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

[Marc Gonzalez <marc_gonzalez@sigmadesigns.com>]

Hello everyone,

On 07/10/2015 01:09, Daniel Lezcano wrote:

> 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.

OK.

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

OK.

(84583983c319 didn't seem to follow that convention)

>> 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

OK.

>>   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.

For my education: this header is already indirectly included;
The directive should be explicit to prevent breakage in case
other (implicit) includes are reorganized?

>> +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)

What about read_clocksource? and read_xtal_counter?

>> +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.

OK.

>> +	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.

OK.

New patch coming up.

Regards.