[PATCH 03/14] i2c: omap: wakeup the controller during suspend callback

[Thomas Richard]

A device may need the controller up during suspend_noirq or
resume_noirq.
But if the controller is autosuspended, there is no way to wakeup it
during suspend_noirq or resume_noirq because runtime pm is disabled
at this time.

The suspend callback wakes up the controller, so it is available until
its suspend_noirq callback (pm_runtime_force_suspend).
During the resume, it's restored by resume_noirq callback
(pm_runtime_force_resume). Then resume callback enables autosuspend.

So the controller is up during a little time slot in suspend and resume
sequences even if it's not used.

Signed-off-by: Thomas Richard <thomas.richard at bootlin.com>
---
 drivers/i2c/busses/i2c-omap.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 42165ef57946..57f0738fa748 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -1575,9 +1575,24 @@ static int __maybe_unused omap_i2c_runtime_resume(struct device *dev)
 	return 0;
 }
 
+
+static int omap_i2c_suspend(struct device *dev)
+{
+	return pm_runtime_resume_and_get(dev);
+}
+
+static int omap_i2c_resume(struct device *dev)
+{
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+	return 0;
+}
+
 static const struct dev_pm_ops omap_i2c_pm_ops = {
 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
 				      pm_runtime_force_resume)
+	SET_SYSTEM_SLEEP_PM_OPS(omap_i2c_suspend, omap_i2c_resume)
 	SET_RUNTIME_PM_OPS(omap_i2c_runtime_suspend,
 			   omap_i2c_runtime_resume, NULL)
 };

-- 
2.39.2