On Mon, Jul 30, 2018 at 06:01:54PM +0800, Yangbo Lu wrote:

The ptp_qoriq driver initialized the 1588 timer with the
configurations provided by the properties of device tree
node. For example,

  fsl,tclk-period = <5>;
  fsl,tmr-prsc    = <2>;
  fsl,tmr-add     = <0xaaaaaaab>;
  fsl,tmr-fiper1  = <999999995>;
  fsl,tmr-fiper2  = <99990>;
  fsl,max-adj     = <499999999>;

These things actually were runtime configurations which
were not proper to be put into dts.

That is debatable.  While I agree that the dts isn't ideal for these,
still it is the lesser of two or more evils.

This patch is to convert
to use module parameters for 1588 timer initialization, and
to support initial register values calculation.

It is hard for me to understand how using module parameters improves
the situation.

If the parameters are not provided, the driver will calculate
register values with a set of default parameters. With this
patch, those dts properties are no longer needed for new
platform to support 1588 timer, and many QorIQ DPAA platforms
(some P series and T series platforms of PowerPC, and some
LS series platforms of ARM64) could use this driver for their
fman ptp timer with default module parameters. However, this
patch didn't remove the dts method. Because there were still
many old platforms using the dts method. We need to clean up
their dts files, verify module parameters on them, and convert
them to the new method gradually in case of breaking any
function.

In addition, like it or not, because the dts is an ABI, you must
continue support of the dts values as a legacy option.

Thanks,
Richard