[PATCH 40/93] clocksource/drivers/samsung_pwm: Convert init function to return error

From: Daniel Lezcano
Date: Thu Jul 07 2016 - 04:27:58 EST


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@xxxxxxxxxx>
---
drivers/clocksource/samsung_pwm_timer.c | 62 ++++++++++++++++++---------------
1 file changed, 33 insertions(+), 29 deletions(-)

diff --git a/drivers/clocksource/samsung_pwm_timer.c b/drivers/clocksource/samsung_pwm_timer.c
index 47e0515..27a9797 100644
--- 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
--
1.9.1