Hi,
> From: Roger Quadros
> Sent: Tuesday, April 05, 2016 11:05 PM
>
> It provides APIs for the following tasks
>
> - Registering an OTG/dual-role capable controller
> - Registering Host and Gadget controllers to OTG core
> - Providing inputs to and kicking the OTG state machine
>
> Provide a dual-role device (DRD) state machine.
> DRD mode is a reduced functionality OTG mode. In this mode
> we don't support SRP, HNP and dynamic role-swap.
>
> In DRD operation, the controller mode (Host or Peripheral)
> is decided based on the ID pin status. Once a cable plug (Type-A
> or Type-B) is attached the controller selects the state
> and doesn't change till the cable in unplugged and a different
> cable type is inserted.
>
> As we don't need most of the complex OTG states and OTG timers
> we implement a lean DRD state machine in usb-otg.c.
> The DRD state machine is only interested in 2 hardware inputs
> 'id' and 'b_sess_vld'.
>
> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
> ---
I tried to implement this framework on my environment,
and it seemed work if I added a local hack to this patch :)
< snip >
> + /* HCD will be started by OTG fsm when needed */
> + mutex_lock(&otg->fsm.lock);
> + if (otg->primary_hcd.hcd) {
> + /* probably a shared HCD ? */
> + if (usb_otg_hcd_is_primary_hcd(hcd)) {
> + dev_err(otg_dev, "otg: primary host already registered\n");
My environment is arm64 / r8a7795, renesas_usbhs (as a gadget), EHCI and OHCI.
In this case, OHCI driver is also a primary_hcd. So, this error happened.
To avoid this, I assumes that the OHCI hcd is as shared_hcd like a patch below:
diff --git a/drivers/usb/common/usb-otg.c b/drivers/usb/common/usb-otg.c
index 41e762a..4d7f043 100644
--- a/drivers/usb/common/usb-otg.c
+++ b/drivers/usb/common/usb-otg.c
@@ -825,11 +825,16 @@ int usb_otg_register_hcd(struct usb_hcd *hcd, unsigned int irqnum,
if (otg->primary_hcd.hcd) {
/* probably a shared HCD ? */
if (usb_otg_hcd_is_primary_hcd(hcd)) {
+ if (hcd->driver->flags & HCD_USB11) {
+ dev_info(otg_dev, "this assumes usb 1.1 hc is as shared_hcd\n");
+ goto check_shared_hcd;
+ }
dev_err(otg_dev, "otg: primary host already registered\n");
goto err;
}
if (hcd->shared_hcd == otg->primary_hcd.hcd) {
+check_shared_hcd:
if (otg->shared_hcd.hcd) {
dev_err(otg_dev, "otg: shared host already registered\n");
goto err;
What do you think this local hack?
I also wonder if array of hcd may be good for both xHCI and EHCI/OHCI.
For example of xHCI:
- otg->hcds[0] = primary_hcd
- otg->hcds[1] = shared_hcd
For example of EHCI/OHCI:
- otg->hcds[0] = primary_hcd of EHCI
- otg->hcds[1] = primary_hcd of OHCI
Best regards,
Yoshihiro Shimoda
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