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Date:   Tue, 13 Apr 2021 11:37:00 +0400
In-Reply-To: <cover.1618297800.git.Arthur.Petrosyan@synopsys.com>
References: <cover.1618297800.git.Arthur.Petrosyan@synopsys.com>
From:   Artur Petrosyan <Arthur.Petrosyan@synopsys.com>
Subject: [PATCH v2 08/12] usb: dwc2: Update exit clock gating when port is resumed
To:     Felipe Balbi <balbi@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     John Youn <John.Youn@synopsys.com>,
        Artur Petrosyan <Arthur.Petrosyan@synopsys.com>
Message-Id: <20210413073701.367E0A022E@mailhost.synopsys.com>
Precedence: bulk

Updates the implementation of exiting clock gating mode
when core receives port resume.
Instead of setting the required bit fields of the registers
inline, called the "dwc2_host_exit_clock_gating()" function.

Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com>
---
 Changes in v2:
 - None

 drivers/usb/dwc2/hcd.c | 29 ++++-------------------------
 1 file changed, 4 insertions(+), 25 deletions(-)

diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index e1225fe6c61a..8a42675ab94e 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -3359,8 +3359,6 @@ int dwc2_port_suspend(struct dwc2_hsotg *hsotg, u16 windex)
 int dwc2_port_resume(struct dwc2_hsotg *hsotg)
 {
 	unsigned long flags;
-	u32 hprt0;
-	u32 pcgctl;
 	int ret = 0;
 
 	spin_lock_irqsave(&hsotg->lock, flags);
@@ -3374,33 +3372,14 @@ int dwc2_port_resume(struct dwc2_hsotg *hsotg)
 		break;
 	case DWC2_POWER_DOWN_PARAM_HIBERNATION:
 	case DWC2_POWER_DOWN_PARAM_NONE:
-	default:
 		/*
-		 * If power_down is supported, Phy clock is already resumed
-		 * after registers restore.
+		 * If not hibernation nor partial power down are supported,
+		 * port resume is done using the clock gating programming flow.
 		 */
-		if (!hsotg->params.power_down) {
-			pcgctl = dwc2_readl(hsotg, PCGCTL);
-			pcgctl &= ~PCGCTL_STOPPCLK;
-			dwc2_writel(hsotg, pcgctl, PCGCTL);
-			spin_unlock_irqrestore(&hsotg->lock, flags);
-			msleep(20);
-			spin_lock_irqsave(&hsotg->lock, flags);
-		}
-
-		hprt0 = dwc2_read_hprt0(hsotg);
-		hprt0 |= HPRT0_RES;
-		hprt0 &= ~HPRT0_SUSP;
-		dwc2_writel(hsotg, hprt0, HPRT0);
 		spin_unlock_irqrestore(&hsotg->lock, flags);
-
-		msleep(USB_RESUME_TIMEOUT);
-
+		dwc2_host_exit_clock_gating(hsotg, 0);
 		spin_lock_irqsave(&hsotg->lock, flags);
-		hprt0 = dwc2_read_hprt0(hsotg);
-		hprt0 &= ~(HPRT0_RES | HPRT0_SUSP);
-		dwc2_writel(hsotg, hprt0, HPRT0);
-		hsotg->bus_suspended = false;
+		break;
 	}
 
 	spin_unlock_irqrestore(&hsotg->lock, flags);
-- 
2.25.1