static int __init orion_timer_init()

in timer-orion.c [117:191]

• 57 lines of code
• 7 McCabe index (conditional complexity)

static int __init orion_timer_init(struct device_node *np)
{
	unsigned long rate;
	struct clk *clk;
	int irq, ret;

	/* timer registers are shared with watchdog timer */
	timer_base = of_iomap(np, 0);
	if (!timer_base) {
		pr_err("%pOFn: unable to map resource\n", np);
		return -ENXIO;
	}

	clk = of_clk_get(np, 0);
	if (IS_ERR(clk)) {
		pr_err("%pOFn: unable to get clk\n", np);
		return PTR_ERR(clk);
	}

	ret = clk_prepare_enable(clk);
	if (ret) {
		pr_err("Failed to prepare clock\n");
		return ret;
	}

	/* we are only interested in timer1 irq */
	irq = irq_of_parse_and_map(np, 1);
	if (irq <= 0) {
		pr_err("%pOFn: unable to parse timer1 irq\n", np);
		ret = -EINVAL;
		goto out_unprep_clk;
	}

	rate = clk_get_rate(clk);

	/* setup timer0 as free-running clocksource */
	writel(~0, timer_base + TIMER0_VAL);
	writel(~0, timer_base + TIMER0_RELOAD);
	atomic_io_modify(timer_base + TIMER_CTRL,
		TIMER0_RELOAD_EN | TIMER0_EN,
		TIMER0_RELOAD_EN | TIMER0_EN);

	ret = clocksource_mmio_init(timer_base + TIMER0_VAL,
				    "orion_clocksource", rate, 300, 32,
				    clocksource_mmio_readl_down);
	if (ret) {
		pr_err("Failed to initialize mmio timer\n");
		goto out_unprep_clk;
	}

	sched_clock_register(orion_read_sched_clock, 32, rate);

	/* setup timer1 as clockevent timer */
	ret = request_irq(irq, orion_clkevt_irq_handler, IRQF_TIMER,
			  "orion_event", NULL);
	if (ret) {
		pr_err("%pOFn: unable to setup irq\n", np);
		goto out_unprep_clk;
	}

	ticks_per_jiffy = (clk_get_rate(clk) + HZ/2) / HZ;
	orion_clkevt.cpumask = cpumask_of(0);
	orion_clkevt.irq = irq;
	clockevents_config_and_register(&orion_clkevt, rate,
					ORION_ONESHOT_MIN, ORION_ONESHOT_MAX);


	orion_delay_timer_init(rate);

	return 0;

out_unprep_clk:
	clk_disable_unprepare(clk);
	return ret;
}