Synopsys Databook 2.60a has a note that if we're
sending a Start Transfer command we _must_ make sure
that DWC3_GUSB2PHY(n).SUSPHY bit is cleared.
This patch implements that particular detail.
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
---
drivers/usb/dwc3/gadget.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 0967b5d8fb75..8b3a676db346 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -227,10 +227,29 @@ int dwc3_send_gadget_ep_cmd(struct dwc3 *dwc, unsigned ep,
struct dwc3_ep *dep = dwc->eps[ep];
u32 timeout = 500;
u32 reg;
+
+ int susphy = false;
int ret = -EINVAL;
trace_dwc3_gadget_ep_cmd(dep, cmd, params);
+ /*
+ * Synopsys Databook 2.60a states, on section 6.3.2.5.5, that if we're
+ * issuing a Start Transfer command, we must check if GUSB2PHYCFG.SUSPHY
+ * bit is set. If it is, then we need to clear it.
+ *
+ * We will also set SUSPHY bit to what it was before returning as stated
+ * by the same section on Synopsys databook.
+ */
+ if (cmd == DWC3_DEPCMD_STARTTRANSFER) {
+ reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
+ if (unlikely(reg & DWC3_GUSB2PHYCFG_SUSPHY)) {
+ susphy = true;
+ reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
+ dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
+ }
+ }
+
dwc3_writel(dwc->regs, DWC3_DEPCMDPAR0(ep), params->param0);
dwc3_writel(dwc->regs, DWC3_DEPCMDPAR1(ep), params->param1);
dwc3_writel(dwc->regs, DWC3_DEPCMDPAR2(ep), params->param2);
@@ -263,6 +282,12 @@ int dwc3_send_gadget_ep_cmd(struct dwc3 *dwc, unsigned ep,
udelay(1);
} while (1);
+ if (unlikely(susphy)) {
+ reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
+ reg |= DWC3_GUSB2PHYCFG_SUSPHY;
+ dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
+ }
+
return ret;
}
--
2.8.0.rc2
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