[RFC 2/2] clocksource: arm_global_timer: Convert driver to use clocksource context field

[Sascha Hauer]

On Fri, Jun 10, 2022 at 11:56:32AM +0300, Alexander Shiyan wrote:
> Signed-off-by: Alexander Shiyan <eagle.alexander923 at gmail.com>
> ---
>  drivers/clocksource/arm_global_timer.c | 27 +++++++++++++++-----------
>  1 file changed, 16 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/arm_global_timer.c
> index 6e2fae9ba4..3e9b90059a 100644
> --- a/drivers/clocksource/arm_global_timer.c
> +++ b/drivers/clocksource/arm_global_timer.c
> @@ -27,8 +27,6 @@
>  #define GT_CONTROL	0x08
>  #define GT_CONTROL_TIMER_ENABLE		BIT(0)  /* this bit is NOT banked */
>  
> -static void __iomem *gt_base;
> -
>  /*
>   * To get the value from the Global Timer Counter register proceed as follows:
>   * 1. Read the upper 32-bit timer counter register
> @@ -39,6 +37,7 @@ static void __iomem *gt_base;
>   */
>  static uint64_t arm_global_clocksource_read(void *ctx)
>  {
> +	void __iomem *gt_base = ctx;
>  	uint64_t counter;
>  	uint32_t lower;
>  	uint32_t upper, old_upper;
> @@ -56,11 +55,25 @@ static uint64_t arm_global_clocksource_read(void *ctx)
>  	return counter;
>  }
>  
> +static int arm_global_timer_init(struct clocksource *cs)
> +{
> +	void __iomem *gt_base = cs->ctx;
> +
> +	writel(0, gt_base + GT_CONTROL);
> +	writel(0, gt_base + GT_COUNTER0);
> +	writel(0, gt_base + GT_COUNTER1);
> +	/* enables timer on all the cores */
> +	writel(GT_CONTROL_TIMER_ENABLE, gt_base + GT_CONTROL);
> +
> +	return 0;
> +}
> +
>  static struct clocksource cs = {
>  	.read	= arm_global_clocksource_read,
>  	.mask	= CLOCKSOURCE_MASK(64),
>  	.shift	= 0,
>  	.priority = 70,
> +	.init	= arm_global_timer_init,
>  };
>  
>  static int arm_global_timer_probe(struct device_d *dev)
> @@ -86,17 +99,9 @@ static int arm_global_timer_probe(struct device_d *dev)
>  		return ret;
>  	}
>  
> -	gt_base = IOMEM(iores->start);
> -
>  	cs.mult = clocksource_hz2mult(clk_get_rate(clk), cs.shift);
>  
> -	writel(0, gt_base + GT_CONTROL);
> -	writel(0, gt_base + GT_COUNTER0);
> -	writel(0, gt_base + GT_COUNTER1);
> -	/* enables timer on all the cores */
> -	writel(GT_CONTROL_TIMER_ENABLE, gt_base + GT_CONTROL);
> -
> -	return init_clock(&cs, NULL);
> +	return init_clock(&cs, IOMEM(iores->start));

As long as the statically allocated &cs is used it's not really useful
to store the context pointer in there.

Sascha

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