[PATCH v4 0/3] [PART 1/4] USB: ohci-da8xx: Allow a regulator for VBUS and over current

[PATCH v4 0/3] [PART 1/4] USB: ohci-da8xx: Allow a regulator for VBUS and over current

[Axel Haslam]

This is the first of 4 series of patches to convert the
da8xx-ohci driver to use a regulator and probe form device tree 

To be able to use device tree to probe the driver, we need to remove
the platform callbacks that are handling vbus and over current.

These patches prepare the stage by allowing to use a regulator
instead of the platform callbacks.

DEPENDENCIES:
1. [PATCH 0/3] fix ohci phy name
https://lkml.org/lkml/2016/11/2/208
2. [PATCH/RFC v2 0/3] regulator: handling of error conditions for usb drivers
https://lkml.org/lkml/2016/11/3/188

A branch with all the dependencies can be found here:
https://github.com/axelhaslamx/linux-axel/commits/ohci-da8xx-dt-v4

Changes from v3->v4
* separate the series into smaller series for driver and arch/arm code,
  to ease review and merging to different trees.

Changes form v2->v3
* drop patches that have been integrated to arch/arm
* drop regulator patches which will be integrated through regulator tree
* use of the accepted regulator API to get over current status
* better patch separation with the use of wrappers

Changes from v1->v2
* Rebased and added patch to make ohci a separate driver
* Use a regulator instead of handling Gpios (David Lechner)
* Add an over current mode to regulator framework
* Fixed regulator is able to register for and over current irq
* Added patch by Alexandre to remove build warnings
* Moved global variables into private hcd structure.

Axel Haslam (3):
  USB: ohci: da8xx: use ohci priv data instead of globals
  USB: ohci: da8xx: Prepare to remove platform callbacks
  USB: ohci: da8xx: Allow a regulator to handle VBUS

 drivers/usb/host/ohci-da8xx.c | 284 ++++++++++++++++++++++++++++++++++--------
 1 file changed, 234 insertions(+), 50 deletions(-)

-- 
2.10.1

[PATCH v4 1/3] USB: ohci: da8xx: use ohci priv data instead of globals

[Axel Haslam]

Instead of global variables, use the extra_priv_size of
the ohci driver.

We cannot yet move the ocic mask because this is used on
the interrupt handler which is registerded through platform
data and does not have an hcd pointer. This will be moved
on a later patch.

Signed-off-by: Axel Haslam <ahaslam@baylibre.com>
---
 drivers/usb/host/ohci-da8xx.c | 72 +++++++++++++++++++++++++------------------
 1 file changed, 42 insertions(+), 30 deletions(-)

diff --git a/drivers/usb/host/ohci-da8xx.c b/drivers/usb/host/ohci-da8xx.c
index 429d58b..0442c64 100644
--- a/drivers/usb/host/ohci-da8xx.c
+++ b/drivers/usb/host/ohci-da8xx.c
@@ -35,43 +35,49 @@ static int (*orig_ohci_hub_control)(struct usb_hcd  *hcd, u16 typeReq,
 			u16 wValue, u16 wIndex, char *buf, u16 wLength);
 static int (*orig_ohci_hub_status_data)(struct usb_hcd *hcd, char *buf);
 
-static struct clk *usb11_clk;
-static struct phy *usb11_phy;
+struct da8xx_ohci_hcd {
+	struct clk *usb11_clk;
+	struct phy *usb11_phy;
+};
+#define to_da8xx_ohci(hcd) (struct da8xx_ohci_hcd *)(hcd_to_ohci(hcd)->priv)
 
 /* Over-current indicator change bitmask */
 static volatile u16 ocic_mask;
 
-static int ohci_da8xx_enable(void)
+static int ohci_da8xx_enable(struct usb_hcd *hcd)
 {
+	struct da8xx_ohci_hcd *da8xx_ohci = to_da8xx_ohci(hcd);
 	int ret;
 
-	ret = clk_prepare_enable(usb11_clk);
+	ret = clk_prepare_enable(da8xx_ohci->usb11_clk);
 	if (ret)
 		return ret;
 
-	ret = phy_init(usb11_phy);
+	ret = phy_init(da8xx_ohci->usb11_phy);
 	if (ret)
 		goto err_phy_init;
 
