Quoting Dario Binacchi (2022-10-30 06:00:46)
>
> I tried to test your suggestions on another platform (I don't have the
> hw to test the driver change) but if I
> don't add pdata.name = of_clk_get_parent_name () the board boot up fails.
>
> As far I can see from the clk_core_populate_parent_map()
>
> ....
> /* Copy everything over because it might be __initdata */
> for (i = 0, parent = parents; i < num_parents; i++, parent++) {
> parent->index = -1;
> if (parent_names) {
> /* throw a WARN if any entries are NULL */
> WARN(!parent_names[i],
> "%s: invalid NULL in %s's .parent_names\n",
> __func__, core->name);
> ret = clk_cpy_name(&parent->name, parent_names[i],
> true);
> } else if (parent_data) {
> parent->hw = parent_data[i].hw;
> parent->index = parent_data[i].index;
> ret = clk_cpy_name(&parent->fw_name,
> parent_data[i].fw_name, false);
> if (!ret)
> ret = clk_cpy_name(&parent->name,
> parent_data[i].name,
> false);
> ...
>
>
> The function clk_cpy_name() is called with the parameter "mus_exist"
> to true in the path "parent_names" and false
> in the path "parent_data". Therefore, in the path "parent_data" it is
> allowed that parent-> name is not set.
> In doing so, therefore, the change would not even be backward compatible.
>
> So, IMHO, there are 2 possible options:
> 1 okay to use parent_data, but we keep using of_clk_get_parent_name
> () to set parent_data::name.
> 2 okay to use the version v2 of the patch.
>
> What do you think?
I am confused.
The struct clk_parent_data::name being used is whatever string is
returned by of_clk_get_parent_name(node, 0). That is the same as setting
struct clk_parent_data::index to 0, and not assigning the 'name' or
'fw_name' field of the parent data structure. This is a compatible
change because of_clk_get_parent_name() is getting the name of the clk
in 'clocks' for 'node' at index 0. Using the index 0 in clk_parent_data
tells clk framework that the parent of the clk being registered is the
clk in 'clocks' for the 'dev->node' that is passed in during
clk_register(). If you don't have a device pointer, use
of_clk_hw_register() to pass 'node' directly. It looks like you will
have to do that in this case to get the node pointer registered with
this clk.
