usb: dwc3: support new revisions of DWC3 core

Recent cores (>= 1.94a) have a set of new features,
commands and a slightly different programming model.

This patch aims to support those changes.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/gadget.c

@@ -100,6 +100,23 @@ int dwc3_gadget_set_link_state(struct dwc3 *dwc, enum dwc3_link_state state)
 	int		retries = 10000;
 	u32		reg;
 
+	/*
+	 * Wait until device controller is ready. Only applies to 1.94a and
+	 * later RTL.
+	 */
+	if (dwc->revision >= DWC3_REVISION_194A) {
+		while (--retries) {
+			reg = dwc3_readl(dwc->regs, DWC3_DSTS);
+			if (reg & DWC3_DSTS_DCNRD)
+				udelay(5);
+			else
+				break;
+		}
+
+		if (retries <= 0)
+			return -ETIMEDOUT;
+	}
+
 	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
 	reg &= ~DWC3_DCTL_ULSTCHNGREQ_MASK;
 
@@ -107,6 +124,13 @@ int dwc3_gadget_set_link_state(struct dwc3 *dwc, enum dwc3_link_state state)
 	reg |= DWC3_DCTL_ULSTCHNGREQ(state);
 	dwc3_writel(dwc->regs, DWC3_DCTL, reg);
 
+	/*
+	 * The following code is racy when called from dwc3_gadget_wakeup,
+	 * and is not needed, at least on newer versions
+	 */
+	if (dwc->revision >= DWC3_REVISION_194A)
+		return 0;
+
 	/* wait for a change in DSTS */
 	retries = 10000;
 	while (--retries) {
@@ -266,8 +290,8 @@ static const char *dwc3_gadget_ep_cmd_string(u8 cmd)
 		return "Clear Stall";
 	case DWC3_DEPCMD_SETSTALL:
 		return "Set Stall";
-	case DWC3_DEPCMD_GETSEQNUMBER:
-		return "Get Data Sequence Number";
+	case DWC3_DEPCMD_GETEPSTATE:
+		return "Get Endpoint State";
 	case DWC3_DEPCMD_SETTRANSFRESOURCE:
 		return "Set Endpoint Transfer Resource";
 	case DWC3_DEPCMD_SETEPCONFIG:
@@ -1280,9 +1304,12 @@ static int dwc3_gadget_wakeup(struct usb_gadget *g)
 		goto out;
 	}
 
+	/* Recent versions do this automatically */
+	if (dwc->revision < DWC3_REVISION_194A) {
 		/* write zeroes to Link Change Request */
 		reg &= ~DWC3_DCTL_ULSTCHNGREQ_MASK;
 		dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+	}
 
 	/* poll until Link State changes to ON */
 	timeout = jiffies + msecs_to_jiffies(100);
@@ -1326,9 +1353,14 @@ static void dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on)
 
 	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
 	if (is_on) {
+		if (dwc->revision <= DWC3_REVISION_187A) {
 			reg &= ~DWC3_DCTL_TRGTULST_MASK;
-		reg |= (DWC3_DCTL_RUN_STOP
-				| DWC3_DCTL_TRGTULST_RX_DET);
+			reg |= DWC3_DCTL_TRGTULST_RX_DET;
+		}
+
+		if (dwc->revision >= DWC3_REVISION_194A)
+			reg &= ~DWC3_DCTL_KEEP_CONNECT;
+		reg |= DWC3_DCTL_RUN_STOP;
 	} else {
 		reg &= ~DWC3_DCTL_RUN_STOP;
 	}
@@ -1468,6 +1500,7 @@ static int dwc3_gadget_stop(struct usb_gadget *g,
 
 	return 0;
 }
+
 static const struct usb_gadget_ops dwc3_gadget_ops = {
 	.get_frame		= dwc3_gadget_get_frame,
 	.wakeup			= dwc3_gadget_wakeup,
@@ -1962,9 +1995,12 @@ static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
 	/* after reset -> Default State */
 	dwc->dev_state = DWC3_DEFAULT_STATE;
 
+	/* Recent versions support automatic phy suspend and don't need this */
+	if (dwc->revision < DWC3_REVISION_194A) {
 		/* Resume PHYs */
 		dwc3_gadget_usb2_phy_suspend(dwc, false);
 		dwc3_gadget_usb3_phy_suspend(dwc, false);
+	}
 
 	if (dwc->gadget.speed != USB_SPEED_UNKNOWN)
 		dwc3_disconnect_gadget(dwc);
@@ -2082,8 +2118,11 @@ static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc)
 		break;
 	}
 
-	/* Suspend unneded PHY */
+	/* Recent versions support automatic phy suspend and don't need this */
+	if (dwc->revision < DWC3_REVISION_194A) {
+		/* Suspend unneeded PHY */
 		dwc3_gadget_phy_suspend(dwc, dwc->gadget.speed);
+	}
 
 	dep = dwc->eps[0];
 	ret = __dwc3_gadget_ep_enable(dep, &dwc3_gadget_ep0_desc, NULL);
@@ -2389,6 +2428,24 @@ int __devinit dwc3_gadget_init(struct dwc3 *dwc)
 			DWC3_DEVTEN_DISCONNEVTEN);
 	dwc3_writel(dwc->regs, DWC3_DEVTEN, reg);
 
+	/* Enable USB2 LPM and automatic phy suspend only on recent versions */
+	if (dwc->revision >= DWC3_REVISION_194A) {
+		reg = dwc3_readl(dwc->regs, DWC3_DCFG);
+		reg |= DWC3_DCFG_LPM_CAP;
+		dwc3_writel(dwc->regs, DWC3_DCFG, reg);
+
+		reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+		reg &= ~(DWC3_DCTL_HIRD_THRES_MASK | DWC3_DCTL_L1_HIBER_EN);
+
+		/* TODO: This should be configurable */
+		reg |= DWC3_DCTL_HIRD_THRES(31);
+
+		dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+
+		dwc3_gadget_usb2_phy_suspend(dwc, true);
+		dwc3_gadget_usb3_phy_suspend(dwc, true);
+	}
+
 	ret = device_register(&dwc->gadget.dev);
 	if (ret) {
 		dev_err(dwc->dev, "failed to register gadget device\n");