Re: [PATCH V5 4/4] clocksource: mips-gic: Add device-tree support

[Daniel Lezcano <daniel.lezcano@linaro.org>]

On 11/12/2014 08:43 PM, Andrew Bresticker wrote:
> Parse the GIC timer frequency and interrupt from the device-tree.
>
> Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
> Acked-by: Arnd Bergmann <arnd@arndb.de>

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

> ---
> Changes from v4:
>   - don't probe from irqchip; just warn if DT is wrong
> Changes from v3:
>   - probe from GIC irqchip
> New for v3.
> ---
>   drivers/clocksource/Kconfig          |  1 +
>   drivers/clocksource/mips-gic-timer.c | 41 ++++++++++++++++++++++++++++++------
>   2 files changed, 35 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
> index cb7e7f4..89836dc 100644
> --- a/drivers/clocksource/Kconfig
> +++ b/drivers/clocksource/Kconfig
> @@ -226,5 +226,6 @@ config CLKSRC_VERSATILE
>   config CLKSRC_MIPS_GIC
>   	bool
>   	depends on MIPS_GIC
> +	select CLKSRC_OF
>
>   endmenu
> diff --git a/drivers/clocksource/mips-gic-timer.c b/drivers/clocksource/mips-gic-timer.c
> index a749c81..3bd31b1 100644
> --- a/drivers/clocksource/mips-gic-timer.c
> +++ b/drivers/clocksource/mips-gic-timer.c
> @@ -11,6 +11,7 @@
>   #include <linux/interrupt.h>
>   #include <linux/irqchip/mips-gic.h>
>   #include <linux/notifier.h>
> +#include <linux/of_irq.h>
>   #include <linux/percpu.h>
>   #include <linux/smp.h>
>   #include <linux/time.h>
> @@ -101,8 +102,6 @@ static int gic_clockevent_init(void)
>   	if (!cpu_has_counter || !gic_frequency)
>   		return -ENXIO;
>
> -	gic_timer_irq = MIPS_GIC_IRQ_BASE +
> -		GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_COMPARE);
>   	setup_percpu_irq(gic_timer_irq, &gic_compare_irqaction);
>
>   	register_cpu_notifier(&gic_cpu_nb);
> @@ -123,17 +122,45 @@ static struct clocksource gic_clocksource = {
>   	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
>   };
>
> -void __init gic_clocksource_init(unsigned int frequency)
> +static void __init __gic_clocksource_init(void)
>   {
> -	gic_frequency = frequency;
> -
>   	/* Set clocksource mask. */
>   	gic_clocksource.mask = CLOCKSOURCE_MASK(gic_get_count_width());
>
>   	/* Calculate a somewhat reasonable rating value. */
> -	gic_clocksource.rating = 200 + frequency / 10000000;
> +	gic_clocksource.rating = 200 + gic_frequency / 10000000;
>
> -	clocksource_register_hz(&gic_clocksource, frequency);
> +	clocksource_register_hz(&gic_clocksource, gic_frequency);
>
>   	gic_clockevent_init();
>   }
> +
> +void __init gic_clocksource_init(unsigned int frequency)
> +{
> +	gic_frequency = frequency;
> +	gic_timer_irq = MIPS_GIC_IRQ_BASE +
> +		GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_COMPARE);
> +
> +	__gic_clocksource_init();
> +}
> +
> +static void __init gic_clocksource_of_init(struct device_node *node)
> +{
> +	if (WARN_ON(!gic_present || !node->parent ||
> +		    !of_device_is_compatible(node->parent, "mti,gic")))
> +		return;
> +
> +	if (of_property_read_u32(node, "clock-frequency", &gic_frequency)) {
> +		pr_err("GIC frequency not specified.\n");
> +		return;
> +	}
> +	gic_timer_irq = irq_of_parse_and_map(node, 0);
> +	if (!gic_timer_irq) {
> +		pr_err("GIC timer IRQ not specified.\n");
> +		return;
> +	}
> +
> +	__gic_clocksource_init();
> +}
> +CLOCKSOURCE_OF_DECLARE(mips_gic_timer, "mti,gic-timer",
> +		       gic_clocksource_of_init);
>


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