Re: [PATCH v6 1/3] fpga: mgr: Use standard dev_release for class driver

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

On 6/22/21 12:32 AM, Xu Yilun wrote:
> Good to me overall, minor fixes see inline.
>
> On Mon, Jun 21, 2021 at 03:22:47PM -0700, Russ Weight wrote:
>> The FPGA manager class driver data structure is being treated as a
>> managed resource instead of using standard dev_release call-back
>> to release the class data structure. This change removes the
>> managed resource code for the freeing of the class data structure
>> and combines the create() and register() functions into a single
>> register() function.
>>
>> The devm_fpga_mgr_register() function is retained.
>>
>> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
>> ---
>> v6:
>>   - Moved FPGA manager optional parameters out of the ops structure and
>>     back into the FPGA manager structure.
>>   - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
>>     accept an info data structure to provide flexibility in passing optional
>>     parameters.
>>   - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
>>     functions to support current parameters for users that don't require
>>     the use of optional parameters.
> These description should be added to the commit message if the idea is
> to be accepted.
I'll update the commit messages for the next version.

>
>> 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.
>> 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.
>> v3:
>>   - Cleaned up comment header for fpga_mgr_register()
>>   - Fix error return on ida_simple_get() failure
>> v2:
>>   - Restored devm_fpga_mgr_register() functionality, 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.
>> ---
>>  drivers/fpga/altera-cvp.c        |  12 +-
>>  drivers/fpga/altera-pr-ip-core.c |   9 +-
>>  drivers/fpga/altera-ps-spi.c     |  10 +-
>>  drivers/fpga/dfl-fme-mgr.c       |  23 ++--
>>  drivers/fpga/fpga-mgr.c          | 212 +++++++++++++------------------
>>  drivers/fpga/ice40-spi.c         |  10 +-
>>  drivers/fpga/machxo2-spi.c       |  11 +-
>>  drivers/fpga/socfpga-a10.c       |  16 +--
>>  drivers/fpga/socfpga.c           |  10 +-
>>  drivers/fpga/stratix10-soc.c     |  16 +--
>>  drivers/fpga/ts73xx-fpga.c       |  10 +-
>>  drivers/fpga/xilinx-spi.c        |  12 +-
>>  drivers/fpga/zynq-fpga.c         |  16 +--
>>  drivers/fpga/zynqmp-fpga.c       |  10 +-
>>  include/linux/fpga/fpga-mgr.h    |  62 ++++++---
>>  15 files changed, 204 insertions(+), 235 deletions(-)
>>
>> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
>> index ccf4546eff29..ddf2ffe3f138 100644
>> --- a/drivers/fpga/altera-cvp.c
>> +++ b/drivers/fpga/altera-cvp.c
>> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
>>  	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
>>  		 ALTERA_CVP_MGR_NAME, pci_name(pdev));
>>  
>> -	mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
>> -				   &altera_cvp_ops, conf);
>> -	if (!mgr) {
>> -		ret = -ENOMEM;
>> +	mgr = fpga_mgr_register_simple(&pdev->dev, conf->mgr_name,
>> +				       &altera_cvp_ops, conf);
>> +	if (IS_ERR(mgr)) {
>> +		ret = PTR_ERR(mgr);
>>  		goto err_unmap;
>>  	}
>>  
>>  	pci_set_drvdata(pdev, mgr);
>>  
>> -	ret = fpga_mgr_register(mgr);
>> -	if (ret)
>> -		goto err_unmap;
>> -
>>  	return 0;
>>  
>>  err_unmap:
>> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
>> index dfdf21ed34c4..fa3e2697d285 100644
>> --- a/drivers/fpga/altera-pr-ip-core.c
>> +++ b/drivers/fpga/altera-pr-ip-core.c
>> @@ -191,11 +191,12 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
>>  		(val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
>>  		(int)(val & ALT_PR_CSR_PR_START));
>>  
>> -	mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> +	mgr = devm_fpga_mgr_register_simple(dev, dev_name(dev),
>> +					    &alt_pr_ops, priv);
>> +	if (IS_ERR(mgr))
>> +		return PTR_ERR(mgr);
>>  
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	return 0;
> I just remember there is a macro PTR_ERR_OR_ZERO() for this, or lkp robot
> will make the suggestion.
