usb: dwc3: core: re-factor init and exit paths

The idea of this patch is for dwc3_core_init() to
abstract all the details about how to initialize
dwc3 and dwc3_core_exit() to do the same for
teardown.

With this, we can simplify suspend/resume operations
by a large margin and always know that we're going
to start dwc3 from a known starting point.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/core.c

@@ -506,6 +506,21 @@ static int dwc3_phy_setup(struct dwc3 *dwc)
 	return 0;
 }
 
+static void dwc3_core_exit(struct dwc3 *dwc)
+{
+	dwc3_event_buffers_cleanup(dwc);
+
+	usb_phy_shutdown(dwc->usb2_phy);
+	usb_phy_shutdown(dwc->usb3_phy);
+	phy_exit(dwc->usb2_generic_phy);
+	phy_exit(dwc->usb3_generic_phy);
+
+	usb_phy_set_suspend(dwc->usb2_phy, 1);
+	usb_phy_set_suspend(dwc->usb3_phy, 1);
+	phy_power_off(dwc->usb2_generic_phy);
+	phy_power_off(dwc->usb3_generic_phy);
+}
+
 /**
  * dwc3_core_init - Low-level initialization of DWC3 Core
  * @dwc: Pointer to our controller context structure
@@ -555,6 +570,10 @@ static int dwc3_core_init(struct dwc3 *dwc)
 	if (ret)
 		goto err0;
 
+	ret = dwc3_phy_setup(dwc);
+	if (ret)
+		goto err0;
+
 	reg = dwc3_readl(dwc->regs, DWC3_GCTL);
 	reg &= ~DWC3_GCTL_SCALEDOWN_MASK;
 
@@ -621,22 +640,45 @@ static int dwc3_core_init(struct dwc3 *dwc)
 	if (dwc->revision < DWC3_REVISION_190A)
 		reg |= DWC3_GCTL_U2RSTECN;
 
-	dwc3_core_num_eps(dwc);
-
 	dwc3_writel(dwc->regs, DWC3_GCTL, reg);
 
-	ret = dwc3_alloc_scratch_buffers(dwc);
-	if (ret)
-		goto err1;
+	dwc3_core_num_eps(dwc);
 
 	ret = dwc3_setup_scratch_buffers(dwc);
 	if (ret)
+		goto err1;
+
+	/* Adjust Frame Length */
+	dwc3_frame_length_adjustment(dwc);
+
+	usb_phy_set_suspend(dwc->usb2_phy, 0);
+	usb_phy_set_suspend(dwc->usb3_phy, 0);
+	ret = phy_power_on(dwc->usb2_generic_phy);
+	if (ret < 0)
 		goto err2;
 
+	ret = phy_power_on(dwc->usb3_generic_phy);
+	if (ret < 0)
+		goto err3;
+
+	ret = dwc3_event_buffers_setup(dwc);
+	if (ret) {
+		dev_err(dwc->dev, "failed to setup event buffers\n");
+		goto err4;
+	}
+
 	return 0;
 
+err4:
+	phy_power_off(dwc->usb2_generic_phy);
+
+err3:
+	phy_power_off(dwc->usb3_generic_phy);
+
 err2:
-	dwc3_free_scratch_buffers(dwc);
+	usb_phy_set_suspend(dwc->usb2_phy, 1);
+	usb_phy_set_suspend(dwc->usb3_phy, 1);
+	dwc3_core_exit(dwc);
 
 err1:
 	usb_phy_shutdown(dwc->usb2_phy);
@@ -648,15 +690,6 @@ err0:
 	return ret;
 }
 
-static void dwc3_core_exit(struct dwc3 *dwc)
-{
-	dwc3_free_scratch_buffers(dwc);
-	usb_phy_shutdown(dwc->usb2_phy);
-	usb_phy_shutdown(dwc->usb3_phy);
-	phy_exit(dwc->usb2_generic_phy);
-	phy_exit(dwc->usb3_generic_phy);
-}
-
 static int dwc3_core_get_phy(struct dwc3 *dwc)
 {
 	struct device		*dev = dwc->dev;
@@ -951,10 +984,6 @@ static int dwc3_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, dwc);
 	dwc3_cache_hwparams(dwc);
 
