usb: musb: ux500: add otg notifier support

Add transceiver notifier event handling to the ux500 driver to set vbus
on specific transceiver events.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org>

[ balbi@ti.com: fix build error due to missing
	otg_state_string() ]

Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/drivers/usb/musb/ux500.c b/drivers/usb/musb/ux500.c
index 0332fcd286f7..0ae9472a68a8 100644
--- a/drivers/usb/musb/ux500.c
+++ b/drivers/usb/musb/ux500.c
@@ -98,6 +98,37 @@ static void ux500_musb_set_vbus(struct musb *musb, int is_on)
                 musb_readb(musb->mregs, MUSB_DEVCTL));
 }
 
+static int musb_otg_notifications(struct notifier_block *nb,
+                unsigned long event, void *unused)
+{
+        struct musb *musb = container_of(nb, struct musb, nb);
+
+        dev_dbg(musb->controller, "musb_otg_notifications %ld %s\n",
+                        event, usb_otg_state_string(musb->xceiv->state));
+
+        switch (event) {
+        case USB_EVENT_ID:
+                dev_dbg(musb->controller, "ID GND\n");
+                ux500_musb_set_vbus(musb, 1);
+                break;
+        case USB_EVENT_VBUS:
+                dev_dbg(musb->controller, "VBUS Connect\n");
+                ux500_musb_set_vbus(musb, 0);
+                break;
+        case USB_EVENT_NONE:
+                dev_dbg(musb->controller, "VBUS Disconnect\n");
+                if (is_host_active(musb))
+                        ux500_musb_set_vbus(musb, 0);
+                else
+                        musb->xceiv->state = OTG_STATE_B_IDLE;
+                break;
+        default:
+                dev_dbg(musb->controller, "ID float\n");
+                return NOTIFY_DONE;
+        }
+        return NOTIFY_OK;
+}
+
 static irqreturn_t ux500_musb_interrupt(int irq, void *__hci)
 {
         unsigned long   flags;
@@ -120,12 +151,21 @@ static irqreturn_t ux500_musb_interrupt(int irq, void *__hci)
 
 static int ux500_musb_init(struct musb *musb)
 {
+        int status;
+
         musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
         if (IS_ERR_OR_NULL(musb->xceiv)) {
                 pr_err("HS USB OTG: no transceiver configured\n");
                 return -EPROBE_DEFER;
         }
 
+        musb->nb.notifier_call = musb_otg_notifications;
+        status = usb_register_notifier(musb->xceiv, &musb->nb);
+        if (status < 0) {
+                dev_dbg(musb->controller, "notification register failed\n");
+                return status;
+        }
+
         musb->isr = ux500_musb_interrupt;
 
         return 0;
@@ -133,6 +173,8 @@ static int ux500_musb_init(struct musb *musb)
 
 static int ux500_musb_exit(struct musb *musb)
 {
+        usb_unregister_notifier(musb->xceiv, &musb->nb);
+
         usb_put_phy(musb->xceiv);
 
         return 0;