usb: musb: Allow running without CONFIG_USB_PHY

Modify the core so that musb->xceiv is never deferenced without being
checked first.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20221026182657.146630-4-paul@crapouillou.netSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/musb/musb_core.c

@@ -2448,7 +2448,7 @@ musb_init_controller(struct device *dev, int nIrq, void __iomem *ctrl)
 	else
 		musb->io.set_toggle = musb_default_set_toggle;
 
-	if (!musb->xceiv->io_ops) {
+	if (IS_ENABLED(CONFIG_USB_PHY) && musb->xceiv && !musb->xceiv->io_ops) {
 		musb->xceiv->io_dev = musb->controller;
 		musb->xceiv->io_priv = musb->mregs;
 		musb->xceiv->io_ops = &musb_ulpi_access;

drivers/usb/musb/musb_core.h

@@ -339,6 +339,8 @@ struct musb {
 	struct usb_phy		*xceiv;
 	struct phy		*phy;
 
+	enum usb_otg_state	otg_state;
+
 	int nIrq;
 	unsigned		irq_wake:1;
 
@@ -595,12 +597,18 @@ static inline void musb_platform_clear_ep_rxintr(struct musb *musb, int epnum)
 static inline void musb_set_state(struct musb *musb,
 				  enum usb_otg_state otg_state)
 {
-	musb->xceiv->otg->state = otg_state;
+	if (musb->xceiv)
+		musb->xceiv->otg->state = otg_state;
+	else
+		musb->otg_state = otg_state;
 }
 
 static inline enum usb_otg_state musb_get_state(struct musb *musb)
 {
-	return musb->xceiv->otg->state;
+	if (musb->xceiv)
+		return musb->xceiv->otg->state;
+
+	return musb->otg_state;
 }
 
 static inline const char *musb_otg_state_string(struct musb *musb)

drivers/usb/musb/musb_gadget.c

@@ -1552,9 +1552,11 @@ static int musb_gadget_wakeup(struct usb_gadget *gadget)
 				break;
 		}
 
-		spin_unlock_irqrestore(&musb->lock, flags);
-		otg_start_srp(musb->xceiv->otg);
-		spin_lock_irqsave(&musb->lock, flags);
+		if (musb->xceiv) {
+			spin_unlock_irqrestore(&musb->lock, flags);
+			otg_start_srp(musb->xceiv->otg);
+			spin_lock_irqsave(&musb->lock, flags);
+		}
 
 		/* Block idling for at least 1s */
 		musb_platform_try_idle(musb,
@@ -1628,7 +1630,7 @@ static int musb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
 {
 	struct musb	*musb = gadget_to_musb(gadget);
 
-	if (!musb->xceiv->set_power)
+	if (!musb->xceiv || !musb->xceiv->set_power)
 		return -EOPNOTSUPP;
 	return usb_phy_set_power(musb->xceiv, mA);
 }
@@ -1834,7 +1836,6 @@ static int musb_gadget_start(struct usb_gadget *g,
 		struct usb_gadget_driver *driver)
 {
 	struct musb		*musb = gadget_to_musb(g);
-	struct usb_otg		*otg = musb->xceiv->otg;
 	unsigned long		flags;
 	int			retval = 0;
 
@@ -1851,7 +1852,9 @@ static int musb_gadget_start(struct usb_gadget *g,
 	spin_lock_irqsave(&musb->lock, flags);
 	musb->is_active = 1;
 
-	otg_set_peripheral(otg, &musb->g);
+	if (musb->xceiv)
+		otg_set_peripheral(musb->xceiv->otg, &musb->g);
+
 	musb_set_state(musb, OTG_STATE_B_IDLE);
 	spin_unlock_irqrestore(&musb->lock, flags);
 
