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i2c: omap: wakeup the controller during suspend() callback

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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.

Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Thomas Richard <thomas.richard@bootlin.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
This commit is contained in:
Thomas Richard 2024-06-13 15:13:28 +02:00 committed by Andi Shyti
parent 2cb21a62ba
commit 7da7fd7e66
1 changed files with 22 additions and 0 deletions
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22
drivers/i2c/busses/i2c-omap.c
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@ -1574,9 +1574,31 @@ static int omap_i2c_runtime_resume(struct device *dev)
return 0;
}
static int omap_i2c_suspend(struct device *dev)
{
/*
* If the controller is autosuspended, there is no way to wakeup it once
* runtime pm is disabled (in suspend_late()).
* But a device may need the controller up during suspend_noirq() or
* resume_noirq().
* Wakeup the controller while runtime pm is enabled, so it is available
* until its suspend_noirq(), and from resume_noirq().
*/
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 = {
NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
pm_runtime_force_resume)
SYSTEM_SLEEP_PM_OPS(omap_i2c_suspend, omap_i2c_resume)
RUNTIME_PM_OPS(omap_i2c_runtime_suspend,
omap_i2c_runtime_resume, NULL)
};