-	ret = phy_power_on(usb11_phy);
+	ret = phy_power_on(da8xx_ohci->usb11_phy);
 	if (ret)
 		goto err_phy_power_on;
 
 	return 0;
 
 err_phy_power_on:
-	phy_exit(usb11_phy);
+	phy_exit(da8xx_ohci->usb11_phy);
 err_phy_init:
-	clk_disable_unprepare(usb11_clk);
+	clk_disable_unprepare(da8xx_ohci->usb11_clk);
 
 	return ret;
 }
 
-static void ohci_da8xx_disable(void)
+static void ohci_da8xx_disable(struct usb_hcd *hcd)
 {
-	phy_power_off(usb11_phy);
-	phy_exit(usb11_phy);
-	clk_disable_unprepare(usb11_clk);
+	struct da8xx_ohci_hcd *da8xx_ohci = to_da8xx_ohci(hcd);
+
+	phy_power_off(da8xx_ohci->usb11_phy);
+	phy_exit(da8xx_ohci->usb11_phy);
+	clk_disable_unprepare(da8xx_ohci->usb11_clk);
 }
 
 /*
@@ -97,7 +103,7 @@ static int ohci_da8xx_reset(struct usb_hcd *hcd)
 
 	dev_dbg(dev, "starting USB controller\n");
 
-	result = ohci_da8xx_enable();
+	result = ohci_da8xx_enable(hcd);
 	if (result < 0)
 		return result;
 
@@ -109,7 +115,7 @@ static int ohci_da8xx_reset(struct usb_hcd *hcd)
 
 	result = ohci_setup(hcd);
 	if (result < 0) {
-		ohci_da8xx_disable();
+		ohci_da8xx_disable(hcd);
 		return result;
 	}
 
@@ -231,6 +237,7 @@ static int ohci_da8xx_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 static int ohci_da8xx_probe(struct platform_device *pdev)
 {
 	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(&pdev->dev);
+	struct da8xx_ohci_hcd *da8xx_ohci;
 	struct usb_hcd	*hcd;
 	struct resource *mem;
 	int error, irq;
@@ -238,25 +245,29 @@ static int ohci_da8xx_probe(struct platform_device *pdev)
 	if (hub == NULL)
 		return -ENODEV;
 
-	usb11_clk = devm_clk_get(&pdev->dev, "usb11");
-	if (IS_ERR(usb11_clk)) {
-		if (PTR_ERR(usb11_clk) != -EPROBE_DEFER)
+	hcd = usb_create_hcd(&ohci_da8xx_hc_driver, &pdev->dev,
+				dev_name(&pdev->dev));
+	if (!hcd)
+		return -ENOMEM;
+
+	da8xx_ohci = to_da8xx_ohci(hcd);
+
+	da8xx_ohci->usb11_clk = devm_clk_get(&pdev->dev, "usb11");
+	if (IS_ERR(da8xx_ohci->usb11_clk)) {
+		if (PTR_ERR(da8xx_ohci->usb11_clk) != -EPROBE_DEFER)
 			dev_err(&pdev->dev, "Failed to get clock.\n");
-		return PTR_ERR(usb11_clk);
+		error = PTR_ERR(da8xx_ohci->usb11_clk);
+		goto err;
 	}
 
-	usb11_phy = devm_phy_get(&pdev->dev, "usb-phy");
-	if (IS_ERR(usb11_phy)) {
-		if (PTR_ERR(usb11_phy) != -EPROBE_DEFER)
+	da8xx_ohci->usb11_phy = devm_phy_get(&pdev->dev, "usb-phy");
+	if (IS_ERR(da8xx_ohci->usb11_phy)) {
+		if (PTR_ERR(da8xx_ohci->usb11_phy) != -EPROBE_DEFER)
 			dev_err(&pdev->dev, "Failed to get phy.\n");
-		return PTR_ERR(usb11_phy);
+		error = PTR_ERR(da8xx_ohci->usb11_phy);
+		goto err;
 	}
 
-	hcd = usb_create_hcd(&ohci_da8xx_hc_driver, &pdev->dev,
-				dev_name(&pdev->dev));
-	if (!hcd)
-		return -ENOMEM;
-
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	hcd->regs = devm_ioremap_resource(&pdev->dev, mem);
 	if (IS_ERR(hcd->regs)) {
@@ -321,7 +332,7 @@ static int ohci_da8xx_suspend(struct platform_device *pdev,
 	if (ret)
 		return ret;
 
