usb: musb: set the controller speed based on the config setting

Set the Power register HSENAB bit based on musb->config->maximum_speed,
so that the glue layer can control MUSB to work in high- or full-speed.

Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/musb/musb_core.c

@@ -1028,18 +1028,22 @@ void musb_start(struct musb *musb)
 {
 	void __iomem    *regs = musb->mregs;
 	u8              devctl = musb_readb(regs, MUSB_DEVCTL);
+	u8		power;
 
 	dev_dbg(musb->controller, "<== devctl %02x\n", devctl);
 
 	musb_enable_interrupts(musb);
 	musb_writeb(regs, MUSB_TESTMODE, 0);
 
-	/* put into basic highspeed mode and start session */
-	musb_writeb(regs, MUSB_POWER, MUSB_POWER_ISOUPDATE
-			| MUSB_POWER_HSENAB
-			/* ENSUSPEND wedges tusb */
-			/* | MUSB_POWER_ENSUSPEND */
-		   );
+	power = MUSB_POWER_ISOUPDATE;
+	/*
+	 * treating UNKNOWN as unspecified maximum speed, in which case
+	 * we will default to high-speed.
+	 */
+	if (musb->config->maximum_speed == USB_SPEED_HIGH ||
+			musb->config->maximum_speed == USB_SPEED_UNKNOWN)
+		power |= MUSB_POWER_HSENAB;
+	musb_writeb(regs, MUSB_POWER, power);
 
 	musb->is_active = 0;
 	devctl = musb_readb(regs, MUSB_DEVCTL);

include/linux/usb/musb.h

@@ -95,7 +95,7 @@ struct musb_hdrc_config {
 	/* musb CLKIN in Blackfin in MHZ */
 	unsigned char   clkin;
 #endif
-
+	u32		maximum_speed;
 };
 
 struct musb_hdrc_platform_data {