[v1,10/14] usb: dwc2: Fix hibernation between host and device modes.

From: Artur Petrosyan <Arthur.Petrosyan@synopsys.com>
To: Felipe Balbi <balbi@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>,
	"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>
Cc: John Youn <John.Youn@synopsys.com>,
	Artur Petrosyan <Arthur.Petrosyan@synopsys.com>
Subject: [v1,10/14] usb: dwc2: Fix hibernation between host and device modes.
Date: Fri, 19 Apr 2019 11:25:09 +0000	[thread overview]
Message-ID: <40708a6888d43ff5e29b5d06f0c53beda840b096.1555672441.git.arturp@synopsys.com> (raw)

When core is in hibernation in host mode and a device cable
was connected than driver exited from device hibernation.
However, registers saved for host mode and when exited from
device hibernation register restore would be done for device
register which was wrong because there was no device registers
stored to restore.

- Added dwc_handle_gpwrdn_disc_det() function which handles
  gpwrdn disconnect detect flow and exits hibernation
  without restoring the registers.
- Updated exiting from hibernation in GPWRDN_STS_CHGINT with
  calling dwc_handle_gpwrdn_disc_det() function. Here no register
  is restored which is the solution described above.
- Increased the waiting timeout for HPRT0.PrtSusp register field
  to be set. Because on HiKey 960 board HPRT0.PrtSusp wasn't
  generated with the existing timeout.

Signed-off-by: Artur Petrosyan <arturp@synopsys.com>
Signed-off-by: Minas Harutyunyan <hminas@synopsys.com>
---
 drivers/usb/dwc2/core_intr.c | 139 ++++++++++++++++++++++++-------------------
 drivers/usb/dwc2/hcd.c       |   2 +-
 2 files changed, 80 insertions(+), 61 deletions(-)

-- 
2.11.0

diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c
index fc465707b7a1..40d296d9b6fb 100644
--- a/drivers/usb/dwc2/core_intr.c
+++ b/drivers/usb/dwc2/core_intr.c
@@ -662,6 +662,70 @@ static u32 dwc2_read_common_intr(struct dwc2_hsotg *hsotg)
 		return 0;
 }
 
+/**
+ * This function handles the gpwrdn disconnect detect.
+ * Exits hibernation without restoring registers.
+ *
+ * @hsotg: Programming view of DWC_otg controller
+ * @gpwrdn: GPWRDN register
+ */
+static inline void dwc_handle_gpwrdn_disc_det(struct dwc2_hsotg *hsotg,
+					      u32 gpwrdn)
+{
+	u32 gpwrdn_tmp;
+
+	/* Switch-on voltage to the core */
+	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
+	gpwrdn_tmp &= ~GPWRDN_PWRDNSWTCH;
+	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
+	udelay(10);
+
+	/* Reset core */
+	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
+	gpwrdn_tmp &= ~GPWRDN_PWRDNRSTN;
+	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
+	udelay(10);
+
+	/* Disable Power Down Clamp */
+	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
+	gpwrdn_tmp &= ~GPWRDN_PWRDNCLMP;
+	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
+	udelay(10);
+
+	/* Deassert reset core */
+	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
+	gpwrdn_tmp |= GPWRDN_PWRDNRSTN;
+	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
+	udelay(10);
+
+	/* Disable PMU interrupt */
+	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
+	gpwrdn_tmp &= ~GPWRDN_PMUINTSEL;
+	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
+
+	/* De-assert Wakeup Logic */
+	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
+	gpwrdn_tmp &= ~GPWRDN_PMUACTV;
+	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
+
+	hsotg->hibernated = 0;
+
+	if (gpwrdn & GPWRDN_IDSTS) {
+		hsotg->op_state = OTG_STATE_B_PERIPHERAL;
+		dwc2_core_init(hsotg, false);
+		dwc2_enable_global_interrupts(hsotg);
+		dwc2_hsotg_core_init_disconnected(hsotg, false);
+		dwc2_hsotg_core_connect(hsotg);
+	} else {
+		hsotg->op_state = OTG_STATE_A_HOST;
+
+		/* Initialize the Core for Host mode */
+		dwc2_core_init(hsotg, false);
+		dwc2_enable_global_interrupts(hsotg);
+		dwc2_hcd_start(hsotg);
+	}
+}
+
 /*
  * GPWRDN interrupt handler.
  *
@@ -683,60 +747,12 @@ static void dwc2_handle_gpwrdn_intr(struct dwc2_hsotg *hsotg)
 