-	ohci_da8xx_disable();
+	ohci_da8xx_disable(hcd);
 	hcd->state = HC_STATE_SUSPENDED;
 
 	return ret;
@@ -337,7 +348,7 @@ static int ohci_da8xx_resume(struct platform_device *dev)
 		msleep(5);
 	ohci->next_statechange = jiffies;
 
-	ret = ohci_da8xx_enable();
+	ret = ohci_da8xx_enable(hcd);
 	if (ret)
 		return ret;
 
@@ -349,7 +360,8 @@ static int ohci_da8xx_resume(struct platform_device *dev)
 #endif
 
 static const struct ohci_driver_overrides da8xx_overrides __initconst = {
-	.reset		= ohci_da8xx_reset,
+	.reset		 = ohci_da8xx_reset,
+	.extra_priv_size = sizeof(struct da8xx_ohci_hcd),
 };
 
 /*
-- 
2.10.1

[PATCH v4 2/3] USB: ohci: da8xx: Prepare to remove platform callbacks

[Axel Haslam]

Wrap the platform data callbacks into separate functions.
This will help migrate to using a regulator by providing a well defined
place to implement the regulator functions while the platform calls
are still in place and users have not been converted.

The platform callbacks will be removed on a following patch.

Signed-off-by: Axel Haslam <ahaslam@baylibre.com>
---
 drivers/usb/host/ohci-da8xx.c | 125 ++++++++++++++++++++++++++++++++++--------
 1 file changed, 102 insertions(+), 23 deletions(-)

diff --git a/drivers/usb/host/ohci-da8xx.c b/drivers/usb/host/ohci-da8xx.c
index 0442c64..9ed43c7 100644
--- a/drivers/usb/host/ohci-da8xx.c
+++ b/drivers/usb/host/ohci-da8xx.c
@@ -80,6 +80,72 @@ static void ohci_da8xx_disable(struct usb_hcd *hcd)
 	clk_disable_unprepare(da8xx_ohci->usb11_clk);
 }
 
+static int ohci_da8xx_set_power(struct usb_hcd *hcd, int on)
+{
+	struct device *dev		= hcd->self.controller;
+	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(dev);
+
+	if (hub && hub->set_power)
+		return hub->set_power(1, on);
+
+	return 0;
+}
+
+static int ohci_da8xx_get_power(struct usb_hcd *hcd)
+{
+	struct device *dev		= hcd->self.controller;
+	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(dev);
+
+	if (hub && hub->get_power)
+		return hub->get_power(1);
+
+	return 1;
+}
+
+static int ohci_da8xx_get_oci(struct usb_hcd *hcd)
+{
+	struct device *dev		= hcd->self.controller;
+	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(dev);
+
+	if (hub && hub->get_oci)
+		return hub->get_oci(1);
+
+	return 0;
+}
+
+static int ohci_da8xx_has_set_power(struct usb_hcd *hcd)
+{
+	struct device *dev		= hcd->self.controller;
+	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(dev);
+
+	if (hub && hub->set_power)
+		return 1;
+
+	return 0;
+}
+
+static int ohci_da8xx_has_oci(struct usb_hcd *hcd)
+{
+	struct device *dev		= hcd->self.controller;
+	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(dev);
+
+	if (hub && hub->get_oci)
+		return 1;
+
+	return 0;
+}
+
+static int ohci_da8xx_has_potpgt(struct usb_hcd *hcd)
+{
+	struct device *dev		= hcd->self.controller;
+	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(dev);
+
+	if (hub && hub->potpgt)
+		return 1;
+
+	return 0;
+}
+
 /*
  * Handle the port over-current indicator change.
  */
@@ -93,6 +159,26 @@ static void ohci_da8xx_ocic_handler(struct da8xx_ohci_root_hub *hub,
 		hub->set_power(port, 0);
 }
 
