clocksource/drivers/atmel-pit: 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>

1 files changed, 29 insertions, 14 deletions

diff --git a/drivers/clocksource/timer-atmel-pit.c b/drivers/clocksource/timer-atmel-pit.c
index d911c5dca8f1..ffaca7c2c996 100644
--- a/drivers/clocksource/timer-atmel-pit.c
+++ b/drivers/clocksource/timer-atmel-pit.c
@@ -177,7 +177,7 @@ static irqreturn_t at91sam926x_pit_interrupt(int irq, void *dev_id)
 /*
  * Set up both clocksource and clockevent support.
  */
-static void __init at91sam926x_pit_common_init(struct pit_data *data)
+static int __init at91sam926x_pit_common_init(struct pit_data *data)
 {
         unsigned long   pit_rate;
         unsigned        bits;
@@ -204,14 +204,21 @@ static void __init at91sam926x_pit_common_init(struct pit_data *data)
         data->clksrc.rating = 175;
         data->clksrc.read = read_pit_clk;
         data->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
-        clocksource_register_hz(&data->clksrc, pit_rate);
+        
+        ret = clocksource_register_hz(&data->clksrc, pit_rate);
+        if (ret) {
+                pr_err("Failed to register clocksource");
+                return ret;
+        }
 
         /* Set up irq handler */
         ret = request_irq(data->irq, at91sam926x_pit_interrupt,
                           IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL,
                           "at91_tick", data);
-        if (ret)
-                panic(pr_fmt("Unable to setup IRQ\n"));
+        if (ret) {
+                pr_err("Unable to setup IRQ\n");
+                return ret;
+        }
 
         /* Set up and register clockevents */
         data->clkevt.name = "pit";
@@ -226,34 +233,42 @@ static void __init at91sam926x_pit_common_init(struct pit_data *data)
         data->clkevt.resume = at91sam926x_pit_resume;
         data->clkevt.suspend = at91sam926x_pit_suspend;
         clockevents_register_device(&data->clkevt);
+
+        return 0;
 }
 
-static void __init at91sam926x_pit_dt_init(struct device_node *node)
+static int __init at91sam926x_pit_dt_init(struct device_node *node)
 {
         struct pit_data *data;
 
         data = kzalloc(sizeof(*data), GFP_KERNEL);
         if (!data)
-                panic(pr_fmt("Unable to allocate memory\n"));
+                return -ENOMEM;
 
         data->base = of_iomap(node, 0);
-        if (!data->base)
-                panic(pr_fmt("Could not map PIT address\n"));
+        if (!data->base) {
+                pr_err("Could not map PIT address\n");
+                return -ENXIO;
+        }
 
         data->mck = of_clk_get(node, 0);
         if (IS_ERR(data->mck))
                 /* Fallback on clkdev for !CCF-based boards */
                 data->mck = clk_get(NULL, "mck");
 
-        if (IS_ERR(data->mck))
-                panic(pr_fmt("Unable to get mck clk\n"));
+        if (IS_ERR(data->mck)) {
+                pr_err("Unable to get mck clk\n");
+                return PTR_ERR(data->mck);
+        }
 
         /* Get the interrupts property */
         data->irq = irq_of_parse_and_map(node, 0);
-        if (!data->irq)
-                panic(pr_fmt("Unable to get IRQ from DT\n"));
+        if (!data->irq) {
+                pr_err("Unable to get IRQ from DT\n");
+                return -EINVAL;
+        }
 
-        at91sam926x_pit_common_init(data);
+        return at91sam926x_pit_common_init(data);
 }
-CLOCKSOURCE_OF_DECLARE(at91sam926x_pit, "atmel,at91sam9260-pit",
+CLOCKSOURCE_OF_DECLARE_RET(at91sam926x_pit, "atmel,at91sam9260-pit",
                        at91sam926x_pit_dt_init);