static int __init mxs_timer_init()

in mxs_timer.c [203:272]

• 49 lines of code
• 10 McCabe index (conditional complexity)

static int __init mxs_timer_init(struct device_node *np)
{
	struct clk *timer_clk;
	int irq, ret;

	mxs_timrot_base = of_iomap(np, 0);
	WARN_ON(!mxs_timrot_base);

	timer_clk = of_clk_get(np, 0);
	if (IS_ERR(timer_clk)) {
		pr_err("%s: failed to get clk\n", __func__);
		return PTR_ERR(timer_clk);
	}

	ret = clk_prepare_enable(timer_clk);
	if (ret)
		return ret;

	/*
	 * Initialize timers to a known state
	 */
	stmp_reset_block(mxs_timrot_base + HW_TIMROT_ROTCTRL);

	/* get timrot version */
	timrot_major_version = __raw_readl(mxs_timrot_base +
			(of_device_is_compatible(np, "fsl,imx23-timrot") ?
						MX23_TIMROT_VERSION_OFFSET :
						MX28_TIMROT_VERSION_OFFSET));
	timrot_major_version >>= BP_TIMROT_MAJOR_VERSION;

	/* one for clock_event */
	__raw_writel((timrot_is_v1() ?
			BV_TIMROTv1_TIMCTRLn_SELECT__32KHZ_XTAL :
			BV_TIMROTv2_TIMCTRLn_SELECT__TICK_ALWAYS) |
			BM_TIMROT_TIMCTRLn_UPDATE |
			BM_TIMROT_TIMCTRLn_IRQ_EN,
			mxs_timrot_base + HW_TIMROT_TIMCTRLn(0));

	/* another for clocksource */
	__raw_writel((timrot_is_v1() ?
			BV_TIMROTv1_TIMCTRLn_SELECT__32KHZ_XTAL :
			BV_TIMROTv2_TIMCTRLn_SELECT__TICK_ALWAYS) |
			BM_TIMROT_TIMCTRLn_RELOAD,
			mxs_timrot_base + HW_TIMROT_TIMCTRLn(1));

	/* set clocksource timer fixed count to the maximum */
	if (timrot_is_v1())
		__raw_writel(0xffff,
			mxs_timrot_base + HW_TIMROT_TIMCOUNTn(1));
	else
		__raw_writel(0xffffffff,
			mxs_timrot_base + HW_TIMROT_FIXED_COUNTn(1));

	/* init and register the timer to the framework */
	ret = mxs_clocksource_init(timer_clk);
	if (ret)
		return ret;

	ret = mxs_clockevent_init(timer_clk);
	if (ret)
		return ret;

	/* Make irqs happen */
	irq = irq_of_parse_and_map(np, 0);
	if (irq <= 0)
		return -EINVAL;

	return request_irq(irq, mxs_timer_interrupt, IRQF_TIMER | IRQF_IRQPOLL,
			   "MXS Timer Tick", &mxs_clockevent_device);
}