From: Benjamin Gaignard <[email protected]> The scene is set for the clocksource, let's add it for this driver.
Signed-off-by: Benjamin Gaignard <[email protected]> Signed-off-by: Daniel Lezcano <[email protected]> --- drivers/clocksource/timer-stm32.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/drivers/clocksource/timer-stm32.c b/drivers/clocksource/timer-stm32.c index 1891924..4634f4d 100644 --- a/drivers/clocksource/timer-stm32.c +++ b/drivers/clocksource/timer-stm32.c @@ -16,6 +16,7 @@ #include <linux/of_irq.h> #include <linux/clk.h> #include <linux/reset.h> +#include <linux/sched_clock.h> #include <linux/slab.h> #include "timer-of.h" @@ -80,6 +81,13 @@ static int stm32_timer_of_bits_get(struct timer_of *to) return pd->bits; } +static void __iomem *stm32_timer_cnt __read_mostly; + +static u64 notrace stm32_read_sched_clock(void) +{ + return readl_relaxed(stm32_timer_cnt); +} + static void stm32_clock_event_disable(struct timer_of *to) { writel_relaxed(0, timer_of_base(to) + TIM_DIER); @@ -204,6 +212,31 @@ static void __init stm32_timer_set_prescaler(struct timer_of *to) to->of_clk.period = DIV_ROUND_UP(to->of_clk.rate, HZ); } +static int __init stm32_clocksource_init(struct timer_of *to) +{ + u32 bits = stm32_timer_of_bits_get(to); + const char *name = to->np->full_name; + + /* + * This driver allows to register several timers and relies on + * the generic time framework to select the right one. + * However, nothing allows to do the same for the + * sched_clock. We are not interested in a sched_clock for the + * 16bits timers but only for the 32bits, so if no 32bits + * timer registered yet, we select this 32bits timer as a + * sched_clock. + */ + if (bits == 32 && !stm32_timer_cnt) { + stm32_timer_cnt = timer_of_base(to) + TIM_CNT; + sched_clock_register(stm32_read_sched_clock, bits, timer_of_rate(to)); + pr_info("%s: STM32 sched_clock registered\n", name); + } + + return clocksource_mmio_init(timer_of_base(to) + TIM_CNT, name, + timer_of_rate(to), bits == 32 ? 250 : 100, + bits, clocksource_mmio_readl_up); +} + static void __init stm32_clockevent_init(struct timer_of *to) { u32 bits = stm32_timer_of_bits_get(to); @@ -256,6 +289,10 @@ static int __init stm32_timer_init(struct device_node *node) stm32_timer_set_prescaler(to); + ret = stm32_clocksource_init(to); + if (ret) + goto deinit; + stm32_clockevent_init(to); return 0; -- 2.7.4
