clocksource/drivers/bcm2835_timer: 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>
Acked-by: Eric Anholt <eric@anholt.net>

diff --git a/drivers/clocksource/bcm2835_timer.c b/drivers/clocksource/bcm2835_timer.c
index 6f28229..2dcf896 100644 (file)
--- a/drivers/clocksource/bcm2835_timer.c
+++ b/drivers/clocksource/bcm2835_timer.c
@@ -80,19 +80,24 @@ static irqreturn_t bcm2835_time_interrupt(int irq, void *dev_id)
        }
 }
 
-static void __init bcm2835_timer_init(struct device_node *node)
+static int __init bcm2835_timer_init(struct device_node *node)
 {
        void __iomem *base;
        u32 freq;
-       int irq;
+       int irq, ret;
        struct bcm2835_timer *timer;
 
        base = of_iomap(node, 0);
-       if (!base)
-               panic("Can't remap registers");
+       if (!base) {
+               pr_err("Can't remap registers");
+               return -ENXIO;
+       }
 
-       if (of_property_read_u32(node, "clock-frequency", &freq))
-               panic("Can't read clock-frequency");
+       ret = of_property_read_u32(node, "clock-frequency", &freq);
+       if (ret) {
+               pr_err("Can't read clock-frequency");
+               return ret;
+       }
 
        system_clock = base + REG_COUNTER_LO;
        sched_clock_register(bcm2835_sched_read, 32, freq);
@@ -101,12 +106,16 @@ static void __init bcm2835_timer_init(struct device_node *node)
                freq, 300, 32, clocksource_mmio_readl_up);
 
        irq = irq_of_parse_and_map(node, DEFAULT_TIMER);
-       if (irq <= 0)
-               panic("Can't parse IRQ");
+       if (irq <= 0) {
+               pr_err("Can't parse IRQ");
+               return -EINVAL;
+       }
 
        timer = kzalloc(sizeof(*timer), GFP_KERNEL);
-       if (!timer)
-               panic("Can't allocate timer struct\n");
+       if (!timer) {
+               pr_err("Can't allocate timer struct\n");
+               return -ENOMEM;
+       }
 
        timer->control = base + REG_CONTROL;
        timer->compare = base + REG_COMPARE(DEFAULT_TIMER);
@@ -121,12 +130,17 @@ static void __init bcm2835_timer_init(struct device_node *node)
        timer->act.dev_id = timer;
        timer->act.handler = bcm2835_time_interrupt;
 
-       if (setup_irq(irq, &timer->act))
-               panic("Can't set up timer IRQ\n");
+       ret = setup_irq(irq, &timer->act);
+       if (ret) {
+               pr_err("Can't set up timer IRQ\n");
+               return ret;
+       }
 
        clockevents_config_and_register(&timer->evt, freq, 0xf, 0xffffffff);
 
        pr_info("bcm2835: system timer (irq = %d)\n", irq);
+
+       return 0;
 }
-CLOCKSOURCE_OF_DECLARE(bcm2835, "brcm,bcm2835-system-timer",
+CLOCKSOURCE_OF_DECLARE_RET(bcm2835, "brcm,bcm2835-system-timer",
                        bcm2835_timer_init);