phy: rcar-gen3-usb2: change the mode to OTG on the combined channel

To use the channel 0 of R-Car gen3 as periperal mode, This patch changes
the mode to OTG instead of HOST. Then, this driver needs to set some
registers to enable host mode and detects ID pin and VBUS pin at
phy_init() timing.

For now, the channel 0 can be used as host mode only.

Signed-off-by: Yoshihiro Shimoda <[e-mail]>
Signed-off-by: Kishon Vijay Abraham I <[e-mail]>

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

···
 #define USB2_USBCTR		0x00c
 #define USB2_SPD_RSM_TIMSET	0x10c
 #define USB2_OC_TIMSET		0x110
+#define USB2_COMMCTRL		0x600
+#define USB2_VBCTRL		0x60c
+#define USB2_LINECTRL1		0x610
+#define USB2_ADPCTRL		0x630
 
 /* INT_ENABLE */
 #define USB2_INT_ENABLE_USBH_INTB_EN	BIT(2)
···
 
 /* OC_TIMSET */
 #define USB2_OC_TIMSET_INIT		0x000209ab
+
+/* COMMCTRL */
+#define USB2_COMMCTRL_OTG_PERI		BIT(31)	/* 1 = Peripheral mode */
+
+/* VBCTRL */
+#define USB2_VBCTRL_DRVVBUSSEL		BIT(8)
+
+/* LINECTRL1 */
+#define USB2_LINECTRL1_DPRPD_EN		BIT(19)
+#define USB2_LINECTRL1_DP_RPD		BIT(18)
+#define USB2_LINECTRL1_DMRPD_EN		BIT(17)
+#define USB2_LINECTRL1_DM_RPD		BIT(16)
+
+/* ADPCTRL */
+#define USB2_ADPCTRL_OTGSESSVLD		BIT(20)
+#define USB2_ADPCTRL_IDDIG		BIT(19)
+#define USB2_ADPCTRL_IDPULLUP		BIT(5)	/* 1 = ID sampling is enabled */
+#define USB2_ADPCTRL_DRVVBUS		BIT(4)
 
 /******* HSUSB registers (original offset is +0x100) *******/
 #define HSUSB_LPSTS			0x02
···
 	struct phy *phy;
 };
 
+static void rcar_gen3_set_host_mode(struct rcar_gen3_chan *ch, int host)
+{
+	void __iomem *usb2_base = ch->usb2.base;
+	u32 val = readl(usb2_base + USB2_COMMCTRL);
+
+	dev_vdbg(&ch->phy->dev, "%s: %08x, %d\n", __func__, val, host);
+	if (host)
+		val &= ~USB2_COMMCTRL_OTG_PERI;
+	else
+		val |= USB2_COMMCTRL_OTG_PERI;
+	writel(val, usb2_base + USB2_COMMCTRL);
+}
+
+static void rcar_gen3_set_linectrl(struct rcar_gen3_chan *ch, int dp, int dm)
+{
+	void __iomem *usb2_base = ch->usb2.base;
+	u32 val = readl(usb2_base + USB2_LINECTRL1);
+
+	dev_vdbg(&ch->phy->dev, "%s: %08x, %d, %d\n", __func__, val, dp, dm);
+	val &= ~(USB2_LINECTRL1_DP_RPD | USB2_LINECTRL1_DM_RPD);
+	if (dp)
+		val |= USB2_LINECTRL1_DP_RPD;
+	if (dm)
+		val |= USB2_LINECTRL1_DM_RPD;
+	writel(val, usb2_base + USB2_LINECTRL1);
+}
+
+static void rcar_gen3_enable_vbus_ctrl(struct rcar_gen3_chan *ch, int vbus)
+{
+	void __iomem *usb2_base = ch->usb2.base;
+	u32 val = readl(usb2_base + USB2_ADPCTRL);
+
+	dev_vdbg(&ch->phy->dev, "%s: %08x, %d\n", __func__, val, vbus);
+	if (vbus)
+		val |= USB2_ADPCTRL_DRVVBUS;
+	else
+		val &= ~USB2_ADPCTRL_DRVVBUS;
+	writel(val, usb2_base + USB2_ADPCTRL);
+}
+
+static void rcar_gen3_init_for_host(struct rcar_gen3_chan *ch)
+{
+	rcar_gen3_set_linectrl(ch, 1, 1);
+	rcar_gen3_set_host_mode(ch, 1);
+	rcar_gen3_enable_vbus_ctrl(ch, 1);
+}
+
+static void rcar_gen3_init_for_peri(struct rcar_gen3_chan *ch)
+{
+	rcar_gen3_set_linectrl(ch, 0, 1);
+	rcar_gen3_set_host_mode(ch, 0);
+	rcar_gen3_enable_vbus_ctrl(ch, 0);
+}
+
+static bool rcar_gen3_check_vbus(struct rcar_gen3_chan *ch)
+{
+	return !!(readl(ch->usb2.base + USB2_ADPCTRL) &
+		  USB2_ADPCTRL_OTGSESSVLD);
+}
+
+static bool rcar_gen3_check_id(struct rcar_gen3_chan *ch)
+{
+	return !!(readl(ch->usb2.base + USB2_ADPCTRL) & USB2_ADPCTRL_IDDIG);
+}
+
+static void rcar_gen3_device_recognition(struct rcar_gen3_chan *ch)
+{
+	bool is_host = true;
+
+	/* B-device? */
+	if (rcar_gen3_check_id(ch) && rcar_gen3_check_vbus(ch))
+		is_host = false;
+
+	if (is_host)
+		rcar_gen3_init_for_host(ch);
+	else
+		rcar_gen3_init_for_peri(ch);
+}
+
+static void rcar_gen3_init_otg(struct rcar_gen3_chan *ch)
+{
+	void __iomem *usb2_base = ch->usb2.base;
+	u32 val;
+
+	val = readl(usb2_base + USB2_VBCTRL);
+	writel(val | USB2_VBCTRL_DRVVBUSSEL, usb2_base + USB2_VBCTRL);
+	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);
+
+	rcar_gen3_device_recognition(ch);
+}
+
 static int rcar_gen3_phy_usb2_init(struct phy *p)
 {
 	struct rcar_gen3_chan *channel = phy_get_drvdata(p);
···
 
 	/* Initialize HSUSB part */
 	if (hsusb_base) {
-		/* TODO: support "OTG" mode */
 		val = readl(hsusb_base + HSUSB_UGCTRL2);
 		val = (val & ~HSUSB_UGCTRL2_USB0SEL) |
-		      HSUSB_UGCTRL2_USB0SEL_HOST;
+		      HSUSB_UGCTRL2_USB0SEL_OTG;
 		writel(val & HSUSB_UGCTRL2_MASK, hsusb_base + HSUSB_UGCTRL2);
+
+		/* Initialize otg part */
+		rcar_gen3_init_otg(channel);
 	}
 
 	return 0;