16 bits hardware are not enough accure to be used.
Do no allow them to be probed by tested max counter value.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxx>
---
drivers/clocksource/timer-stm32.c | 26 ++++++++++++--------------
1 file changed, 12 insertions(+), 14 deletions(-)
diff --git a/drivers/clocksource/timer-stm32.c b/drivers/clocksource/timer-stm32.c
index 67dcf48..c834648 100644
--- a/drivers/clocksource/timer-stm32.c
+++ b/drivers/clocksource/timer-stm32.c
@@ -81,9 +81,9 @@ static irqreturn_t stm32_clock_event_handler(int irq, void *dev_id)
static int __init stm32_clockevent_init(struct device_node *node)
{
struct reset_control *rstc;
- unsigned long max_delta;
- int ret, bits, prescaler = 1;
+ unsigned long max_arr;
struct timer_of *to;
+ int ret;
to = kzalloc(sizeof(*to), GFP_KERNEL);
if (!to)
@@ -113,29 +113,27 @@ static int __init stm32_clockevent_init(struct device_node *node)
/* Detect whether the timer is 16 or 32 bits */
writel_relaxed(~0U, timer_of_base(to) + TIM_ARR);
- max_delta = readl_relaxed(timer_of_base(to) + TIM_ARR);
- if (max_delta == ~0U) {
- prescaler = 1;
- bits = 32;
- } else {
- prescaler = 1024;
- bits = 16;
+ max_arr = readl_relaxed(timer_of_base(to) + TIM_ARR);
+ if (max_arr != ~0U) {
+ pr_err("32 bits timer is needed\n");
+ ret = -EINVAL;
+ goto deinit;
}
+
writel_relaxed(0, timer_of_base(to) + TIM_ARR);
- writel_relaxed(prescaler - 1, timer_of_base(to) + TIM_PSC);
+ writel_relaxed(0, timer_of_base(to) + TIM_PSC);
writel_relaxed(TIM_EGR_UG, timer_of_base(to) + TIM_EGR);
writel_relaxed(TIM_DIER_UIE, timer_of_base(to) + TIM_DIER);
writel_relaxed(0, timer_of_base(to) + TIM_SR);
clockevents_config_and_register(&to->clkevt,
- timer_of_period(to), 0x60, max_delta);
-
- pr_info("%pOF: STM32 clockevent driver initialized (%d bits)\n",
- node, bits);
+ timer_of_period(to), 0x60, ~0U);
return 0;
+deinit:
+ timer_of_deinit(to);
err:
kfree(to);
return ret;
--
2.7.4
--
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