linux-kernel - usb:xhci: support disable usb2 LPM Remote Wakeup

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Message-Id: <1480855321-5047-1-git-send-email-tqnguyen@apm.com>
Date:   Sun,  4 Dec 2016 19:42:01 +0700
From:   "Thang Q. Nguyen" <tqnguyen@....com>
To:     Rob Herring <robh+dt@...nel.org>, Pawel Moll <pawel.moll@....com>,
        Mark Rutland <mark.rutland@....com>,
        Ian Campbell <ijc+devicetree@...lion.org.uk>,
        Kumar Gala <galak@...eaurora.org>,
        Mathias Nyman <mathias.nyman@...el.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-usb@...r.kernel.org
Cc:     Thang Nguyen <tqnguyen@....com>, Phong Vo <pvo@....com>,
        Loc Ho <lho@....com>, Vu Nguyen <vnguyen@....com>,
        patches@....com
Subject: usb:xhci: support disable usb2 LPM Remote Wakeup

From: Thang Nguyen <tqnguyen@....com>

As per USB 2.0 link power management addendum ECN, table 1-2, page 4,
device or host initiated via resume signaling; device-initiated resumes
can be optionally enabled/disabled by software. This patch adds support
to control enabling the USB2 RWE feature via DT/ACPI attribute.

Signed-off-by: Vu Nguyen <vnguyen@....com>
Signed-off-by: Thang Nguyen <tqnguyen@....com>
---
 Documentation/devicetree/bindings/usb/usb-xhci.txt | 1 +
 drivers/usb/host/xhci-plat.c                       | 3 +++
 drivers/usb/host/xhci.c                            | 5 ++++-
 drivers/usb/host/xhci.h                            | 1 +
 4 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt b/Documentation/devicetree/bindings/usb/usb-xhci.txt
index 966885c..9b4cd14 100644
--- a/Documentation/devicetree/bindings/usb/usb-xhci.txt
+++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt
@@ -25,6 +25,7 @@ Required properties:
 
 Optional properties:
   - clocks: reference to a clock
+  - usb2-rwe-disable: disable USB2 LPM Remote Wakeup capable
   - usb3-lpm-capable: determines if platform is USB3 LPM capable
 
 Example:
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index ed56bf9..15c540d 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -220,6 +220,9 @@ static int xhci_plat_probe(struct platform_device *pdev)
 		goto disable_clk;
 	}
 
+	if (device_property_read_bool(&pdev->dev, "usb2-rwe-disable"))
+		xhci->quirks |= XHCI_RWE_DISABLE;
+
 	if (device_property_read_bool(&pdev->dev, "usb3-lpm-capable"))
 		xhci->quirks |= XHCI_LPM_SUPPORT;
 
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 1a4ca02..f804868 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4183,7 +4183,10 @@ int xhci_set_usb2_hardware_lpm(struct usb_hcd *hcd,
 		}
 
 		pm_val &= ~PORT_HIRD_MASK;
-		pm_val |= PORT_HIRD(hird) | PORT_RWE | PORT_L1DS(udev->slot_id);
+		if ((xhci->quirks & XHCI_RWE_DISABLE) && (xhci->hci_version <= 0x100))
+			pm_val |= PORT_HIRD(hird) | PORT_L1DS(udev->slot_id);
+		else
+			pm_val |= PORT_HIRD(hird) | PORT_RWE | PORT_L1DS(udev->slot_id);
 		writel(pm_val, pm_addr);
 		pm_val = readl(pm_addr);
 		pm_val |= PORT_HLE;
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index f945380..2b9bc33 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1656,6 +1656,7 @@ struct xhci_hcd {
 #define XHCI_SSIC_PORT_UNUSED	(1 << 22)
 #define XHCI_NO_64BIT_SUPPORT	(1 << 23)
 #define XHCI_MISSING_CAS	(1 << 24)
+#define XHCI_RWE_DISABLE	(1 << 25)
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;
 	/* There are two roothubs to keep track of bus suspend info for */
-- 
2.7.4