On 13/08/2018 16:37:48-0600, Rob Herring wrote:

quoted

I'm fine with a define for the second value (which is basically the enum
serdes_type I've defined at the beginning of the serdes driver) but I
don't see the point of defining the index of the SerDes. What would it
look like?

enum serdes_type {
	SERDES1G = 1,
	SERDES6G = 6,
}

#define SERDES1G_0	0
#define SERDES1G_1	1
#define SERDES1G_2	2
#define SERDES6G_0	0
#define SERDES6G_1	1

Then, e.g.:

&port5 {
	phys = <&serdes 5 SERDES1G SERDES1G_0>
};

If you want a define for the pair (serdes_type, serdes_index), I don't
see how I could re-use it on the driver side but it makes more sense on the
DeviceTree side:

#define SERDES1G_0	1 0
#define SERDES1G_1	1 1
#define SERDES1G_2	1 2
#define SERDES6G_0	6 0
#define SERDES6G_1	6 1

I prefer #defines which are a single number. Otherwise if you read a dts 
file when #phy-cells is 3, it will look like an error in that you have 
what looks like 2 cells.

Maybe we should not have the type in DT and simply have an index. The
driver will now what the serdes type is anyway and the defines would be:

#define SERDES1G_0  0
#define SERDES1G_1  1
#define SERDES1G_2  2
#define SERDES6G_0  3
#define SERDES6G_1  4

The main drawback is that this requires one include file per soc.

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com