On Tue, Aug 12, 2025, Krishna Kurapati wrote:
> In certain situations like role switching, the glue layers need to be
> informed of these events, so that they can take any necessary action.
> But in non-flattened implementations, the glue drivers have no data on
> when the core driver probe was successful post invoking of_platform_
> populate. Now that the core driver supports flattened implementations
> as well, introduce vendor callbacks that can be passed on from glue to
> core before invoking dwc3_core_probe.
>
> Introduce callbacks to notify glue layer of role_switch and run_stop
> changes. These can be used by flattened implementation of Qualcomm
> glue layer to generate connect/disconnect events in controller during
> cable connect and run stop modifications by udc in device mode.
>
> Signed-off-by: Krishna Kurapati <krishna.kurapati@xxxxxxxxxxxxxxxx>
> ---
> drivers/usb/dwc3/core.c | 1 +
> drivers/usb/dwc3/core.h | 26 ++++++++++++++++++++++++++
> drivers/usb/dwc3/drd.c | 1 +
> drivers/usb/dwc3/gadget.c | 1 +
> 4 files changed, 29 insertions(+)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 8002c23a5a02..392ba86c69f5 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -2351,6 +2351,7 @@ static int dwc3_probe(struct platform_device *pdev)
> return -ENOMEM;
>
> dwc->dev = &pdev->dev;
> + dwc->glue_ops = NULL;
>
> probe_data.dwc = dwc;
> probe_data.res = res;
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index d5b985fa12f4..a5fc92c4ffa3 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -992,6 +992,17 @@ struct dwc3_scratchpad_array {
> __le64 dma_adr[DWC3_MAX_HIBER_SCRATCHBUFS];
> };
>
> +/**
> + * struct dwc3_glue_ops - The ops indicate the notifications that
> + * need to be passed on to glue layer
> + * @pre_set_role: Notify glue of role switch notifications
> + * @pre_run_stop: Notify run stop enable/disable information to glue
> + */
> +struct dwc3_glue_ops {
> + void (*pre_set_role)(struct dwc3 *dwc, enum usb_role role);
> + void (*pre_run_stop)(struct dwc3 *dwc, bool is_on);
> +};
> +
> /**
> * struct dwc3 - representation of our controller
> * @drd_work: workqueue used for role swapping
> @@ -1012,6 +1023,7 @@ struct dwc3_scratchpad_array {
> * @eps: endpoint array
> * @gadget: device side representation of the peripheral controller
> * @gadget_driver: pointer to the gadget driver
> + * @glue_ops: Vendor callbacks for flattened device implementations.
> * @bus_clk: clock for accessing the registers
> * @ref_clk: reference clock
> * @susp_clk: clock used when the SS phy is in low power (S3) state
> @@ -1197,6 +1209,8 @@ struct dwc3 {
> struct usb_gadget *gadget;
> struct usb_gadget_driver *gadget_driver;
>
> + const struct dwc3_glue_ops *glue_ops;
> +
> struct clk *bus_clk;
> struct clk *ref_clk;
> struct clk *susp_clk;
> @@ -1614,6 +1628,18 @@ void dwc3_event_buffers_cleanup(struct dwc3 *dwc);
> int dwc3_core_soft_reset(struct dwc3 *dwc);
> void dwc3_enable_susphy(struct dwc3 *dwc, bool enable);
>
> +static inline void dwc3_pre_set_role(struct dwc3 *dwc, enum usb_role role)
> +{
> + if (dwc->glue_ops && dwc->glue_ops->pre_set_role)
> + dwc->glue_ops->pre_set_role(dwc, role);
> +}
> +
> +static inline void dwc3_pre_run_stop(struct dwc3 *dwc, bool is_on)
> +{
> + if (dwc->glue_ops && dwc->glue_ops->pre_run_stop)
> + dwc->glue_ops->pre_run_stop(dwc, is_on);
> +}
> +
> #if IS_ENABLED(CONFIG_USB_DWC3_HOST) || IS_ENABLED(CONFIG_USB_DWC3_DUAL_ROLE)
> int dwc3_host_init(struct dwc3 *dwc);
> void dwc3_host_exit(struct dwc3 *dwc);
> diff --git a/drivers/usb/dwc3/drd.c b/drivers/usb/dwc3/drd.c
> index 7977860932b1..4c91240eb429 100644
> --- a/drivers/usb/dwc3/drd.c
> +++ b/drivers/usb/dwc3/drd.c
> @@ -464,6 +464,7 @@ static int dwc3_usb_role_switch_set(struct usb_role_switch *sw,
> break;
> }
>
> + dwc3_pre_set_role(dwc, role);
> dwc3_set_mode(dwc, mode);
> return 0;
> }
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index 25db36c63951..999b2e436622 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -2658,6 +2658,7 @@ static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on)
> dwc->pullups_connected = false;
> }
>
> + dwc3_pre_run_stop(dwc, is_on);
> dwc3_gadget_dctl_write_safe(dwc, reg);
>
> do {
> --
> 2.34.1
>
Acked-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
Thanks,
Thinh