Sure - I'll use PTR_ERR_OR_ZERO() where I can

>
>>  }
>>  EXPORT_SYMBOL_GPL(alt_pr_register);
>>  
>> diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
>> index 23bfd4d1ad0f..990689cf8d67 100644
>> --- a/drivers/fpga/altera-ps-spi.c
>> +++ b/drivers/fpga/altera-ps-spi.c
>> @@ -302,12 +302,12 @@ static int altera_ps_probe(struct spi_device *spi)
>>  	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
>>  		 dev_driver_string(&spi->dev), dev_name(&spi->dev));
>>  
>> -	mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
>> -				   &altera_ps_ops, conf);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> +	mgr = devm_fpga_mgr_register_simple(&spi->dev, conf->mgr_name,
>> +					    &altera_ps_ops, conf);
>> +	if (IS_ERR(mgr))
>> +		return PTR_ERR(mgr);
>>  
>> -	return devm_fpga_mgr_register(&spi->dev, mgr);
>> +	return 0;
> PTR_ERR_OR_ZERO()
>
>>  }
>>  
>>  static const struct spi_device_id altera_ps_spi_ids[] = {
>> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
>> index d5861d13b306..36add746ac42 100644
>> --- a/drivers/fpga/dfl-fme-mgr.c
>> +++ b/drivers/fpga/dfl-fme-mgr.c
>> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
>>  static int fme_mgr_probe(struct platform_device *pdev)
>>  {
>>  	struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
>> -	struct fpga_compat_id *compat_id;
>> +	struct fpga_manager_info info = { 0 };
>>  	struct device *dev = &pdev->dev;
>>  	struct fme_mgr_priv *priv;
>>  	struct fpga_manager *mgr;
>> @@ -302,20 +302,19 @@ static int fme_mgr_probe(struct platform_device *pdev)
>>  			return PTR_ERR(priv->ioaddr);
>>  	}
>>  
>> -	compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
>> -	if (!compat_id)
>> +	info.name = "DFL FME FPGA Manager";
>> +	info.mops = &fme_mgr_ops;
>> +	info.priv = priv;
>> +	info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
>> +	if (!info.compat_id)
>>  		return -ENOMEM;
>>  
>> -	fme_mgr_get_compat_id(priv->ioaddr, compat_id);
>> +	fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
>> +	mgr = devm_fpga_mgr_register(dev, &info);
>> +	if (IS_ERR(mgr))
>> +		return PTR_ERR(mgr);
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
>> -				   &fme_mgr_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	mgr->compat_id = compat_id;
>> -
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	return 0;
> PTR_ERR_OR_ZERO()
>
>>  }
>>  
>>  static struct platform_driver fme_mgr_driver = {
>> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
>> index ecb4c3c795fa..fa2f1a95de82 100644
>> --- a/drivers/fpga/fpga-mgr.c
>> +++ b/drivers/fpga/fpga-mgr.c
>> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
>>  EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
>>  
>>  /**
>> - * fpga_mgr_create - create and initialize an FPGA manager struct
>> + * fpga_mgr_register - create and register an FPGA Manager device
>>   * @parent:	fpga manager device from pdev
>> - * @name:	fpga manager name
>> - * @mops:	pointer to structure of fpga manager ops
>> - * @priv:	fpga manager private data
>> + * @info:	parameters for fpga manager
>>   *
>> - * The caller of this function is responsible for freeing the struct with
>> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>> + * Using devm_fpga_mgr_register instead is recommended.
>             devm_fpga_mgr_register()
I'll look though the comment headers and make sure I'm using the ()'s consistently.

>
>>   *
>> - * Return: pointer to struct fpga_manager or NULL
>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>   */
>> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>> -				     const struct fpga_manager_ops *mops,
>> -				     void *priv)
>> +struct fpga_manager *
>> +fpga_mgr_register(struct device *parent, struct fpga_manager_info *info)
> 				      const struct fpga_manager_info *info
Sure - I'll change the function prototypes and definitions to use const.