 	if ((gpwrdn & GPWRDN_DISCONN_DET) &&
 	    (gpwrdn & GPWRDN_DISCONN_DET_MSK) && !linestate) {
-		u32 gpwrdn_tmp;
-
 		dev_dbg(hsotg->dev, "%s: GPWRDN_DISCONN_DET\n", __func__);
-
-		/* Switch-on voltage to the core */
-		gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
-		gpwrdn_tmp &= ~GPWRDN_PWRDNSWTCH;
-		dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
-		udelay(10);
-
-		/* Reset core */
-		gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
-		gpwrdn_tmp &= ~GPWRDN_PWRDNRSTN;
-		dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
-		udelay(10);
-
-		/* Disable Power Down Clamp */
-		gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
-		gpwrdn_tmp &= ~GPWRDN_PWRDNCLMP;
-		dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
-		udelay(10);
-
-		/* Deassert reset core */
-		gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
-		gpwrdn_tmp |= GPWRDN_PWRDNRSTN;
-		dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
-		udelay(10);
-
-		/* Disable PMU interrupt */
-		gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
-		gpwrdn_tmp &= ~GPWRDN_PMUINTSEL;
-		dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
-
-		/* De-assert Wakeup Logic */
-		gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
-		gpwrdn_tmp &= ~GPWRDN_PMUACTV;
-		dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
-
-		hsotg->hibernated = 0;
-
-		if (gpwrdn & GPWRDN_IDSTS) {
-			hsotg->op_state = OTG_STATE_B_PERIPHERAL;
-			dwc2_core_init(hsotg, false);
-			dwc2_enable_global_interrupts(hsotg);
-			dwc2_hsotg_core_init_disconnected(hsotg, false);
-			dwc2_hsotg_core_connect(hsotg);
-		} else {
-			hsotg->op_state = OTG_STATE_A_HOST;
-
-			/* Initialize the Core for Host mode */
-			dwc2_core_init(hsotg, false);
-			dwc2_enable_global_interrupts(hsotg);
-			dwc2_hcd_start(hsotg);
-		}
+		/*
+		 * Call disconnect detect function to exit from
+		 * hibernation
+		 */
+		dwc_handle_gpwrdn_disc_det(hsotg, gpwrdn);
 	}
 
 	if ((gpwrdn & GPWRDN_LNSTSCHG) &&
@@ -752,22 +768,25 @@ static void dwc2_handle_gpwrdn_intr(struct dwc2_hsotg *hsotg)
 			}
 		}
 	}
+
 	if ((gpwrdn & GPWRDN_RST_DET) && (gpwrdn & GPWRDN_RST_DET_MSK)) {
 		dev_dbg(hsotg->dev, "%s: GPWRDN_RST_DET\n", __func__);
 		if (!linestate && (gpwrdn & GPWRDN_BSESSVLD))
 			dwc2_exit_hibernation(hsotg, 0, 1, 0);
 	}
+
 	if ((gpwrdn & GPWRDN_STS_CHGINT) &&
-	    (gpwrdn & GPWRDN_STS_CHGINT_MSK) && linestate) {
+	    (gpwrdn & GPWRDN_STS_CHGINT_MSK)) {
 		dev_dbg(hsotg->dev, "%s: GPWRDN_STS_CHGINT\n", __func__);
 		if (hsotg->hw_params.hibernation &&
 		    hsotg->hibernated) {
-			if (gpwrdn & GPWRDN_IDSTS) {
-				dwc2_exit_hibernation(hsotg, 0, 0, 0);
-				call_gadget(hsotg, resume);
-			} else {
-				dwc2_exit_hibernation(hsotg, 1, 0, 1);
-			}
+			/*
+			 * As GPWRDN_STS_CHGINT exit from hibernation flow is
+			 * the same as in GPWRDN_DISCONN_DET flow. Call
+			 * disconnect detect helper function to exit from
+			 * hibernation.
+			 */
+			dwc_handle_gpwrdn_disc_det(hsotg, gpwrdn);
 		}
 	}
 }
diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 54450fa352cf..45d4a3e1ebd2 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -5570,7 +5570,7 @@ int dwc2_host_enter_hibernation(struct dwc2_hsotg *hsotg)
 	dwc2_writel(hsotg, hprt0, HPRT0);
 
 	/* Wait for the HPRT0.PrtSusp register field to be set */
-	if (dwc2_hsotg_wait_bit_set(hsotg, HPRT0, HPRT0_SUSP, 3000))
+	if (dwc2_hsotg_wait_bit_set(hsotg, HPRT0, HPRT0_SUSP, 5000))
 		dev_warn(hsotg->dev, "Suspend wasn't generated\n");
 
 	/*
