[PATCH] Revert "usb: cdns3: use VBUS Valid to determine role for dr_mode OTG"

[Marek Vasut]

On 3/12/26 2:50 PM, Tom Rini wrote:
> On Thu, Mar 12, 2026 at 07:02:47PM +0530, Prasanth Babu Mantena wrote:
> 
>> While USB DFU boot works with this patch, but the non USB boot modes like
>> SD Boot and flash boot fails for J784S4 EVM device.
>>
>> So, Reverting this patch.
>>
>> This reverts commit bfb530e06ca6c19f66c079601e568c761a001993.
>>
>> Signed-off-by: Prasanth Babu Mantena <p-mantena at ti.com>
>> ---
>>   drivers/usb/cdns3/core.c | 53 ----------------------------------------
>>   drivers/usb/cdns3/drd.c  | 11 ---------
>>   2 files changed, 64 deletions(-)
>>
>> diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c
>> index 10bc4cabed4..4434dc15bec 100644
>> --- a/drivers/usb/cdns3/core.c
>> +++ b/drivers/usb/cdns3/core.c
>> @@ -392,52 +392,6 @@ static const struct udevice_id cdns3_ids[] = {
>>   	{ },
>>   };
>>   
>> -/*
>> - * The VBUS Valid Bit in the OTG Status register can be used to determine
>> - * the role. When VBUS Valid is set, it indicates that a USB Host is supplying
>> - * power, so the Controller should assume the PERIPHERAL role. If it isn't set,
>> - * it indicates the absence of a USB Host, so the Controller should assume the
>> - * HOST role. If the OTG Status register is inaccessible, return an error.
>> - */
>> -static int cdns3_get_otg_mode(struct udevice *parent, enum usb_dr_mode *mode)
>> -{
>> -	/* Create a temporary child device for using devfdt_remap_addr_name() */
>> -	struct udevice child = {
>> -		.parent = parent,
>> -	};
>> -	struct cdns3 cdns, *cdnsp;
>> -	void __iomem *otg_regs;
>> -
>> -	dev_set_ofnode(&child, ofnode_first_subnode(dev_ofnode(parent)));
>> -	otg_regs = devfdt_remap_addr_name(&child, "otg");
>> -	if (!otg_regs) {
>> -		dev_err(parent, "failed to get otg registers for child node\n");
>> -		return -ENXIO;
>> -	}
>> -
>> -	/*
>> -	 * As mentioned in drivers/usb/cdns3/drd.c, there are two versions
>> -	 * of the Controller. The following logic detects the version of the
>> -	 * Controller and interprets the register layout accordingly.
>> -	 */
>> -	cdnsp = &cdns;
>> -	cdnsp->otg_v0_regs = otg_regs;
>> -	if (!readl(&cdnsp->otg_v0_regs->cmd)) {
>> -		cdnsp->otg_regs = otg_regs;
>> -	} else {
>> -		cdnsp->otg_v1_regs = otg_regs;
>> -		cdnsp->otg_regs = (void *)&cdnsp->otg_v1_regs->cmd;
>> -	}
>> -
>> -	/* Use VBUS Valid to determine role */
>> -	if (readl(&cdnsp->otg_regs->sts) & OTGSTS_VBUS_VALID)
>> -		*mode = USB_DR_MODE_PERIPHERAL;
>> -	else
>> -		*mode = USB_DR_MODE_HOST;
>> -
>> -	return 0;
>> -}
>> -
>>   int cdns3_bind(struct udevice *parent)
>>   {
>>   	enum usb_dr_mode dr_mode;
>> @@ -459,13 +413,6 @@ int cdns3_bind(struct udevice *parent)
>>   	if (dr_mode == USB_DR_MODE_UNKNOWN)
>>   		dr_mode = usb_get_dr_mode(dev_ofnode(parent));
>>   
>> -	/* Use VBUS Valid to determine role */
>> -	if (dr_mode == USB_DR_MODE_OTG) {
>> -		ret = cdns3_get_otg_mode(parent, &dr_mode);
>> -		if (ret < 0)
>> -			return ret;
>> -	}
>> -
>>   	switch (dr_mode) {
>>   #if defined(CONFIG_SPL_USB_HOST) || \
>>   	(!defined(CONFIG_XPL_BUILD) && defined(CONFIG_USB_HOST))
>> diff --git a/drivers/usb/cdns3/drd.c b/drivers/usb/cdns3/drd.c
>> index 0ca40a5cc8d..cbb13342343 100644
>> --- a/drivers/usb/cdns3/drd.c
>> +++ b/drivers/usb/cdns3/drd.c
>> @@ -301,17 +301,6 @@ int cdns3_drd_init(struct cdns3 *cdns)
>>   		cdns->dr_mode = USB_DR_MODE_PERIPHERAL;
>>   	}
>>   
>> -	/*
>> -	 * In the absence of STRAP configuration, use VBUS Valid to
>> -	 * determine the appropriate role to be assigned to dr_mode.
>> -	 */
>> -	if (cdns->dr_mode == USB_DR_MODE_OTG) {
>> -		if (cdns3_get_vbus(cdns))
>> -			cdns->dr_mode = USB_DR_MODE_PERIPHERAL;
>> -		else
>> -			cdns->dr_mode = USB_DR_MODE_HOST;
>> -	}
>> -
>>   	state = readl(&cdns->otg_regs->sts);
>>   	if (OTGSTS_OTG_NRDY(state) != 0) {
>>   		dev_err(cdns->dev, "Cadence USB3 OTG device not ready\n");
> 
> Adding in the USB custodian as this revert is intended for master and
> v2026.04 I assume as the commit being reverted is also in master.
> Thanks.
This may be related to

[PATCH] usb: cdns3: fix cdns3_bind() to avoid returning error and probe 
parent

?

Can you coordinate with Siddharth Vadapalli ?