usb: dwc3: ep0: add LPM handling

On device loading the driver enables LPM and the acceptance of U1 and U2
states. The [Set|Clear]Feature requests for "U1/U2" are forwarded
directly to the hardware and allow / forbid the initiation of the low
power links.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index dda56b8f8617..906db570ef4f 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1933,6 +1933,7 @@ static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
 
         reg = dwc3_readl(dwc->regs, DWC3_DCTL);
         reg &= ~DWC3_DCTL_TSTCTRL_MASK;
+        reg &= ~(DWC3_DCTL_INITU1ENA | DWC3_DCTL_INITU2ENA);
         dwc3_writel(dwc->regs, DWC3_DCTL, reg);
         dwc->test_mode = false;
 
@@ -2330,6 +2331,14 @@ int __devinit dwc3_gadget_init(struct dwc3 *dwc)
                 goto err5;
         }
 
+        reg = dwc3_readl(dwc->regs, DWC3_DCFG);
+        reg |= DWC3_DCFG_LPM_CAP;
+        dwc3_writel(dwc->regs, DWC3_DCFG, reg);
+
+        reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+        reg |= DWC3_DCTL_ACCEPTU1ENA | DWC3_DCTL_ACCEPTU2ENA;
+        dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+
         /* Enable all but Start and End of Frame IRQs */
         reg = (DWC3_DEVTEN_VNDRDEVTSTRCVEDEN |
                         DWC3_DEVTEN_EVNTOVERFLOWEN |