clocksource/drivers/nomadik-mtu: 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/drivers/clocksource/nomadik-mtu.c b/drivers/clocksource/nomadik-mtu.c
index bc8dd443c72711f776eafd90562a35949ccd0856..d2be5b3e0318788d495741f4a4463cf0601948b3 100644 (file)
--- a/drivers/clocksource/nomadik-mtu.c
+++ b/drivers/clocksource/nomadik-mtu.c
@@ -193,10 +193,11 @@ static struct irqaction nmdk_timer_irq = {
        .dev_id         = &nmdk_clkevt,
 };
 
-static void __init nmdk_timer_init(void __iomem *base, int irq,
+static int __init nmdk_timer_init(void __iomem *base, int irq,
                                   struct clk *pclk, struct clk *clk)
 {
        unsigned long rate;
+       int ret;
 
        mtu_base = base;
 
@@ -226,10 +227,12 @@ static void __init nmdk_timer_init(void __iomem *base, int irq,
        /* Timer 0 is the free running clocksource */
        nmdk_clksrc_reset();
 
-       if (clocksource_mmio_init(mtu_base + MTU_VAL(0), "mtu_0",
-                       rate, 200, 32, clocksource_mmio_readl_down))
-               pr_err("timer: failed to initialize clock source %s\n",
-                      "mtu_0");
+       ret = clocksource_mmio_init(mtu_base + MTU_VAL(0), "mtu_0",
+                                   rate, 200, 32, clocksource_mmio_readl_down);
+       if (ret) {
+               pr_err("timer: failed to initialize clock source %s\n", "mtu_0");
+               return ret;
+       }
 
 #ifdef CONFIG_CLKSRC_NOMADIK_MTU_SCHED_CLOCK
        sched_clock_register(nomadik_read_sched_clock, 32, rate);
@@ -244,9 +247,11 @@ static void __init nmdk_timer_init(void __iomem *base, int irq,
        mtu_delay_timer.read_current_timer = &nmdk_timer_read_current_timer;
        mtu_delay_timer.freq = rate;
        register_current_timer_delay(&mtu_delay_timer);
+
+       return 0;
 }
 
-static void __init nmdk_timer_of_init(struct device_node *node)
+static int __init nmdk_timer_of_init(struct device_node *node)
 {
        struct clk *pclk;
        struct clk *clk;
@@ -254,22 +259,30 @@ static void __init nmdk_timer_of_init(struct device_node *node)
        int irq;
 
        base = of_iomap(node, 0);
-       if (!base)
-               panic("Can't remap registers");
+       if (!base) {
+               pr_err("Can't remap registers");
+               return -ENXIO;
+       }
 
        pclk = of_clk_get_by_name(node, "apb_pclk");
-       if (IS_ERR(pclk))
-               panic("could not get apb_pclk");
+       if (IS_ERR(pclk)) {
+               pr_err("could not get apb_pclk");
+               return PTR_ERR(pclk);
+       }
 
        clk = of_clk_get_by_name(node, "timclk");
-       if (IS_ERR(clk))
-               panic("could not get timclk");
+       if (IS_ERR(clk)) {
+               pr_err("could not get timclk");
+               return PTR_ERR(clk);
+       }
 
        irq = irq_of_parse_and_map(node, 0);
-       if (irq <= 0)
-               panic("Can't parse IRQ");
+       if (irq <= 0) {
+               pr_err("Can't parse IRQ");
+               return -EINVAL;
+       }
 
-       nmdk_timer_init(base, irq, pclk, clk);
+       return nmdk_timer_init(base, irq, pclk, clk);
 }
-CLOCKSOURCE_OF_DECLARE(nomadik_mtu, "st,nomadik-mtu",
+CLOCKSOURCE_OF_DECLARE_RET(nomadik_mtu, "st,nomadik-mtu",
                       nmdk_timer_of_init);