>
>>  {
>> +	const struct fpga_manager_ops *mops = info->mops;
>>  	struct fpga_manager *mgr;
>>  	int id, ret;
>>  
>> @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>  	    !mops->write_init || (!mops->write && !mops->write_sg) ||
>>  	    (mops->write && mops->write_sg)) {
>>  		dev_err(parent, "Attempt to register without fpga_manager_ops\n");
>> -		return NULL;
>> +		return ERR_PTR(-EINVAL);
>>  	}
>>  
>> -	if (!name || !strlen(name)) {
>> +	if (!info->name || !strlen(info->name)) {
>>  		dev_err(parent, "Attempt to register with no name!\n");
>> -		return NULL;
>> +		return ERR_PTR(-EINVAL);
>>  	}
>>  
>>  	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
>>  	if (!mgr)
>> -		return NULL;
>> +		return ERR_PTR(-ENOMEM);
>>  
>>  	id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
>> -	if (id < 0)
>> +	if (id < 0) {
>> +		ret = id;
>>  		goto error_kfree;
>> +	}
>>  
>>  	mutex_init(&mgr->ref_mutex);
>>  
>> -	mgr->name = name;
>> -	mgr->mops = mops;
>> -	mgr->priv = priv;
>> +	mgr->name = info->name;
>> +	mgr->mops = info->mops;
>> +	mgr->priv = info->priv;
>> +	mgr->compat_id = info->compat_id;
>>  
>> -	device_initialize(&mgr->dev);
>>  	mgr->dev.class = fpga_mgr_class;
>>  	mgr->dev.groups = mops->groups;
>>  	mgr->dev.parent = parent;
>> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>  	if (ret)
>>  		goto error_device;
>>  
>> +	/*
>> +	 * Initialize framework state by requesting low level driver read state
>> +	 * from device.  FPGA may be in reset mode or may have been programmed
>> +	 * by bootloader or EEPROM.
>> +	 */
>> +	mgr->state = mgr->mops->state(mgr);
>> +
>> +	ret = device_register(&mgr->dev);
>> +	if (ret) {
>> +		put_device(&mgr->dev);
>> +		return ERR_PTR(ret);
>> +	}
>> +
>>  	return mgr;
>>  
>>  error_device:
>> @@ -612,98 +625,38 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>  error_kfree:
>>  	kfree(mgr);
>>  
>> -	return NULL;
>> -}
>> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
>> -
>> -/**
>> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
>> - * @mgr:	fpga manager struct
>> - */
>> -void fpga_mgr_free(struct fpga_manager *mgr)
>> -{
>> -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>> -	kfree(mgr);
>> -}
>> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
>> -
>> -static void devm_fpga_mgr_release(struct device *dev, void *res)
>> -{
>> -	struct fpga_mgr_devres *dr = res;
>> -
>> -	fpga_mgr_free(dr->mgr);
>> +	return ERR_PTR(ret);
>>  }
>> +EXPORT_SYMBOL_GPL(fpga_mgr_register);
>>  
>>  /**
>> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
>> + * fpga_mgr_register_simple - create and register an FPGA Manager device
>>   * @parent:	fpga manager device from pdev
>>   * @name:	fpga manager name
>>   * @mops:	pointer to structure of fpga manager ops
>>   * @priv:	fpga manager private data
>>   *
>> - * This function is intended for use in an FPGA manager driver's probe function.
>> - * After the manager driver creates the manager struct with
>> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
>> - * manager driver's remove function should call fpga_mgr_unregister().  The
>> - * manager struct allocated with this function will be freed automatically on
>> - * driver detach.  This includes the case of a probe function returning error
>> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
>> - *
>> - * Return: pointer to struct fpga_manager or NULL
>> - */
>> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
>> -					  const struct fpga_manager_ops *mops,
>> -					  void *priv)
>> -{
>> -	struct fpga_mgr_devres *dr;
>> -
>> -	dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
>> -	if (!dr)
>> -		return NULL;
>> -
>> -	dr->mgr = fpga_mgr_create(parent, name, mops, priv);
>> -	if (!dr->mgr) {
>> -		devres_free(dr);
>> -		return NULL;
>> -	}
>> -
>> -	devres_add(parent, dr);
>> -
>> -	return dr->mgr;
>> -}
>> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
>> -
>> -/**
>> - * fpga_mgr_register - register an FPGA manager
>> - * @mgr: fpga manager struct
>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>> + * Using devm_fpga_mgr_register_simple instead is recommended. This simple
>             devm_fpga_mgr_register_simple()
>
>> + * version of the register function should be sufficient for most users. The
>> + * fpga_mgr_register function is available for users that need to pass
>> + * additional, optional parameters.
