[PATCH] misc: atsha204a: Add support for atsha204 chip

[Stefan Roese]

On 4/5/22 15:28, Pali Rohár wrote:
> On Tuesday 05 April 2022 15:14:52 Stefan Roese wrote:
>> On 4/5/22 14:49, Pali Rohár wrote:
>>> atsha204 chip is predecessor of atsha204a chip. Current U-Boot driver
>>> atsha204a-i2c.c can use both atsha204 and atsha204a chips because it does
>>> not call specific functions to just one of these chips.
>>>
>>> So just add compatible string for atsha204.
>>>
>>> Signed-off-by: Pali Rohár <pali at kernel.org>
>>> ---
>>>    drivers/misc/atsha204a-i2c.c | 1 +
>>>    1 file changed, 1 insertion(+)
>>>
>>> diff --git a/drivers/misc/atsha204a-i2c.c b/drivers/misc/atsha204a-i2c.c
>>> index 63fe541dade3..8b0055f99893 100644
>>> --- a/drivers/misc/atsha204a-i2c.c
>>> +++ b/drivers/misc/atsha204a-i2c.c
>>> @@ -399,6 +399,7 @@ static int atsha204a_of_to_plat(struct udevice *dev)
>>>    }
>>>    static const struct udevice_id atsha204a_ids[] = {
>>> +	{ .compatible = "atmel,atsha204" },
>>>    	{ .compatible = "atmel,atsha204a" },
>>>    	{ }
>>>    };
>>
>> Why do we need this new compatible here in the driver?
> 
> They are different chips,

Sure...

> so should have different compatible strings.

... but is this really necessary and "best practice"? If the driver
can handle both chips without any changes, why do you need the new
compatible here?

Don't get me wrong. I'm not blocking this change, just want to be sure
that it's really necessary.

Thanks,
Stefan

>> A quick grep
>> doesn't show this in any of the dts files, not in U-Boot and not in the
>> Kernel.
> 
> Not yet. I'm preparing patches for a board which has atsha204 and will
> use this u-boot driver.
> 
>> Just checking...
>>
>> Thanks,
>> Stefan