[PATCH] clk: tests: Add tests for clk lookup by name

[Brian Masney]

On Thu, Oct 02, 2025 at 05:20:35PM +0800, Chen-Yu Tsai wrote:
> Clk lookup (by name) recently gained some performance improvements at
> the expense of more complexity within the lookup code.
> 
> To make sure that this works as intended and doesn't break, add some
> basic tests for this part of the CCF.
> 
> A new "clk_hw_lookup()" function is added purely for running kunit
> tests.
> 
> Signed-off-by: Chen-Yu Tsai <wenst at chromium.org>
> ---
>  drivers/clk/clk.c      | 11 +++++++
>  drivers/clk/clk.h      |  4 +++
>  drivers/clk/clk_test.c | 66 +++++++++++++++++++++++++++++++++++++++++-
>  3 files changed, 80 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index 85d2f2481acf..a17d0070d11f 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -778,6 +778,17 @@ struct clk *__clk_lookup(const char *name)
>  	return !core ? NULL : core->hw->clk;
>  }
>  
> +#if IS_ENABLED(CONFIG_CLK_KUNIT_TEST)
> +/* This is only provided for kunit tests to test the core lookup functions. */
> +struct clk_hw *clk_hw_lookup(const char *name)
> +{
> +	struct clk_core *core = clk_core_lookup(name);
> +
> +	return !core ? NULL : core->hw;
> +}
> +EXPORT_SYMBOL_GPL(clk_hw_lookup);
> +#endif

Use EXPORT_SYMBOL_IF_KUNIT instead for consistency with the rest of the
kernel. In clk_test.c, you'll also need to add:

MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");

Since clk_hw_lookup() is only used by kunit, why not just put this new
function in clk-test.c, and use EXPORT_SYMBOL_IF_KUNIT on
clk_core_lookup?

Brian