[PATCH v14 06/15] clk: Add Lynx 10G SerDes PLL driver

Sean Anderson sean.anderson at seco.com
Tue May 9 08:26:12 PDT 2023


On 5/9/23 09:00, Vinod Koul wrote:
> On 08-05-23, 11:31, Sean Anderson wrote:
>> On 5/8/23 05:15, Vinod Koul wrote:
> 
>> >> +int lynx_clks_init(struct device *dev, struct regmap *regmap,
>> >> +		   struct clk *plls[2], struct clk *ex_dlys[2], bool compat);
>> > 
>> > so you have an exported symbol for clk driver init in phy driver header?
>> > can you please explain why..?
>> 
>> So that it can be called at the appropriate time during the phy's probe function.
>> 
>> This is really an integral part of the phy driver, but I was directed to split it
>> off and put it in another subsystem's directory.
> 
> That is right clock should be belong to clk driver. IIUC the hardware is
> phy along with clocks and you are doing the clk init. I think that may
> not be correct model, you should really have a device tree node to
> represent the clock and the phy node
> 
> 
> What stops this from being modelled as it is in the hardware?

It *is* modeled as it is in hardware. With just the serdes compatible,
we have all the information we need to create the clocks. So we do so.
There's no need for a separate device just to create four clocks.

These clocks cannot be used by any other device (except possibly by
putting a lane into test mode). So there is no benefit from making them
a separate device, except an increase in complexity due to ordering and
dynamic lookup. By doing things this way we know that either there was
an error or the clocks all exist, and the lifetime of the clocks matches
the serdes.

--Sean



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