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[0/3] omap-gpmc wait pin additions

Message ID 20220901124144.1006238-1-benedikt.niedermayr@siemens.com (mailing list archive)
Headers show
Series omap-gpmc wait pin additions | expand

Message

B. Niedermayr Sept. 1, 2022, 12:41 p.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). 


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. 1, 2022, 12:56 p.m. UTC | #1
On 01/09/2022 15:41, 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). 

Please base your patches on a recent Linux kernel (judging by CC list
this is something old) - either current RC or linux-next.

Best regards,
Krzysztof
B. Niedermayr Sept. 1, 2022, 1:02 p.m. UTC | #2
On Thu, 2022-09-01 at 15:56 +0300, Krzysztof Kozlowski wrote:
> On 01/09/2022 15:41, 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). 
> 
> Please base your patches on a recent Linux kernel (judging by CC list
> this is something old) - either current RC or linux-next.
> 
> Best regards,
> Krzysztof


... and create a v2 patch series then?

Best regards,

Benedikt
Krzysztof Kozlowski Sept. 1, 2022, 1:11 p.m. UTC | #3
On 01/09/2022 16:02, Niedermayr, BENEDIKT wrote:
> On Thu, 2022-09-01 at 15:56 +0300, Krzysztof Kozlowski wrote:
>> On 01/09/2022 15:41, 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). 
>>
>> Please base your patches on a recent Linux kernel (judging by CC list
>> this is something old) - either current RC or linux-next.
>>
>> Best regards,
>> Krzysztof
> 
> 
> ... and create a v2 patch series then?

Just for updating email addresses - no need. If the code was rebased and
tested on something old, then yes, please.

Best regards,
Krzysztof