I will amend accordingly and submit new patch. Thanks for review. JC On 9/28/20 10:06 PM, Thierry Reding wrote: > On Wed, Sep 09, 2020 at 04:10:41PM +0800, JC Kuo wrote: >> This commit implements the complete programming sequence for ELPG >> entry and exit. >> >> 1. At ELPG entry, invokes tegra_xusb_padctl_enable_phy_sleepwalk() >> and tegra_xusb_padctl_enable_phy_wake() to configure XUSB PADCTL >> sleepwalk and wake detection circuits to maintain USB lines level >> and respond to wake events (wake-on-connect, wake-on-disconnect, >> device-initiated-wake). >> >> 2. At ELPG exit, invokes tegra_xusb_padctl_disable_phy_sleepwalk() >> and tegra_xusb_padctl_disable_phy_wake() to disarm sleepwalk and >> wake detection circuits. >> >> At runtime suspend, XUSB host controller can enter ELPG to reduce >> power consumption. When XUSB PADCTL wake detection circuit detects >> a wake event, an interrupt will be raised. xhci-tegra driver then >> will invoke pm_runtime_resume() for xhci-tegra. >> >> Runtime resume could also be triggered by protocol drivers, this is >> the host-initiated-wake event. At runtime resume, xhci-tegra driver >> brings XUSB host controller out of ELPG to handle the wake events. >> >> The same ELPG enter/exit procedure will be performed for system >> suspend/resume path so USB devices can remain connected across SC7. >> >> Signed-off-by: JC Kuo <jckuo@xxxxxxxxxx> >> --- >> v3: >> use 'unsigned int' for PHY index >> remove unnecessary 'else' >> drop IRQF_TRIGGER_HIGH when invokes devm_request_threaded_irq() >> >> drivers/usb/host/xhci-tegra.c | 389 +++++++++++++++++++++++++++++++--- >> 1 file changed, 360 insertions(+), 29 deletions(-) >> >> diff --git a/drivers/usb/host/xhci-tegra.c b/drivers/usb/host/xhci-tegra.c >> index aabff8ee0bb3..ba3f40e78171 100644 >> --- a/drivers/usb/host/xhci-tegra.c >> +++ b/drivers/usb/host/xhci-tegra.c >> @@ -15,9 +15,11 @@ >> #include <linux/kernel.h> >> #include <linux/module.h> >> #include <linux/of_device.h> >> +#include <linux/of_irq.h> >> #include <linux/phy/phy.h> >> #include <linux/phy/tegra/xusb.h> >> #include <linux/platform_device.h> >> +#include <linux/usb/ch9.h> >> #include <linux/pm.h> >> #include <linux/pm_domain.h> >> #include <linux/pm_runtime.h> >> @@ -224,6 +226,7 @@ struct tegra_xusb { >> >> int xhci_irq; >> int mbox_irq; >> + int padctl_irq; >> >> void __iomem *ipfs_base; >> void __iomem *fpci_base; >> @@ -269,10 +272,13 @@ struct tegra_xusb { >> dma_addr_t phys; >> } fw; >> >> + bool suspended; >> struct tegra_xusb_context context; >> }; >> >> static struct hc_driver __read_mostly tegra_xhci_hc_driver; >> +static int tegra_xusb_exit_elpg(struct tegra_xusb *tegra, bool runtime); >> +static int tegra_xusb_enter_elpg(struct tegra_xusb *tegra, bool runtime); > > Can we reshuffle the code to avoid these predeclarations? Looks like > they're only used in tegra_xusb_runtime_{suspend,resume}(), so perhaps > move the implementations right before those? > > Thierry >