sunxi: musb: Implement dfu_usb_get_reset()

This is necessary to distinguish between the "dfu-util --detach" and
the "dfu-util --reset" requests.

The default weak implementation of dfu_usb_get_reset() unconditionally
reboots the device, but we want to be able to continue the boot.scr
execution after writing the kernel, fdt and ramdisk to RAM via DFU.

Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/usb/musb-new/sunxi.c

@@ -165,6 +165,17 @@ static void USBC_ConfigFIFO_Base(void)
 	writel(reg_value, SUNXI_SRAMC_BASE + 0x04);
 }
 
+/******************************************************************************
+ * Needed for the DFU polling magic
+ ******************************************************************************/
+
+static u8 last_int_usb;
+
+bool dfu_usb_get_reset(void)
+{
+	return !!(last_int_usb & MUSB_INTR_RESET);
+}
+
 /******************************************************************************
  * MUSB Glue code
  ******************************************************************************/
@@ -176,6 +187,7 @@ static irqreturn_t sunxi_musb_interrupt(int irq, void *__hci)
 
 	/* read and flush interrupts */
 	musb->int_usb = musb_readb(musb->mregs, MUSB_INTRUSB);
+	last_int_usb = musb->int_usb;
 	if (musb->int_usb)
 		musb_writeb(musb->mregs, MUSB_INTRUSB, musb->int_usb);
 	musb->int_tx = musb_readw(musb->mregs, MUSB_INTRTX);