From: Bartosz Golaszewski <[email protected]> Extend the davinci-timer driver to also register a clock source.
Signed-off-by: Bartosz Golaszewski <[email protected]> --- drivers/clocksource/timer-davinci.c | 70 +++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) diff --git a/drivers/clocksource/timer-davinci.c b/drivers/clocksource/timer-davinci.c index a8fc7b3805c9..c478991da253 100644 --- a/drivers/clocksource/timer-davinci.c +++ b/drivers/clocksource/timer-davinci.c @@ -42,6 +42,8 @@ #define DAVINCI_TIMER_MIN_DELTA 0x01 #define DAVINCI_TIMER_MAX_DELTA 0xfffffffe +#define DAVINCI_TIMER_CLKSRC_BITS 32 + #define DAVINCI_TIMER_TGCR_DEFAULT \ (DAVINCI_TIMER_TIMMODE_32BIT_UNCHAINED | DAVINCI_TIMER_UNRESET) @@ -61,6 +63,16 @@ struct davinci_clockevent { unsigned int enamode_mask; }; +/* + * This must be globally accessible by davinci_timer_read_sched_clock(), so + * let's keep it here. + */ +static struct { + struct clocksource dev; + void __iomem *base; + unsigned int tim_off; +} davinci_clocksource; + static struct davinci_clockevent * to_davinci_clockevent(struct clock_event_device *clockevent) { @@ -159,6 +171,32 @@ static irqreturn_t davinci_timer_irq_timer(int irq, void *data) return IRQ_HANDLED; } +static u64 notrace davinci_timer_read_sched_clock(void) +{ + return readl_relaxed(davinci_clocksource.base + + davinci_clocksource.tim_off); +} + +static u64 davinci_clocksource_read(struct clocksource *dev) +{ + return davinci_timer_read_sched_clock(); +} + +static void davinci_clocksource_init(void __iomem *base, unsigned int tim_off, + unsigned int prd_off, unsigned int shift) +{ + davinci_tcr_update(base, + DAVINCI_TIMER_ENAMODE_MASK << shift, + DAVINCI_TIMER_ENAMODE_DISABLED << shift); + + writel_relaxed(0x0, base + tim_off); + writel_relaxed(UINT_MAX, base + prd_off); + + davinci_tcr_update(base, + DAVINCI_TIMER_ENAMODE_MASK << shift, + DAVINCI_TIMER_ENAMODE_ONESHOT << shift); +} + static void davinci_timer_init(void __iomem *base) { /* Set clock to internal mode and disable it. */ @@ -248,6 +286,38 @@ int __init davinci_timer_register(struct clk *clk, DAVINCI_TIMER_MIN_DELTA, DAVINCI_TIMER_MAX_DELTA); + davinci_clocksource.dev.rating = 300; + davinci_clocksource.dev.read = davinci_clocksource_read; + davinci_clocksource.dev.mask = + CLOCKSOURCE_MASK(DAVINCI_TIMER_CLKSRC_BITS); + davinci_clocksource.dev.flags = CLOCK_SOURCE_IS_CONTINUOUS; + davinci_clocksource.base = base; + + if (timer_cfg->cmp_off) { + davinci_clocksource.dev.name = "tim12"; + davinci_clocksource.tim_off = DAVINCI_TIMER_REG_TIM12; + davinci_clocksource_init(base, + DAVINCI_TIMER_REG_TIM12, + DAVINCI_TIMER_REG_PRD12, + DAVINCI_TIMER_ENAMODE_SHIFT_TIM12); + } else { + davinci_clocksource.dev.name = "tim34"; + davinci_clocksource.tim_off = DAVINCI_TIMER_REG_TIM34; + davinci_clocksource_init(base, + DAVINCI_TIMER_REG_TIM34, + DAVINCI_TIMER_REG_PRD34, + DAVINCI_TIMER_ENAMODE_SHIFT_TIM34); + } + + rv = clocksource_register_hz(&davinci_clocksource.dev, tick_rate); + if (rv) { + pr_err("Unable to register clocksource"); + return rv; + } + + sched_clock_register(davinci_timer_read_sched_clock, + DAVINCI_TIMER_CLKSRC_BITS, tick_rate); + return 0; } -- 2.21.0
