Re: [PATCH v1] clocksource: Sigma Designs Tango 27 MHz xtal

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

Hi Marc,

On 10/06/2015 05:10 PM, Marc Gonzalez wrote:
> Date: Tue, 6 Oct 2015 16:49:28 +0200
> Subject: [PATCH] clocksource: Sigma Designs Tango 27 MHz xtal

Fix the patch format.

Subject is clocksource/drivers/tango_xtal: Add new timer ...

> Sigma Designs Tango platforms provide a 27 MHz crystal oscillator.
> Use it for clocksource, sched_clock, and delay_timer.
>
> Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
> ---
>   drivers/clocksource/Makefile     |  1 +
>   drivers/clocksource/tango_xtal.c | 46 ++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 47 insertions(+)
>   create mode 100644 drivers/clocksource/tango_xtal.c
>
> diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
> index f228354961ca..46e405673d75 100644
> --- a/drivers/clocksource/Makefile
> +++ b/drivers/clocksource/Makefile
> @@ -24,6 +24,7 @@ obj-$(CONFIG_ARCH_CLPS711X)	+= clps711x-timer.o
>   obj-$(CONFIG_ARCH_ATLAS7)	+= timer-atlas7.o
>   obj-$(CONFIG_ARCH_MOXART)	+= moxart_timer.o
>   obj-$(CONFIG_ARCH_MXS)		+= mxs_timer.o
> +obj-$(CONFIG_ARCH_TANGOX)	+= tango_xtal.o

Please use the following scheme:

Add in the clocksource's Kconfig an entry:

config CLKSRC_TANGO_XTAL
	bool "bla bla" if COMPILE_TEST
	select CLKSRC_OF

and then in the arch's Kconfig:

select CLKSRC_TANGO_XTAL


>   obj-$(CONFIG_CLKSRC_PXA)	+= pxa_timer.o
>   obj-$(CONFIG_ARCH_PRIMA2)	+= timer-prima2.o
>   obj-$(CONFIG_ARCH_U300)		+= timer-u300.o
> diff --git a/drivers/clocksource/tango_xtal.c b/drivers/clocksource/tango_xtal.c
> new file mode 100644
> index 000000000000..0f2fb293ab75
> --- /dev/null
> +++ b/drivers/clocksource/tango_xtal.c
> @@ -0,0 +1,46 @@
> +#include <linux/clocksource.h>
> +#include <linux/sched_clock.h>
> +#include <linux/of_address.h>
> +#include <linux/delay.h>
> +#include <linux/clk.h>

#include <linux/init.h> is missing.

> +
> +static void __iomem *xtal_in_cnt;
> +static struct delay_timer delay_timer;
> +
> +static unsigned long read_xtal_counter(void)
> +{
> +	return readl_relaxed(xtal_in_cnt);
> +}
> +
> +static u64 read_sched_clock(void)
> +{
> +	return read_xtal_counter();
> +}

static u64 *notrace* read_sched_clock(void)

> +static cycle_t read_clocksource(struct clocksource *cs)
> +{
> +	return read_xtal_counter();
> +}
> +
> +static struct clocksource tango_xtal = {
> +	.name	= "tango-xtal",
> +	.rating	= 350,
> +	.read	= read_clocksource,
> +	.mask	= CLOCKSOURCE_MASK(32),
> +	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
> +};
> +
> +static void __init tango_clocksource_init(struct device_node *np)
> +{
> +	struct clk *clk = of_clk_get(np, 0);
> +	unsigned int xtal_freq = clk_get_rate(clk);
> +	xtal_in_cnt = of_iomap(np, 0);

check return code.

> +	delay_timer.freq = xtal_freq;
> +	delay_timer.read_current_timer = read_xtal_counter;
> +	register_current_timer_delay(&delay_timer);
> +	sched_clock_register(read_sched_clock, 32, xtal_freq);
> +	clocksource_register_hz(&tango_xtal, xtal_freq);

check return code.

> +}
> +
> +CLOCKSOURCE_OF_DECLARE(tango, "sigma,tick-counter", tango_clocksource_init);
>


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