Re: [PATCH v3 1/3] i2c: core: add managed function for adding i2c adapters

[Yicong Yang <yangyicong@hisilicon.com>]

On 2021/3/23 0:45, Dmitry Osipenko wrote:
> 22.03.2021 14:10, Yicong Yang пишет:
>> Some I2C controller drivers will only unregister the I2C
>> adapter in their .remove() callback, which can be done
>> by simply using a managed variant to add the I2C adapter.
>>
>> So add the managed functions for adding the I2C adapter.
>>
>> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
>> ---
>>  drivers/i2c/i2c-core-base.c | 39 +++++++++++++++++++++++++++++++++++++++
>>  include/linux/i2c.h         |  1 +
>>  2 files changed, 40 insertions(+)
>>
>> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
>> index 63ebf72..61486dc 100644
>> --- a/drivers/i2c/i2c-core-base.c
>> +++ b/drivers/i2c/i2c-core-base.c
>> @@ -1550,6 +1550,38 @@ int i2c_add_adapter(struct i2c_adapter *adapter)
>>  }
>>  EXPORT_SYMBOL(i2c_add_adapter);
>>  
>> +static void devm_i2c_del_adapter(struct device *dev, void *ptr);
>> +
>> +/**
>> + * devm_i2c_add_adapter - device-managed variant of i2c_add_adapter()
>> + * @dev: managing device for adding this I2C adapter
>> + * @adapter: the adapter to add
>> + * Context: can sleep
>> + *
>> + * Add adapter with dynamic bus number, same with i2c_add_adapter()
>> + * but the adapter will be auto deleted on driver detach.
>> + */
>> +int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter)
>> +{
>> +	struct i2c_adapter **ptr;
>> +	int ret;
>> +
>> +	ptr = devres_alloc(devm_i2c_del_adapter, sizeof(*ptr), GFP_KERNEL);
>> +	if (!ptr)
>> +		return -ENOMEM;
>> +
>> +	ret = i2c_add_adapter(adapter);
>> +	if (!ret) {
>> +		*ptr = adapter;
>> +		devres_add(dev, ptr);
>> +	} else {
>> +		devres_free(ptr);
>> +	}
> 
> This could be simplified using devm_add_action_or_reset().

thanks for the hint. i'll see whether i can change to that.

> 
>> +	return ret;
>> +}
>> +EXPORT_SYMBOL(devm_i2c_add_adapter);
> 
> EXPORT_SYMBOL_GPL

considering i2c_add_adapter exported with no GPL, i think the variant should
keep the same.

Thanks,
Yicong

> 
> .
>