clocksource/drivers/nios2: 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>

diff --git a/arch/nios2/kernel/time.c b/arch/nios2/kernel/time.c
index e835dda..b75e40e 100644 (file)
--- a/arch/nios2/kernel/time.c
+++ b/arch/nios2/kernel/time.c
@@ -206,15 +206,21 @@ irqreturn_t timer_interrupt(int irq, void *dev_id)
        return IRQ_HANDLED;
 }
 
-static void __init nios2_timer_get_base_and_freq(struct device_node *np,
+static int __init nios2_timer_get_base_and_freq(struct device_node *np,
                                void __iomem **base, u32 *freq)
 {
        *base = of_iomap(np, 0);
-       if (!*base)
-               panic("Unable to map reg for %s\n", np->name);
+       if (!*base) {
+               pr_crit("Unable to map reg for %s\n", np->name);
+               return -ENXIO;
+       }
+
+       if (of_property_read_u32(np, "clock-frequency", freq)) {
+               pr_crit("Unable to get %s clock frequency\n", np->name);
+               return -EINVAL;
+       }
 
-       if (of_property_read_u32(np, "clock-frequency", freq))
-               panic("Unable to get %s clock frequency\n", np->name);
+       return 0;
 }
 
 static struct nios2_clockevent_dev nios2_ce = {
@@ -231,17 +237,21 @@ static struct nios2_clockevent_dev nios2_ce = {
        },
 };
 
-static __init void nios2_clockevent_init(struct device_node *timer)
+static __init int nios2_clockevent_init(struct device_node *timer)
 {
        void __iomem *iobase;
        u32 freq;
-       int irq;
+       int irq, ret;
 
-       nios2_timer_get_base_and_freq(timer, &iobase, &freq);
+       ret = nios2_timer_get_base_and_freq(timer, &iobase, &freq);
+       if (ret)
+               return ret;
 
        irq = irq_of_parse_and_map(timer, 0);
-       if (!irq)
-               panic("Unable to parse timer irq\n");
+       if (!irq) {
+               pr_crit("Unable to parse timer irq\n");
+               return -EINVAL;
+       }
 
        nios2_ce.timer.base = iobase;
        nios2_ce.timer.freq = freq;
@@ -253,25 +263,35 @@ static __init void nios2_clockevent_init(struct device_node *timer)
        /* clear pending interrupt */
        timer_writew(&nios2_ce.timer, 0, ALTERA_TIMER_STATUS_REG);
 
-       if (request_irq(irq, timer_interrupt, IRQF_TIMER, timer->name,
-               &nios2_ce.ced))
-               panic("Unable to setup timer irq\n");
+       ret = request_irq(irq, timer_interrupt, IRQF_TIMER, timer->name,
+                         &nios2_ce.ced);
+       if (ret) {
+               pr_crit("Unable to setup timer irq\n");
+               return ret;
+       }
 
        clockevents_config_and_register(&nios2_ce.ced, freq, 1, ULONG_MAX);
+
+       return 0;
 }
 
-static __init void nios2_clocksource_init(struct device_node *timer)
+static __init int nios2_clocksource_init(struct device_node *timer)
 {
        unsigned int ctrl;
        void __iomem *iobase;
        u32 freq;
+       int ret;
 
-       nios2_timer_get_base_and_freq(timer, &iobase, &freq);
+       ret = nios2_timer_get_base_and_freq(timer, &iobase, &freq);
+       if (ret)
+               return ret;
 
        nios2_cs.timer.base = iobase;
        nios2_cs.timer.freq = freq;
 
-       clocksource_register_hz(&nios2_cs.cs, freq);
+       ret = clocksource_register_hz(&nios2_cs.cs, freq);
+       if (ret)
+               return ret;
 
        timer_writew(&nios2_cs.timer, USHRT_MAX, ALTERA_TIMER_PERIODL_REG);
        timer_writew(&nios2_cs.timer, USHRT_MAX, ALTERA_TIMER_PERIODH_REG);
@@ -282,6 +302,8 @@ static __init void nios2_clocksource_init(struct device_node *timer)
 
        /* Calibrate the delay loop directly */
        lpj_fine = freq / HZ;
+
+       return 0;
 }
 
 /*
@@ -289,22 +311,25 @@ static __init void nios2_clocksource_init(struct device_node *timer)
  * more instances, the second one gets used as clocksource and all
  * others are unused.
 */
-static void __init nios2_time_init(struct device_node *timer)
+static int __init nios2_time_init(struct device_node *timer)
 {
        static int num_called;
+       int ret;
 
        switch (num_called) {
        case 0:
-               nios2_clockevent_init(timer);
+               ret = nios2_clockevent_init(timer);
                break;
        case 1:
-               nios2_clocksource_init(timer);
+               ret = nios2_clocksource_init(timer);
                break;
        default:
                break;
        }
 
        num_called++;
+
+       return ret;
 }
 
 void read_persistent_clock(struct timespec *ts)
@@ -327,4 +352,4 @@ void __init time_init(void)
        clocksource_probe();
 }
 
-CLOCKSOURCE_OF_DECLARE(nios2_timer, ALTR_TIMER_COMPATIBLE, nios2_time_init);
+CLOCKSOURCE_OF_DECLARE_RET(nios2_timer, ALTR_TIMER_COMPATIBLE, nios2_time_init);