[PATCH 10/16] serial: sh: Add RZ/G2L SCIF support

[Marek Vasut]

On 10/5/23 18:18, Paul Barker wrote:
> On 04/10/2023 13:26, Marek Vasut wrote:
>> On 10/4/23 10:48, Paul Barker wrote:
>>> On 03/10/2023 14:23, Marek Vasut wrote:
>>>> On 9/20/23 14:42, Paul Barker wrote:
>>>>> +	if (IS_ENABLED(CONFIG_RZG2L)) {
>>>>> +		struct reset_ctl rst;
>>>>> +		int ret;
>>>>> +
>>>>> +		ret = reset_get_by_index(dev, 0, &rst);
>>>>> +		if (ret < 0) {
>>>>> +			dev_err(dev, "failed to get reset line\n");
>>>>> +			return ret;
>>>>> +		}
>>>>> +
>>>>> +		ret = reset_deassert(&rst);
>>>>> +		if (ret < 0) {
>>>>> +			dev_err(dev, "failed to de-assert reset line\n");
>>>>> +			return ret;
>>>>> +		}
>>>>> +	}
>>>>
>>>> devm_reset_control_get_optional() or something should do here too , right ?
>>>>
>>>> Note that R-Car does have SCIF reset too, so this can be generic code.
>>>
>>> For R-Car systems the current behaviour is working and well tested, we
>>> concluded that we shouldn't change it so this reset de-assert was made
>>> RZ/G2L specific.
>>
>> I can test on R-Car just fine, no worries.
>>
>> SH R2Dplus is even tested in CI nightly.
>>
>>> For RZ/G2L, de-asserting the reset is not optional.
>>
>> Let's avoid special-cases like that.
> 
> Looking at this again, I don't see how we can avoid a special case here,
> de-asserting the reset is required for the RZ/G2L. It may be optional on
> other SoCs (I don't know), but it's definitely not optional here, so I
> don't think we should be using the devm_reset_control_get_optional()
> function.

I'd say let's just unconditionally assume reset is needed for all 
platforms. That should work, right ?