Re: [RESEND PATCH v10 0/3] fpga: Use standard class dev_release function

[Russ Weight <russell.h.weight@intel.com>]

On 7/27/21 6:24 AM, Tom Rix wrote:
>
> On 7/26/21 2:33 PM, Russ Weight wrote:
>> Hi Moritz,
>>
>> I sent this version of the patchset out on July 8th. The only discussion has
>> been around the compat-id structure. I think there is agreement that this can
>> be treated separately. What are your thoughts? Do you think this patchset is
>> ready?
>
> While I agree the compat_id can be treated separately, i still have a problem with the 2 register functions.
>
> In this discussion,
>
> https://lore.kernel.org/linux-fpga/DM6PR11MB38194D113950FA4B75C7F2C485E49@DM6PR11MB3819.namprd11.prod.outlook.com/
>
> *register_full(..., *info) becomes
>
> *register(..., *info)
>
> and
>
> *register_simple() is moved out of the public api and becomes private to the subsystem.

Somehow I missed that part of the email. I'm not sure I understand the part about
register_simple() "becomes private to the subsystem". Most users would call the simple
version of the API. Is the proposal to replicate the register_simple() interface
for each driver that calls it?

> Tom
>
>>
>> Thanks,
>> - Russ
>>
>>
>> On 7/26/21 2:27 PM, Russ Weight wrote:
>>> The FPGA framework has a convention of using managed resource functions
>>> to allow parent drivers to manage the data structures allocated by the
>>> class drivers. They use an empty *_dev_release() function to satisfy the
>>> class driver.
>>>
>>> This is inconsistent with linux driver model.
>>>
>>> These changes remove the managed resource functions and populate the class
>>> dev_release callback functions. They also merge the create() and register()
>>> functions into a single register() or register_full() function for each of
>>> the fpga-mgr, fpga-region, and fpga-bridge class drivers.
>>>
>>> The new *register_full() functions accept an info data structure to provide
>>> flexibility in passing optional parameters. The *register() functions
>>> support the legacy parameter list for users that don't require the use of
>>> optional parameters.
>>>
>>> For more context, refer to this email thread:
>>>
>>> https://marc.info/?l=linux-fpga&m=162127412218557&w=2
>>>
>>> I turned on the configs assocated with each of the modified files, but I
>>> must have been missing some dependencies, because not all of them compiled.
>>> I did a run-time test specifically with the dfl-fme infrastructure. This
>>> would have exercised the region, bridge, and fpga-mgr frameworks.
>>>
>>> Changelog v9 -> v10:
>>>    - Fixed commit messages to reference register_full() instead of
>>>      register_simple().
>>>    - Removed the fpga_bridge_register_full() function, because there is
>>>      not need for it yet. Updated the documentation and commit message
>>>      accordingly.
>>>    - Updated documentation to reference the fpga_manager_info and
>>>      fpga_region_info structures.
>>>
>>> Changelog v8 -> v9:
>>>    - Cleaned up documentation for the FPGA Manager, Bridge, and Region
>>>      register functions
>>>    - Renamed fpga_*_register() to fpga_*_register_full()
>>>    - Renamed fpga_*_register_simple() to fpga_*_register()
>>>    - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
>>>    - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
>>>
>>> Changelog v7 -> v8:
>>>    - Added reviewed-by tags.
>>>    - Updated Documentation/driver-api/fpga/ files: fpga-mgr.rst,
>>>      fpga-bridge.rst, and fpga-region.rst.
>>>
>>> Changelog v6 -> v7:
>>>    - Update the commit messages to describe the new parameters for the
>>>      *register() functions and to mention the *register_simple() functions.
>>>    - Fix function prototypes in header file to rename dev to parent.
>>>    - Make use of the PTR_ERR_OR_ZERO() macro when possible.
>>>    - Some cleanup of comments.
>>>    - Update function definitions/prototypes to apply const to the new info
>>>      parameter.
>>>    - Verify that info->br_ops is non-null in the fpga_bridge_register()
>>>      function.
>>>    - Verify a non-null info pointer in the fpga_region_register() function.
>>>
>>> Changelog v5 -> v6:
>>>    - Moved FPGA manager/bridge/region optional parameters out of the ops
>>>      structure and back into the FPGA class driver structure.
