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, 61 insertions, 2 deletions

diff --git a/drivers/misc/mic/host/mic_main.c b/drivers/misc/mic/host/mic_main.c
index ca06aa9..b352085 100644
--- a/drivers/misc/mic/host/mic_main.c
+++ b/drivers/misc/mic/host/mic_main.c
@@ -26,6 +26,7 @@
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/poll.h>
+#include <linux/suspend.h>
 
 #include <linux/mic_common.h>
 #include "../common/mic_dev.h"
@@ -187,6 +188,43 @@ static enum mic_hw_family mic_get_family(struct pci_dev *pdev)
 }
 
 /**
+* mic_pm_notifier: Notifier callback function that handles
+* PM notifications.
+*
+* @notifier_block: The notifier structure.
+* @pm_event: The event for which the driver was notified.
+* @unused: Meaningless. Always NULL.
+*
+* returns NOTIFY_DONE
+*/
+static int mic_pm_notifier(struct notifier_block *notifier,
+		unsigned long pm_event, void *unused)
+{
+	struct mic_device *mdev = container_of(notifier,
+		struct mic_device, pm_notifier);
+
+	switch (pm_event) {
+	case PM_HIBERNATION_PREPARE:
+		/* Fall through */
+	case PM_SUSPEND_PREPARE:
+		mic_prepare_suspend(mdev);
+		break;
+	case PM_POST_HIBERNATION:
+		/* Fall through */
+	case PM_POST_SUSPEND:
+		/* Fall through */
+	case PM_POST_RESTORE:
+		mic_complete_resume(mdev);
+		break;
+	case PM_RESTORE_PREPARE:
+		break;
+	default:
+		break;
+	}
+	return NOTIFY_DONE;
+}
+
+/**
  * mic_device_init - Allocates and initializes the MIC device structure
  *
  * @mdev: pointer to mic_device instance
@@ -194,9 +232,11 @@ static enum mic_hw_family mic_get_family(struct pci_dev *pdev)
  *
  * returns none.
  */
-static void
+static int
 mic_device_init(struct mic_device *mdev, struct pci_dev *pdev)
 {
+	int rc;
+
 	mdev->family = mic_get_family(pdev);
 	mdev->stepping = pdev->revision;
 	mic_ops_init(mdev);
@@ -205,7 +245,20 @@ mic_device_init(struct mic_device *mdev, struct pci_dev *pdev)
 	mdev->irq_info.next_avail_src = 0;
 	INIT_WORK(&mdev->reset_trigger_work, mic_reset_trigger_work);
 	INIT_WORK(&mdev->shutdown_work, mic_shutdown_work);
+	init_completion(&mdev->reset_wait);
 	INIT_LIST_HEAD(&mdev->vdev_list);
+	mdev->pm_notifier.notifier_call = mic_pm_notifier;
+	rc = register_pm_notifier(&mdev->pm_notifier);
+	if (rc) {
+		dev_err(&pdev->dev, "register_pm_notifier failed rc %d\n",
+			rc);
+		goto register_pm_notifier_fail;
+	}
+	return 0;
+register_pm_notifier_fail:
+	flush_work(&mdev->shutdown_work);
+	flush_work(&mdev->reset_trigger_work);
+	return rc;
 }
 
 /**
@@ -224,6 +277,7 @@ static void mic_device_uninit(struct mic_device *mdev)
 	kfree(mdev->bootmode);
 	flush_work(&mdev->reset_trigger_work);
 	flush_work(&mdev->shutdown_work);
+	unregister_pm_notifier(&mdev->pm_notifier);
 }
 
 /**
@@ -253,7 +307,11 @@ static int mic_probe(struct pci_dev *pdev,
 		goto ida_fail;
 	}
 
-	mic_device_init(mdev, pdev);
+	rc = mic_device_init(mdev, pdev);
+	if (rc) {
+		dev_err(&pdev->dev, "mic_device_init failed rc %d\n", rc);
+		goto device_init_fail;
+	}
 
 	rc = pci_enable_device(pdev);
 	if (rc) {
@@ -376,6 +434,7 @@ disable_device:
 	pci_disable_device(pdev);
 uninit_device:
 	mic_device_uninit(mdev);
+device_init_fail:
 	ida_simple_remove(&g_mic_ida, mdev->id);
 ida_fail:
 	kfree(mdev);