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Date:   Tue, 13 Apr 2021 11:36:52 +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 07/12] usb: dwc2: Update enter clock gating when port is suspended
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: <20210413073653.9F493A0094@mailhost.synopsys.com>
Precedence: bulk

Updates the implementation of entering clock gating mode
when core receives port suspend.
Instead of setting the required bit fields of the registers
inline, called the "dwc2_host_enter_clock_gating()" function.

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

 drivers/usb/dwc2/hcd.c | 19 ++++---------------
 1 file changed, 4 insertions(+), 15 deletions(-)

diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 27f030d5de54..e1225fe6c61a 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -3298,7 +3298,6 @@ static int dwc2_host_is_b_hnp_enabled(struct dwc2_hsotg *hsotg)
 int dwc2_port_suspend(struct dwc2_hsotg *hsotg, u16 windex)
 {
 	unsigned long flags;
-	u32 hprt0;
 	u32 pcgctl;
 	u32 gotgctl;
 	int ret = 0;
@@ -3323,22 +3322,12 @@ int dwc2_port_suspend(struct dwc2_hsotg *hsotg, u16 windex)
 		break;
 	case DWC2_POWER_DOWN_PARAM_HIBERNATION:
 	case DWC2_POWER_DOWN_PARAM_NONE:
-	default:
-		hprt0 = dwc2_read_hprt0(hsotg);
-		hprt0 |= HPRT0_SUSP;
-		dwc2_writel(hsotg, hprt0, HPRT0);
-		hsotg->bus_suspended = true;
 		/*
-		 * If power_down is supported, Phy clock will be suspended
-		 * after registers are backuped.
+		 * If not hibernation nor partial power down are supported,
+		 * clock gating is used to save power.
 		 */
-		if (!hsotg->params.power_down) {
-			/* Suspend the Phy Clock */
-			pcgctl = dwc2_readl(hsotg, PCGCTL);
-			pcgctl |= PCGCTL_STOPPCLK;
-			dwc2_writel(hsotg, pcgctl, PCGCTL);
-			udelay(10);
-		}
+		dwc2_host_enter_clock_gating(hsotg);
+		break;
 	}
 
 	/* For HNP the bus must be suspended for at least 200ms */
-- 
2.25.1