[PATCH 2/2] usb: ehci-vf: enable the vbus supply of the port

[Mehmet Fide <mehmet.fide@gmail.com>]

From: Mehmet Fide <mehmet.fide@screeningeagle.com>

The driver never looks at the vbus-supply of its port, so on a board
where VBUS is switched by a regulator, as it is on the Colibri VF50 and
VF61 carriers, the port stays unpowered and no device is ever found.

Take the regulator the way ehci-mx6 does: look it up in probe, enable it
in host mode and disable it in device mode when the controller comes up,
and turn it off again when the controller is removed.

Tested on a Colibri VF50 V1.2A on an Iris carrier, U-Boot 2026.07 from
NAND, with a USB stick in the host port:

  Colibri VFxx # usb start
  Bus usb@400b4000: 2 USB Device(s) found
         scanning usb for storage devices... 1 Storage Device(s) found
  Colibri VFxx # usb storage
    Device 0: Vendor: SanDisk  Rev: DL17 Prod: SanDisk 3.2 Gen1
              Type: Removable Hard Disk
              Capacity: 61584.0 MB = 60.1 GB (126124032 x 512)

Reading the partition table and blocks off the stick works.

Signed-off-by: Mehmet Fide <mehmet.fide@screeningeagle.com>
---
 drivers/usb/host/ehci-vf.c | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/ehci-vf.c b/drivers/usb/host/ehci-vf.c
index fb305569a15..4ac7f8bf53f 100644
--- a/drivers/usb/host/ehci-vf.c
+++ b/drivers/usb/host/ehci-vf.c
@@ -21,6 +21,7 @@
 #include <asm/mach-imx/regs-usbphy.h>
 #include <linux/delay.h>
 #include <usb/ehci-ci.h>
+#include <power/regulator.h>
 #include <linux/libfdt.h>
 #include <fdtdec.h>
 
@@ -54,6 +55,7 @@ struct ehci_vf_priv_data {
 	struct anadig_reg __iomem *anatop_addr;
 	void __iomem *phy_addr;
 	void __iomem *misc_addr;
+	struct udevice *vbus_supply;
 	int portnr;
 };
 
@@ -144,6 +146,16 @@ static int ehci_vf_common_init(struct ehci_vf_priv_data *priv)
 	usb_internal_phy_clock_gate(priv->phy_addr);
 	usb_phy_enable(priv->phy_addr, priv->ehci);
 
+	if (CONFIG_IS_ENABLED(DM_REGULATOR) && priv->vbus_supply) {
+		ret = regulator_set_enable_if_allowed(priv->vbus_supply,
+						      priv->init_type !=
+						      USB_INIT_DEVICE);
+		if (ret && ret != -ENOSYS) {
+			printf("Error enabling VBUS supply (ret=%i)\n", ret);
+			return ret;
+		}
+	}
+
 	return 0;
 }
 
@@ -288,6 +300,13 @@ static int ehci_usb_probe(struct udevice *dev)
 	struct ehci_hcor *hcor;
 	int ret;
 
+	if (CONFIG_IS_ENABLED(DM_REGULATOR)) {
+		ret = device_get_supply_regulator(dev, "vbus-supply",
+						  &priv->vbus_supply);
+		if (ret)
+			debug("%s: no vbus supply\n", dev->name);
+	}
+
 	ret = ehci_vf_common_init(priv);
 	if (ret)
 		return ret;
@@ -315,12 +334,22 @@ static const struct udevice_id vf_usb_ids[] = {
 	{ }
 };
 
+static int ehci_usb_remove(struct udevice *dev)
+{
+	struct ehci_vf_priv_data *priv = dev_get_priv(dev);
+
+	if (CONFIG_IS_ENABLED(DM_REGULATOR) && priv->vbus_supply)
+		regulator_set_enable_if_allowed(priv->vbus_supply, false);
+
+	return ehci_deregister(dev);
+}
+
 U_BOOT_DRIVER(ehci_vf) = {
 	.name = "ehci_vf",
 	.id = UCLASS_USB,
 	.of_match = vf_usb_ids,
 	.probe = ehci_usb_probe,
-	.remove = ehci_deregister,
+	.remove = ehci_usb_remove,
 	.ops = &ehci_usb_ops,
 	.of_to_plat = vf_usb_of_to_plat,
 	.plat_auto	= sizeof(struct usb_plat),
-- 
2.54.0