Re: [PATCH v1 1/2] dt-binding: ptp: add bindings document for dte based ptp clock

From: Arun Parameswaran
Date: Wed Jun 14 2017 - 14:39:13 EST




On 17-06-14 11:18 AM, Ray Jui wrote:
>
>
> On 6/13/17 10:46 AM, Arun Parameswaran wrote:
>>
>> Hi Richard,
>>
>> On 17-06-12 10:09 PM, Richard Cochran wrote:
>>> On Mon, Jun 12, 2017 at 01:26:00PM -0700, Arun Parameswaran wrote:
>>>> +Example:
>>>> +
>>>> +ptp_dte: ptp_dte@180af650 {
>>>> + compatible = "brcm,ptp-dte";
>>>> + reg = <0x180af650 0x10>;
>>>> + status = "okay";
>>>> +};
>>> This patch set looks okay, as far as it goes, but how does one
>>> actually use the clock?
>>>
>>> How does one connect this node to an Ethernet MAC, for example?
>> In some of the SoC's, the DTE's NCO is synced in hardware with the Ethernet's
>> 1588 Shim NCO (used for time-stamping the packets). We are working on getting
>> all the future SoC's synced this way (for Ethernet).
>>
>
> So apparently you do not need any phandle based DT binding defined for
> the connection between the Ethernet device node and the PTP device node?
>
Correct. This driver doesn't need any phandle.

The Ethernet driver, in SoC's where the hardware link is not available,
might need the phandle to this driver.

>> In other scenarios, we use an user-space app to perform the sync based on
>> time-stamps from external hardware sources like the Wi-Fi.
>>> Thanks,
>>> Richard
>>