Messages in this thread Patch in this message | | | From | Bartosz Golaszewski <> | Subject | [RFC 2/2] clocksource: timer-davinci: add support for clocksource | Date | Wed, 17 Apr 2019 16:47:09 +0200 |
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From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Extend the davinci-timer driver to also register a clock source.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> --- 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 d30f81a4088e..d630fca98123 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) @@ -59,6 +61,16 @@ 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) { @@ -148,6 +160,32 @@ 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_reg_update(base, DAVINCI_TIMER_REG_TCR, + DAVINCI_TIMER_ENAMODE_MASK << shift, + DAVINCI_TIMER_ENAMODE_DISABLED << shift); + + writel_relaxed(0x0, base + tim_off); + writel_relaxed(UINT_MAX, base + prd_off); + + davinci_reg_update(base, DAVINCI_TIMER_REG_TCR, + DAVINCI_TIMER_ENAMODE_MASK << shift, + DAVINCI_TIMER_ENAMODE_PERIODIC << shift); +} + static void davinci_timer_init(void __iomem *base) { /* Set clock to internal mode and disable it. */ @@ -235,6 +273,38 @@ 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
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