[RFC PATCH 13/16] clk: hifiberry-dacpro: add "sclk" lookup

[Stephen Boyd]

Quoting Pierre-Louis Bossart (2020-04-09 12:58:38)
> devm_clk_get() fails on ACPI platforms when a NULL string is used.
> Create a "sclk" lookup to make sure codec and machine drivers can get
> the clock.
> 
> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
> ---
>  drivers/clk/clk-hifiberry-dacpro.c | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
> 
> diff --git a/drivers/clk/clk-hifiberry-dacpro.c b/drivers/clk/clk-hifiberry-dacpro.c
> index d01a90fed51b..36210f52c624 100644
> --- a/drivers/clk/clk-hifiberry-dacpro.c
> +++ b/drivers/clk/clk-hifiberry-dacpro.c
> @@ -24,10 +24,12 @@
>   * struct clk_hifiberry_hw - Common struct to the HiFiBerry DAC Pro
>   * @hw: clk_hw for the common clk framework
>   * @mode: 0 => CLK44EN, 1 => CLK48EN
> + * @sclk_lookup: handle for "sclk"
>   */
>  struct clk_hifiberry_hw {
>         struct clk_hw hw;
>         u8 mode;
> +       struct clk_lookup *sclk_lookup;
>  };
>  
>  #define to_hifiberry_clk(_hw) container_of(_hw, struct clk_hifiberry_hw, hw)
> @@ -121,15 +123,34 @@ static int clk_hifiberry_dacpro_probe(struct platform_device *pdev)
>         ret = devm_clk_hw_register_clkdev(dev, &proclk->hw,
>                                           init.name, NULL);
>  #endif
> +       if (ret) {
> +               dev_err(dev, "Fail to add clock driver\n");
> +               return ret;
> +       }
> +
> +       proclk->sclk_lookup = clkdev_hw_create(&proclk->hw, "sclk", NULL);
> +       if (!proclk->sclk_lookup) {
> +#ifndef CONFIG_ACPI

Is it to save code space? Otherwise the ifdefs are pretty ugly and I'd
prefer we just call of_clk APIs and rely on the inline stubs when
CONFIG_OF isn't enabled to be optimized out.

> +               of_clk_del_provider(dev->of_node);
> +#endif
> +               return -ENOMEM;
> +       }
> +