clocksource/drivers/sp804: 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>

2 files changed, 63 insertions, 35 deletions

diff --git a/drivers/clocksource/timer-sp804.c b/drivers/clocksource/timer-sp804.c
index 5f45b9adef60..3dc47efc9298 100644
--- a/drivers/clocksource/timer-sp804.c
+++ b/drivers/clocksource/timer-sp804.c
@@ -77,7 +77,7 @@ void __init sp804_timer_disable(void __iomem *base)
         writel(0, base + TIMER_CTRL);
 }
 
-void __init __sp804_clocksource_and_sched_clock_init(void __iomem *base,
+int  __init __sp804_clocksource_and_sched_clock_init(void __iomem *base,
                                                      const char *name,
                                                      struct clk *clk,
                                                      int use_sched_clock)
@@ -89,14 +89,13 @@ void __init __sp804_clocksource_and_sched_clock_init(void __iomem *base,
                 if (IS_ERR(clk)) {
                         pr_err("sp804: clock not found: %d\n",
                                (int)PTR_ERR(clk));
-                        return;
+                        return PTR_ERR(clk);
                 }
         }
 
         rate = sp804_get_clock_rate(clk);
-
         if (rate < 0)
-                return;
+                return -EINVAL;
 
         /* setup timer 0 as free-running clocksource */
         writel(0, base + TIMER_CTRL);
@@ -112,6 +111,8 @@ void __init __sp804_clocksource_and_sched_clock_init(void __iomem *base,
                 sched_clock_base = base;
                 sched_clock_register(sp804_read, 32, rate);
         }
+
+        return 0;
 }
 
 
@@ -186,7 +187,7 @@ static struct irqaction sp804_timer_irq = {
         .dev_id         = &sp804_clockevent,
 };
 
-void __init __sp804_clockevents_init(void __iomem *base, unsigned int irq, struct clk *clk, const char *name)
+int __init __sp804_clockevents_init(void __iomem *base, unsigned int irq, struct clk *clk, const char *name)
 {
         struct clock_event_device *evt = &sp804_clockevent;
         long rate;
@@ -196,12 +197,12 @@ void __init __sp804_clockevents_init(void __iomem *base, unsigned int irq, struc
         if (IS_ERR(clk)) {
                 pr_err("sp804: %s clock not found: %d\n", name,
                         (int)PTR_ERR(clk));
-                return;
+                return PTR_ERR(clk);
         }
 
         rate = sp804_get_clock_rate(clk);
         if (rate < 0)
-                return;
+                return -EINVAL;
 
         clkevt_base = base;
         clkevt_reload = DIV_ROUND_CLOSEST(rate, HZ);
@@ -213,27 +214,31 @@ void __init __sp804_clockevents_init(void __iomem *base, unsigned int irq, struc
 
         setup_irq(irq, &sp804_timer_irq);
         clockevents_config_and_register(evt, rate, 0xf, 0xffffffff);
+
+        return 0;
 }
 
-static void __init sp804_of_init(struct device_node *np)
+static int __init sp804_of_init(struct device_node *np)
 {
         static bool initialized = false;
         void __iomem *base;
-        int irq;
+        int irq, ret = -EINVAL;
         u32 irq_num = 0;
         struct clk *clk1, *clk2;
         const char *name = of_get_property(np, "compatible", NULL);
 
         base = of_iomap(np, 0);
-        if (WARN_ON(!base))
-                return;
+        if (!base)
+                return -ENXIO;
 
         /* Ensure timers are disabled */
         writel(0, base + TIMER_CTRL);
         writel(0, base + TIMER_2_BASE + TIMER_CTRL);
 
