[PATCH] usb: chipidea: udc: Link otg and gadget

[PATCH] usb: chipidea: udc: Link otg and gadget

[Johan Korsnes]

Link OTG with gadget, same as other UDC drivers.

Signed-off-by: Johan Korsnes <johan.korsnes@remarkable.no>
Cc: Xu Yang <xu.yang_2@nxp.com>
Cc: Peter Chen <peter.chen@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/chipidea/udc.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
index 64a421ae0f05..1d2f9543ea37 100644
--- a/drivers/usb/chipidea/udc.c
+++ b/drivers/usb/chipidea/udc.c
@@ -2125,6 +2125,9 @@ static int ci_udc_start(struct usb_gadget *gadget,
 
 	ci->driver = driver;
 
+	if (!IS_ERR_OR_NULL(ci->usb_phy))
+		otg_set_peripheral(ci->usb_phy->otg, &ci->gadget);
+
 	/* Start otg fsm for B-device */
 	if (ci_otg_is_fsm_mode(ci) && ci->fsm.id) {
 		ci_hdrc_otg_fsm_start(ci);
@@ -2166,6 +2169,9 @@ static int ci_udc_stop(struct usb_gadget *gadget)
 	spin_lock_irqsave(&ci->lock, flags);
 	ci->driver = NULL;
 
+	if (!IS_ERR_OR_NULL(ci->usb_phy))
+		otg_set_peripheral(ci->usb_phy->otg, NULL);
+
 	if (ci->vbus_active) {
 		hw_device_state(ci, 0);
 		spin_unlock_irqrestore(&ci->lock, flags);
-- 
2.51.0

Re: [PATCH] usb: chipidea: udc: Link otg and gadget

[Greg Kroah-Hartman]

On Wed, Nov 19, 2025 at 04:26:41PM +0100, Johan Korsnes wrote:
> Link OTG with gadget, same as other UDC drivers.

I do not understand this changelog, sorry.  Can you please expand on it?

thanks,

greg k-h

Re: [PATCH] usb: chipidea: udc: Link otg and gadget

[Johan Korsnes]

On 19/11/2025 16:32, Greg Kroah-Hartman wrote:
> On Wed, Nov 19, 2025 at 04:26:41PM +0100, Johan Korsnes wrote:
>> Link OTG with gadget, same as other UDC drivers.
> 
> I do not understand this changelog, sorry.  Can you please expand on it?
> 
> thanks,
> 
> greg k-h

I'll submit a v2 with a proper description. It might also be that this
link between otg and gadget is not appropriate for the ChipIdea driver.

I've (ab)used this link to obtain the gadget state via the usb_phy in
a different driver. Since some of the other UDC drivers set up the link
I just assumed it had been forgotten for the CI one. I'll double check!

Kind regards,
Johan