>>>    - Changed fpga_*_register() function parameters to accept an info data
>>>      structure to provide flexibility in passing optional parameters.
>>>    - Added fpga_*_register_simple() functions to support current parameters
>>>      for users that don't require use of optional parameters.
>>>
>>> Changelog v4 -> v5:
>>>    - Rebased on top of recently accepted patches.
>>>    - Removed compat_id from the fpga_mgr_register() parameter list
>>>      and added it to the fpga_manager_ops structure. This also required
>>>      dynamically allocating the dfl-fme-ops structure in order to add
>>>      the appropriate compat_id.
>>>    - Created the fpga_region_ops data structure which is optionally passed
>>>      to fpga_region_register(). compat_id, the get_bridges() pointer, and
>>>      the priv pointer are included in the fpga_region_ops structure.
>>>
>>> Changelog v3 -> v4:
>>>    - Added the compat_id parameter to fpga_mgr_register() and
>>>      devm_fpga_mgr_register() to ensure that the compat_id is set before
>>>      the device_register() call.
>>>    - Added the compat_id parameter to fpga_region_register() to ensure
>>>      that the compat_id is set before the device_register() call.
>>>    - Modified the dfl_fpga_feature_devs_enumerate() function to restore
>>>      the fpga_region_register() call to the correct location.
>>>
>>> Changelog v2 -> v3:
>>>    - Cleaned up comment headers for fpga_mgr_register(), fpga_bridge_register(),
>>>      and fpga_region_register().
>>>    - Fixed error return on ida_simple_get() failure for fpga_mgr_register(),
>>>      fpga_bridge_register(), and fpga_region_register().
>>>    - Fixed error return value for fpga_bridge_register(): ERR_PTR(ret) instead
>>>      of NULL.
>>>
>>> Changelog v1 -> v2:
>>>    - Restored devm_fpga_mgr_register() functionality to the fpga-mgr
>>>      class driver, adapted for the combined create/register functionality.
>>>    - All previous callers of devm_fpga_mgr_register() will continue to call
>>>      devm_fpga_mgr_register().
>>>    - replaced unnecessary ternary operators in return statements with
>>>      standard if conditions.
>>>
>>> Russ Weight (3):
>>>    fpga: mgr: Use standard dev_release for class driver
>>>    fpga: bridge: Use standard dev_release for class driver
>>>    fpga: region: Use standard dev_release for class driver
>>>
>>>   Documentation/driver-api/fpga/fpga-bridge.rst |   6 +-
>>>   Documentation/driver-api/fpga/fpga-mgr.rst    |  38 +++-
>>>   Documentation/driver-api/fpga/fpga-region.rst |  12 +-
>>>   drivers/fpga/altera-cvp.c                     |  12 +-
>>>   drivers/fpga/altera-fpga2sdram.c              |  12 +-
>>>   drivers/fpga/altera-freeze-bridge.c           |  10 +-
>>>   drivers/fpga/altera-hps2fpga.c                |  12 +-
>>>   drivers/fpga/altera-pr-ip-core.c              |   7 +-
>>>   drivers/fpga/altera-ps-spi.c                  |   9 +-
>>>   drivers/fpga/dfl-fme-br.c                     |  10 +-
>>>   drivers/fpga/dfl-fme-mgr.c                    |  22 +-
>>>   drivers/fpga/dfl-fme-region.c                 |  17 +-
>>>   drivers/fpga/dfl.c                            |  12 +-
>>>   drivers/fpga/fpga-bridge.c                    | 122 +++-------
>>>   drivers/fpga/fpga-mgr.c                       | 215 ++++++++----------
>>>   drivers/fpga/fpga-region.c                    | 119 ++++------
>>>   drivers/fpga/ice40-spi.c                      |   9 +-
>>>   drivers/fpga/machxo2-spi.c                    |   9 +-
>>>   drivers/fpga/of-fpga-region.c                 |  10 +-
>>>   drivers/fpga/socfpga-a10.c                    |  16 +-
>>>   drivers/fpga/socfpga.c                        |   9 +-
>>>   drivers/fpga/stratix10-soc.c                  |  16 +-
>>>   drivers/fpga/ts73xx-fpga.c                    |   9 +-
>>>   drivers/fpga/xilinx-pr-decoupler.c            |  17 +-
>>>   drivers/fpga/xilinx-spi.c                     |  11 +-
>>>   drivers/fpga/zynq-fpga.c                      |  16 +-
>>>   drivers/fpga/zynqmp-fpga.c                    |   9 +-
>>>   include/linux/fpga/fpga-bridge.h              |  30 ++-
>>>   include/linux/fpga/fpga-mgr.h                 |  62 +++--
>>>   include/linux/fpga/fpga-region.h              |  36 ++-
>>>   30 files changed, 383 insertions(+), 511 deletions(-)
>>>
>