From a1198f83407ae3421f3f58355a0f296d5ea6249c Mon Sep 17 00:00:00 2001 From: Heiko Stuebner Date: Tue, 4 Jun 2013 11:37:02 +0200 Subject: [PATCH] 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 Acked-by: Linus Walleij Acked-by: Jamie Iles --- drivers/clocksource/dw_apb_timer_of.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-) diff --git a/drivers/clocksource/dw_apb_timer_of.c b/drivers/clocksource/dw_apb_timer_of.c index ab09ed3742ee..d6c0fda76a7e 100644 --- a/drivers/clocksource/dw_apb_timer_of.c +++ b/drivers/clocksource/dw_apb_timer_of.c @@ -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 = {