clocksource/drivers/moxart: 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/moxart_timer.c

@@ -119,34 +119,45 @@ static struct irqaction moxart_timer_irq = {
 	.dev_id		= &moxart_clockevent,
 };
 
-static void __init moxart_timer_init(struct device_node *node)
+static int __init moxart_timer_init(struct device_node *node)
 {
 	int ret, irq;
 	unsigned long pclk;
 	struct clk *clk;
 
 	base = of_iomap(node, 0);
-	if (!base)
-		panic("%s: of_iomap failed\n", node->full_name);
+	if (!base) {
+		pr_err("%s: of_iomap failed\n", node->full_name);
+		return -ENXIO;
+	}
 
 	irq = irq_of_parse_and_map(node, 0);
-	if (irq <= 0)
-		panic("%s: irq_of_parse_and_map failed\n", node->full_name);
+	if (irq <= 0) {
+		pr_err("%s: irq_of_parse_and_map failed\n", node->full_name);
+		return -EINVAL;
+	}
 
 	ret = setup_irq(irq, &moxart_timer_irq);
-	if (ret)
-		panic("%s: setup_irq failed\n", node->full_name);
+	if (ret) {
+		pr_err("%s: setup_irq failed\n", node->full_name);
+		return ret;
+	}
 
 	clk = of_clk_get(node, 0);
-	if (IS_ERR(clk))
-		panic("%s: of_clk_get failed\n", node->full_name);
+	if (IS_ERR(clk))  {
+		pr_err("%s: of_clk_get failed\n", node->full_name);
+		return PTR_ERR(clk);
+	}
 
 	pclk = clk_get_rate(clk);
 
-	if (clocksource_mmio_init(base + TIMER2_BASE + REG_COUNT,
-				  "moxart_timer", pclk, 200, 32,
-				  clocksource_mmio_readl_down))
-		panic("%s: clocksource_mmio_init failed\n", node->full_name);
+	ret = clocksource_mmio_init(base + TIMER2_BASE + REG_COUNT,
+				    "moxart_timer", pclk, 200, 32,
+				    clocksource_mmio_readl_down);
+	if (ret) {
+		pr_err("%s: clocksource_mmio_init failed\n", node->full_name);
+		return ret;
+	}
 
 	clock_count_per_tick = DIV_ROUND_CLOSEST(pclk, HZ);
 
@@ -164,5 +175,7 @@ static void __init moxart_timer_init(struct device_node *node)
 	 */
 	clockevents_config_and_register(&moxart_clockevent, pclk,
 					0x4, 0xfffffffe);
+
+	return 0;
 }
-CLOCKSOURCE_OF_DECLARE(moxart, "moxa,moxart-timer", moxart_timer_init);
+CLOCKSOURCE_OF_DECLARE_RET(moxart, "moxa,moxart-timer", moxart_timer_init);