Add software trigger USB device suspend resume function hook.
Do port suspend & resume in terms of xHCI spec.

Port Suspend:
Stop all endpoints via Stop Endpoint Command with Suspend (SP) flag set.
Place individual ports into suspend mode by writing '3' for Port Link State
(PLS) field into PORTSC register. This can only be done when the port is in
Enabled state. When writing, the Port Link State Write Strobe (LWS) bit shall
be set to '1'.
Allocate an xhci_command and stash it in xhci_virt_device to wait completion for
the last Stop Endpoint Command.  Use the Suspend bit in TRB to indicate the Stop
Endpoint Command is for port suspend. Based on Sarah's suggestion.

Port Resume:
Write '0' in PLS field, device will transition to running state.
Ring an endpoints' doorbell to restart it.

Ref: USB device remote wake need another patch to implement. For details of
how USB subsystem do power management, please see:
    Documentation/usb/power-management.txt
Signed-off-by: NCrane Cai <crane.cai@amd.com>
Signed-off-by: NLibin Yang <libin.yang@amd.com>
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Our virtual xHCI device can have as many ports as we like - I've tested
this patch with 31.
Signed-off-by: NWilliam Gulland <wgulland@vmware.com>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as1349b) clears up the confusion in many USB host
controller drivers between port features and port statuses.  In mosty
cases it's true that the status bit is in the position given by the
corresponding feature value, but that's not always true and it's not
guaranteed in the USB spec.

There's no functional change, just replacing expressions of the form
(1 << USB_PORT_FEAT_x) with USB_PORT_STAT_x, which has the same value.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as1348) removes the bogus
USB_PORT_FEAT_{HIGHSPEED,SUPERSPEED} symbols from ch11.h.  No such
features are defined by the USB spec.  (There is a PORT_LOWSPEED
feature, but the spec doesn't mention it except to say that host
software should never use it.)  The speed indicators are port
statuses, not port features.

As a temporary workaround for the xhci-hcd driver, a fictional
USB_PORT_STAT_SUPER_SPEED symbol is added.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
CC: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add the hub emulation code to allow ports on an xHCI root hub to be
disabled.  Add the code to clear the port enabled/disabled bit, and clear
the port enabled/disabled change bit.  Like EHCI, the port cannot be
enabled by setting the port enabled/disabled bit.  Instead, a port is
enabled by the host controller after a reset.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Refactor the code to clear the port change bits in the port status
register.  All port status change bits are write one to clear.

Remove a redundant port status read that was supposed to unblock any
posted writes.  We read the port after the write to get the updated status
for debugging, so the port read after that is unnecessary.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add functionality for getting port status and hub descriptor for xHCI root
hubs.  This is WIP because the USB 3.0 hub descriptor is different from
the USB 2.0 hub descriptor.  For now, we lie about the root hub descriptor
because the changes won't effect how the core talks to the root hub.
Later we will need to add the USB 3.0 hub descriptor for real hubs, and
this code might change.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>