net: mdio: Handle bus level GPIO Reset

Some platforms have bus level Reset controlled
by a GPIO line. If available then handle bus reset
via GPIO.

Signed-off-by: Roger Quadros <rogerq@kernel.org>
diff --git a/include/phy.h b/include/phy.h
index e02cbdb..ae23814 100644
--- a/include/phy.h
+++ b/include/phy.h
@@ -9,6 +9,7 @@
 #ifndef _PHY_H
 #define _PHY_H
 
+#include <asm-generic/gpio.h>
 #include <log.h>
 #include <phy_interface.h>
 #include <dm/ofnode.h>
@@ -76,6 +77,12 @@
 	int (*reset)(struct mii_dev *bus);
 	struct phy_device *phymap[PHY_MAX_ADDR];
 	u32 phy_mask;
+	/** @reset_delay_us: Bus GPIO reset pulse width in microseconds */
+	int reset_delay_us;
+	/** @reset_post_delay_us: Bus GPIO reset deassert delay in microseconds */
+	int reset_post_delay_us;
+	/** @reset_gpiod: Bus Reset GPIO descriptor pointer */
+	struct gpio_desc reset_gpiod;
 };
 
 /* struct phy_driver: a structure which defines PHY behavior