clocksource/drivers/time-armada-370-xp: 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-armada-370-xp.c

@@ -260,14 +260,22 @@ static struct delay_timer armada_370_delay_timer = {
 	.read_current_timer = armada_370_delay_timer_read,
 };
 
-static void __init armada_370_xp_timer_common_init(struct device_node *np)
+static int __init armada_370_xp_timer_common_init(struct device_node *np)
 {
 	u32 clr = 0, set = 0;
 	int res;
 
 	timer_base = of_iomap(np, 0);
-	WARN_ON(!timer_base);
+	if (!timer_base) {
+		pr_err("Failed to iomap");
+		return -ENXIO;
+	}
+
 	local_base = of_iomap(np, 1);
+	if (!local_base) {
+		pr_err("Failed to iomap");
+		return -ENXIO;
+	}
 
 	if (timer25Mhz) {
 		set = TIMER0_25MHZ;		
@@ -306,14 +314,19 @@ static void __init armada_370_xp_timer_common_init(struct device_node *np)
 	 */
 	sched_clock_register(armada_370_xp_read_sched_clock, 32, timer_clk);
 
-	clocksource_mmio_init(timer_base + TIMER0_VAL_OFF,
-			      "armada_370_xp_clocksource",
-			      timer_clk, 300, 32, clocksource_mmio_readl_down);
+	res = clocksource_mmio_init(timer_base + TIMER0_VAL_OFF,
+				    "armada_370_xp_clocksource",
+				    timer_clk, 300, 32, clocksource_mmio_readl_down);
+	if (res) {
+		pr_err("Failed to initialize clocksource mmio");
+		return res;
+	}
 
 	register_cpu_notifier(&armada_370_xp_timer_cpu_nb);
 
 	armada_370_xp_evt = alloc_percpu(struct clock_event_device);
-
+	if (!armada_370_xp_evt)
+		return -ENOMEM;
 
 	/*
 	 * Setup clockevent timer (interrupt-driven).
@@ -323,33 +336,54 @@ static void __init armada_370_xp_timer_common_init(struct device_node *np)
 				"armada_370_xp_per_cpu_tick",
 				armada_370_xp_evt);
 	/* Immediately configure the timer on the boot CPU */
-	if (!res)
-		armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt));
+	if (res) {
+		pr_err("Failed to request percpu irq");
+		return res;
+	}
+
+	res = armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt));
+	if (!res) {
+		pr_err("Failed to setup timer");
+		return res;
+	}
 
 	register_syscore_ops(&armada_370_xp_timer_syscore_ops);
+	
+	return 0;
 }
 
-static void __init armada_xp_timer_init(struct device_node *np)
+static int __init armada_xp_timer_init(struct device_node *np)
 {
 	struct clk *clk = of_clk_get_by_name(np, "fixed");
+	int ret;
+
+	clk = of_clk_get(np, 0);
+	if (IS_ERR(clk)) {
+		pr_err("Failed to get clock");
+		return PTR_ERR(clk);
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		return ret;
 
-	/* The 25Mhz fixed clock is mandatory, and must always be available */
-	BUG_ON(IS_ERR(clk));
-	clk_prepare_enable(clk);
 	timer_clk = clk_get_rate(clk);
 
-	armada_370_xp_timer_common_init(np);
+	return armada_370_xp_timer_common_init(np);
 }
-CLOCKSOURCE_OF_DECLARE(armada_xp, "marvell,armada-xp-timer",
+CLOCKSOURCE_OF_DECLARE_RET(armada_xp, "marvell,armada-xp-timer",
 		       armada_xp_timer_init);
 
-static void __init armada_375_timer_init(struct device_node *np)
+static int __init armada_375_timer_init(struct device_node *np)
 {
 	struct clk *clk;
+	int ret;
 
 	clk = of_clk_get_by_name(np, "fixed");
 	if (!IS_ERR(clk)) {
-		clk_prepare_enable(clk);
+		ret = clk_prepare_enable(clk);
+		if (ret)
+			return ret;
 		timer_clk = clk_get_rate(clk);
 	} else {
 
@@ -360,27 +394,43 @@ static void __init armada_375_timer_init(struct device_node *np)
 		clk = of_clk_get(np, 0);
 
 		/* Must have at least a clock */
-		BUG_ON(IS_ERR(clk));
-		clk_prepare_enable(clk);
+		if (IS_ERR(clk)) {
+			pr_err("Failed to get clock");
+			return PTR_ERR(clk);
+		}
+
+		ret = clk_prepare_enable(clk);
+		if (ret)
+			return ret;
+
 		timer_clk = clk_get_rate(clk) / TIMER_DIVIDER;
 		timer25Mhz = false;
 	}
 
-	armada_370_xp_timer_common_init(np);
+	return armada_370_xp_timer_common_init(np);
 }
-CLOCKSOURCE_OF_DECLARE(armada_375, "marvell,armada-375-timer",
+CLOCKSOURCE_OF_DECLARE_RET(armada_375, "marvell,armada-375-timer",
 		       armada_375_timer_init);
 
-static void __init armada_370_timer_init(struct device_node *np)
+static int __init armada_370_timer_init(struct device_node *np)
 {
-	struct clk *clk = of_clk_get(np, 0);
+	struct clk *clk;
+	int ret;
+
+	clk = of_clk_get(np, 0);
+	if (IS_ERR(clk)) {
+		pr_err("Failed to get clock");
+		return PTR_ERR(clk);
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		return ret;
 
-	BUG_ON(IS_ERR(clk));
-	clk_prepare_enable(clk);
 	timer_clk = clk_get_rate(clk) / TIMER_DIVIDER;
 	timer25Mhz = false;
 
-	armada_370_xp_timer_common_init(np);
+	return armada_370_xp_timer_common_init(np);
 }
-CLOCKSOURCE_OF_DECLARE(armada_370, "marvell,armada-370-timer",
+CLOCKSOURCE_OF_DECLARE_RET(armada_370, "marvell,armada-370-timer",
 		       armada_370_timer_init);