>>   *
>> - * Return: 0 on success, negative error code otherwise.
>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>   */
>> -int fpga_mgr_register(struct fpga_manager *mgr)
>> +struct fpga_manager *
>> +fpga_mgr_register_simple(struct device *parent, const char *name,
>> +			 const struct fpga_manager_ops *mops, void *priv)
>>  {
>> -	int ret;
>> +	struct fpga_manager_info info = { 0 };
>>  
>> -	/*
>> -	 * Initialize framework state by requesting low level driver read state
>> -	 * from device.  FPGA may be in reset mode or may have been programmed
>> -	 * by bootloader or EEPROM.
>> -	 */
>> -	mgr->state = mgr->mops->state(mgr);
>> +	info.name = name;
>> +	info.mops = mops;
>> +	info.priv = priv;
>>  
>> -	ret = device_add(&mgr->dev);
>> -	if (ret)
>> -		goto error_device;
>> -
>> -	dev_info(&mgr->dev, "%s registered\n", mgr->name);
>> -
>> -	return 0;
>> -
>> -error_device:
>> -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>> -
>> -	return ret;
>> +	return fpga_mgr_register(parent, &info);
>>  }
>> -EXPORT_SYMBOL_GPL(fpga_mgr_register);
>> +EXPORT_SYMBOL_GPL(fpga_mgr_register_simple);
>>  
>>  /**
>>   * fpga_mgr_unregister - unregister an FPGA manager
>> @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
>>  }
>>  EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
>>  
>> -static int fpga_mgr_devres_match(struct device *dev, void *res,
>> -				 void *match_data)
>> -{
>> -	struct fpga_mgr_devres *dr = res;
>> -
>> -	return match_data == dr->mgr;
>> -}
>> -
>>  static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>  {
>>  	struct fpga_mgr_devres *dr = res;
>> @@ -743,44 +688,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>  
>>  /**
>>   * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>> - * @dev: managing device for this FPGA manager
>> - * @mgr: fpga manager struct
>> + * @parent:	fpga manager device from pdev
>> + * @info:	parameters for fpga manager
>>   *
>>   * This is the devres variant of fpga_mgr_register() for which the unregister
>>   * function will be called automatically when the managing device is detached.
>>   */
>> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
>> +struct fpga_manager *
>> +devm_fpga_mgr_register(struct device *dev, struct fpga_manager_info *info)
> 					const struct fpga_manager_info
>
>>  {
>>  	struct fpga_mgr_devres *dr;
>> -	int ret;
>> -
>> -	/*
>> -	 * Make sure that the struct fpga_manager * that is passed in is
>> -	 * managed itself.
>> -	 */
>> -	if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
>> -				 fpga_mgr_devres_match, mgr)))
>> -		return -EINVAL;
>> +	struct fpga_manager *mgr;
>>  
>>  	dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
>>  	if (!dr)
>> -		return -ENOMEM;
>> +		return ERR_PTR(-ENOMEM);
>>  
>> -	ret = fpga_mgr_register(mgr);
>> -	if (ret) {
>> +	mgr = fpga_mgr_register(dev, info);
>> +	if (IS_ERR(mgr)) {
>>  		devres_free(dr);
>> -		return ret;
>> +		return mgr;
>>  	}
>>  
>>  	dr->mgr = mgr;
>>  	devres_add(dev, dr);
>>  
>> -	return 0;
>> +	return mgr;
>>  }
>>  EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
>>  
>> +/**
>> + * devm_fpga_mgr_register_simple - resource managed variant of
>> + *				   fpga_mgr_register_simple()
>> + * @dev:	fpga manager device from pdev
>       @parent:

Thanks - I'll fix that.

- Russ

>
>> + * @name:	fpga manager name
>> + * @mops:	pointer to structure of fpga manager ops
>> + * @priv:	fpga manager private data
>> + *
>> + * This is the devres variant of fpga_mgr_register_simple() for which the
>> + * unregister function will be called automatically when the managing
>> + * device is detached.
