phy: rockchip-usb: use rockchip_usb_phy_reset to reset phy during wakeup

It is a hardware bug in RK3288, the only way to solve it is to
reset the phy.

Signed-off-by: Randy Li <[e-mail]>
Signed-off-by: Kishon Vijay Abraham I <[e-mail]>

Documentation/devicetree/bindings/phy/rockchip-usb-phy.txt

···
 - clocks : phandle + clock specifier for the phy clocks
 - clock-names: string, clock name, must be "phyclk"
 - #clock-cells: for users of the phy-pll, should be 0
+- reset-names: Only allow the following entries:
+ - phy-reset
+- resets: Must contain an entry for each entry in reset-names.
 
 Example:
 

drivers/phy/phy-rockchip-usb.c

···
 #include <linux/reset.h>
 #include <linux/regmap.h>
 #include <linux/mfd/syscon.h>
+#include <linux/delay.h>
 
 static int enable_usb_uart;
 
···
 	struct clk_hw	clk480m_hw;
 	struct phy	*phy;
 	bool		uart_enabled;
+	struct reset_control *reset;
 };
 
 static int rockchip_usb_phy_power(struct rockchip_usb_phy *phy,
···
 	return clk_prepare_enable(phy->clk480m);
 }
 
+static int rockchip_usb_phy_reset(struct phy *_phy)
+{
+	struct rockchip_usb_phy *phy = phy_get_drvdata(_phy);
+
+	if (phy->reset) {
+		reset_control_assert(phy->reset);
+		udelay(10);
+		reset_control_deassert(phy->reset);
+	}
+
+	return 0;
+}
+
 static const struct phy_ops ops = {
 	.power_on	= rockchip_usb_phy_power_on,
 	.power_off	= rockchip_usb_phy_power_off,
+	.reset		= rockchip_usb_phy_reset,
 	.owner		= THIS_MODULE,
 };
 
···
 			child->name);
 		return -EINVAL;
 	}
+
+	rk_phy->reset = of_reset_control_get(child, "phy-reset");
+	if (IS_ERR(rk_phy->reset))
+		rk_phy->reset = NULL;
 
 	rk_phy->reg_offset = reg_offset;