-        if (initialized || !of_device_is_available(np))
+        if (initialized || !of_device_is_available(np)) {
+                ret = -EINVAL;
                 goto err;
+        }
 
         clk1 = of_clk_get(np, 0);
         if (IS_ERR(clk1))
@@ -256,35 +261,53 @@ static void __init sp804_of_init(struct device_node *np)
 
         of_property_read_u32(np, "arm,sp804-has-irq", &irq_num);
         if (irq_num == 2) {
-                __sp804_clockevents_init(base + TIMER_2_BASE, irq, clk2, name);
-                __sp804_clocksource_and_sched_clock_init(base, name, clk1, 1);
+
+                ret = __sp804_clockevents_init(base + TIMER_2_BASE, irq, clk2, name);
+                if (ret)
+                        goto err;
+
+                ret = __sp804_clocksource_and_sched_clock_init(base, name, clk1, 1);
+                if (ret)
+                        goto err;
         } else {
-                __sp804_clockevents_init(base, irq, clk1 , name);
-                __sp804_clocksource_and_sched_clock_init(base + TIMER_2_BASE,
-                                                         name, clk2, 1);
+
+                ret = __sp804_clockevents_init(base, irq, clk1 , name);
+                if (ret)
+                        goto err;
+
+                ret =__sp804_clocksource_and_sched_clock_init(base + TIMER_2_BASE,
+                                                              name, clk2, 1);
+                if (ret)
+                        goto err;
         }
         initialized = true;
 
-        return;
+        return 0;
 err:
         iounmap(base);
+        return ret;
 }
-CLOCKSOURCE_OF_DECLARE(sp804, "arm,sp804", sp804_of_init);
+CLOCKSOURCE_OF_DECLARE_RET(sp804, "arm,sp804", sp804_of_init);
 
-static void __init integrator_cp_of_init(struct device_node *np)
+static int __init integrator_cp_of_init(struct device_node *np)
 {
         static int init_count = 0;
         void __iomem *base;
-        int irq;
+        int irq, ret = -EINVAL;
         const char *name = of_get_property(np, "compatible", NULL);
         struct clk *clk;
 
         base = of_iomap(np, 0);
-        if (WARN_ON(!base))
-                return;
+        if (!base) {
+                pr_err("Failed to iomap");
+                return -ENXIO;
+        }
+
         clk = of_clk_get(np, 0);
-        if (WARN_ON(IS_ERR(clk)))
-                return;
+        if (IS_ERR(clk)) {
+                pr_err("Failed to get clock");
+                return PTR_ERR(clk);
+        }
 
         /* Ensure timer is disabled */
         writel(0, base + TIMER_CTRL);
@@ -292,19 +315,24 @@ static void __init integrator_cp_of_init(struct device_node *np)
         if (init_count == 2 || !of_device_is_available(np))
                 goto err;
 
-        if (!init_count)
-                __sp804_clocksource_and_sched_clock_init(base, name, clk, 0);
-        else {
+        if (!init_count) {
+                ret = __sp804_clocksource_and_sched_clock_init(base, name, clk, 0);
+                if (ret)
+                        goto err;
+        } else {
                 irq = irq_of_parse_and_map(np, 0);
                 if (irq <= 0)
                         goto err;
 
-                __sp804_clockevents_init(base, irq, clk, name);
+                ret = __sp804_clockevents_init(base, irq, clk, name);
+                if (ret)
+                        goto err;
         }
 
         init_count++;
-        return;
+        return 0;
 err:
         iounmap(base);
+        return ret;
 }
-CLOCKSOURCE_OF_DECLARE(intcp, "arm,integrator-cp-timer", integrator_cp_of_init);
+CLOCKSOURCE_OF_DECLARE_RET(intcp, "arm,integrator-cp-timer", integrator_cp_of_init);
diff --git a/include/clocksource/timer-sp804.h b/include/clocksource/timer-sp804.h
index 1f8a1caa7cb4..7654d71243dd 100644
--- a/include/clocksource/timer-sp804.h
+++ b/include/clocksource/timer-sp804.h
@@ -3,10 +3,10 @@
 
 struct clk;
 
-void __sp804_clocksource_and_sched_clock_init(void __iomem *,
-                                              const char *, struct clk *, int);
-void __sp804_clockevents_init(void __iomem *, unsigned int,
-                              struct clk *, const char *);
+int __sp804_clocksource_and_sched_clock_init(void __iomem *,
+                                             const char *, struct clk *, int);
+int __sp804_clockevents_init(void __iomem *, unsigned int,
+                             struct clk *, const char *);
 void sp804_timer_disable(void __iomem *);
 
 static inline void sp804_clocksource_init(void __iomem *base, const char *name)