>> + */
>> +struct fpga_manager *
>> +devm_fpga_mgr_register_simple(struct device *parent, const char *name,
>> +			      const struct fpga_manager_ops *mops, void *priv)
>> +{
>> +	struct fpga_manager_info info = { 0 };
>> +
>> +	info.name = name;
>> +	info.mops = mops;
>> +	info.priv = priv;
>> +
>> +	return devm_fpga_mgr_register(parent, &info);
>> +}
>> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_simple);
>> +
>>  static void fpga_mgr_dev_release(struct device *dev)
>>  {
>> +	struct fpga_manager *mgr = to_fpga_manager(dev);
>> +
>> +	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>> +	kfree(mgr);
>>  }
>>  
>>  static int __init fpga_mgr_class_init(void)
>> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
>> index 69dec5af23c3..498f05cf425d 100644
>> --- a/drivers/fpga/ice40-spi.c
>> +++ b/drivers/fpga/ice40-spi.c
>> @@ -178,12 +178,12 @@ static int ice40_fpga_probe(struct spi_device *spi)
>>  		return ret;
>>  	}
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
>> -				   &ice40_fpga_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> +	mgr = devm_fpga_mgr_register_simple(dev, "Lattice iCE40 FPGA Manager",
>> +					    &ice40_fpga_ops, priv);
>> +	if (IS_ERR(mgr))
>> +		return PTR_ERR(mgr);
>>  
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	return 0;
> PTR_ERR_OR_ZERO()
>
>>  }
>>  
>>  static const struct of_device_id ice40_fpga_of_match[] = {
>> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
>> index 114a64d2b7a4..f0a15b724b87 100644
>> --- a/drivers/fpga/machxo2-spi.c
>> +++ b/drivers/fpga/machxo2-spi.c
>> @@ -366,12 +366,13 @@ static int machxo2_spi_probe(struct spi_device *spi)
>>  		return -EINVAL;
>>  	}
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
>> -				   &machxo2_ops, spi);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> +	mgr = devm_fpga_mgr_register_simple(dev,
>> +					    "Lattice MachXO2 SPI FPGA Manager",
>> +					    &machxo2_ops, spi);
>> +	if (IS_ERR(mgr))
>> +		return PTR_ERR(mgr);
>>  
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	return 0;
> PTR_ERR_OR_ZERO()
>
>>  }
>>  
>>  static const struct of_device_id of_match[] = {
>> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
>> index 573d88bdf730..5ffefaa3eb07 100644
>> --- a/drivers/fpga/socfpga-a10.c
>> +++ b/drivers/fpga/socfpga-a10.c
>> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
>>  		return -EBUSY;
>>  	}
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
>> -				   &socfpga_a10_fpga_mgr_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	platform_set_drvdata(pdev, mgr);
>> -
>> -	ret = fpga_mgr_register(mgr);
>> -	if (ret) {
>> +	mgr = fpga_mgr_register_simple(dev, "SoCFPGA Arria10 FPGA Manager",
>> +				       &socfpga_a10_fpga_mgr_ops, priv);
>> +	if (IS_ERR(mgr)) {
>>  		clk_disable_unprepare(priv->clk);
>> -		return ret;
>> +		return PTR_ERR(mgr);
>>  	}
>>  
>> +	platform_set_drvdata(pdev, mgr);
>> +
>>  	return 0;
>>  }
>>  
>> diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
>> index 1f467173fc1f..9b4ca0ad7466 100644
>> --- a/drivers/fpga/socfpga.c
>> +++ b/drivers/fpga/socfpga.c
>> @@ -571,12 +571,12 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
>>  	if (ret)
>>  		return ret;
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>> -				   &socfpga_fpga_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> +	mgr = devm_fpga_mgr_register_simple(dev, "Altera SOCFPGA FPGA Manager",
>> +					    &socfpga_fpga_ops, priv);
>> +	if (IS_ERR(mgr))
>> +		return PTR_ERR(mgr);
>>  
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	return 0;
> PTR_ERR_OR_ZERO()
>
>>  }
>>  
>>  #ifdef CONFIG_OF
>> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
