Hi,

On 19.09.25 23:40, Thinh Nguyen wrote:

On Sat, Sep 06, 2025, Sven Peter wrote:

quoted

We need fine grained control over mode switched on the DWC3 controller
present on Apple Silicon. Export core, host and gadget init and exit,
ptrcap and susphy control functions. Also introduce an additional
parameter to probe_data that allows to skip the final initialization
step that would bring up host or gadget mode.

Signed-off-by: Sven Peter <sven@kernel.org>
---
  drivers/usb/dwc3/core.c   | 16 +++++++++++-----
  drivers/usb/dwc3/gadget.c |  2 ++
  drivers/usb/dwc3/glue.h   | 14 ++++++++++++++
  drivers/usb/dwc3/host.c   |  2 ++
  4 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 8002c23a5a02acb8f3e87b2662a53998a4cf4f5c..18056fac44c8732278a650ac2be8b493892c92dd 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c

@@ -132,6 +132,7 @@ void dwc3_enable_susphy(struct dwc3 *dwc, bool enable)
  		dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(i), reg);
  	}
  }
+EXPORT_SYMBOL_GPL(dwc3_enable_susphy);
  
  void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode, bool ignore_susphy)
  {

@@ -157,6 +158,7 @@ void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode, bool ignore_susphy)
  
  	dwc->current_dr_role = mode;
  }
+EXPORT_SYMBOL_GPL(dwc3_set_prtcap);

I'm hesitant to export this as is. This function may change the susphy
bits and expect them to be restored later. It's not meant to be a
standalone use. At least, we should document how it should be used along
with the other newly added interfaces.

Sure, I can otherwise also open-code the susphy change inside 
dwc3_apple_phy_set_mode anyway if you prefer to keep this private to the 
dwc3 core. I should restore it there to the original value anyway I 
guess after phy_set_mode.

quoted

  
  static void __dwc3_set_mode(struct work_struct *work)

[...]

quoted

  int dwc3_gadget_suspend(struct dwc3 *dwc)
  {

diff --git a/drivers/usb/dwc3/glue.h b/drivers/usb/dwc3/glue.h
index 2efd00e763be4fc51911f32d43054059e61fb43a..633268c76fe4c7fdc312c9705dfa7cf7ccf3544c 100644
--- a/drivers/usb/dwc3/glue.h
+++ b/drivers/usb/dwc3/glue.h

@@ -15,16 +15,30 @@
   * @res: resource for the DWC3 core mmio region
   * @ignore_clocks_and_resets: clocks and resets defined for the device should
   *		be ignored by the DWC3 core, as they are managed by the glue
+ * @skip_core_init_mode: skip the finial initialization of the target mode, as

finial -> final?

Whoops, yes, I thought I ran a spell checker over this because I usually 
add a lot of typos but must've forgotten :-)

quoted

+ *		it must be managed by the glue
   */

[...]

quoted

  
+int dwc3_core_init(struct dwc3 *dwc);
+void dwc3_core_exit(struct dwc3 *dwc);
+
+int dwc3_host_init(struct dwc3 *dwc);
+void dwc3_host_exit(struct dwc3 *dwc);
+int dwc3_gadget_init(struct dwc3 *dwc);
+void dwc3_gadget_exit(struct dwc3 *dwc);
+
+void dwc3_enable_susphy(struct dwc3 *dwc, bool enable);
+void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode, bool ignore_susphy);
+

We should document these interfaces. The dwc3_core_probe() does all of
the above in the proper order. It's not obvious why these are needed and
how they should be used.

Very good point, I'll add documentation for all of these!


Thanks for the review,


Sven