[PATCH v4 7/8] clocksource: kona: Add basic use of external clock

[Daniel Lezcano]

On 12/05/2013 08:20 PM, Tim Kryger wrote:
> When an clock is specified in the device tree, enable it and use it to
> determine the external clock frequency.
>
> Signed-off-by: Tim Kryger <tim.kryger at linaro.org>
> Reviewed-by: Markus Mayer <markus.mayer at linaro.org>
> Reviewed-by: Matt Porter <matt.porter at linaro.org>

Acked-by: Daniel Lezcano <daniel.lezcano at linaro.org>

> ---
>   drivers/clocksource/bcm_kona_timer.c | 14 +++++++++++---
>   1 file changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/clocksource/bcm_kona_timer.c b/drivers/clocksource/bcm_kona_timer.c
> index 0d7d8c3..8a4ab36 100644
> --- a/drivers/clocksource/bcm_kona_timer.c
> +++ b/drivers/clocksource/bcm_kona_timer.c
> @@ -17,6 +17,7 @@
>   #include <linux/jiffies.h>
>   #include <linux/clockchips.h>
>   #include <linux/types.h>
> +#include <linux/clk.h>
>
>   #include <linux/io.h>
>   #include <asm/mach/time.h>
> @@ -107,11 +108,18 @@ static const struct of_device_id bcm_timer_ids[] __initconst = {
>   static void __init kona_timers_init(struct device_node *node)
>   {
>   	u32 freq;
> +	struct clk *external_clk;
>
> -	if (!of_property_read_u32(node, "clock-frequency", &freq))
> +	external_clk = of_clk_get_by_name(node, NULL);
> +
> +	if (!IS_ERR(external_clk)) {
> +		arch_timer_rate = clk_get_rate(external_clk);
> +		clk_prepare_enable(external_clk);
> +	} else if (!of_property_read_u32(node, "clock-frequency", &freq)) {
>   		arch_timer_rate = freq;
> -	else
> -		panic("clock-frequency not set in the .dts file");
> +	} else {
> +		panic("unable to determine clock-frequency");
> +	}
>
>   	/* Setup IRQ numbers */
>   	timers.tmr_irq = irq_of_parse_and_map(node, 0);
>


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