phy: renesas: rcar-gen3-usb2: follow the hardware manual procedure

This patch modifies rcar_gen3_init_otg() procedure to follow Figure
73.4 of "R-Car Series, 3rd Generation User's Manual: Hardware Rev.1.00".
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/phy/renesas/phy-rcar-gen3-usb2.c

@@ -307,16 +307,21 @@ static void rcar_gen3_init_otg(struct rcar_gen3_chan *ch)
 	void __iomem *usb2_base = ch->base;
 	u32 val;
 
+	/* Should not use functions of read-modify-write a register */
+	val = readl(usb2_base + USB2_LINECTRL1);
+	val = (val & ~USB2_LINECTRL1_DP_RPD) | USB2_LINECTRL1_DPRPD_EN |
+	      USB2_LINECTRL1_DMRPD_EN | USB2_LINECTRL1_DM_RPD;
+	writel(val, usb2_base + USB2_LINECTRL1);
+
 	val = readl(usb2_base + USB2_VBCTRL);
 	writel(val | USB2_VBCTRL_DRVVBUSSEL, usb2_base + USB2_VBCTRL);
-	writel(USB2_OBINT_BITS, usb2_base + USB2_OBINTSTA);
-	rcar_gen3_control_otg_irq(ch, 1);
 	val = readl(usb2_base + USB2_ADPCTRL);
 	writel(val | USB2_ADPCTRL_IDPULLUP, usb2_base + USB2_ADPCTRL);
-	val = readl(usb2_base + USB2_LINECTRL1);
-	rcar_gen3_set_linectrl(ch, 0, 0);
-	writel(val | USB2_LINECTRL1_DPRPD_EN | USB2_LINECTRL1_DMRPD_EN,
-	       usb2_base + USB2_LINECTRL1);
+
+	msleep(20);
+
+	writel(0xffffffff, usb2_base + USB2_OBINTSTA);
+	writel(USB2_OBINT_BITS, usb2_base + USB2_OBINTEN);
 
 	rcar_gen3_device_recognition(ch);
 }