+static int ohci_da8xx_register_notify(struct usb_hcd *hcd)
+{
+	struct device *dev		= hcd->self.controller;
+	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(dev);
+
+	if (hub && hub->ocic_notify)
+		return hub->ocic_notify(ohci_da8xx_ocic_handler);
+
+	return 0;
+}
+
+static void ohci_da8xx_unregister_notify(struct usb_hcd *hcd)
+{
+	struct device *dev		= hcd->self.controller;
+	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(dev);
+
+	if (hub && hub->ocic_notify)
+		hub->ocic_notify(NULL);
+}
+
 static int ohci_da8xx_reset(struct usb_hcd *hcd)
 {
 	struct device *dev		= hcd->self.controller;
@@ -126,16 +212,18 @@ static int ohci_da8xx_reset(struct usb_hcd *hcd)
 	 * the correct hub descriptor...
 	 */
 	rh_a = ohci_readl(ohci, &ohci->regs->roothub.a);
-	if (hub->set_power) {
+	if (ohci_da8xx_has_set_power(hcd)) {
 		rh_a &= ~RH_A_NPS;
 		rh_a |=  RH_A_PSM;
 	}
-	if (hub->get_oci) {
+	if (ohci_da8xx_has_oci(hcd)) {
 		rh_a &= ~RH_A_NOCP;
 		rh_a |=  RH_A_OCPM;
 	}
-	rh_a &= ~RH_A_POTPGT;
-	rh_a |= hub->potpgt << 24;
+	if (ohci_da8xx_has_potpgt(hcd)) {
+		rh_a &= ~RH_A_POTPGT;
+		rh_a |= hub->potpgt << 24;
+	}
 	ohci_writel(ohci, rh_a, &ohci->regs->roothub.a);
 
 	return result;
@@ -168,7 +256,6 @@ static int ohci_da8xx_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 				  u16 wIndex, char *buf, u16 wLength)
 {
 	struct device *dev		= hcd->self.controller;
-	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(dev);
 	int temp;
 
 	switch (typeReq) {
@@ -182,11 +269,11 @@ static int ohci_da8xx_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 		temp = roothub_portstatus(hcd_to_ohci(hcd), wIndex - 1);
 
 		/* The port power status (PPS) bit defaults to 1 */
-		if (hub->get_power && hub->get_power(wIndex) == 0)
+		if (!ohci_da8xx_get_power(hcd))
 			temp &= ~RH_PS_PPS;
 
 		/* The port over-current indicator (POCI) bit is always 0 */
-		if (hub->get_oci && hub->get_oci(wIndex) > 0)
+		if (ohci_da8xx_get_oci(hcd))
 			temp |=  RH_PS_POCI;
 
 		/* The over-current indicator change (OCIC) bit is 0 too */
@@ -211,10 +298,7 @@ static int ohci_da8xx_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 			dev_dbg(dev, "%sPortFeature(%u): %s\n",
 				temp ? "Set" : "Clear", wIndex, "POWER");
 
-			if (!hub->set_power)
-				return -EPIPE;
-
-			return hub->set_power(wIndex, temp) ? -EPIPE : 0;
+			return ohci_da8xx_set_power(hcd, temp) ? -EPIPE : 0;
 		case USB_PORT_FEAT_C_OVER_CURRENT:
 			dev_dbg(dev, "%sPortFeature(%u): %s\n",
 				temp ? "Set" : "Clear", wIndex,
@@ -236,15 +320,10 @@ static int ohci_da8xx_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 
 static int ohci_da8xx_probe(struct platform_device *pdev)
 {
-	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(&pdev->dev);
 	struct da8xx_ohci_hcd *da8xx_ohci;
 	struct usb_hcd	*hcd;
 	struct resource *mem;
 	int error, irq;
-
-	if (hub == NULL)
-		return -ENODEV;
-
 	hcd = usb_create_hcd(&ohci_da8xx_hc_driver, &pdev->dev,
 				dev_name(&pdev->dev));
 	if (!hcd)
@@ -290,12 +369,13 @@ static int ohci_da8xx_probe(struct platform_device *pdev)
 
 	device_wakeup_enable(hcd->self.controller);
 
-	if (hub->ocic_notify) {
-		error = hub->ocic_notify(ohci_da8xx_ocic_handler);
-		if (!error)
-			return 0;
-	}
+	error = ohci_da8xx_register_notify(hcd);
+	if (error)
+		goto err_remove_hcd;
+
+	return 0;
 
+err_remove_hcd:
 	usb_remove_hcd(hcd);
 err:
 	usb_put_hcd(hcd);
@@ -305,9 +385,8 @@ static int ohci_da8xx_probe(struct platform_device *pdev)
 static int ohci_da8xx_remove(struct platform_device *pdev)
 {
 	struct usb_hcd	*hcd = platform_get_drvdata(pdev);
-	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(&pdev->dev);
 
