usb: musb: omap2430: Add support for idling phy when musb is idle

I noticed that musb is blocking core retention for omap4 unlike for omap3. This is because for omap3 we have phy-twl4030-usb implement it's own PM runtime to handle errata "VUSB3V1 VBUS overvoltage debouncer not working when the PHY is powered down". That is done in order to keep the USB PHY powered when phy-twl4030-usb is loaded.

For the other USB PHYs, we need to enable and disable the PHY based on musb PM runtime. With the session bit based PM runtime for musb core, we can now idle the USB PHY always when musb is idle.

Note that adding these calls will not affect the twl4030 driver as it's phy functions will just query the PHY state without powering the PHY on or off.

Signed-off-by Tony Lindgren <[email protected]>

---
 drivers/usb/musb/omap2430.c | 6 ++++++
 1 file changed, 6 insertions(+)

drivers/usb/musb/omap2430.c +3 -0

@@ -531,6 +531,9 @@ static int omap2430_runtime_suspend(struct device *dev)
 
 	omap2430_low_level_exit(musb);
 
+	phy_power_off(musb->phy);
+	phy_exit(musb->phy);
+
 	return 0;
 }