[PATCH AUTOSEL 5.15 05/47] usb: host: xhci-plat: suspend and resume clocks

Sasha Levin
2022-10-13T00:30:51Z

From: Justin Chen <justinpopo6@gmail.com>

[ Upstream commit 8bd954c56197caf5e3a804d989094bc3fe6329aa ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 dc570ce4e831..2687662f26b6 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -447,7 +447,16 @@ 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)
@@ -456,6 +465,11 @@ 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 10a4230d95c3..3b39501f26ea 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1903,6 +1903,7 @@ 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;
--
2.35.1