From 8bd954c56197caf5e3a804d989094bc3fe6329aa Mon Sep 17 00:00:00 2001
From: Justin Chen <justinpopo6@gmail.com>
Date: Wed, 10 Aug 2022 15:27:34 -0700
Subject: [PATCH] usb: host: xhci-plat: suspend and resume clocks
Git-commit: 8bd954c56197caf5e3a804d989094bc3fe6329aa
Patch-mainline: v6.1-rc1
References: git-fixes

Introduce XHCI_SUSPEND_RESUME_CLKS quirk as a means to suspend and resume
clocks if the hardware is capable of doing so. We assume that clocks will
be needed if the device may wake.

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Justin Chen <justinpopo6@gmail.com>
Link: https://lore.kernel.org/r/1660170455-15781-2-git-send-email-justinpopo6@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/usb/host/xhci-plat.c | 16 +++++++++++++++-
 drivers/usb/host/xhci.h      |  1 +
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 044855818cb1..a68b2b017b74 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -432,7 +432,16 @@ static int __maybe_unused xhci_plat_suspend(struct device *dev)
 	 * xhci_suspend() needs `do_wakeup` to know whether host is allowed
 	 * to do wakeup during suspend.
 	 */
-	return xhci_suspend(xhci, device_may_wakeup(dev));
+	ret = xhci_suspend(xhci, device_may_wakeup(dev));
+	if (ret)
+		return ret;
+
+	if (!device_may_wakeup(dev) && (xhci->quirks & XHCI_SUSPEND_RESUME_CLKS)) {
+		clk_disable_unprepare(xhci->clk);
+		clk_disable_unprepare(xhci->reg_clk);
+	}
+
+	return 0;
 }
 
 static int __maybe_unused xhci_plat_resume(struct device *dev)
@@ -441,6 +450,11 @@ static int __maybe_unused xhci_plat_resume(struct device *dev)
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
 	int ret;
 
+	if (!device_may_wakeup(dev) && (xhci->quirks & XHCI_SUSPEND_RESUME_CLKS)) {
+		clk_prepare_enable(xhci->clk);
+		clk_prepare_enable(xhci->reg_clk);
+	}
+
 	ret = xhci_priv_resume_quirk(hcd);
 	if (ret)
 		return ret;
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 1960b47acfb2..182d1d4792d1 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1899,6 +1899,7 @@ struct xhci_hcd {
 #define XHCI_NO_SOFT_RETRY	BIT_ULL(40)
 #define XHCI_BROKEN_D3COLD	BIT_ULL(41)
 #define XHCI_EP_CTX_BROKEN_DCS	BIT_ULL(42)
+#define XHCI_SUSPEND_RESUME_CLKS	BIT_ULL(43)
 
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;
-- 
2.35.3