Re: [PATCH 2/2] clocksource: mediatek: add clk13m and bus clock support

[Rob Herring]

On Sat, Oct 17, 2020 at 05:38:57PM +0200, Fabien Parent wrote:
> Some MediaTek SoC like MT8516 need to enable additional clocks
> for the GPT timer. Enable them if present.
> 
> Signed-off-by: Fabien Parent <fparent@xxxxxxxxxxxx>
> ---
>  drivers/clocksource/timer-mediatek.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/clocksource/timer-mediatek.c b/drivers/clocksource/timer-mediatek.c
> index 9318edcd8963..42e2d2090484 100644
> --- a/drivers/clocksource/timer-mediatek.c
> +++ b/drivers/clocksource/timer-mediatek.c
> @@ -9,6 +9,7 @@
>  
>  #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
>  
> +#include <linux/clk.h>
>  #include <linux/clockchips.h>
>  #include <linux/clocksource.h>
>  #include <linux/interrupt.h>
> @@ -278,8 +279,19 @@ static int __init mtk_syst_init(struct device_node *node)
>  
>  static int __init mtk_gpt_init(struct device_node *node)
>  {
> +	struct clk *clk_13m, *clk_bus;
>  	int ret;
>  
> +	/* Optional clock*/

Then use the optional api variant.

> +	clk_13m = of_clk_get_by_name(node, "clk13m");
> +	if (!IS_ERR(clk_13m))

And then you can drop this check (or handle it for any error other than 
clock is not present).

> +		clk_prepare_enable(clk_13m);
> +
> +	/* Optional clock*/
> +	clk_bus = of_clk_get_by_name(node, "bus");
> +	if (!IS_ERR(clk_bus))
> +		clk_prepare_enable(clk_bus);
> +
>  	to.clkevt.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
>  	to.clkevt.set_state_shutdown = mtk_gpt_clkevt_shutdown;
>  	to.clkevt.set_state_periodic = mtk_gpt_clkevt_set_periodic;
> -- 
> 2.28.0
>