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

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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>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
This commit is contained in:
Marc Gonzalez 2015-10-09 16:59:18 +02:00 committed by Daniel Lezcano
parent f1c08c9bc8
commit ccd63ce471
3 changed files with 71 additions and 0 deletions
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4
drivers/clocksource/Kconfig
View file

@ -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

1
drivers/clocksource/Makefile
View file

@ -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

66
drivers/clocksource/tango_xtal.c Normal file
View file

@ -0,0 +1,66 @@
#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);