[PATCH] rtc: imxdi: add wakeup support

From: Martin Kaiser
Date: Fri Apr 30 2021 - 05:32:44 EST


The DryIce-based RTC supports alarms that trigger an interrupt.

Add an option to configure this interrupt as a wakeup source that wakes
the system up from standby mode.

Signed-off-by: Martin Kaiser <martin@xxxxxxxxx>
---

simple test

[root@board ]# echo enabled > /sys/class/rtc/rtc0/device/power/wakeup
[root@board ]# rtcwake -s 3 -m mem
wakeup from "mem" at Fri Apr 30 09:23:52 2021
...
[root@board ]#

drivers/rtc/rtc-imxdi.c | 39 ++++++++++++++++++++++++++++++++++-----
1 file changed, 34 insertions(+), 5 deletions(-)

diff --git a/drivers/rtc/rtc-imxdi.c b/drivers/rtc/rtc-imxdi.c
index c1806f4d68e7..63957be25759 100644
--- a/drivers/rtc/rtc-imxdi.c
+++ b/drivers/rtc/rtc-imxdi.c
@@ -98,6 +98,7 @@
* @pdev: pointer to platform dev
* @rtc: pointer to rtc struct
* @ioaddr: IO registers pointer
+ * @norm_irq: irq number of the "normal" irq
* @clk: input reference clock
* @dsr: copy of the DSR register
* @irq_lock: interrupt enable register (DIER) lock
@@ -109,6 +110,7 @@ struct imxdi_dev {
struct platform_device *pdev;
struct rtc_device *rtc;
void __iomem *ioaddr;
+ int norm_irq;
struct clk *clk;
u32 dsr;
spinlock_t irq_lock;
@@ -741,7 +743,7 @@ static void dryice_work(struct work_struct *work)
static int __init dryice_rtc_probe(struct platform_device *pdev)
{
struct imxdi_dev *imxdi;
- int norm_irq, sec_irq;
+ int sec_irq;
int rc;

imxdi = devm_kzalloc(&pdev->dev, sizeof(*imxdi), GFP_KERNEL);
@@ -756,9 +758,9 @@ static int __init dryice_rtc_probe(struct platform_device *pdev)

spin_lock_init(&imxdi->irq_lock);

- norm_irq = platform_get_irq(pdev, 0);
- if (norm_irq < 0)
- return norm_irq;
+ imxdi->norm_irq = platform_get_irq(pdev, 0);
+ if (imxdi->norm_irq < 0)
+ return imxdi->norm_irq;

/* the 2nd irq is the security violation irq
* make this optional, don't break the device tree ABI
@@ -795,7 +797,7 @@ static int __init dryice_rtc_probe(struct platform_device *pdev)
if (rc != 0)
goto err;

- rc = devm_request_irq(&pdev->dev, norm_irq, dryice_irq,
+ rc = devm_request_irq(&pdev->dev, imxdi->norm_irq, dryice_irq,
IRQF_SHARED, pdev->name, imxdi);
if (rc) {
dev_warn(&pdev->dev, "interrupt not available.\n");
@@ -811,6 +813,8 @@ static int __init dryice_rtc_probe(struct platform_device *pdev)

platform_set_drvdata(pdev, imxdi);

+ device_set_wakeup_capable(&pdev->dev, true);
+
imxdi->rtc->ops = &dryice_rtc_ops;
imxdi->rtc->range_max = U32_MAX;

@@ -830,6 +834,8 @@ static int __exit dryice_rtc_remove(struct platform_device *pdev)
{
struct imxdi_dev *imxdi = platform_get_drvdata(pdev);

+ device_set_wakeup_capable(&pdev->dev, false);
+
flush_work(&imxdi->work);

/* mask all interrupts */
@@ -847,10 +853,33 @@ static const struct of_device_id dryice_dt_ids[] = {

MODULE_DEVICE_TABLE(of, dryice_dt_ids);

+#ifdef CONFIG_PM_SLEEP
+static int dryice_suspend(struct device *dev)
+{
+ struct imxdi_dev *imxdi = dev_get_drvdata(dev);
+
+ if (device_may_wakeup(dev))
+ enable_irq_wake(imxdi->norm_irq);
+ return 0;
+}
+
+static int dryice_resume(struct device *dev)
+{
+ struct imxdi_dev *imxdi = dev_get_drvdata(dev);
+
+ if (device_may_wakeup(dev))
+ disable_irq_wake(imxdi->norm_irq);
+ return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(dryice_pm, dryice_suspend, dryice_resume);
+
static struct platform_driver dryice_rtc_driver = {
.driver = {
.name = "imxdi_rtc",
.of_match_table = dryice_dt_ids,
+ .pm = &dryice_pm,
},
.remove = __exit_p(dryice_rtc_remove),
};
--
2.20.1