misc: mic: Enable OSPM suspend and resume support.

This patch enables support for OSPM suspend and resume in the MIC
driver. During a host suspend event, the driver performs an
orderly shutdown of the cards if they are online. Upon resume, any
cards that were previously online before suspend are rebooted.
The driver performs an orderly shutdown of the card primarily to
ensure that applications in the card are terminated and mounted
devices are safely un-mounted before the card is powered down in
the event of an OSPM suspend.

The driver makes use of the MIC daemon to accomplish OSPM suspend
and resume. The driver registers a PM notifier per MIC device.
The devices get notified synchronously during PM_SUSPEND_PREPARE and
PM_POST_SUSPEND phases.

During the PM_SUSPEND_PREPARE phase, the driver performs one of the
following three tasks.
1) If the card is 'offline', the driver sets the card to a
   'suspended' state and returns.
2) If the card is 'online', the driver initiates card shutdown by
   setting the card state to suspending. This notifies the MIC
   daemon which invokes shutdown and sets card state to 'suspended'.
   The driver returns after the shutdown is complete.
3) If the card is already being shutdown, possibly by a host user
   space application, the driver sets the card state to 'suspended'
   and returns after the shutdown is complete.

During the PM_POST_SUSPEND phase, the driver simply notifies the
daemon and returns. The daemon boots those cards that were previously
online during the suspend phase.

Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
Signed-off-by: Harshavardhan R Kharche <harshavardhan.r.kharche@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/Documentation/mic/mic_overview.txt b/Documentation/mic/mic_overview.txt
index c4424ed..b419292 100644
--- a/Documentation/mic/mic_overview.txt
+++ b/Documentation/mic/mic_overview.txt
@@ -4,7 +4,9 @@ that runs a Linux OS. It is a PCIe endpoint in a platform and therefore
 implements the three required standard address spaces i.e. configuration,
 memory and I/O. The host OS loads a device driver as is typical for
 PCIe devices. The card itself runs a bootstrap after reset that
-transfers control to the card OS downloaded from the host driver.
+transfers control to the card OS downloaded from the host driver. The
+host driver supports OSPM suspend and resume operations. It shuts down
+the card during suspend and reboots the card OS during resume.
 The card OS as shipped by Intel is a Linux kernel with modifications
 for the X100 devices.