[PATCH 6/6] rtc: brcmstb-waketimer: allow use as non-wake alarm

Doug Berger
2023-01-20T19:02:55Z

The wake interrupt only fires when the system is in a suspend
state. Fortunately we have another interrupt that fires in a
non-suspend state at the L2 controller UPG_AUX_AON. Add support
for this interrupt line so we can use the alarm in a non-wake
context.

Signed-off-by: Doug Berger <opendmb@gmail.com>
---
drivers/rtc/rtc-brcmstb-waketimer.c | 55 +++++++++++++++++++++++++++--
1 file changed, 52 insertions(+), 3 deletions(-)

diff --git a/drivers/rtc/rtc-brcmstb-waketimer.c b/drivers/rtc/rtc-brcmstb-waketimer.c
index e25f9fcd6ed1..1efa81cecc27 100644
--- a/drivers/rtc/rtc-brcmstb-waketimer.c
+++ b/drivers/rtc/rtc-brcmstb-waketimer.c
@@ -28,6 +28,7 @@ struct brcmstb_waketmr {
struct device *dev;
void __iomem *base;
unsigned int wake_irq;
+ unsigned int alarm_irq;
struct notifier_block reboot_notifier;
struct clk *clk;
u32 rate;
@@ -56,6 +57,8 @@ static inline void brcmstb_waketmr_clear_alarm(struct brcmstb_waketmr *timer)
{
u32 reg;

+ if (timer->alarm_en && timer->alarm_irq)
+ disable_irq(timer->alarm_irq);
timer->alarm_en = false;
reg = readl_relaxed(timer->base + BRCMSTB_WKTMR_COUNTER);
writel_relaxed(reg - 1, timer->base + BRCMSTB_WKTMR_ALARM);
@@ -88,7 +91,25 @@ static irqreturn_t brcmstb_waketmr_irq(int irq, void *data)
{
struct brcmstb_waketmr *timer = data;

- pm_wakeup_event(timer->dev, 0);
+ if (!timer->alarm_irq)
+ pm_wakeup_event(timer->dev, 0);
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t brcmstb_alarm_irq(int irq, void *data)
+{
+ struct brcmstb_waketmr *timer = data;
+
+ /* Ignore spurious interrupts */
+ if (!brcmstb_waketmr_is_pending(timer))
+ return IRQ_HANDLED;
+
+ if (timer->alarm_en) {
+ if (!device_may_wakeup(timer->dev))
+ writel_relaxed(WKTMR_ALARM_EVENT,
+ timer->base + BRCMSTB_WKTMR_EVENT);
+ rtc_update_irq(timer->rtc, 1, RTC_IRQF | RTC_AF);
+ }

return IRQ_HANDLED;
}
@@ -114,7 +135,7 @@ static void wktmr_read(struct brcmstb_waketmr *timer,
static int brcmstb_waketmr_prepare_suspend(struct brcmstb_waketmr *timer)
{
struct device *dev = timer->dev;
- int ret = 0;
+ int ret;

if (device_may_wakeup(dev)) {
ret = enable_irq_wake(timer->wake_irq);
@@ -122,9 +143,17 @@ static int brcmstb_waketmr_prepare_suspend(struct brcmstb_waketmr *timer)
dev_err(dev, "failed to enable wake-up interrupt\n");
return ret;
}
+ if (timer->alarm_en && timer->alarm_irq) {
+ ret = enable_irq_wake(timer->alarm_irq);
+ if (ret) {
+ dev_err(dev, "failed to enable rtc interrupt\n");
+ disable_irq_wake(timer->wake_irq);
+ return ret;
+ }
+ }
}

- return ret;
+ return 0;
}

/* If enabled as a wakeup-source, arm the timer when powering off */
@@ -192,7 +221,11 @@ static int brcmstb_waketmr_alarm_enable(struct device *dev,
!brcmstb_waketmr_is_pending(timer))
return -EINVAL;
timer->alarm_en = true;
+ if (timer->alarm_irq)
+ enable_irq(timer->alarm_irq);
} else if (!enabled && timer->alarm_en) {
+ if (timer->alarm_irq)
+ disable_irq(timer->alarm_irq);
timer->alarm_en = false;
}

@@ -269,6 +302,19 @@ static int brcmstb_waketmr_probe(struct platform_device *pdev)
if (ret < 0)
goto err_clk;

+ brcmstb_waketmr_clear_alarm(timer);
+
+ /* Attempt to initialize non-wake irq */
+ ret = platform_get_irq(pdev, 1);
+ if (ret > 0) {
+ timer->alarm_irq = (unsigned int)ret;
+ ret = devm_request_irq(dev, timer->alarm_irq, brcmstb_alarm_irq,
+ IRQF_NO_AUTOEN, "brcmstb-waketimer-rtc",
+ timer);
+ if (ret < 0)
+ timer->alarm_irq = 0;
+ }
+
timer->reboot_notifier.notifier_call = brcmstb_waketmr_reboot;
register_reboot_notifier(&timer->reboot_notifier);

@@ -317,6 +363,8 @@ static int brcmstb_waketmr_resume(struct device *dev)
return 0;

ret = disable_irq_wake(timer->wake_irq);
+ if (timer->alarm_en && timer->alarm_irq)
+ disable_irq_wake(timer->alarm_irq);

brcmstb_waketmr_clear_alarm(timer);

@@ -346,4 +394,5 @@ module_platform_driver(brcmstb_waketmr_driver);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Brian Norris");
MODULE_AUTHOR("Markus Mayer");
+MODULE_AUTHOR("Doug Berger");
MODULE_DESCRIPTION("Wake-up timer driver for STB chips");
--
2.25.1