usb: host: xhci-plat: suspend and resume clocks

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>

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 044855818cb11c0e142576453faf16cb12c64656..a68b2b017b740b1c4bb16e79894dda587d3413b1 100644 (file)
--- 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 1960b47acfb28cb570b24dcb13e195c823da286e..182d1d4792d1b45dbcd18f6ed062aecb98ca47db 100644 (file)
--- 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;