usb: dwc2: gadget: Add OUTTKNEPDIS and NAKINTRPT handlers

[cascardo/linux.git] / drivers / usb / dwc2 / gadget.c

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 7db9f9f..256c929 100644 (file)
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -1999,6 +1999,94 @@ static u32 dwc2_gadget_read_ep_interrupts(struct dwc2_hsotg *hsotg,
        return ints;
 }
 
+/**
+ * dwc2_gadget_handle_out_token_ep_disabled - handle DXEPINT_OUTTKNEPDIS
+ * @hs_ep: The endpoint on which interrupt is asserted.
+ *
+ * This is starting point for ISOC-OUT transfer, synchronization done with
+ * first out token received from host while corresponding EP is disabled.
+ *
+ * Device does not know initial frame in which out token will come. For this
+ * HW generates OUTTKNEPDIS - out token is received while EP is disabled. Upon
+ * getting this interrupt SW starts calculation for next transfer frame.
+ */
+static void dwc2_gadget_handle_out_token_ep_disabled(struct dwc2_hsotg_ep *ep)
+{
+       struct dwc2_hsotg *hsotg = ep->parent;
+       int dir_in = ep->dir_in;
+       u32 doepmsk;
+
+       if (dir_in || !ep->isochronous)
+               return;
+
+       dwc2_hsotg_complete_request(hsotg, ep, get_ep_head(ep), -ENODATA);
+
+       if (ep->interval > 1 &&
+           ep->target_frame == TARGET_FRAME_INITIAL) {
+               u32 dsts;
+               u32 ctrl;
+
+               dsts = dwc2_readl(hsotg->regs + DSTS);
+               ep->target_frame = dwc2_hsotg_read_frameno(hsotg);
+               dwc2_gadget_incr_frame_num(ep);
+
+               ctrl = dwc2_readl(hsotg->regs + DOEPCTL(ep->index));
+               if (ep->target_frame & 0x1)
+                       ctrl |= DXEPCTL_SETODDFR;
+               else
+                       ctrl |= DXEPCTL_SETEVENFR;
+
+               dwc2_writel(ctrl, hsotg->regs + DOEPCTL(ep->index));
+       }
+
+       dwc2_gadget_start_next_request(ep);
+       doepmsk = dwc2_readl(hsotg->regs + DOEPMSK);
+       doepmsk &= ~DOEPMSK_OUTTKNEPDISMSK;
+       dwc2_writel(doepmsk, hsotg->regs + DOEPMSK);
+}
+
+/**
+* dwc2_gadget_handle_nak - handle NAK interrupt
+* @hs_ep: The endpoint on which interrupt is asserted.
+*
+* This is starting point for ISOC-IN transfer, synchronization done with
+* first IN token received from host while corresponding EP is disabled.
+*
+* Device does not know when first one token will arrive from host. On first
+* token arrival HW generates 2 interrupts: 'in token received while FIFO empty'
+* and 'NAK'. NAK interrupt for ISOC-IN means that token has arrived and ZLP was
+* sent in response to that as there was no data in FIFO. SW is basing on this
+* interrupt to obtain frame in which token has come and then based on the
+* interval calculates next frame for transfer.
+*/
+static void dwc2_gadget_handle_nak(struct dwc2_hsotg_ep *hs_ep)
+{
+       struct dwc2_hsotg *hsotg = hs_ep->parent;
+       int dir_in = hs_ep->dir_in;
+
+       if (!dir_in || !hs_ep->isochronous)
+               return;
+
+       if (hs_ep->target_frame == TARGET_FRAME_INITIAL) {
+               hs_ep->target_frame = dwc2_hsotg_read_frameno(hsotg);
+               if (hs_ep->interval > 1) {
+                       u32 ctrl = dwc2_readl(hsotg->regs +
+                                             DIEPCTL(hs_ep->index));
+                       if (hs_ep->target_frame & 0x1)
+                               ctrl |= DXEPCTL_SETODDFR;
+                       else
+                               ctrl |= DXEPCTL_SETEVENFR;
+
+                       dwc2_writel(ctrl, hsotg->regs + DIEPCTL(hs_ep->index));
+               }
+
+               dwc2_hsotg_complete_request(hsotg, hs_ep,
+                                           get_ep_head(hs_ep), 0);
+       }
+
+       dwc2_gadget_incr_frame_num(hs_ep);
+}
+
 /**
  * dwc2_hsotg_epint - handle an in/out endpoint interrupt
  * @hsotg: The driver state
@@ -2083,6 +2171,12 @@ static void dwc2_hsotg_epint(struct dwc2_hsotg *hsotg, unsigned int idx,
                }
        }
 
+       if (ints & DXEPINT_OUTTKNEPDIS)
+               dwc2_gadget_handle_out_token_ep_disabled(hs_ep);
+
+       if (ints & DXEPINT_NAKINTRPT)
+               dwc2_gadget_handle_nak(hs_ep);
+
        if (ints & DXEPINT_AHBERR)
                dev_dbg(hsotg->dev, "%s: AHBErr\n", __func__);