clocksource: dw_apb_timer_of: enable the use the clocksource as sched clock

Currently the dw_apb_timer always expects a separate special timer to be
availbable for the sched_clock. Some devices using dw_apb_timers do not
have this sptimer but can use the clocksource as sched_clock instead.

Therefore enable the driver to distiguish between devices with and without
sptimer based on the devicetree data and select the correct timer as
sched_clock.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jamie Iles <jamie@jamieiles.com>
This commit is contained in:
Heiko Stuebner 2013-06-04 11:37:02 +02:00
parent e4aa937ec7
commit a1198f8340

View File

@ -57,6 +57,9 @@ static void add_clockevent(struct device_node *event_timer)
dw_apb_clockevent_register(ced);
}
static void __iomem *sched_io_base;
static u32 sched_rate;
static void add_clocksource(struct device_node *source_timer)
{
void __iomem *iobase;
@ -71,9 +74,15 @@ static void add_clocksource(struct device_node *source_timer)
dw_apb_clocksource_start(cs);
dw_apb_clocksource_register(cs);
}
static void __iomem *sched_io_base;
/*
* Fallback to use the clocksource as sched_clock if no separate
* timer is found. sched_io_base then points to the current_value
* register of the clocksource timer.
*/
sched_io_base = iobase + 0x04;
sched_rate = rate;
}
static u32 read_sched_clock(void)
{
@ -89,16 +98,15 @@ static const struct of_device_id sptimer_ids[] __initconst = {
static void init_sched_clock(void)
{
struct device_node *sched_timer;
u32 rate;
sched_timer = of_find_matching_node(NULL, sptimer_ids);
if (!sched_timer)
panic("No RTC for sched clock to use");
if (sched_timer) {
timer_get_base_and_rate(sched_timer, &sched_io_base,
&sched_rate);
of_node_put(sched_timer);
}
timer_get_base_and_rate(sched_timer, &sched_io_base, &rate);
of_node_put(sched_timer);
setup_sched_clock(read_sched_clock, 32, rate);
setup_sched_clock(read_sched_clock, 32, sched_rate);
}
static const struct of_device_id osctimer_ids[] __initconst = {