-	hub->ocic_notify(NULL);
+	ohci_da8xx_unregister_notify(hcd);
 	usb_remove_hcd(hcd);
 	usb_put_hcd(hcd);
 
-- 
2.10.1

[PATCH v4 3/3] USB: ohci: da8xx: Allow a regulator to handle VBUS

[Axel Haslam]

We need to remove the platform callbacks to be able to probe
the driver using device tree. Using a regulator to handle VBUS will
eliminate the need for these callbacks once all users are converted
to use a regulator.

The regulator equivalents to the platform callbacks are:
    set_power   ->  regulator_enable/regulator_disable
    get_power   ->  regulator_is_enabled
    get_oci     ->  regulator_get_error_flags
    ocic_notify ->  regulator event notification

Signed-off-by: Axel Haslam <ahaslam@baylibre.com>
---
 drivers/usb/host/ohci-da8xx.c | 97 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 95 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/ohci-da8xx.c b/drivers/usb/host/ohci-da8xx.c
index 9ed43c7..0a4b885 100644
--- a/drivers/usb/host/ohci-da8xx.c
+++ b/drivers/usb/host/ohci-da8xx.c
@@ -20,6 +20,7 @@
 #include <linux/platform_device.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_data/usb-davinci.h>
+#include <linux/regulator/consumer.h>
 #include <linux/usb.h>
 #include <linux/usb/hcd.h>
 #include <asm/unaligned.h>
@@ -36,8 +37,12 @@ static int (*orig_ohci_hub_control)(struct usb_hcd  *hcd, u16 typeReq,
 static int (*orig_ohci_hub_status_data)(struct usb_hcd *hcd, char *buf);
 
 struct da8xx_ohci_hcd {
+	struct usb_hcd *hcd;
 	struct clk *usb11_clk;
 	struct phy *usb11_phy;
+	struct regulator *vbus_reg;
+	struct notifier_block nb;
+	unsigned int is_powered;
 };
 #define to_da8xx_ohci(hcd) (struct da8xx_ohci_hcd *)(hcd_to_ohci(hcd)->priv)
 
@@ -82,56 +87,105 @@ static void ohci_da8xx_disable(struct usb_hcd *hcd)
 
 static int ohci_da8xx_set_power(struct usb_hcd *hcd, int on)
 {
+	struct da8xx_ohci_hcd *da8xx_ohci = to_da8xx_ohci(hcd);
 	struct device *dev		= hcd->self.controller;
 	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(dev);
+	int ret;
 
 	if (hub && hub->set_power)
 		return hub->set_power(1, on);
 
+	if (!da8xx_ohci->vbus_reg)
+		return 0;
+
+	if (on && !da8xx_ohci->is_powered) {
+		ret = regulator_enable(da8xx_ohci->vbus_reg);
+		if (ret) {
+			dev_err(dev, "Fail to enable regulator: %d\n", ret);
+			return ret;
+		}
+		da8xx_ohci->is_powered = 1;
+
+	} else if (!on && da8xx_ohci->is_powered) {
+		ret = regulator_disable(da8xx_ohci->vbus_reg);
+		if (ret) {
+			dev_err(dev, "Fail to disable regulator: %d\n", ret);
+			return ret;
+		}
+		da8xx_ohci->is_powered = 0;
+	}
+
 	return 0;
 }
 
 static int ohci_da8xx_get_power(struct usb_hcd *hcd)
 {
+	struct da8xx_ohci_hcd *da8xx_ohci = to_da8xx_ohci(hcd);
 	struct device *dev		= hcd->self.controller;
 	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(dev);
 
 	if (hub && hub->get_power)
 		return hub->get_power(1);
 
+	if (da8xx_ohci->vbus_reg)
+		return regulator_is_enabled(da8xx_ohci->vbus_reg);
+
 	return 1;
 }
 
 static int ohci_da8xx_get_oci(struct usb_hcd *hcd)
 {
+	struct da8xx_ohci_hcd *da8xx_ohci = to_da8xx_ohci(hcd);
 	struct device *dev		= hcd->self.controller;
 	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(dev);
+	unsigned int flags;
+	int ret;
 
 	if (hub && hub->get_oci)
 		return hub->get_oci(1);
 
