Re: [PATCH v2 4/6] dt-bindings: soc/fsl: qe: document new fsl,qe-snums binding

On 01/05/2019 17.12, Joakim Tjernlund wrote:

On Wed, 2019-05-01 at 09:29 +0000, Rasmus Villemoes wrote:

quoted

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Reading table 4-30, and its footnotes, of the QUICC Engine Block
Reference Manual shows that the set of snum _values_ is not
necessarily just a function of the _number_ of snums, as given in the
fsl,qe-num-snums property.

As an alternative, to make it easier to add support for other variants
of the QUICC engine IP, this introduces a new binding fsl,qe-snums,
which automatically encodes both the number of snums and the actual
values to use.

For example, for the MPC8309, one would specify the property as

               fsl,qe-snums = /bits/ 8 <
                       0x88 0x89 0x98 0x99 0xa8 0xa9 0xb8 0xb9
                       0xc8 0xc9 0xd8 0xd9 0xe8 0xe9>;

I think you need add this example to the qe.txt doc itselft.

Sure, can do.

BTW, what is /bits/ ?

That indicates that the numbers should be stored as an array of u8, and
not as by default an array of (big-endian) 32-bit numbers. See

https://git.kernel.org/pub/scm/utils/dtc/dtc.git/tree/Documentation/dts-format.txt#n46

This is already used in some bindings and existing .dts (e.g.
hwmon/aspeed-pwm-tacho.txt, but git grep shows many more).

Rasmus