clocksource/drivers/samsung_pwm: 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/samsung_pwm_timer.c b/drivers/clocksource/samsung_pwm_timer.c
index 47e0515..27a9797 100644 (file)
--- a/drivers/clocksource/samsung_pwm_timer.c
+++ b/drivers/clocksource/samsung_pwm_timer.c
@@ -333,11 +333,10 @@ static u64 notrace samsung_read_sched_clock(void)
        return samsung_clocksource_read(NULL);
 }
 
-static void __init samsung_clocksource_init(void)
+static int __init samsung_clocksource_init(void)
 {
        unsigned long pclk;
        unsigned long clock_rate;
-       int ret;
 
        pclk = clk_get_rate(pwm.timerclk);
 
@@ -358,9 +357,7 @@ static void __init samsung_clocksource_init(void)
                                                pwm.variant.bits, clock_rate);
 
        samsung_clocksource.mask = CLOCKSOURCE_MASK(pwm.variant.bits);
-       ret = clocksource_register_hz(&samsung_clocksource, clock_rate);
-       if (ret)
-               panic("samsung_clocksource_timer: can't register clocksource\n");
+       return clocksource_register_hz(&samsung_clocksource, clock_rate);
 }
 
 static void __init samsung_timer_resources(void)
@@ -380,26 +377,31 @@ static void __init samsung_timer_resources(void)
 /*
  * PWM master driver
  */
-static void __init _samsung_pwm_clocksource_init(void)
+static int __init _samsung_pwm_clocksource_init(void)
 {
        u8 mask;
        int channel;
 
        mask = ~pwm.variant.output_mask & ((1 << SAMSUNG_PWM_NUM) - 1);
        channel = fls(mask) - 1;
-       if (channel < 0)
-               panic("failed to find PWM channel for clocksource");
+       if (channel < 0) {
+               pr_crit("failed to find PWM channel for clocksource");
+               return -EINVAL;
+       }
        pwm.source_id = channel;
 
        mask &= ~(1 << channel);
        channel = fls(mask) - 1;
-       if (channel < 0)
-               panic("failed to find PWM channel for clock event");
+       if (channel < 0) {
+               pr_crit("failed to find PWM channel for clock event");
+               return -EINVAL;
+       }
        pwm.event_id = channel;
 
        samsung_timer_resources();
        samsung_clockevent_init();
-       samsung_clocksource_init();
+
+       return samsung_clocksource_init();
 }
 
 void __init samsung_pwm_clocksource_init(void __iomem *base,
@@ -417,8 +419,8 @@ void __init samsung_pwm_clocksource_init(void __iomem *base,
 }
 
 #ifdef CONFIG_CLKSRC_OF
-static void __init samsung_pwm_alloc(struct device_node *np,
-                                    const struct samsung_pwm_variant *variant)
+static int __init samsung_pwm_alloc(struct device_node *np,
+                                   const struct samsung_pwm_variant *variant)
 {
        struct property *prop;
        const __be32 *cur;
@@ -441,14 +443,16 @@ static void __init samsung_pwm_alloc(struct device_node *np,
        pwm.base = of_iomap(np, 0);
        if (!pwm.base) {
                pr_err("%s: failed to map PWM registers\n", __func__);
-               return;
+               return -ENXIO;
        }
 
        pwm.timerclk = of_clk_get_by_name(np, "timers");
-       if (IS_ERR(pwm.timerclk))
-               panic("failed to get timers clock for timer");
+       if (IS_ERR(pwm.timerclk)) {
+               pr_crit("failed to get timers clock for timer");
+               return PTR_ERR(pwm.timerclk);
+       }
 
-       _samsung_pwm_clocksource_init();
+       return _samsung_pwm_clocksource_init();
 }
 
 static const struct samsung_pwm_variant s3c24xx_variant = {
@@ -458,11 +462,11 @@ static const struct samsung_pwm_variant s3c24xx_variant = {
        .tclk_mask      = (1 << 4),
 };
 
-static void __init s3c2410_pwm_clocksource_init(struct device_node *np)
+static int __init s3c2410_pwm_clocksource_init(struct device_node *np)
 {
-       samsung_pwm_alloc(np, &s3c24xx_variant);
+       return samsung_pwm_alloc(np, &s3c24xx_variant);
 }
-CLOCKSOURCE_OF_DECLARE(s3c2410_pwm, "samsung,s3c2410-pwm", s3c2410_pwm_clocksource_init);
+CLOCKSOURCE_OF_DECLARE_RET(s3c2410_pwm, "samsung,s3c2410-pwm", s3c2410_pwm_clocksource_init);
 
 static const struct samsung_pwm_variant s3c64xx_variant = {
        .bits           = 32,
@@ -471,11 +475,11 @@ static const struct samsung_pwm_variant s3c64xx_variant = {
        .tclk_mask      = (1 << 7) | (1 << 6) | (1 << 5),
 };
 
-static void __init s3c64xx_pwm_clocksource_init(struct device_node *np)
+static int __init s3c64xx_pwm_clocksource_init(struct device_node *np)
 {
-       samsung_pwm_alloc(np, &s3c64xx_variant);
+       return samsung_pwm_alloc(np, &s3c64xx_variant);
 }
-CLOCKSOURCE_OF_DECLARE(s3c6400_pwm, "samsung,s3c6400-pwm", s3c64xx_pwm_clocksource_init);
+CLOCKSOURCE_OF_DECLARE_RET(s3c6400_pwm, "samsung,s3c6400-pwm", s3c64xx_pwm_clocksource_init);
 
 static const struct samsung_pwm_variant s5p64x0_variant = {
        .bits           = 32,
@@ -484,11 +488,11 @@ static const struct samsung_pwm_variant s5p64x0_variant = {
        .tclk_mask      = 0,
 };
 
-static void __init s5p64x0_pwm_clocksource_init(struct device_node *np)
+static int __init s5p64x0_pwm_clocksource_init(struct device_node *np)
 {
-       samsung_pwm_alloc(np, &s5p64x0_variant);
+       return samsung_pwm_alloc(np, &s5p64x0_variant);
 }
-CLOCKSOURCE_OF_DECLARE(s5p6440_pwm, "samsung,s5p6440-pwm", s5p64x0_pwm_clocksource_init);
+CLOCKSOURCE_OF_DECLARE_RET(s5p6440_pwm, "samsung,s5p6440-pwm", s5p64x0_pwm_clocksource_init);
 
 static const struct samsung_pwm_variant s5p_variant = {
        .bits           = 32,
@@ -497,9 +501,9 @@ static const struct samsung_pwm_variant s5p_variant = {
        .tclk_mask      = (1 << 5),
 };
 
-static void __init s5p_pwm_clocksource_init(struct device_node *np)
+static int __init s5p_pwm_clocksource_init(struct device_node *np)
 {
-       samsung_pwm_alloc(np, &s5p_variant);
+       return samsung_pwm_alloc(np, &s5p_variant);
 }
-CLOCKSOURCE_OF_DECLARE(s5pc100_pwm, "samsung,s5pc100-pwm", s5p_pwm_clocksource_init);
+CLOCKSOURCE_OF_DECLARE_RET(s5pc100_pwm, "samsung,s5pc100-pwm", s5p_pwm_clocksource_init);
 #endif