[PATCH v2] clk: fixed-rate: Use "clock-output-names" to name fixed clocks

[Fabio Estevam]

Hi Marek,

On Fri, Apr 18, 2025 at 11:53 AM Marek Vasut <marex at denx.de> wrote:

> The "clock-output-names" is NEVER used for any clock look up.

In Linux, "clock-output-names" is used to register the name of the
fixed-rate clock.

>From Linux drivers/clk/clk-fixed-rate.c:

```
static struct clk_hw *_of_fixed_clk_setup(struct device_node *node)
{
....

of_property_read_string(node, "clock-output-names", &clk_name);

hw = clk_hw_register_fixed_rate_with_accuracy(NULL, clk_name, NULL,
    0, rate, accuracy);
```

In U-Boot, we should register a fixed-rate clock with the same name as in Linux.

This patch aims to make the U-Boot fixed-rate clock name conform to
Linux standards.

> I am fine with the first half of the description, but the second half is
> wrong and this actually does not fix anything. Simply remove
> clock-output-names from the osc_24m and the code will be broken again.

In Linux, if "clock-output-names" is removed from the osc_24m node,
the console becomes corrupted
on an imx8mp-evk.

> The clk_resolve_parent_clk() is meant to perform the aforementioned
> resolution(), that is what "[PATCH v2 00/24] clk: Add
> clk_resolve_parent_clk() and fix up iMX clock drivers" actually fixed.
> It seems there is something still missing and clk_resolve_parent_clk()
> does not do the resolution properly for some clock, but that is what
> needs to be understood and fixed, not worked around this way.

Please try to reproduce the problem on your end.

On an imx8mp-based board, run 'usb start' in U-Boot, and this command will fail.

Thanks