clocksource/drivers/atmel-st: 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, 28 insertions, 16 deletions

diff --git a/drivers/clocksource/timer-atmel-st.c b/drivers/clocksource/timer-atmel-st.c
index 29d21d68df5a..e9331d36965b 100644
--- a/drivers/clocksource/timer-atmel-st.c
+++ b/drivers/clocksource/timer-atmel-st.c
@@ -194,15 +194,17 @@ static struct clock_event_device clkevt = {
 /*
  * ST (system timer) module supports both clockevents and clocksource.
  */
-static void __init atmel_st_timer_init(struct device_node *node)
+static int __init atmel_st_timer_init(struct device_node *node)
 {
         struct clk *sclk;
         unsigned int sclk_rate, val;
         int irq, ret;
 
         regmap_st = syscon_node_to_regmap(node);
-        if (IS_ERR(regmap_st))
-                panic(pr_fmt("Unable to get regmap\n"));
+        if (IS_ERR(regmap_st)) {
+                pr_err("Unable to get regmap\n");
+                return PTR_ERR(regmap_st);
+        }
 
         /* Disable all timer interrupts, and clear any pending ones */
         regmap_write(regmap_st, AT91_ST_IDR,
@@ -211,27 +213,37 @@ static void __init atmel_st_timer_init(struct device_node *node)
 
         /* Get the interrupts property */
         irq  = irq_of_parse_and_map(node, 0);
-        if (!irq)
-                panic(pr_fmt("Unable to get IRQ from DT\n"));
+        if (!irq) {
+                pr_err("Unable to get IRQ from DT\n");
+                return -EINVAL;
+        }
 
         /* Make IRQs happen for the system timer */
         ret = request_irq(irq, at91rm9200_timer_interrupt,
                           IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL,
                           "at91_tick", regmap_st);
-        if (ret)
-                panic(pr_fmt("Unable to setup IRQ\n"));
+        if (ret) {
+                pr_err("Unable to setup IRQ\n");
+                return ret;
+        }
 
         sclk = of_clk_get(node, 0);
-        if (IS_ERR(sclk))
-                panic(pr_fmt("Unable to get slow clock\n"));
+        if (IS_ERR(sclk)) {
+                pr_err("Unable to get slow clock\n");
+                return PTR_ERR(sclk);
+        }
 
-        clk_prepare_enable(sclk);
-        if (ret)
-                panic(pr_fmt("Could not enable slow clock\n"));
+        ret = clk_prepare_enable(sclk);
+        if (ret) {
+                pr_err("Could not enable slow clock\n");
+                return ret;
+        }
 
         sclk_rate = clk_get_rate(sclk);
-        if (!sclk_rate)
-                panic(pr_fmt("Invalid slow clock rate\n"));
+        if (!sclk_rate) {
+                pr_err("Invalid slow clock rate\n");
+                return -EINVAL;
+        }
         timer_latch = (sclk_rate + HZ / 2) / HZ;
 
         /* The 32KiHz "Slow Clock" (tick every 30517.58 nanoseconds) is used
@@ -246,7 +258,7 @@ static void __init atmel_st_timer_init(struct device_node *node)
                                         2, AT91_ST_ALMV);
 
         /* register clocksource */
-        clocksource_register_hz(&clk32k, sclk_rate);
+        return clocksource_register_hz(&clk32k, sclk_rate);
 }
-CLOCKSOURCE_OF_DECLARE(atmel_st_timer, "atmel,at91rm9200-st",
+CLOCKSOURCE_OF_DECLARE_RET(atmel_st_timer, "atmel,at91rm9200-st",
                        atmel_st_timer_init);