phy: sun4i-usb: support automatically switch PHY0 route to MUSB/HCI

On newer Allwinner SoCs (H3 and after), the PHY0 node is routed to both
MUSB controller for peripheral and host support (the host support is
slightly broken), and a pair of EHCI/OHCI controllers, which provide a
better support for host mode.

Add support for automatically switch the route of PHY0 according to the
status of dr_mode and id det pin.

Only H3 have this function enabled in this patch, as further SoCs will
be tested later and then have it enabled.

As H5 is reusing the PHY driver of H3, this function is also enabled.
Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/phy/phy-sun4i-usb.c

@@ -49,12 +49,14 @@
 #define REG_PHYBIST			0x08
 #define REG_PHYTUNE			0x0c
 #define REG_PHYCTL_A33			0x10
-#define REG_PHY_UNK_H3			0x20
+#define REG_PHY_OTGCTL			0x20
 
 #define REG_PMU_UNK1			0x10
 
 #define PHYCTL_DATA			BIT(7)
 
+#define OTGCTL_ROUTE_MUSB		BIT(0)
+
 #define SUNXI_AHB_ICHR8_EN		BIT(10)
 #define SUNXI_AHB_INCR4_BURST_EN	BIT(9)
 #define SUNXI_AHB_INCRX_ALIGN_EN	BIT(8)
@@ -110,6 +112,7 @@ struct sun4i_usb_phy_cfg {
 	u8 phyctl_offset;
 	bool dedicated_clocks;
 	bool enable_pmu_unk1;
+	bool phy0_dual_route;
 };
 
 struct sun4i_usb_phy_data {
@@ -269,12 +272,6 @@ static int sun4i_usb_phy_init(struct phy *_phy)
 		writel(val & ~2, phy->pmu + REG_PMU_UNK1);
 	}
 
-	if (data->cfg->type == sun8i_h3_phy) {
-		if (phy->index == 0) {
-			val = readl(data->base + REG_PHY_UNK_H3);
-			writel(val & ~1, data->base + REG_PHY_UNK_H3);
-		}
-	} else {
 	/* Enable USB 45 Ohm resistor calibration */
 	if (phy->index == 0)
 		sun4i_usb_phy_write(phy, PHY_RES45_CAL_EN, 0x01, 1);
@@ -285,7 +282,6 @@ static int sun4i_usb_phy_init(struct phy *_phy)
 	/* Disconnect threshold adjustment */
 	sun4i_usb_phy_write(phy, PHY_DISCON_TH_SEL,
 			    data->cfg->disc_thresh, 2);
-	}
 
 	sun4i_usb_phy_passby(phy, 1);
 
@@ -484,6 +480,21 @@ static const struct phy_ops sun4i_usb_phy_ops = {
 	.owner		= THIS_MODULE,
 };
 
+static void sun4i_usb_phy0_reroute(struct sun4i_usb_phy_data *data, int id_det)
+{
+	u32 regval;
+
+	regval = readl(data->base + REG_PHY_OTGCTL);
+	if (id_det == 0) {
+		/* Host mode. Route phy0 to EHCI/OHCI */
+		regval &= ~OTGCTL_ROUTE_MUSB;
+	} else {
+		/* Peripheral mode. Route phy0 to MUSB */
+		regval |= OTGCTL_ROUTE_MUSB;
+	}
+	writel(regval, data->base + REG_PHY_OTGCTL);
+}
+
 static void sun4i_usb_phy0_id_vbus_det_scan(struct work_struct *work)
 {
 	struct sun4i_usb_phy_data *data =
@@ -544,6 +555,10 @@ static void sun4i_usb_phy0_id_vbus_det_scan(struct work_struct *work)
 			sun4i_usb_phy0_set_vbus_detect(phy0, 1);
 			mutex_unlock(&phy0->mutex);
 		}
+
+		/* Re-route PHY0 if necessary */
+		if (data->cfg->phy0_dual_route)
+			sun4i_usb_phy0_reroute(data, id_det);
 	}
 
 	if (vbus_notify)
@@ -698,7 +713,7 @@ static int sun4i_usb_phy_probe(struct platform_device *pdev)
 			return PTR_ERR(phy->reset);
 		}
 
-		if (i) { /* No pmu for usbc0 */
+		if (i || data->cfg->phy0_dual_route) { /* No pmu for musb */
 			snprintf(name, sizeof(name), "pmu%d", i);
 			res = platform_get_resource_byname(pdev,
 							IORESOURCE_MEM, name);
@@ -824,6 +839,7 @@ static const struct sun4i_usb_phy_cfg sun8i_h3_cfg = {
 	.phyctl_offset = REG_PHYCTL_A33,
 	.dedicated_clocks = true,
 	.enable_pmu_unk1 = true,
+	.phy0_dual_route = true,
 };
 
 static const struct sun4i_usb_phy_cfg sun8i_v3s_cfg = {