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Subject[PATCH V2 07/63] clocksource/drivers/cadence_ttc: Convert init function to return error
Date
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>
---
drivers/clocksource/cadence_ttc_timer.c | 76 ++++++++++++++++++++-------------
1 file changed, 47 insertions(+), 29 deletions(-)

diff --git a/drivers/clocksource/cadence_ttc_timer.c b/drivers/clocksource/cadence_ttc_timer.c
index 9be6018..e2e7631 100644
--- a/drivers/clocksource/cadence_ttc_timer.c
+++ b/drivers/clocksource/cadence_ttc_timer.c
@@ -322,22 +322,22 @@ static int ttc_rate_change_clocksource_cb(struct notifier_block *nb,
return NOTIFY_DONE;
}

-static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base,
+static int __init ttc_setup_clocksource(struct clk *clk, void __iomem *base,
u32 timer_width)
{
struct ttc_timer_clocksource *ttccs;
int err;

ttccs = kzalloc(sizeof(*ttccs), GFP_KERNEL);
- if (WARN_ON(!ttccs))
- return;
+ if (!ttccs)
+ return -ENOMEM;

ttccs->ttc.clk = clk;

err = clk_prepare_enable(ttccs->ttc.clk);
- if (WARN_ON(err)) {
+ if (err) {
kfree(ttccs);
- return;
+ return err;
}

ttccs->ttc.freq = clk_get_rate(ttccs->ttc.clk);
@@ -345,8 +345,10 @@ static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base,
ttccs->ttc.clk_rate_change_nb.notifier_call =
ttc_rate_change_clocksource_cb;
ttccs->ttc.clk_rate_change_nb.next = NULL;
- if (clk_notifier_register(ttccs->ttc.clk,
- &ttccs->ttc.clk_rate_change_nb))
+
+ err = clk_notifier_register(ttccs->ttc.clk,
+ &ttccs->ttc.clk_rate_change_nb);
+ if (err)
pr_warn("Unable to register clock notifier.\n");

ttccs->ttc.base_addr = base;
@@ -368,14 +370,16 @@ static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base,
ttccs->ttc.base_addr + TTC_CNT_CNTRL_OFFSET);

err = clocksource_register_hz(&ttccs->cs, ttccs->ttc.freq / PRESCALE);
- if (WARN_ON(err)) {
+ if (err) {
kfree(ttccs);
- return;
+ return err;
}

ttc_sched_clock_val_reg = base + TTC_COUNT_VAL_OFFSET;
sched_clock_register(ttc_sched_clock_read, timer_width,
ttccs->ttc.freq / PRESCALE);
+
+ return 0;
}

static int ttc_rate_change_clockevent_cb(struct notifier_block *nb,
@@ -401,30 +405,35 @@ static int ttc_rate_change_clockevent_cb(struct notifier_block *nb,
}
}

-static void __init ttc_setup_clockevent(struct clk *clk,
- void __iomem *base, u32 irq)
+static int __init ttc_setup_clockevent(struct clk *clk,
+ void __iomem *base, u32 irq)
{
struct ttc_timer_clockevent *ttcce;
int err;

ttcce = kzalloc(sizeof(*ttcce), GFP_KERNEL);
- if (WARN_ON(!ttcce))
- return;
+ if (!ttcce)
+ return -ENOMEM;

ttcce->ttc.clk = clk;

err = clk_prepare_enable(ttcce->ttc.clk);
- if (WARN_ON(err)) {
+ if (err) {
kfree(ttcce);
- return;
+ return err;
}

ttcce->ttc.clk_rate_change_nb.notifier_call =
ttc_rate_change_clockevent_cb;
ttcce->ttc.clk_rate_change_nb.next = NULL;
- if (clk_notifier_register(ttcce->ttc.clk,
- &ttcce->ttc.clk_rate_change_nb))
+
+ err = clk_notifier_register(ttcce->ttc.clk,
+ &ttcce->ttc.clk_rate_change_nb);
+ if (err) {
pr_warn("Unable to register clock notifier.\n");
+ return err;
+ }
+
ttcce->ttc.freq = clk_get_rate(ttcce->ttc.clk);

ttcce->ttc.base_addr = base;
@@ -451,13 +460,15 @@ static void __init ttc_setup_clockevent(struct clk *clk,

err = request_irq(irq, ttc_clock_event_interrupt,
IRQF_TIMER, ttcce->ce.name, ttcce);
- if (WARN_ON(err)) {
+ if (err) {
kfree(ttcce);
- return;
+ return err;
}

clockevents_config_and_register(&ttcce->ce,
ttcce->ttc.freq / PRESCALE, 1, 0xfffe);
+
+ return 0;
}

/**
@@ -466,17 +477,17 @@ static void __init ttc_setup_clockevent(struct clk *clk,
* Initializes the timer hardware and register the clock source and clock event
* timers with Linux kernal timer framework
*/
-static void __init ttc_timer_init(struct device_node *timer)
+static int __init ttc_timer_init(struct device_node *timer)
{
unsigned int irq;
void __iomem *timer_baseaddr;
struct clk *clk_cs, *clk_ce;
static int initialized;
- int clksel;
+ int clksel, ret;
u32 timer_width = 16;

if (initialized)
- return;
+ return 0;

initialized = 1;

@@ -488,13 +499,13 @@ static void __init ttc_timer_init(struct device_node *timer)
timer_baseaddr = of_iomap(timer, 0);
if (!timer_baseaddr) {
pr_err("ERROR: invalid timer base address\n");
- BUG();
+ return -ENXIO;
}

irq = irq_of_parse_and_map(timer, 1);
if (irq <= 0) {
pr_err("ERROR: invalid interrupt number\n");
- BUG();
+ return -EINVAL;
}

of_property_read_u32(timer, "timer-width", &timer_width);
@@ -504,7 +515,7 @@ static void __init ttc_timer_init(struct device_node *timer)
clk_cs = of_clk_get(timer, clksel);
if (IS_ERR(clk_cs)) {
pr_err("ERROR: timer input clock not found\n");
- BUG();
+ return PTR_ERR(clk_cs);
}

clksel = readl_relaxed(timer_baseaddr + 4 + TTC_CLK_CNTRL_OFFSET);
@@ -512,13 +523,20 @@ static void __init ttc_timer_init(struct device_node *timer)
clk_ce = of_clk_get(timer, clksel);
if (IS_ERR(clk_ce)) {
pr_err("ERROR: timer input clock not found\n");
- BUG();
+ return PTR_ERR(clk_cs);
}

- ttc_setup_clocksource(clk_cs, timer_baseaddr, timer_width);
- ttc_setup_clockevent(clk_ce, timer_baseaddr + 4, irq);
+ ret = ttc_setup_clocksource(clk_cs, timer_baseaddr, timer_width);
+ if (ret)
+ return ret;
+
+ ret = ttc_setup_clockevent(clk_ce, timer_baseaddr + 4, irq);
+ if (ret)
+ return ret;

pr_info("%s #0 at %p, irq=%d\n", timer->name, timer_baseaddr, irq);
+
+ return 0;
}

-CLOCKSOURCE_OF_DECLARE(ttc, "cdns,ttc", ttc_timer_init);
+CLOCKSOURCE_OF_DECLARE_RET(ttc, "cdns,ttc", ttc_timer_init);
--
1.9.1
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