[PATCH] clk: sp810: hardwire parent to 1MHz clock

[Sascha Hauer]

On Thu, Nov 16, 2017 at 10:19:46PM +0100, Lucas Stach wrote:
> This works around a limitation in our handling of the vexpress
> config bus. For now just hardcode the clock parent to the 1MHz
> clock, which is the default as emulated by QEMU and also the
> setting the Linux kernel will configure later.
> 
> This fixes the vexpress clocksource running at a wrong rate
> leading to bogus delays and sleep times.
> 
> Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
> ---

Applied, thanks

Sascha

>  drivers/clk/vexpress/clk-sp810.c | 20 +++++++-------------
>  1 file changed, 7 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/clk/vexpress/clk-sp810.c b/drivers/clk/vexpress/clk-sp810.c
> index af72c7402..959661e19 100644
> --- a/drivers/clk/vexpress/clk-sp810.c
> +++ b/drivers/clk/vexpress/clk-sp810.c
> @@ -44,10 +44,7 @@ struct clk_sp810 {
>  
>  static int clk_sp810_timerclken_get_parent(struct clk *hw)
>  {
> -	struct clk_sp810_timerclken *timerclken = to_clk_sp810_timerclken(hw);
> -	u32 val = readl(timerclken->sp810->base + SCCTRL);
> -
> -	return !!(val & (1 << SCCTRL_TIMERENnSEL_SHIFT(timerclken->channel)));
> +	return 1;
>  }
>  
>  static int clk_sp810_timerclken_set_parent(struct clk *hw, u8 index)
> @@ -59,6 +56,9 @@ static int clk_sp810_timerclken_set_parent(struct clk *hw, u8 index)
>  	if (WARN_ON(index > 1))
>  		return -EINVAL;
>  
> +	if (index == 0)
> +		return -EINVAL;
> +
>  	val = readl(sp810->base + SCCTRL);
>  	val &= ~(1 << shift);
>  	val |= index << shift;
> @@ -92,7 +92,6 @@ static void clk_sp810_of_setup(struct device_node *node)
>  	char name[12];
>  	static int instance;
>  	int i;
> -	bool deprecated;
>  
>  	if (!sp810)
>  		return;
> @@ -106,8 +105,6 @@ static void clk_sp810_of_setup(struct device_node *node)
>  	sp810->node = node;
>  	sp810->base = of_iomap(node, 0);
>  
> -	deprecated = !of_find_property(node, "assigned-clock-parents", NULL);
> -
>  	for (i = 0; i < ARRAY_SIZE(sp810->timerclken); i++) {
>  		snprintf(name, sizeof(name), "sp810_%d_%d", instance, i);
>  
> @@ -119,13 +116,10 @@ static void clk_sp810_of_setup(struct device_node *node)
>  		sp810->timerclken[i].hw.ops = &clk_sp810_timerclken_ops;
>  
>  		/*
> -		 * If DT isn't setting the parent, force it to be
> -		 * the 1 MHz clock without going through the framework.
> -		 * We do this before clk_register() so that it can determine
> -		 * the parent and setup the tree properly.
> +		 * Always set parent to 1MHz clock to match QEMU emulation
> +		 * and satisfy requirements on real HW.
>  		 */
> -		if (deprecated)
> -			clk_sp810_timerclken_set_parent(&sp810->timerclken[i].hw, 1);
> +		clk_sp810_timerclken_set_parent(&sp810->timerclken[i].hw, 1);
>  
>  		clk_register(&sp810->timerclken[i].hw);
>  	}
> -- 
> 2.13.6
> 
> 
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