Re: [PATCH 1/6] phy: Add max_bitrate attribute & phy_get_max_bitrate()

From: Faiz Abbas
Date: Mon Nov 05 2018 - 06:11:54 EST


Hi,

On Monday 05 November 2018 03:07 PM, Marc Kleine-Budde wrote:
> On 11/05/2018 07:27 AM, Faiz Abbas wrote:
>> I remove the transceiver child node binding documentation in patch 5/6.
>>
>> The existing implementation is pretty limiting as it just has a child
>> node with no associated device. What if a transceiver requires its own
>> configurations before it can start sending/receiving messages (for
>> example, my usecase requires it to pull the standby line low)?
>>
>> I think that can be solved by implementing the transceiver as a phy and
>> exposing a generic get_max_bitrate API. That way, the transceiver device
>> can do all its startup configuration in the phy probe function.
>>
>> In any case, do suggest if you have a better idea on how to implement
>> pull gpio low requirement.
>
> As long as we don't have any proper transceiver/phy driver, that does
> more than swtich on/off a GPIO, please add a "xceiver" regulator to your
> driver. Look for:
>
>> devm_regulator_get(&pdev->dev, "xceiver");
>

The transceiver is not specific to m_can. The pull down would be
required even if it were connected to some other controller.

Thanks,
Faiz