[PATCH 51/93] clocksource/drivers/atmel-st: Convert init function to return error

From: Daniel Lezcano
Date: Thu Jul 07 2016 - 04:13:49 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/timer-atmel-st.c | 44 +++++++++++++++++++++++-------------
1 file changed, 28 insertions(+), 16 deletions(-)

diff --git a/drivers/clocksource/timer-atmel-st.c b/drivers/clocksource/timer-atmel-st.c
index 29d21d6..e9331d3 100644
--- a/drivers/clocksource/timer-atmel-st.c
+++ b/drivers/clocksource/timer-atmel-st.c
@@ -194,15 +194,17 @@ static struct clock_event_device clkevt = {
/*
* ST (system timer) module supports both clockevents and clocksource.
*/
-static void __init atmel_st_timer_init(struct device_node *node)
+static int __init atmel_st_timer_init(struct device_node *node)
{
struct clk *sclk;
unsigned int sclk_rate, val;
int irq, ret;

regmap_st = syscon_node_to_regmap(node);
- if (IS_ERR(regmap_st))
- panic(pr_fmt("Unable to get regmap\n"));
+ if (IS_ERR(regmap_st)) {
+ pr_err("Unable to get regmap\n");
+ return PTR_ERR(regmap_st);
+ }

/* Disable all timer interrupts, and clear any pending ones */
regmap_write(regmap_st, AT91_ST_IDR,
@@ -211,27 +213,37 @@ static void __init atmel_st_timer_init(struct device_node *node)

/* Get the interrupts property */
irq = irq_of_parse_and_map(node, 0);
- if (!irq)
- panic(pr_fmt("Unable to get IRQ from DT\n"));
+ if (!irq) {
+ pr_err("Unable to get IRQ from DT\n");
+ return -EINVAL;
+ }

/* Make IRQs happen for the system timer */
ret = request_irq(irq, at91rm9200_timer_interrupt,
IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL,
"at91_tick", regmap_st);
- if (ret)
- panic(pr_fmt("Unable to setup IRQ\n"));
+ if (ret) {
+ pr_err("Unable to setup IRQ\n");
+ return ret;
+ }

sclk = of_clk_get(node, 0);
- if (IS_ERR(sclk))
- panic(pr_fmt("Unable to get slow clock\n"));
+ if (IS_ERR(sclk)) {
+ pr_err("Unable to get slow clock\n");
+ return PTR_ERR(sclk);
+ }

- clk_prepare_enable(sclk);
- if (ret)
- panic(pr_fmt("Could not enable slow clock\n"));
+ ret = clk_prepare_enable(sclk);
+ if (ret) {
+ pr_err("Could not enable slow clock\n");
+ return ret;
+ }

sclk_rate = clk_get_rate(sclk);
- if (!sclk_rate)
- panic(pr_fmt("Invalid slow clock rate\n"));
+ if (!sclk_rate) {
+ pr_err("Invalid slow clock rate\n");
+ return -EINVAL;
+ }
timer_latch = (sclk_rate + HZ / 2) / HZ;

/* The 32KiHz "Slow Clock" (tick every 30517.58 nanoseconds) is used
@@ -246,7 +258,7 @@ static void __init atmel_st_timer_init(struct device_node *node)
2, AT91_ST_ALMV);

/* register clocksource */
- clocksource_register_hz(&clk32k, sclk_rate);
+ return clocksource_register_hz(&clk32k, sclk_rate);
}
-CLOCKSOURCE_OF_DECLARE(atmel_st_timer, "atmel,at91rm9200-st",
+CLOCKSOURCE_OF_DECLARE_RET(atmel_st_timer, "atmel,at91rm9200-st",
atmel_st_timer_init);
--
1.9.1