usb: xhci-pci: Move reset logic out of XHCI core

Resetting an XHCI controller inside xhci_register undoes any register
setup performed by the platform driver. And at least on the Allwinner
H6, resetting the XHCI controller also resets the PHY, which prevents
the controller from working. That means the controller must be taken out
of reset before initializing the PHY, which must be done before calling
xhci_register.

The logic in the XHCI core was added to support the Raspberry Pi 4
(although this was not mentioned in the commit log!), which uses the
xhci-pci platform driver. Move the reset logic to the platform driver,
where it belongs, and where it cannot interfere with other platform
drivers.

This also fixes a failure to call reset_free if xhci_register failed.

Fixes: 0b80371b35 ("usb: xhci: Add reset controller support")
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

drivers/usb/host/xhci-mem.c

@@ -180,8 +180,6 @@ void xhci_cleanup(struct xhci_ctrl *ctrl)
 	xhci_free_virt_devices(ctrl);
 	free(ctrl->erst.entries);
 	free(ctrl->dcbaa);
-	if (reset_valid(&ctrl->reset))
-		reset_free(&ctrl->reset);
 	memset(ctrl, '\0', sizeof(struct xhci_ctrl));
 }
 

drivers/usb/host/xhci-pci.c

@@ -7,12 +7,18 @@
 
 #include <common.h>
 #include <dm.h>
+#include <dm/device_compat.h>
 #include <init.h>
 #include <log.h>
 #include <pci.h>
+#include <reset.h>
 #include <usb.h>
 #include <usb/xhci.h>
 
+struct xhci_pci_plat {
+	struct reset_ctl reset;
+};
+
 static int xhci_pci_init(struct udevice *dev, struct xhci_hccr **ret_hccr,
 			 struct xhci_hcor **ret_hcor)
 {
@@ -45,15 +51,53 @@ static int xhci_pci_init(struct udevice *dev, struct xhci_hccr **ret_hccr,
 
 static int xhci_pci_probe(struct udevice *dev)
 {
+	struct xhci_pci_plat *plat = dev_get_plat(dev);
 	struct xhci_hccr *hccr;
 	struct xhci_hcor *hcor;
 	int ret;
 
+	ret = reset_get_by_index(dev, 0, &plat->reset);
+	if (ret && ret != -ENOENT && ret != -ENOTSUPP) {
+		dev_err(dev, "failed to get reset\n");
+		return ret;
+	}
+
+	if (reset_valid(&plat->reset)) {
+		ret = reset_assert(&plat->reset);
+		if (ret)
+			goto err_reset;
+
+		ret = reset_deassert(&plat->reset);
+		if (ret)
+			goto err_reset;
+	}
+
 	ret = xhci_pci_init(dev, &hccr, &hcor);
 	if (ret)
-		return ret;
+		goto err_reset;
 
-	return xhci_register(dev, hccr, hcor);
+	ret = xhci_register(dev, hccr, hcor);
+	if (ret)
+		goto err_reset;
+
+	return 0;
+
+err_reset:
+	if (reset_valid(&plat->reset))
+		reset_free(&plat->reset);
+
+	return ret;
+}
+
+static int xhci_pci_remove(struct udevice *dev)
+{
+	struct xhci_pci_plat *plat = dev_get_plat(dev);
+
+	xhci_deregister(dev);
+	if (reset_valid(&plat->reset))
+		reset_free(&plat->reset);
+
+	return 0;
 }
 
 static const struct udevice_id xhci_pci_ids[] = {
@@ -65,10 +109,10 @@ U_BOOT_DRIVER(xhci_pci) = {
 	.name	= "xhci_pci",
 	.id	= UCLASS_USB,
 	.probe = xhci_pci_probe,
-	.remove = xhci_deregister,
+	.remove	= xhci_pci_remove,
 	.of_match = xhci_pci_ids,
 	.ops	= &xhci_usb_ops,
-	.plat_auto	= sizeof(struct usb_plat),
+	.plat_auto	= sizeof(struct xhci_pci_plat),
 	.priv_auto	= sizeof(struct xhci_ctrl),
 	.flags	= DM_FLAG_OS_PREPARE | DM_FLAG_ALLOC_PRIV_DMA,
 };

drivers/usb/host/xhci.c

@@ -188,37 +188,6 @@ static int xhci_start(struct xhci_hcor *hcor)
 	return ret;
 }
 
-#if CONFIG_IS_ENABLED(DM_USB)
-/**
- * Resets XHCI Hardware
- *
- * @param ctrl	pointer to host controller
- * @return 0 if OK, or a negative error code.
- */
-static int xhci_reset_hw(struct xhci_ctrl *ctrl)
-{
-	int ret;
-
-	ret = reset_get_by_index(ctrl->dev, 0, &ctrl->reset);
-	if (ret && ret != -ENOENT && ret != -ENOTSUPP) {
-		dev_err(ctrl->dev, "failed to get reset\n");
-		return ret;
-	}
-
-	if (reset_valid(&ctrl->reset)) {
-		ret = reset_assert(&ctrl->reset);
-		if (ret)
-			return ret;
-
-		ret = reset_deassert(&ctrl->reset);
-		if (ret)
-			return ret;
-	}
-
-	return 0;
-}
-#endif
-
 /**
  * Resets the XHCI Controller
  *
@@ -1534,10 +1503,6 @@ int xhci_register(struct udevice *dev, struct xhci_hccr *hccr,
 
 	ctrl->dev = dev;
 
-	ret = xhci_reset_hw(ctrl);
-	if (ret)
-		goto err;
-
 	/*
 	 * XHCI needs to issue a Address device command to setup
 	 * proper device context structures, before it can interact

include/usb/xhci.h

@@ -17,7 +17,6 @@
 #define HOST_XHCI_H_
 
 #include <phys2bus.h>
-#include <reset.h>
 #include <asm/types.h>
 #include <asm/cache.h>
 #include <asm/io.h>
@@ -1200,7 +1199,6 @@ struct xhci_ctrl {
 #if CONFIG_IS_ENABLED(DM_USB)
 	struct udevice *dev;
 #endif
-	struct reset_ctl reset;
 	struct xhci_hccr *hccr;	/* R/O registers, not need for volatile */
 	struct xhci_hcor *hcor;
 	struct xhci_doorbell_array *dba;