static int __init fttmr010_common_init()

in timer-fttmr010.c [273:437]

• 125 lines of code
• 12 McCabe index (conditional complexity)

static int __init fttmr010_common_init(struct device_node *np,
				       bool is_aspeed, bool is_ast2600)
{
	struct fttmr010 *fttmr010;
	int irq;
	struct clk *clk;
	int ret;
	u32 val;

	/*
	 * These implementations require a clock reference.
	 * FIXME: we currently only support clocking using PCLK
	 * and using EXTCLK is not supported in the driver.
	 */
	clk = of_clk_get_by_name(np, "PCLK");
	if (IS_ERR(clk)) {
		pr_err("could not get PCLK\n");
		return PTR_ERR(clk);
	}
	ret = clk_prepare_enable(clk);
	if (ret) {
		pr_err("failed to enable PCLK\n");
		return ret;
	}

	fttmr010 = kzalloc(sizeof(*fttmr010), GFP_KERNEL);
	if (!fttmr010) {
		ret = -ENOMEM;
		goto out_disable_clock;
	}
	fttmr010->tick_rate = clk_get_rate(clk);

	fttmr010->base = of_iomap(np, 0);
	if (!fttmr010->base) {
		pr_err("Can't remap registers\n");
		ret = -ENXIO;
		goto out_free;
	}
	/* IRQ for timer 1 */
	irq = irq_of_parse_and_map(np, 0);
	if (irq <= 0) {
		pr_err("Can't parse IRQ\n");
		ret = -EINVAL;
		goto out_unmap;
	}

	/*
	 * The Aspeed timers move bits around in the control register.
	 */
	if (is_aspeed) {
		fttmr010->t1_enable_val = TIMER_1_CR_ASPEED_ENABLE |
			TIMER_1_CR_ASPEED_INT;
		fttmr010->is_aspeed = true;
	} else {
		fttmr010->t1_enable_val = TIMER_1_CR_ENABLE | TIMER_1_CR_INT;

		/*
		 * Reset the interrupt mask and status
		 */
		writel(TIMER_INT_ALL_MASK, fttmr010->base + TIMER_INTR_MASK);
		writel(0, fttmr010->base + TIMER_INTR_STATE);
	}

	/*
	 * Enable timer 1 count up, timer 2 count up, except on Aspeed,
	 * where everything just counts down.
	 */
	if (is_aspeed)
		val = TIMER_2_CR_ASPEED_ENABLE;
	else {
		val = TIMER_2_CR_ENABLE | TIMER_1_CR_UPDOWN |
			TIMER_2_CR_UPDOWN;
	}
	writel(val, fttmr010->base + TIMER_CR);

	/*
	 * Setup free-running clocksource timer (interrupts
	 * disabled.)
	 */
	local_fttmr = fttmr010;
	writel(0, fttmr010->base + TIMER2_COUNT);
	writel(0, fttmr010->base + TIMER2_MATCH1);
	writel(0, fttmr010->base + TIMER2_MATCH2);

	if (fttmr010->is_aspeed) {
		writel(~0, fttmr010->base + TIMER2_LOAD);
		clocksource_mmio_init(fttmr010->base + TIMER2_COUNT,
				      "FTTMR010-TIMER2",
				      fttmr010->tick_rate,
				      300, 32, clocksource_mmio_readl_down);
		sched_clock_register(fttmr010_read_sched_clock_down, 32,
				     fttmr010->tick_rate);
	} else {
		writel(0, fttmr010->base + TIMER2_LOAD);
		clocksource_mmio_init(fttmr010->base + TIMER2_COUNT,
				      "FTTMR010-TIMER2",
				      fttmr010->tick_rate,
				      300, 32, clocksource_mmio_readl_up);
		sched_clock_register(fttmr010_read_sched_clock_up, 32,
				     fttmr010->tick_rate);
	}

	/*
	 * Setup clockevent timer (interrupt-driven) on timer 1.
	 */
	writel(0, fttmr010->base + TIMER1_COUNT);
	writel(0, fttmr010->base + TIMER1_LOAD);
	writel(0, fttmr010->base + TIMER1_MATCH1);
	writel(0, fttmr010->base + TIMER1_MATCH2);

	if (is_ast2600) {
		fttmr010->timer_shutdown = ast2600_timer_shutdown;
		ret = request_irq(irq, ast2600_timer_interrupt,
				  IRQF_TIMER, "FTTMR010-TIMER1",
				  &fttmr010->clkevt);
	} else {
		fttmr010->timer_shutdown = fttmr010_timer_shutdown;
		ret = request_irq(irq, fttmr010_timer_interrupt,
				  IRQF_TIMER, "FTTMR010-TIMER1",
				  &fttmr010->clkevt);
	}
	if (ret) {
		pr_err("FTTMR010-TIMER1 no IRQ\n");
		goto out_unmap;
	}

	fttmr010->clkevt.name = "FTTMR010-TIMER1";
	/* Reasonably fast and accurate clock event */
	fttmr010->clkevt.rating = 300;
	fttmr010->clkevt.features = CLOCK_EVT_FEAT_PERIODIC |
		CLOCK_EVT_FEAT_ONESHOT;
	fttmr010->clkevt.set_next_event = fttmr010_timer_set_next_event;
	fttmr010->clkevt.set_state_shutdown = fttmr010->timer_shutdown;
	fttmr010->clkevt.set_state_periodic = fttmr010_timer_set_periodic;
	fttmr010->clkevt.set_state_oneshot = fttmr010_timer_set_oneshot;
	fttmr010->clkevt.tick_resume = fttmr010->timer_shutdown;
	fttmr010->clkevt.cpumask = cpumask_of(0);
	fttmr010->clkevt.irq = irq;
	clockevents_config_and_register(&fttmr010->clkevt,
					fttmr010->tick_rate,
					1, 0xffffffff);

#ifdef CONFIG_ARM
	/* Also use this timer for delays */
	if (fttmr010->is_aspeed)
		fttmr010->delay_timer.read_current_timer =
			fttmr010_read_current_timer_down;
	else
		fttmr010->delay_timer.read_current_timer =
			fttmr010_read_current_timer_up;
	fttmr010->delay_timer.freq = fttmr010->tick_rate;
	register_current_timer_delay(&fttmr010->delay_timer);
#endif

	return 0;

out_unmap:
	iounmap(fttmr010->base);
out_free:
	kfree(fttmr010);
out_disable_clock:
	clk_disable_unprepare(clk);

	return ret;
}