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

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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
1 changed files with 17 additions and 9 deletions
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26
drivers/clocksource/dw_apb_timer_of.c
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@ -57,6 +57,9 @@ static void add_clockevent(struct device_node *event_timer)
dw_apb_clockevent_register(ced); dw_apb_clockevent_register(ced);
} }
static void __iomem *sched_io_base;
static u32 sched_rate;
static void add_clocksource(struct device_node *source_timer) static void add_clocksource(struct device_node *source_timer)
{ {
void __iomem *iobase; void __iomem *iobase;
@ -71,9 +74,15 @@ static void add_clocksource(struct device_node *source_timer)
dw_apb_clocksource_start(cs); dw_apb_clocksource_start(cs);
dw_apb_clocksource_register(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) 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) static void init_sched_clock(void)
{ {
struct device_node *sched_timer; struct device_node *sched_timer;
u32 rate;
sched_timer = of_find_matching_node(NULL, sptimer_ids); sched_timer = of_find_matching_node(NULL, sptimer_ids);
if (!sched_timer) if (sched_timer) {
panic("No RTC for sched clock to use"); 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); setup_sched_clock(read_sched_clock, 32, sched_rate);
of_node_put(sched_timer);
setup_sched_clock(read_sched_clock, 32, rate);
} }
static const struct of_device_id osctimer_ids[] __initconst = { static const struct of_device_id osctimer_ids[] __initconst = {