>> index a2cea500f7cc..fb84d88d4ce9 100644
>> --- a/drivers/fpga/stratix10-soc.c
>> +++ b/drivers/fpga/stratix10-soc.c
>> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
>>  
>>  	init_completion(&priv->status_return_completion);
>>  
>> -	mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
>> -			      &s10_ops, priv);
>> -	if (!mgr) {
>> -		dev_err(dev, "unable to create FPGA manager\n");
>> -		ret = -ENOMEM;
>> -		goto probe_err;
>> -	}
>> -
>> -	ret = fpga_mgr_register(mgr);
>> -	if (ret) {
>> +	mgr = fpga_mgr_register_simple(dev, "Stratix10 SOC FPGA Manager",
>> +				       &s10_ops, priv);
>> +	if (IS_ERR(mgr)) {
>>  		dev_err(dev, "unable to register FPGA manager\n");
>> -		fpga_mgr_free(mgr);
>> +		ret = PTR_ERR(mgr);
>>  		goto probe_err;
>>  	}
>>  
>> @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
>>  	struct s10_priv *priv = mgr->priv;
>>  
>>  	fpga_mgr_unregister(mgr);
>> -	fpga_mgr_free(mgr);
>>  	stratix10_svc_free_channel(priv->chan);
>>  
>>  	return 0;
>> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
>> index 101f016c6ed8..2e11eea095ce 100644
>> --- a/drivers/fpga/ts73xx-fpga.c
>> +++ b/drivers/fpga/ts73xx-fpga.c
>> @@ -122,12 +122,12 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
>>  	if (IS_ERR(priv->io_base))
>>  		return PTR_ERR(priv->io_base);
>>  
>> -	mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
>> -				   &ts73xx_fpga_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> +	mgr = devm_fpga_mgr_register_simple(kdev, "TS-73xx FPGA Manager",
>> +					    &ts73xx_fpga_ops, priv);
>> +	if (IS_ERR(mgr))
>> +		return PTR_ERR(mgr);
>>  
>> -	return devm_fpga_mgr_register(kdev, mgr);
>> +	return 0;
> PTR_ERR_OR_ZERO()
>
>>  }
>>  
>>  static struct platform_driver ts73xx_fpga_driver = {
>> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
>> index fee4d0abf6bf..e78b82f9db79 100644
>> --- a/drivers/fpga/xilinx-spi.c
>> +++ b/drivers/fpga/xilinx-spi.c
>> @@ -247,13 +247,13 @@ static int xilinx_spi_probe(struct spi_device *spi)
>>  		return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
>>  				     "Failed to get DONE gpio\n");
>>  
>> -	mgr = devm_fpga_mgr_create(&spi->dev,
>> -				   "Xilinx Slave Serial FPGA Manager",
>> -				   &xilinx_spi_ops, conf);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> +	mgr = devm_fpga_mgr_register_simple(&spi->dev,
>> +					    "Xilinx Slave Serial FPGA Manager",
>> +					    &xilinx_spi_ops, conf);
>> +	if (IS_ERR(mgr))
>> +		return PTR_ERR(mgr);
>>  
>> -	return devm_fpga_mgr_register(&spi->dev, mgr);
>> +	return 0;
>>  }
> PTR_ERR_OR_ZERO()
>
>>  
>>  static const struct of_device_id xlnx_spi_of_match[] = {
>> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
>> index 9b75bd4f93d8..a3de365aadc6 100644
>> --- a/drivers/fpga/zynq-fpga.c
>> +++ b/drivers/fpga/zynq-fpga.c
>> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
>>  
>>  	clk_disable(priv->clk);
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
>> -				   &zynq_fpga_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	platform_set_drvdata(pdev, mgr);
>> -
>> -	err = fpga_mgr_register(mgr);
>> -	if (err) {
>> +	mgr = fpga_mgr_register_simple(dev, "Xilinx Zynq FPGA Manager",
>> +				       &zynq_fpga_ops, priv);
>> +	if (IS_ERR(mgr)) {
>>  		dev_err(dev, "unable to register FPGA manager\n");
>>  		clk_unprepare(priv->clk);
>> -		return err;
>> +		return PTR_ERR(mgr);
>>  	}
>>  
>> +	platform_set_drvdata(pdev, mgr);
>> +
>>  	return 0;
>>  }
>>  
>> diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
>> index 125743c9797f..d743a05cba95 100644
>> --- a/drivers/fpga/zynqmp-fpga.c
>> +++ b/drivers/fpga/zynqmp-fpga.c
>> @@ -102,12 +102,12 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
