int __init davinci_timer_register()

in timer-davinci.c [242:333]

• 78 lines of code
• 9 McCabe index (conditional complexity)

int __init davinci_timer_register(struct clk *clk,
				  const struct davinci_timer_cfg *timer_cfg)
{
	struct davinci_clockevent *clockevent;
	unsigned int tick_rate;
	void __iomem *base;
	int rv;

	rv = clk_prepare_enable(clk);
	if (rv) {
		pr_err("Unable to prepare and enable the timer clock\n");
		return rv;
	}

	if (!request_mem_region(timer_cfg->reg.start,
				resource_size(&timer_cfg->reg),
				"davinci-timer")) {
		pr_err("Unable to request memory region\n");
		return -EBUSY;
	}

	base = ioremap(timer_cfg->reg.start, resource_size(&timer_cfg->reg));
	if (!base) {
		pr_err("Unable to map the register range\n");
		return -ENOMEM;
	}

	davinci_timer_init(base);
	tick_rate = clk_get_rate(clk);

	clockevent = kzalloc(sizeof(*clockevent), GFP_KERNEL);
	if (!clockevent)
		return -ENOMEM;

	clockevent->dev.name = "tim12";
	clockevent->dev.features = CLOCK_EVT_FEAT_ONESHOT;
	clockevent->dev.cpumask = cpumask_of(0);
	clockevent->base = base;

	if (timer_cfg->cmp_off) {
		clockevent->cmp_off = timer_cfg->cmp_off;
		clockevent->dev.set_next_event =
				davinci_clockevent_set_next_event_cmp;
	} else {
		clockevent->dev.set_next_event =
				davinci_clockevent_set_next_event_std;
		clockevent->dev.set_state_oneshot =
				davinci_clockevent_set_oneshot;
		clockevent->dev.set_state_shutdown =
				davinci_clockevent_shutdown;
	}

	rv = request_irq(timer_cfg->irq[DAVINCI_TIMER_CLOCKEVENT_IRQ].start,
			 davinci_timer_irq_timer, IRQF_TIMER,
			 "clockevent/tim12", clockevent);
	if (rv) {
		pr_err("Unable to request the clockevent interrupt\n");
		return rv;
	}

	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_tim12(base);
	} else {
		davinci_clocksource.dev.name = "tim34";
		davinci_clocksource.tim_off = DAVINCI_TIMER_REG_TIM34;
		davinci_clocksource_init_tim34(base);
	}

	clockevents_config_and_register(&clockevent->dev, tick_rate,
					DAVINCI_TIMER_MIN_DELTA,
					DAVINCI_TIMER_MAX_DELTA);

	rv = clocksource_register_hz(&davinci_clocksource.dev, tick_rate);
	if (rv) {
		pr_err("Unable to register clocksource\n");
		return rv;
	}

	sched_clock_register(davinci_timer_read_sched_clock,
			     DAVINCI_TIMER_CLKSRC_BITS, tick_rate);

	return 0;
}