-	ret = dwc3_phy_setup(dwc);
-	if (ret)
-		goto err0;
-
 	ret = dwc3_core_get_phy(dwc);
 	if (ret)
 		goto err0;
@@ -975,7 +1004,7 @@ static int dwc3_probe(struct platform_device *pdev)
 	if (ret) {
 		dev_err(dwc->dev, "failed to allocate event buffers\n");
 		ret = -ENOMEM;
-		goto err1;
+		goto err0;
 	}
 
 	if (IS_ENABLED(CONFIG_USB_DWC3_HOST))
@@ -986,10 +1015,14 @@ static int dwc3_probe(struct platform_device *pdev)
 	if (dwc->dr_mode == USB_DR_MODE_UNKNOWN)
 		dwc->dr_mode = USB_DR_MODE_OTG;
 
+	ret = dwc3_alloc_scratch_buffers(dwc);
+	if (ret)
+		goto err1;
+
 	ret = dwc3_core_init(dwc);
 	if (ret) {
 		dev_err(dev, "failed to initialize core\n");
-		goto err1;
+		goto err2;
 	}
 
 	/* Check the maximum_speed parameter */
@@ -1019,47 +1052,20 @@ static int dwc3_probe(struct platform_device *pdev)
 		break;
 	}
 
-	/* Adjust Frame Length */
-	dwc3_frame_length_adjustment(dwc);
-
-	usb_phy_set_suspend(dwc->usb2_phy, 0);
-	usb_phy_set_suspend(dwc->usb3_phy, 0);
-	ret = phy_power_on(dwc->usb2_generic_phy);
-	if (ret < 0)
-		goto err2;
-
-	ret = phy_power_on(dwc->usb3_generic_phy);
-	if (ret < 0)
-		goto err3;
-
-	ret = dwc3_event_buffers_setup(dwc);
-	if (ret) {
-		dev_err(dwc->dev, "failed to setup event buffers\n");
-		goto err4;
-	}
-
 	ret = dwc3_core_init_mode(dwc);
 	if (ret)
-		goto err5;
+		goto err3;
 
 	dwc3_debugfs_init(dwc);
 	pm_runtime_allow(dev);
 
 	return 0;
 
-err5:
-	dwc3_event_buffers_cleanup(dwc);
-
-err4:
-	phy_power_off(dwc->usb3_generic_phy);
-
 err3:
-	phy_power_off(dwc->usb2_generic_phy);
+	dwc3_event_buffers_cleanup(dwc);
 
 err2:
-	usb_phy_set_suspend(dwc->usb2_phy, 1);
-	usb_phy_set_suspend(dwc->usb3_phy, 1);
-	dwc3_core_exit(dwc);
+	dwc3_free_scratch_buffers(dwc);
 
 err1:
 	dwc3_free_event_buffers(dwc);
@@ -1090,17 +1096,13 @@ static int dwc3_remove(struct platform_device *pdev)
 
 	dwc3_debugfs_exit(dwc);
 	dwc3_core_exit_mode(dwc);
-	dwc3_event_buffers_cleanup(dwc);
-	dwc3_free_event_buffers(dwc);
-
-	usb_phy_set_suspend(dwc->usb2_phy, 1);
-	usb_phy_set_suspend(dwc->usb3_phy, 1);
-	phy_power_off(dwc->usb2_generic_phy);
-	phy_power_off(dwc->usb3_generic_phy);
 
 	dwc3_core_exit(dwc);
 	dwc3_ulpi_exit(dwc);
 
+	dwc3_free_event_buffers(dwc);
+	dwc3_free_scratch_buffers(dwc);
+
 	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);