usb: musb-new: omap2430: Reset the MUSB controller early

When booting from USB peripheral boot, the bootrom will not properly deinit the
MUSB controller, which doesn't clearly indicate an USB disconnection to the host
and leaves U-Boot to deal with the state of the previous USB session.

On some host controller drivers (e.g. xhci_hcd), this ends up in a failure
during set address, caused by the lack of proper disconnection notification.

Resetting the controller early in U-Boot notifies the host of the disconnection
and doesn't hurt other use cases.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
Reviewed-by: Tom Rini <trini@ti.com>

drivers/usb/musb-new/omap2430.c

@@ -321,6 +321,7 @@ static int omap2430_musb_init(struct musb *musb)
 {
 	u32 l;
 	int status = 0;
+	unsigned long int start;
 #ifndef __UBOOT__
 	struct device *dev = musb->controller;
 	struct omap2430_glue *glue = dev_get_drvdata(dev->parent);
@@ -331,6 +332,21 @@ static int omap2430_musb_init(struct musb *musb)
 		(struct omap_musb_board_data *)musb->controller;
 #endif
 
+	/* Reset the controller */
+	musb_writel(musb->mregs, OTG_SYSCONFIG, SOFTRST);
+
+	start = get_timer(0);
+
+	while (1) {
+		l = musb_readl(musb->mregs, OTG_SYSCONFIG);
+		if ((l & SOFTRST) == 0)
+			break;
+
+		if (get_timer(start) > (CONFIG_SYS_HZ / 1000)) {
+			dev_err(musb->controller, "MUSB reset is taking too long\n");
+			return -ENODEV;
+		}
+	}
 
 #ifndef __UBOOT__
 	/* We require some kind of external transceiver, hooked