usb: dwc2: gadget: LPM flow fix

commit 5d69a3b54e5a630c90d82a4c2bdce3d53dc78710 upstream.

Added functionality to exit from L1 state by device initiation
using remote wakeup signaling, in case when function driver queuing
request while core in L1 state.

Fixes: 273d576c4d41 ("usb: dwc2: gadget: Add functionality to exit from LPM L1 state")
Fixes: 88b02f2cb1e1 ("usb: dwc2: Add core state checking")
CC: stable@vger.kernel.org
Signed-off-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Link: https://lore.kernel.org/r/b4d9de5382375dddbf7ef6049d9a82066ad87d5d.1710166393.git.Minas.Harutyunyan@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 47 insertions, 21 deletions

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index 5568448a977b..a141f83aba0c 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -1336,6 +1336,7 @@ int dwc2_backup_global_registers(struct dwc2_hsotg *hsotg);
 int dwc2_restore_global_registers(struct dwc2_hsotg *hsotg);
 
 void dwc2_enable_acg(struct dwc2_hsotg *hsotg);
+void dwc2_wakeup_from_lpm_l1(struct dwc2_hsotg *hsotg, bool remotewakeup);
 
 /* This function should be called on every hardware interrupt. */
 irqreturn_t dwc2_handle_common_intr(int irq, void *dev);
diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c
index f8426e3d2b19..26d752a4c3ca 100644
--- a/drivers/usb/dwc2/core_intr.c
+++ b/drivers/usb/dwc2/core_intr.c
@@ -323,10 +323,11 @@ static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg)
  * @hsotg: Programming view of DWC_otg controller
  *
  */
-static void dwc2_wakeup_from_lpm_l1(struct dwc2_hsotg *hsotg)
+void dwc2_wakeup_from_lpm_l1(struct dwc2_hsotg *hsotg, bool remotewakeup)
 {
 	u32 glpmcfg;
-	u32 i = 0;
+	u32 pcgctl;
+	u32 dctl;
 
 	if (hsotg->lx_state != DWC2_L1) {
 		dev_err(hsotg->dev, "Core isn't in DWC2_L1 state\n");
@@ -335,37 +336,57 @@ static void dwc2_wakeup_from_lpm_l1(struct dwc2_hsotg *hsotg)
 
 	glpmcfg = dwc2_readl(hsotg, GLPMCFG);
 	if (dwc2_is_device_mode(hsotg)) {
-		dev_dbg(hsotg->dev, "Exit from L1 state\n");
+		dev_dbg(hsotg->dev, "Exit from L1 state, remotewakeup=%d\n", remotewakeup);
 		glpmcfg &= ~GLPMCFG_ENBLSLPM;
-		glpmcfg &= ~GLPMCFG_HIRD_THRES_EN;
+		glpmcfg &= ~GLPMCFG_HIRD_THRES_MASK;
 		dwc2_writel(hsotg, glpmcfg, GLPMCFG);
 
-		do {
-			glpmcfg = dwc2_readl(hsotg, GLPMCFG);
+		pcgctl = dwc2_readl(hsotg, PCGCTL);
+		pcgctl &= ~PCGCTL_ENBL_SLEEP_GATING;
+		dwc2_writel(hsotg, pcgctl, PCGCTL);
 
-			if (!(glpmcfg & (GLPMCFG_COREL1RES_MASK |
-					 GLPMCFG_L1RESUMEOK | GLPMCFG_SLPSTS)))
-				break;
+		glpmcfg = dwc2_readl(hsotg, GLPMCFG);
+		if (glpmcfg & GLPMCFG_ENBESL) {
+			glpmcfg |= GLPMCFG_RSTRSLPSTS;
+			dwc2_writel(hsotg, glpmcfg, GLPMCFG);
+		}
+
+		if (remotewakeup) {
+			if (dwc2_hsotg_wait_bit_set(hsotg, GLPMCFG, GLPMCFG_L1RESUMEOK, 1000)) {
+				dev_warn(hsotg->dev, "%s: timeout GLPMCFG_L1RESUMEOK\n", __func__);
+				goto fail;
+				return;
+			}
+
+			dctl = dwc2_readl(hsotg, DCTL);
+			dctl |= DCTL_RMTWKUPSIG;
+			dwc2_writel(hsotg, dctl, DCTL);
 
-			udelay(1);
-		} while (++i < 200);
+			if (dwc2_hsotg_wait_bit_set(hsotg, GINTSTS, GINTSTS_WKUPINT, 1000)) {
+				dev_warn(hsotg->dev, "%s: timeout GINTSTS_WKUPINT\n", __func__);
+				goto fail;
+				return;
+			}
+		}
 
-		if (i == 200) {
-			dev_err(hsotg->dev, "Failed to exit L1 sleep state in 200us.\n");
+		glpmcfg = dwc2_readl(hsotg, GLPMCFG);
+		if (glpmcfg & GLPMCFG_COREL1RES_MASK || glpmcfg & GLPMCFG_SLPSTS ||
+		    glpmcfg & GLPMCFG_L1RESUMEOK) {
+			goto fail;
 			return;
 		}
-		dwc2_gadget_init_lpm(hsotg);
+
+		/* Inform gadget to exit from L1 */
+		call_gadget(hsotg, resume);
+		/* Change to L0 state */
+		hsotg->lx_state = DWC2_L0;
+		hsotg->bus_suspended = false;
+fail:		dwc2_gadget_init_lpm(hsotg);
 	} else {
 		/* TODO */
 		dev_err(hsotg->dev, "Host side LPM is not supported.\n");
 		return;
 	}
-
-	/* Change to L0 state */
-	hsotg->lx_state = DWC2_L0;
-
-	/* Inform gadget to exit from L1 */
-	call_gadget(hsotg, resume);
 }
 
 /*
@@ -386,7 +407,7 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
 	dev_dbg(hsotg->dev, "%s lxstate = %d\n", __func__, hsotg->lx_state);
 
 	if (hsotg->lx_state == DWC2_L1) {
-		dwc2_wakeup_from_lpm_l1(hsotg);
+		dwc2_wakeup_from_lpm_l1(hsotg, false);
 		return;
 	}
 
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 8d3d937c81f9..b2f6da5b65cc 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -1415,6 +1415,10 @@ static int dwc2_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req,
 		ep->name, req, req->length, req->buf, req->no_interrupt,
 		req->zero, req->short_not_ok);
 
+	if (hs->lx_state == DWC2_L1) {
+		dwc2_wakeup_from_lpm_l1(hs, true);
+	}
+
 	/* Prevent new request submission when controller is suspended */
 	if (hs->lx_state != DWC2_L0) {
 		dev_dbg(hs->dev, "%s: submit request only in active state\n",