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From:   Macpaul Lin <macpaul.lin@mediatek.com>
To:     Rob Herring <robh@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Mathias Nyman <mathias.nyman@intel.com>,
        Chunfeng Yun <Chunfeng.Yun@mediatek.com>
CC:     Ainge Hsu <ainge.hsu@mediatek.com>,
        Eddie Hung <eddie.hung@mediatek.com>,
        Chunfeng Yun <chunfeng.yun@mediatek.com>,
        Mediatek WSD Upstream <wsd_upstream@mediatek.com>,
        Macpaul Lin <macpaul.lin@mediatek.com>,
        "Macpaul Lin" <macpaul@gmail.com>, <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-usb@vger.kernel.org>, <linux-mediatek@lists.infradead.org>,
        <stable@vger.kernel.org>
Subject: [PATCH v3 2/2] usb: host: XHCI: xhci-mtk.c: support mediatek,str-clock-on
Date:   Fri, 6 Nov 2020 18:21:37 +0800
Message-ID: <1604658097-5127-2-git-send-email-macpaul.lin@mediatek.com>
In-Reply-To: <1604658097-5127-1-git-send-email-macpaul.lin@mediatek.com>
References: <1604301530-31546-1-git-send-email-macpaul.lin@mediatek.com>
 <1604658097-5127-1-git-send-email-macpaul.lin@mediatek.com>
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Some platform dose not support turn off clock when system suspending.
We add an option "mediatek,str-clock-on" for distinquish these platforms.
When "mediatek,str-clock-on" has been set, xhci-mtk driver will skip
turning clock on and off during system suspend and resume.

Fixes: 0cbd4b34cda9 ("xhci: mediatek: support MTK xHCI host controller")
Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>
Cc: stable@vger.kernel.org
---
Changes for v3:
  - Add "Fixes" tag as a bug fix on phone system.
Changes for v2:
  - Replace "mediatek,keep-clock-on" to "mediatek,str-clock-on" which implies
    this option related to STR functions.

 drivers/usb/host/xhci-mtk.c |    9 +++++++--
 drivers/usb/host/xhci-mtk.h |    1 +
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
index 4311d4c..77b0d7a 100644
--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -464,6 +464,9 @@ static int xhci_mtk_probe(struct platform_device *pdev)
 	of_property_read_u32(node, "mediatek,u3p-dis-msk",
 			     &mtk->u3p_dis_msk);
 
+	/* STR: keep clock on when suspending on some platform */
+	mtk->str_clk_on = of_property_read_bool(node, "mediatek,str-clock-on");
+
 	ret = usb_wakeup_of_property_parse(mtk, node);
 	if (ret) {
 		dev_err(dev, "failed to parse uwk property\n");
@@ -624,7 +627,8 @@ static int __maybe_unused xhci_mtk_suspend(struct device *dev)
 	del_timer_sync(&xhci->shared_hcd->rh_timer);
 
 	xhci_mtk_host_disable(mtk);
-	xhci_mtk_clks_disable(mtk);
+	if (!mtk->str_clk_on)
+		xhci_mtk_clks_disable(mtk);
 	usb_wakeup_set(mtk, true);
 	return 0;
 }
@@ -636,7 +640,8 @@ static int __maybe_unused xhci_mtk_resume(struct device *dev)
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
 
 	usb_wakeup_set(mtk, false);
-	xhci_mtk_clks_enable(mtk);
+	if (!mtk->str_clk_on)
+		xhci_mtk_clks_enable(mtk);
 	xhci_mtk_host_enable(mtk);
 
 	xhci_dbg(xhci, "%s: restart port polling\n", __func__);
diff --git a/drivers/usb/host/xhci-mtk.h b/drivers/usb/host/xhci-mtk.h
index a93cfe8..4039b025 100644
--- a/drivers/usb/host/xhci-mtk.h
+++ b/drivers/usb/host/xhci-mtk.h
@@ -152,6 +152,7 @@ struct xhci_hcd_mtk {
 	struct regmap *uwk;
 	u32 uwk_reg_base;
 	u32 uwk_vers;
+	bool str_clk_on;
 };
 
 static inline struct xhci_hcd_mtk *hcd_to_mtk(struct usb_hcd *hcd)
-- 
1.7.9.5