Commit ccd63ce4 authored by Marc Gonzalez's avatar Marc Gonzalez Committed by Daniel Lezcano
Browse files

clocksource/drivers/tango_xtal: Add new timer for Tango SoCs 



Sigma Designs Tango platforms provide a 27 MHz crystal oscillator.
Use it for clocksource, sched_clock, and delay_timer.

Signed-off-by: default avatarMarc Gonzalez <marc_gonzalez@sigmadesigns.com>
Signed-off-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
parent f1c08c9b

drivers/clocksource/Kconfig

+4 −0
Original line number Diff line number Diff line
@@ -279,6 +279,10 @@ config CLKSRC_MIPS_GIC 
	depends on MIPS_GIC

	select CLKSRC_OF



config CLKSRC_TANGO_XTAL

	bool

	select CLKSRC_OF



config CLKSRC_PXA

	def_bool y if ARCH_PXA || ARCH_SA1100

	select CLKSRC_OF if OF

drivers/clocksource/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -56,6 +56,7 @@ obj-$(CONFIG_ARCH_KEYSTONE) += timer-keystone.o 
obj-$(CONFIG_ARCH_INTEGRATOR_AP)	+= timer-integrator-ap.o

obj-$(CONFIG_CLKSRC_VERSATILE)		+= versatile.o

obj-$(CONFIG_CLKSRC_MIPS_GIC)		+= mips-gic-timer.o

obj-$(CONFIG_CLKSRC_TANGO_XTAL)		+= tango_xtal.o

obj-$(CONFIG_CLKSRC_IMX_GPT)		+= timer-imx-gpt.o

obj-$(CONFIG_ASM9260_TIMER)		+= asm9260_timer.o

obj-$(CONFIG_H8300)			+= h8300_timer8.o

drivers/clocksource/tango_xtal.c

0 → 100644
+66 −0
Original line number Diff line number Diff line 
#include <linux/clocksource.h>

#include <linux/sched_clock.h>

#include <linux/of_address.h>

#include <linux/printk.h>

#include <linux/delay.h>

#include <linux/init.h>

#include <linux/clk.h>



static void __iomem *xtal_in_cnt;

static struct delay_timer delay_timer;



static unsigned long notrace read_xtal_counter(void)

{

	return readl_relaxed(xtal_in_cnt);

}



static u64 notrace read_sched_clock(void)

{

	return 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;

	int xtal_freq, ret;



	xtal_in_cnt = of_iomap(np, 0);

	if (xtal_in_cnt == NULL) {

		pr_err("%s: invalid address\n", np->full_name);

		return;

	}



	clk = of_clk_get(np, 0);

	if (IS_ERR(clk)) {

		pr_err("%s: invalid clock\n", np->full_name);

		return;

	}



	xtal_freq = clk_get_rate(clk);

	delay_timer.freq = xtal_freq;

	delay_timer.read_current_timer = read_xtal_counter;



	ret = clocksource_register_hz(&tango_xtal, xtal_freq);

	if (ret != 0) {

		pr_err("%s: registration failed\n", np->full_name);

		return;

	}



	sched_clock_register(read_sched_clock, 32, xtal_freq);

	register_current_timer_delay(&delay_timer);

}



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