clocksource/drivers/pistachio: 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-pistachio.c

@@ -148,7 +148,7 @@ static struct pistachio_clocksource pcs_gpt = {
 		},
 };
 
-static void __init pistachio_clksrc_of_init(struct device_node *node)
+static int __init pistachio_clksrc_of_init(struct device_node *node)
 {
 	struct clk *sys_clk, *fast_clk;
 	struct regmap *periph_regs;
@@ -158,45 +158,45 @@ static void __init pistachio_clksrc_of_init(struct device_node *node)
 	pcs_gpt.base = of_iomap(node, 0);
 	if (!pcs_gpt.base) {
 		pr_err("cannot iomap\n");
-		return;
+		return -ENXIO;
 	}
 
 	periph_regs = syscon_regmap_lookup_by_phandle(node, "img,cr-periph");
 	if (IS_ERR(periph_regs)) {
 		pr_err("cannot get peripheral regmap (%ld)\n",
 		       PTR_ERR(periph_regs));
-		return;
+		return PTR_ERR(periph_regs);
 	}
 
 	/* Switch to using the fast counter clock */
 	ret = regmap_update_bits(periph_regs, PERIP_TIMER_CONTROL,
 				 0xf, 0x0);
 	if (ret)
-		return;
+		return ret;
 
 	sys_clk = of_clk_get_by_name(node, "sys");
 	if (IS_ERR(sys_clk)) {
 		pr_err("clock get failed (%ld)\n", PTR_ERR(sys_clk));
-		return;
+		return PTR_ERR(sys_clk);
 	}
 
 	fast_clk = of_clk_get_by_name(node, "fast");
 	if (IS_ERR(fast_clk)) {
 		pr_err("clock get failed (%lu)\n", PTR_ERR(fast_clk));
-		return;
+		return PTR_ERR(fast_clk);
 	}
 
 	ret = clk_prepare_enable(sys_clk);
 	if (ret < 0) {
 		pr_err("failed to enable clock (%d)\n", ret);
-		return;
+		return ret;
 	}
 
 	ret = clk_prepare_enable(fast_clk);
 	if (ret < 0) {
 		pr_err("failed to enable clock (%d)\n", ret);
 		clk_disable_unprepare(sys_clk);
-		return;
+		return ret;
 	}
 
 	rate = clk_get_rate(fast_clk);
@@ -212,7 +212,7 @@ static void __init pistachio_clksrc_of_init(struct device_node *node)
 
 	raw_spin_lock_init(&pcs_gpt.lock);
 	sched_clock_register(pistachio_read_sched_clock, 32, rate);
-	clocksource_register_hz(&pcs_gpt.cs, rate);
+	return clocksource_register_hz(&pcs_gpt.cs, rate);
 }
-CLOCKSOURCE_OF_DECLARE(pistachio_gptimer, "img,pistachio-gptimer",
+CLOCKSOURCE_OF_DECLARE_RET(pistachio_gptimer, "img,pistachio-gptimer",
 		       pistachio_clksrc_of_init);