>>  
>>  	priv->dev = dev;
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
>> -				   &zynqmp_fpga_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> +	mgr = devm_fpga_mgr_register_simple(dev, "Xilinx ZynqMP FPGA Manager",
>> +					    &zynqmp_fpga_ops, priv);
>> +	if (IS_ERR(mgr))
>> +		return PTR_ERR(mgr);
>>  
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	return 0;
> PTR_ERR_OR_ZERO()
>
>>  }
>>  
>>  static const struct of_device_id zynqmp_fpga_of_match[] = {
>> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
>> index 474c1f506307..a814407bc588 100644
>> --- a/include/linux/fpga/fpga-mgr.h
>> +++ b/include/linux/fpga/fpga-mgr.h
>> @@ -105,6 +105,36 @@ struct fpga_image_info {
>>  #endif
>>  };
>>  
>> +/**
>> + * struct fpga_compat_id - id for compatibility check
>> + *
>> + * @id_h: high 64bit of the compat_id
>> + * @id_l: low 64bit of the compat_id
>> + */
>> +struct fpga_compat_id {
>> +	u64 id_h;
>> +	u64 id_l;
>> +};
>> +
>> +/**
>> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
>> + * @name: fpga manager name
>> + * @compat_id: FPGA manager id for compatibility check.
>> + * @mops: pointer to structure of fpga manager ops
>> + * @priv: fpga manager private data
>> + *
>> + * fpga_manager_info contains parameters for the register function. These
>> + * are separated into an info structure because they some are optional
>> + * others could be added to in the future. The info structure facilitates
>> + * maintaining a stable API.
>> + */
>> +struct fpga_manager_info {
>> +	const char *name;
>> +	struct fpga_compat_id *compat_id;
>> +	const struct fpga_manager_ops *mops;
>> +	void *priv;
>> +};
>> +
>>  /**
>>   * struct fpga_manager_ops - ops for low level fpga manager drivers
>>   * @initial_header_size: Maximum number of bytes that should be passed into write_init
>> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
>>  #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR		BIT(3)
>>  #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR	BIT(4)
>>  
>> -/**
>> - * struct fpga_compat_id - id for compatibility check
>> - *
>> - * @id_h: high 64bit of the compat_id
>> - * @id_l: low 64bit of the compat_id
>> - */
>> -struct fpga_compat_id {
>> -	u64 id_h;
>> -	u64 id_l;
>> -};
>> -
>>  /**
>>   * struct fpga_manager - fpga manager structure
>>   * @name: name of low level fpga manager
>> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
>>  
>>  void fpga_mgr_put(struct fpga_manager *mgr);
>>  
>> -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
>> -				     const struct fpga_manager_ops *mops,
>> -				     void *priv);
>> -void fpga_mgr_free(struct fpga_manager *mgr);
>> -int fpga_mgr_register(struct fpga_manager *mgr);
>> -void fpga_mgr_unregister(struct fpga_manager *mgr);
>> +struct fpga_manager *
>> +fpga_mgr_register(struct device *dev, struct fpga_manager_info *info);
> 				   const struct fpga_manager_info 
>
>>  
>> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
>> +struct fpga_manager *
>> +fpga_mgr_register_simple(struct device *dev, const char *name,
>> +			 const struct fpga_manager_ops *mops, void *priv);
>> +void fpga_mgr_unregister(struct fpga_manager *mgr);
>>  
>> -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
>> -					  const struct fpga_manager_ops *mops,
>> -					  void *priv);
>> +struct fpga_manager *
>> +devm_fpga_mgr_register(struct device *dev, struct fpga_manager_info *info);
> 				   	const struct fpga_manager_info 
>
>> +struct fpga_manager *
>> +devm_fpga_mgr_register_simple(struct device *dev, const char *name,
>> +			      const struct fpga_manager_ops *mops, void *priv);
>>  
>>  #endif /*_LINUX_FPGA_MGR_H */
>> -- 
>> 2.25.1