usb/isp1760: Allow to optionally trigger low-level chip reset via GPIOLIB.

Properly triggering the reset wire is necessary with the ISP1761 used
on Terasic DE4 Altera-FPGA boards using a NIOS2 processor, for example.

This is an optional implementation for the OF binding only. The other
bindings just pass an invalid GPIO to the isp1760_register() routine.

Example, usage in DTS:
        gpios = <&pio_isp1761rst_0 0 1>;
to point to a GPIO controller from within the ISP1761 node: GPIO 0, active low.

Signed-off-by: Joachim Foerster <joachim.foerster@missinglinkelectronics.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/isp1760-hcd.h b/drivers/usb/host/isp1760-hcd.h
index fda0f2d..33dc79c 100644
--- a/drivers/usb/host/isp1760-hcd.h
+++ b/drivers/usb/host/isp1760-hcd.h
@@ -4,6 +4,7 @@
 /* exports for if */
 struct usb_hcd *isp1760_register(phys_addr_t res_start, resource_size_t res_len,
 				 int irq, unsigned long irqflags,
+				 int rst_gpio,
 				 struct device *dev, const char *busname,
 				 unsigned int devflags);
 int init_kmem_once(void);
@@ -126,6 +127,7 @@
 #define ISP1760_FLAG_ISP1761		0x00000040 /* Chip is ISP1761 */
 #define ISP1760_FLAG_INTR_POL_HIGH	0x00000080 /* Interrupt polarity active high */
 #define ISP1760_FLAG_INTR_EDGE_TRIG	0x00000100 /* Interrupt edge triggered */
+#define ISP1760_FLAG_RESET_ACTIVE_HIGH	0x80000000 /* RESET GPIO active high */
 
 /* chip memory management */
 struct memory_chunk {