usb: dwc3: core: add power management support

Add support for basic power management on
the dwc3 driver. While there is still lots
to improve for full PM support, this minimal
patch will already make sure that we survive
suspend-to-ram and suspend-to-disk without
major issues.

Cc: Vikas C Sajjan <vikas.sajjan@linaro.org>
Tested-by: Vivek Gautam <gautam.vivek@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 61 insertions, 0 deletions

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 04e4812fe2f9..73b0b7fc77f1 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2594,6 +2594,8 @@ err0:
 	return ret;
 }
 
+/* -------------------------------------------------------------------------- */
+
 void dwc3_gadget_exit(struct dwc3 *dwc)
 {
 	usb_del_gadget_udc(&dwc->gadget);
@@ -2611,3 +2613,62 @@ void dwc3_gadget_exit(struct dwc3 *dwc)
 	dma_free_coherent(dwc->dev, sizeof(*dwc->ctrl_req),
 			dwc->ctrl_req, dwc->ctrl_req_addr);
 }
+
+int dwc3_gadget_prepare(struct dwc3 *dwc)
+{
+	if (dwc->pullups_connected)
+		dwc3_gadget_disable_irq(dwc);
+
+	return 0;
+}
+
+void dwc3_gadget_complete(struct dwc3 *dwc)
+{
+	if (dwc->pullups_connected) {
+		dwc3_gadget_enable_irq(dwc);
+		dwc3_gadget_run_stop(dwc, true);
+	}
+}
+
+int dwc3_gadget_suspend(struct dwc3 *dwc)
+{
+	__dwc3_gadget_ep_disable(dwc->eps[0]);
+	__dwc3_gadget_ep_disable(dwc->eps[1]);
+
+	dwc->dcfg = dwc3_readl(dwc->regs, DWC3_DCFG);
+
+	return 0;
+}
+
+int dwc3_gadget_resume(struct dwc3 *dwc)
+{
+	struct dwc3_ep		*dep;
+	int			ret;
+
+	/* Start with SuperSpeed Default */
+	dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);
+
+	dep = dwc->eps[0];
+	ret = __dwc3_gadget_ep_enable(dep, &dwc3_gadget_ep0_desc, NULL, false);
+	if (ret)
+		goto err0;
+
+	dep = dwc->eps[1];
+	ret = __dwc3_gadget_ep_enable(dep, &dwc3_gadget_ep0_desc, NULL, false);
+	if (ret)
+		goto err1;
+
+	/* begin to receive SETUP packets */
+	dwc->ep0state = EP0_SETUP_PHASE;
+	dwc3_ep0_out_start(dwc);
+
+	dwc3_writel(dwc->regs, DWC3_DCFG, dwc->dcfg);
+
+	return 0;
+
+err1:
+	__dwc3_gadget_ep_disable(dwc->eps[0]);
+
+err0:
+	return ret;
+}