clocksource/drivers/integrator-ap: 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, 38 insertions, 21 deletions

diff --git a/drivers/clocksource/timer-integrator-ap.c b/drivers/clocksource/timer-integrator-ap.c
index 3f59ac2180dc..675faceab5d6 100644
--- a/drivers/clocksource/timer-integrator-ap.c
+++ b/drivers/clocksource/timer-integrator-ap.c
@@ -36,11 +36,12 @@ static u64 notrace integrator_read_sched_clock(void)
         return -readl(sched_clk_base + TIMER_VALUE);
 }
 
-static void integrator_clocksource_init(unsigned long inrate,
-                                        void __iomem *base)
+static int integrator_clocksource_init(unsigned long inrate,
+                                       void __iomem *base)
 {
         u32 ctrl = TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC;
         unsigned long rate = inrate;
+        int ret;
 
         if (rate >= 1500000) {
                 rate /= 16;
@@ -50,11 +51,15 @@ static void integrator_clocksource_init(unsigned long inrate,
         writel(0xffff, base + TIMER_LOAD);
         writel(ctrl, base + TIMER_CTRL);
 
-        clocksource_mmio_init(base + TIMER_VALUE, "timer2",
-                        rate, 200, 16, clocksource_mmio_readl_down);
+        ret = clocksource_mmio_init(base + TIMER_VALUE, "timer2",
+                                    rate, 200, 16, clocksource_mmio_readl_down);
+        if (ret)
+                return ret;
 
         sched_clk_base = base;
         sched_clock_register(integrator_read_sched_clock, 16, rate);
+
+        return 0;
 }
 
 static unsigned long timer_reload;
@@ -138,11 +143,12 @@ static struct irqaction integrator_timer_irq = {
         .dev_id         = &integrator_clockevent,
 };
 
-static void integrator_clockevent_init(unsigned long inrate,
-                                void __iomem *base, int irq)
+static int integrator_clockevent_init(unsigned long inrate,
+                                      void __iomem *base, int irq)
 {
         unsigned long rate = inrate;
         unsigned int ctrl = 0;
+        int ret;
 
         clkevt_base = base;
         /* Calculate and program a divisor */
@@ -156,14 +162,18 @@ static void integrator_clockevent_init(unsigned long inrate,
         timer_reload = rate / HZ;
         writel(ctrl, clkevt_base + TIMER_CTRL);
 
-        setup_irq(irq, &integrator_timer_irq);
+        ret = setup_irq(irq, &integrator_timer_irq);
+        if (ret)
+                return ret;
+
         clockevents_config_and_register(&integrator_clockevent,
                                         rate,
                                         1,
                                         0xffffU);
+        return 0;
 }
 
-static void __init integrator_ap_timer_init_of(struct device_node *node)
+static int __init integrator_ap_timer_init_of(struct device_node *node)
 {
         const char *path;
         void __iomem *base;
@@ -176,12 +186,12 @@ static void __init integrator_ap_timer_init_of(struct device_node *node)
 
         base = of_io_request_and_map(node, 0, "integrator-timer");
         if (IS_ERR(base))
-                return;
+                return PTR_ERR(base);
 
         clk = of_clk_get(node, 0);
         if (IS_ERR(clk)) {
                 pr_err("No clock for %s\n", node->name);
-                return;
+                return PTR_ERR(clk);
         }
         clk_prepare_enable(clk);
         rate = clk_get_rate(clk);
@@ -189,31 +199,38 @@ static void __init integrator_ap_timer_init_of(struct device_node *node)
 
         err = of_property_read_string(of_aliases,
                                 "arm,timer-primary", &path);
-        if (WARN_ON(err))
-                return;
+        if (err) {
+                pr_warn("Failed to read property");
+                return err;
+        }
+
         pri_node = of_find_node_by_path(path);
+
         err = of_property_read_string(of_aliases,
                                 "arm,timer-secondary", &path);
-        if (WARN_ON(err))
-                return;
+        if (err) {
+                pr_warn("Failed to read property");             
+                return err;
+        }
+
+
         sec_node = of_find_node_by_path(path);
 
-        if (node == pri_node) {
+        if (node == pri_node)
                 /* The primary timer lacks IRQ, use as clocksource */
-                integrator_clocksource_init(rate, base);
-                return;
-        }
+                return integrator_clocksource_init(rate, base);
 
         if (node == sec_node) {
                 /* The secondary timer will drive the clock event */
                 irq = irq_of_parse_and_map(node, 0);
-                integrator_clockevent_init(rate, base, irq);
-                return;
+                return integrator_clockevent_init(rate, base, irq);
         }
 
         pr_info("Timer @%p unused\n", base);
         clk_disable_unprepare(clk);
+
+        return 0;
 }
 
-CLOCKSOURCE_OF_DECLARE(integrator_ap_timer, "arm,integrator-timer",
+CLOCKSOURCE_OF_DECLARE_RET(integrator_ap_timer, "arm,integrator-timer",
                        integrator_ap_timer_init_of);