clocksource/drivers/orion: Convert init function to return error

The init functions do not return any error. They behave as the following:

  - panic, thus leading to a kernel crash while another timer may work and
       make the system boot up correctly

  or

  - print an error and let the caller unaware if the state of the system

Change that by converting the init functions to return an error conforming
to the CLOCKSOURCE_OF_RET prototype.

Proper error handling (rollback, errno value) will be changed later case
by case, thus this change just return back an error or success in the init
function.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

drivers/clocksource/time-orion.c

@@ -104,25 +104,36 @@ static struct irqaction orion_clkevt_irq = {
 	.handler	= orion_clkevt_irq_handler,
 };
 
-static void __init orion_timer_init(struct device_node *np)
+static int __init orion_timer_init(struct device_node *np)
 {
 	struct clk *clk;
-	int irq;
+	int irq, ret;
 
 	/* timer registers are shared with watchdog timer */
 	timer_base = of_iomap(np, 0);
-	if (!timer_base)
-		panic("%s: unable to map resource\n", np->name);
+	if (!timer_base) {
+		pr_err("%s: unable to map resource\n", np->name);
+		return -ENXIO;
+	}
 
 	clk = of_clk_get(np, 0);
-	if (IS_ERR(clk))
-		panic("%s: unable to get clk\n", np->name);
-	clk_prepare_enable(clk);
+	if (IS_ERR(clk)) {
+		pr_err("%s: unable to get clk\n", np->name);
+		return PTR_ERR(clk);
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		pr_err("Failed to prepare clock");
+		return ret;
+	}
 
 	/* we are only interested in timer1 irq */
 	irq = irq_of_parse_and_map(np, 1);
-	if (irq <= 0)
-		panic("%s: unable to parse timer1 irq\n", np->name);
+	if (irq <= 0) {
+		pr_err("%s: unable to parse timer1 irq\n", np->name);
+		return -EINVAL;
+	}
 
 	/* setup timer0 as free-running clocksource */
 	writel(~0, timer_base + TIMER0_VAL);
@@ -130,19 +141,30 @@ static void __init orion_timer_init(struct device_node *np)
 	atomic_io_modify(timer_base + TIMER_CTRL,
 		TIMER0_RELOAD_EN | TIMER0_EN,
 		TIMER0_RELOAD_EN | TIMER0_EN);
-	clocksource_mmio_init(timer_base + TIMER0_VAL, "orion_clocksource",
+
+	ret = clocksource_mmio_init(timer_base + TIMER0_VAL, "orion_clocksource",
 				    clk_get_rate(clk), 300, 32,
 				    clocksource_mmio_readl_down);
+	if (ret) {
+		pr_err("Failed to initialize mmio timer");
+		return ret;
+	}
+
 	sched_clock_register(orion_read_sched_clock, 32, clk_get_rate(clk));
 
 	/* setup timer1 as clockevent timer */
-	if (setup_irq(irq, &orion_clkevt_irq))
-		panic("%s: unable to setup irq\n", np->name);
+	ret = setup_irq(irq, &orion_clkevt_irq);
+	if (ret) {
+		pr_err("%s: unable to setup irq\n", np->name);
+		return ret;
+	}
 
 	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, clk_get_rate(clk),
 					ORION_ONESHOT_MIN, ORION_ONESHOT_MAX);
+
+	return 0;
 }
-CLOCKSOURCE_OF_DECLARE(orion_timer, "marvell,orion-timer", orion_timer_init);
+CLOCKSOURCE_OF_DECLARE_RET(orion_timer, "marvell,orion-timer", orion_timer_init);