clocksource/drivers/nps: 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>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

drivers/clocksource/timer-nps.c

@@ -55,7 +55,7 @@ static cycle_t nps_clksrc_read(struct clocksource *clksrc)
 	return (cycle_t)ioread32be(nps_msu_reg_low_addr[cluster]);
 }
 
-static void __init nps_setup_clocksource(struct device_node *node,
+static int __init nps_setup_clocksource(struct device_node *node,
 					struct clk *clk)
 {
 	int ret, cluster;
@@ -68,7 +68,7 @@ static void __init nps_setup_clocksource(struct device_node *node,
 	ret = clk_prepare_enable(clk);
 	if (ret) {
 		pr_err("Couldn't enable parent clock\n");
-		return;
+		return ret;
 	}
 
 	nps_timer_rate = clk_get_rate(clk);
@@ -79,20 +79,22 @@ static void __init nps_setup_clocksource(struct device_node *node,
 		pr_err("Couldn't register clock source.\n");
 		clk_disable_unprepare(clk);
 	}
+
+	return ret;
 }
 
-static void __init nps_timer_init(struct device_node *node)
+static int __init nps_timer_init(struct device_node *node)
 {
 	struct clk *clk;
 
 	clk = of_clk_get(node, 0);
 	if (IS_ERR(clk)) {
 		pr_err("Can't get timer clock.\n");
-		return;
+		return PTR_ERR(clk);
 	}
 
-	nps_setup_clocksource(node, clk);
+	return nps_setup_clocksource(node, clk);
 }
 
-CLOCKSOURCE_OF_DECLARE(ezchip_nps400_clksrc, "ezchip,nps400-timer",
+CLOCKSOURCE_OF_DECLARE_RET(ezchip_nps400_clksrc, "ezchip,nps400-timer",
 			   nps_timer_init);