On 1/10/23 14:39, Mattijs Korpershoek wrote:
Hi Harald,
Thank you for your review.
On Tue, Jan 10, 2023 at 14:30, Harald Seiler hws@denx.de wrote:
Hi,
On Tue, 2023-01-10 at 10:11 +0100, Mattijs Korpershoek wrote:
Pullup is used by the usb framework in order to do software-controlled usb_gadget_connect() and usb_gadget_disconnect().
Implement pullup() for dwc2 using the SOFT_DISCONNECT bit in the dctl register.
This is especially useful when a gadget disconnection is initiated but no board_usb_cleanup() is called.
Signed-off-by: Mattijs Korpershoek mkorpershoek@baylibre.com
On some boards using the dwc2 controller, like the Khadas VIM3L, whenever usb_gadget_release() is called, the D+ and D- lines are in an unknown state.
Because of that, the host can't detect usb disconnection.
It was attempted to be be fixed with [1] but ended up doing the gadget disconnection too early, creating issues on NXP-based boards which use uuu [2].
By implementing pullup() in the controller driver, we ensure that the disconnection will only be done when the framework calls usb_gadget_disconnect().
[1] https://lore.kernel.org/all/20220728-reset-usb-controller-v2-1-ef7657ce78b1@... [2] https://lore.kernel.org/all/20230107164807.3597020-1-dario.binacchi@amarulas...
drivers/usb/gadget/dwc2_udc_otg.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
diff --git a/drivers/usb/gadget/dwc2_udc_otg.c b/drivers/usb/gadget/dwc2_udc_otg.c index 77988f78ab30..93ed9712d18a 100644 --- a/drivers/usb/gadget/dwc2_udc_otg.c +++ b/drivers/usb/gadget/dwc2_udc_otg.c @@ -236,6 +236,21 @@ static int udc_enable(struct dwc2_udc *dev) return 0; }
+static int dwc2_gadget_pullup(struct usb_gadget *g, int is_on) +{
- unsigned int uTemp;
Just some minor points about style...
I think the `u32` type should be used for 32-bit registers instead. More explicit and no room for accidentally choosing the wrong size.
Also, U-Boot and Linux don't use hungarian notation for variable names, just call it `tmp` or even better `dctl` to be explicit.
I agree with this. I actually picked up some of the code from reconfig_usbd() where hungarian nototation is used. That's also where the unsigned int comes from.
Sorry I did not convert it to some more Linux/U-Boot oriented style before submitting.
- is_on = !!is_on;
This is superfluous, the if condition works either way.
Ack.
The maintainer (Marek) already picked this up in his usb tree: https://lore.kernel.org/all/1f2c5d74-faae-42f8-5d4d-dfc08cb093aa@denx.de/
Should I send a clean-up/follow-up patch for this?
The maintainer already dropped it and waits for V2 :)