Separate dev_pm_ops for different power events such as suspend, thaw,
and hibernation. This is crucial when dwc3 driver needs to adapt its
behavior based on different power state changes.

Signed-off-by: Guan-Yu Lin <guanyulin@google.com>
---
 drivers/usb/dwc3/core.c | 77 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 76 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index b25d80f318a9..2fdafbcbe44c 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -2582,6 +2582,76 @@ static int dwc3_resume(struct device *dev)
 	return 0;
 }
 
+static int dwc3_freeze(struct device *dev)
+{
+	struct dwc3	*dwc = dev_get_drvdata(dev);
+	int		ret;
+
+	ret = dwc3_suspend_common(dwc, PMSG_FREEZE);
+	if (ret)
+		return ret;
+
+	pinctrl_pm_select_sleep_state(dev);
+
+	return 0;
+}
+
+static int dwc3_thaw(struct device *dev)
+{
+	struct dwc3	*dwc = dev_get_drvdata(dev);
+	int		ret;
+
+	pinctrl_pm_select_default_state(dev);
+
+	pm_runtime_disable(dev);
+	pm_runtime_set_active(dev);
+
+	ret = dwc3_resume_common(dwc, PMSG_THAW);
+	if (ret) {
+		pm_runtime_set_suspended(dev);
+		return ret;
+	}
+
+	pm_runtime_enable(dev);
+
+	return 0;
+}
+
+static int dwc3_poweroff(struct device *dev)
+{
+	struct dwc3	*dwc = dev_get_drvdata(dev);
+	int		ret;
+
+	ret = dwc3_suspend_common(dwc, PMSG_HIBERNATE);
+	if (ret)
+		return ret;
+
+	pinctrl_pm_select_sleep_state(dev);
+
+	return 0;
+}
+
+static int dwc3_restore(struct device *dev)
+{
+	struct dwc3	*dwc = dev_get_drvdata(dev);
+	int		ret;
+
+	pinctrl_pm_select_default_state(dev);
+
+	pm_runtime_disable(dev);
+	pm_runtime_set_active(dev);
+
+	ret = dwc3_resume_common(dwc, PMSG_RESTORE);
+	if (ret) {
+		pm_runtime_set_suspended(dev);
+		return ret;
+	}
+
+	pm_runtime_enable(dev);
+
+	return 0;
+}
+
 static void dwc3_complete(struct device *dev)
 {
 	struct dwc3	*dwc = dev_get_drvdata(dev);
@@ -2599,7 +2669,12 @@ static void dwc3_complete(struct device *dev)
 #endif /* CONFIG_PM_SLEEP */
 
 static const struct dev_pm_ops dwc3_dev_pm_ops = {
-	SET_SYSTEM_SLEEP_PM_OPS(dwc3_suspend, dwc3_resume)
+	.suspend = pm_sleep_ptr(dwc3_suspend),
+	.resume = pm_sleep_ptr(dwc3_resume),
+	.freeze = pm_sleep_ptr(dwc3_freeze),
+	.thaw = pm_sleep_ptr(dwc3_thaw),
+	.poweroff = pm_sleep_ptr(dwc3_poweroff),
+	.restore = pm_sleep_ptr(dwc3_restore),
 	.complete = dwc3_complete,
 	SET_RUNTIME_PM_OPS(dwc3_runtime_suspend, dwc3_runtime_resume,
 			dwc3_runtime_idle)
-- 
2.47.0.rc0.187.ge670bccf7e-goog

On Wed, Oct 09, 2024 at 05:42:55AM +0000, Guan-Yu Lin wrote:
> Separate dev_pm_ops for different power events such as suspend, thaw,
> and hibernation. This is crucial when dwc3 driver needs to adapt its
> behavior based on different power state changes.
> 
> Signed-off-by: Guan-Yu Lin <guanyulin@google.com>
> ---
>  drivers/usb/dwc3/core.c | 77 ++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 76 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index b25d80f318a9..2fdafbcbe44c 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -2582,6 +2582,76 @@ static int dwc3_resume(struct device *dev)
>  	return 0;
>  }
>  
> +static int dwc3_freeze(struct device *dev)
> +{
> +	struct dwc3	*dwc = dev_get_drvdata(dev);
> +	int		ret;
> +
> +	ret = dwc3_suspend_common(dwc, PMSG_FREEZE);
> +	if (ret)
> +		return ret;
> +
> +	pinctrl_pm_select_sleep_state(dev);
> +
> +	return 0;
> +}
> +
> +static int dwc3_thaw(struct device *dev)
> +{
> +	struct dwc3	*dwc = dev_get_drvdata(dev);
> +	int		ret;
> +
> +	pinctrl_pm_select_default_state(dev);
> +
> +	pm_runtime_disable(dev);
> +	pm_runtime_set_active(dev);
> +
> +	ret = dwc3_resume_common(dwc, PMSG_THAW);
> +	if (ret) {
> +		pm_runtime_set_suspended(dev);
> +		return ret;
> +	}
> +
> +	pm_runtime_enable(dev);
> +
> +	return 0;
> +}
> +
> +static int dwc3_poweroff(struct device *dev)
> +{
> +	struct dwc3	*dwc = dev_get_drvdata(dev);
> +	int		ret;
> +
> +	ret = dwc3_suspend_common(dwc, PMSG_HIBERNATE);

Why is power off hibernate?

This needs an ack from the dwc3 maintainer as I can't determine if it's
correct at all...

thanks,

greg k-h

On Wed, Oct 9, 2024 at 8:45 PM Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Wed, Oct 09, 2024 at 05:42:55AM +0000, Guan-Yu Lin wrote:
> > +
> > +static int dwc3_poweroff(struct device *dev)
> > +{
> > +     struct dwc3     *dwc = dev_get_drvdata(dev);
> > +     int             ret;
> > +
> > +     ret = dwc3_suspend_common(dwc, PMSG_HIBERNATE);
>
> Why is power off hibernate?
>
> This needs an ack from the dwc3 maintainer as I can't determine if it's
> correct at all...
>
> thanks,
>
> greg k-h

Described in /include/linux/pm.h, PM_EVENT_HIBERNATE message denotes
the following transition in the PM core code:
"Hibernation image has been saved, call ->prepare() and ->poweroff()
for all devices."
Meantime, the interpretation of the the above description could be
found in /drivers/base/power/main.c:
static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
{
...
        case PM_EVENT_HIBERNATE:
                return ops->poweroff;
...
}
An example in device drivers could be found in usb/drivers/usb/core/usb.c:
static int usb_dev_suspend(struct device *dev)
{
        return usb_suspend(dev, PMSG_SUSPEND);
}

Regards,
Guan-Yu