+	if (!da8xx_ohci->vbus_reg)
+		return 0;
+
+	ret = regulator_get_error_flags(da8xx_ohci->vbus_reg, &flags);
+	if (ret) {
+		dev_err(dev, "could not get regulator error flags: %d\n", ret);
+		return ret;
+	}
+
+	if (flags && REGULATOR_ERROR_OVER_CURRENT)
+		return 1;
+
 	return 0;
 }
 
 static int ohci_da8xx_has_set_power(struct usb_hcd *hcd)
 {
+	struct da8xx_ohci_hcd *da8xx_ohci = to_da8xx_ohci(hcd);
 	struct device *dev		= hcd->self.controller;
 	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(dev);
 
 	if (hub && hub->set_power)
 		return 1;
 
+	if (da8xx_ohci->vbus_reg)
+		return 1;
+
 	return 0;
 }
 
 static int ohci_da8xx_has_oci(struct usb_hcd *hcd)
 {
+	struct da8xx_ohci_hcd *da8xx_ohci = to_da8xx_ohci(hcd);
 	struct device *dev		= hcd->self.controller;
 	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(dev);
 
 	if (hub && hub->get_oci)
 		return 1;
 
+	if (da8xx_ohci->vbus_reg)
+		return 1;
+
 	return 0;
 }
 
@@ -159,15 +213,41 @@ static void ohci_da8xx_ocic_handler(struct da8xx_ohci_root_hub *hub,
 		hub->set_power(port, 0);
 }
 
+static int ohci_da8xx_regulator_event(struct notifier_block *nb,
+				unsigned long event, void *data)
+{
+	struct da8xx_ohci_hcd *da8xx_ohci =
+				container_of(nb, struct da8xx_ohci_hcd, nb);
+	struct device *dev = da8xx_ohci->hcd->self.controller;
+
+	if (event & REGULATOR_EVENT_OVER_CURRENT) {
+		dev_warn(dev, "over current event\n");
+		ocic_mask |= 1;
+		ohci_da8xx_set_power(da8xx_ohci->hcd, 0);
+	}
+
+	return 0;
+}
+
 static int ohci_da8xx_register_notify(struct usb_hcd *hcd)
 {
+	struct da8xx_ohci_hcd *da8xx_ohci = to_da8xx_ohci(hcd);
 	struct device *dev		= hcd->self.controller;
 	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(dev);
+	int ret = 0;
 
 	if (hub && hub->ocic_notify)
-		return hub->ocic_notify(ohci_da8xx_ocic_handler);
+		ret = hub->ocic_notify(ohci_da8xx_ocic_handler);
+	else if (da8xx_ohci->vbus_reg) {
+		da8xx_ohci->nb.notifier_call = ohci_da8xx_regulator_event;
+		ret = devm_regulator_register_notifier(da8xx_ohci->vbus_reg,
+						&da8xx_ohci->nb);
+	}
 
-	return 0;
+	if (ret)
+		dev_err(dev, "Failed to register notifier: %d\n", ret);
+
+	return ret;
 }
 
 static void ohci_da8xx_unregister_notify(struct usb_hcd *hcd)
@@ -330,6 +410,7 @@ static int ohci_da8xx_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	da8xx_ohci = to_da8xx_ohci(hcd);
+	da8xx_ohci->hcd = hcd;
 
 	da8xx_ohci->usb11_clk = devm_clk_get(&pdev->dev, "usb11");
 	if (IS_ERR(da8xx_ohci->usb11_clk)) {
@@ -347,6 +428,18 @@ static int ohci_da8xx_probe(struct platform_device *pdev)
 		goto err;
 	}
 
+	da8xx_ohci->vbus_reg = devm_regulator_get_optional(&pdev->dev, "vbus");
+	if (IS_ERR(da8xx_ohci->vbus_reg)) {
+		error = PTR_ERR(da8xx_ohci->vbus_reg);
+		if (error == -ENODEV)
+			da8xx_ohci->vbus_reg = NULL;
+		else {
+			dev_err(&pdev->dev,
+				"Failed to get regulator: %d\n", error);
+			goto err;
+		}
+	}
+
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	hcd->regs = devm_ioremap_resource(&pdev->dev, mem);
 	if (IS_ERR(hcd->regs)) {
-- 
2.10.1