Hi
I am developing HCD for MSM USB hardware. The controller is compliant to EHCI.
But we need to initialize non-EHCI registers after controller is reset. This
also include workarounds like disabling streaming mode etc.
Due to this, we can not initialize .start method of struct hc_driver to
ehci_run. This function call ehci_reset (after this hardware register settings
are lost) and continue initialization of controller.
Is it okay to introduce a callback function in ehci_hcd struct that gets called
right after ehci_reset()? I have added this method to ehci_hcd instead of hc_driver
struct thinking that this is more like a silicon quirk.
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 34a928d..b6a5448 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -277,6 +277,15 @@ static int ehci_reset (struct ehci_hcd *ehci)
if (ehci_is_TDI(ehci))
tdi_reset (ehci);
+ /* Some controllers require additional hardware initialization after
+ * controller reset.
+ */
+ if (ehci->post_reset) {
+ retval = ehci->post_reset(ehci);
+ if (retval)
+ return retval;
+ }
+
if (ehci->debug)
dbgp_external_startup();
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index bde823f..ad4b0bc 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -131,6 +131,7 @@ struct ehci_hcd { /* one per controller */
unsigned need_io_watchdog:1;
unsigned broken_periodic:1;
unsigned fs_i_thresh:1; /* Intel iso scheduling */
+ int (*post_reset)(struct ehci_hcd *);
/* required for usb32 quirk */
#define OHCI_CTRL_HCFS (3 << 6)
Thanks,
Pavan
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