Quoting Joel Stanley (2019-08-18 19:03:54)

On Fri, 16 Aug 2019 at 17:14, Stephen Boyd [off-list ref] wrote:

quoted

Quoting Joel Stanley (2019-08-16 08:58:06)

quoted

+static const char * const vclk_parent_names[] = {

Can you use the new way of specifying clk parents instead of just using
strings?

How does this work? I had a browse of the APIs in clk-provider.h and
it appeared the functions all take char *s still.

Sorry I didn't reply earlier. I'm going to write a kernel-doc to
describe how to write a "modern" clk driver which should hopefully help
here.

The gist is that you can fill out a clk_parent_data array or a clk_hw
array and set the .name and .fw_name and .index in the clk_parent_data
array to indicate which clks to get from the DT node's "clocks" and
"clock-names" properties.

quoted

quoted

+       hw = clk_hw_register_fixed_factor(NULL, "ahb", "hpll", 0, 1, axi_div * ahb_div);

Take this one for example. If 'hpll' is actually a clk_hw pointer in
hand, then you could do something like:

	clk_hw_register_fixed_factor_parent_hw(NULL, "ahb", &hpll, 0, 1, axi_div * ahb_div);

And if it's something like a clock from DT you could do

	struct clk_parent_data pdata = {
		.name = "hpll",
		.fw_name = <clock-names string>,
		.index = <whatever clock index it is>
	};

	clk_hw_register_fixed_factor_parent_data(NULL, "ahb", &pdata, 0, 1, axi_div * ahb_div);

I haven't actually written the clk_hw_register_fixed_factor_*() APIs,
because I'm thinking that it would be better to register the pdata with
some more parameters so that the
clk_hw_register_fixed_factor_parent_data() API becomes more like:

	clk_hw_register_fixed_factor_parent_data(NULL, "ahb", "hpll",
		<clock-names string>, <whatever clock index it is>, 0, 1,
		axi_div * ahb_div);

Because there's only one parent. For the mux clk it will be a pointer to
parent_data because I don't see a way around it.

quoted

There aren't checks for if these things fail. I guess it doesn't matter
and just let it fail hard?

I think that's sensible here. If the system has run out of memory this
early on then there's not going to be much that works.

Thanks for the review. I've fixed all of the style issues you
mentioned, but would appreciate some guidance on the parent API.

Cool! Thanks.


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