On Tue, Jan 19, 2021 at 04:55:46PM +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> > --- > v6: > fix compiling warning: extra tokens at end of #ifdef directive > v5: > avoid using xhci_get_rhub() > protect ELPG routines with (CONFIG_PM || CONFIG_PM_SLEEP) > v4: > reshuffle the code to avoid these pre-declarations > 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 | 407 ++++++++++++++++++++++++++++++---- > 1 file changed, 370 insertions(+), 37 deletions(-) Acked-by: Thierry Reding <treding@xxxxxxxxxx>
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