@@ -1861,7 +1864,7 @@ static int musb_gadget_start(struct usb_gadget *g,
 	 * handles power budgeting ... this way also
 	 * ensures HdrcStart is indirectly called.
 	 */
-	if (musb->xceiv->last_event == USB_EVENT_ID)
+	if (musb->xceiv && musb->xceiv->last_event == USB_EVENT_ID)
 		musb_platform_set_vbus(musb, 1);
 
 	pm_runtime_mark_last_busy(musb->controller);
@@ -1899,7 +1902,9 @@ static int musb_gadget_stop(struct usb_gadget *g)
 
 	musb_set_state(musb, OTG_STATE_UNDEFINED);
 	musb_stop(musb);
-	otg_set_peripheral(musb->xceiv->otg, NULL);
+
+	if (musb->xceiv)
+		otg_set_peripheral(musb->xceiv->otg, NULL);
 
 	musb->is_active = 0;
 	musb->gadget_driver = NULL;

drivers/usb/musb/musb_host.c

@@ -2722,10 +2722,14 @@ int musb_host_setup(struct musb *musb, int power_budget)
 		MUSB_HST_MODE(musb);
 		musb_set_state(musb, OTG_STATE_A_IDLE);
 	}
-	otg_set_host(musb->xceiv->otg, &hcd->self);
+
+	if (musb->xceiv) {
+		otg_set_host(musb->xceiv->otg, &hcd->self);
+		musb->xceiv->otg->host = &hcd->self;
+	}
+
 	/* don't support otg protocols */
 	hcd->self.otg_port = 0;
-	musb->xceiv->otg->host = &hcd->self;
 	hcd->power_budget = 2 * (power_budget ? : 250);
 	hcd->skip_phy_initialization = 1;
 

drivers/usb/musb/musb_virthub.c

@@ -50,7 +50,6 @@ void musb_host_finish_resume(struct work_struct *work)
 
 int musb_port_suspend(struct musb *musb, bool do_suspend)
 {
-	struct usb_otg	*otg = musb->xceiv->otg;
 	u8		power;
 	void __iomem	*mbase = musb->mregs;
 
@@ -88,7 +87,8 @@ int musb_port_suspend(struct musb *musb, bool do_suspend)
 		switch (musb_get_state(musb)) {
 		case OTG_STATE_A_HOST:
 			musb_set_state(musb, OTG_STATE_A_SUSPEND);
-			musb->is_active = otg->host->b_hnp_enable;
+			musb->is_active = musb->xceiv &&
+				musb->xceiv->otg->host->b_hnp_enable;
 			if (musb->is_active)
 				mod_timer(&musb->otg_timer, jiffies
 					+ msecs_to_jiffies(
@@ -97,7 +97,8 @@ int musb_port_suspend(struct musb *musb, bool do_suspend)
 			break;
 		case OTG_STATE_B_HOST:
 			musb_set_state(musb, OTG_STATE_B_WAIT_ACON);
-			musb->is_active = otg->host->b_hnp_enable;
+			musb->is_active = musb->xceiv &&
+				musb->xceiv->otg->host->b_hnp_enable;
 			musb_platform_try_idle(musb, 0);
 			break;
 		default:
@@ -196,8 +197,6 @@ void musb_port_reset(struct musb *musb, bool do_reset)
 
 void musb_root_disconnect(struct musb *musb)
 {
-	struct usb_otg	*otg = musb->xceiv->otg;
-
 	musb->port1_status = USB_PORT_STAT_POWER
 			| (USB_PORT_STAT_C_CONNECTION << 16);
 
@@ -206,7 +205,7 @@ void musb_root_disconnect(struct musb *musb)
 
 	switch (musb_get_state(musb)) {
 	case OTG_STATE_A_SUSPEND:
-		if (otg->host->b_hnp_enable) {
+		if (musb->xceiv && musb->xceiv->otg->host->b_hnp_enable) {
 			musb_set_state(musb, OTG_STATE_A_PERIPHERAL);
 			musb->g.is_a_peripheral = 1;
 			break;