usb: musb: Add missing PM suspend and resume functions for 2430 glue

Looks like we are missing suspend and resume functions for pm_ops that
are needed to idle the hardware for system suspend for 2430 glue layer.

We can rely on the driver internal PM runtime state, and call driver
functions to idle the hardware on suspend if needed. There is no need
to add a dependency to PM runtime for system suspend here.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20210518074449.17070-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/musb/omap2430.c

@@ -33,6 +33,8 @@ struct omap2430_glue {
 	enum musb_vbus_id_status status;
 	struct work_struct	omap_musb_mailbox_work;
 	struct device		*control_otghs;
+	unsigned int		is_runtime_suspended:1;
+	unsigned int		needs_resume:1;
 };
 #define glue_to_musb(g)		platform_get_drvdata(g->musb)
 
@@ -459,6 +461,8 @@ static int omap2430_runtime_suspend(struct device *dev)
 	phy_power_off(musb->phy);
 	phy_exit(musb->phy);
 
+	glue->is_runtime_suspended = 1;
+
 	return 0;
 }
 
@@ -480,12 +484,40 @@ static int omap2430_runtime_resume(struct device *dev)
 	/* Wait for musb to get oriented. Otherwise we can get babble */
 	usleep_range(200000, 250000);
 
+	glue->is_runtime_suspended = 0;
+
 	return 0;
 }
 
+static int omap2430_suspend(struct device *dev)
+{
+	struct omap2430_glue *glue = dev_get_drvdata(dev);
+
+	if (glue->is_runtime_suspended)
+		return 0;
+
+	glue->needs_resume = 1;
+
+	return omap2430_runtime_suspend(dev);
+}
+
+static int omap2430_resume(struct device *dev)
+{
+	struct omap2430_glue *glue = dev_get_drvdata(dev);
+
+	if (!glue->needs_resume)
+		return 0;
+
+	glue->needs_resume = 0;
+
+	return omap2430_runtime_resume(dev);
+}
+
 static const struct dev_pm_ops omap2430_pm_ops = {
 	.runtime_suspend = omap2430_runtime_suspend,
 	.runtime_resume = omap2430_runtime_resume,
+	.suspend = omap2430_suspend,
+	.resume = omap2430_resume,
 };
 
 #define DEV_PM_OPS	(&omap2430_pm_ops)