | #1
On 02/09/2022 12:10, B. Niedermayr wrote:
> From: Benedikt Niedermayr <benedikt.niedermayr@siemens.com>
> 
> There is currently no possibility for the gpmc to set either the
> waitp-pin polarity or use the same wait-pin for different cs-regions.
> 
> While the current implementation may fullfill most usecases, it may not
> be sufficient for more complex setups (e.g. FPGA/ASIC interfaces), where
> more complex interfacing options where possible.
> 
> For example interfacing an ASIC which offers multiple cs-regions but
> only one waitpin the current driver and dt-bindings are not sufficient.
> 
> While using the same waitpin for different cs-regions worked for older
> kernels (4.14) the omap-gpmc.c driver refused to probe (-EBUSY) with
> newer kernels (>5.10).
> 
> Changes since v1: 
>   * Rebase against recent 6.0.0-rc3 kernel, but the maintainers list
>     stays the same!

No... thanks for rebasing yet still you use wrong address email.

> 
>   ./scripts/get_maintainer.pl drivers/memory/omap-gpmc.c
>   Roger Quadros <rogerq@kernel.org> (maintainer:OMAP GENERAL PURPOSE MEMORY CONTROLLER SUPPORT)
>   Tony Lindgren <tony@atomide.com> (maintainer:OMAP GENERAL PURPOSE MEMORY CONTROLLER SUPPORT)
>   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> (maintainer:MEMORY CONTROLLER DRIVERS)

Different address email.


Best regards,
Krzysztof
Benedikt Niedermayr Sept. 5, 2022, 7:15 a.m. UTC | #2
On Mon, 2022-09-05 at 09:44 +0300, Krzysztof Kozlowski wrote:
> On 02/09/2022 12:10, B. Niedermayr wrote:
> > From: Benedikt Niedermayr <benedikt.niedermayr@siemens.com>
> > 
> > There is currently no possibility for the gpmc to set either the
> > waitp-pin polarity or use the same wait-pin for different cs-
> > regions.
> > 
> > While the current implementation may fullfill most usecases, it may
> > not
> > be sufficient for more complex setups (e.g. FPGA/ASIC interfaces),
> > where
> > more complex interfacing options where possible.
> > 
> > For example interfacing an ASIC which offers multiple cs-regions
> > but
> > only one waitpin the current driver and dt-bindings are not
> > sufficient.
> > 
> > While using the same waitpin for different cs-regions worked for
> > older
> > kernels (4.14) the omap-gpmc.c driver refused to probe (-EBUSY)
> > with
> > newer kernels (>5.10).
> > 
> > Changes since v1: 
> >   * Rebase against recent 6.0.0-rc3 kernel, but the maintainers
> > list
> >     stays the same!
> 
> No... thanks for rebasing yet still you use wrong address email.
> 
> >   ./scripts/get_maintainer.pl drivers/memory/omap-gpmc.c
> >   Roger Quadros <rogerq@kernel.org> (maintainer:OMAP GENERAL
> > PURPOSE MEMORY CONTROLLER SUPPORT)
> >   Tony Lindgren <tony@atomide.com> (maintainer:OMAP GENERAL PURPOSE
> > MEMORY CONTROLLER SUPPORT)
> >   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> > (maintainer:MEMORY CONTROLLER DRIVERS)
> 
> Different address email.
> 
> 
> Best regards,
> Krzysztof
Ok now I see: 
  krzk@kernel.org  has changed to krzysztof.kozlowski@linaro.org