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, 117 insertions, 3 deletions

diff --git a/drivers/misc/mic/host/mic_boot.c b/drivers/misc/mic/host/mic_boot.c
index 60c54d5c43c2..d56b8bf4eaf6 100644
--- a/drivers/misc/mic/host/mic_boot.c
+++ b/drivers/misc/mic/host/mic_boot.c
@@ -37,12 +37,13 @@ static void mic_reset(struct mic_device *mdev)
 
 #define MIC_RESET_TO (45)
 
+	INIT_COMPLETION(mdev->reset_wait);
 	mdev->ops->reset_fw_ready(mdev);
 	mdev->ops->reset(mdev);
 
 	for (i = 0; i < MIC_RESET_TO; i++) {
 		if (mdev->ops->is_fw_ready(mdev))
-			return;
+			goto done;
 		/*
 		 * Resets typically take 10s of seconds to complete.
 		 * Since an MMIO read is required to check if the
@@ -51,6 +52,8 @@ static void mic_reset(struct mic_device *mdev)
 		msleep(1000);
 	}
 	mic_set_state(mdev, MIC_RESET_FAILED);
+done:
+	complete_all(&mdev->reset_wait);
 }
 
 /* Initialize the MIC bootparams */
@@ -123,7 +126,8 @@ void mic_stop(struct mic_device *mdev, bool force)
 		if (MIC_RESET_FAILED == mdev->state)
 			goto unlock;
 		mic_set_shutdown_status(mdev, MIC_NOP);
-		mic_set_state(mdev, MIC_OFFLINE);
+		if (MIC_SUSPENDED != mdev->state)
+			mic_set_state(mdev, MIC_OFFLINE);
 	}
 unlock:
 	mutex_unlock(&mdev->mic_mutex);
@@ -165,7 +169,14 @@ void mic_shutdown_work(struct work_struct *work)
 	mutex_lock(&mdev->mic_mutex);
 	mic_set_shutdown_status(mdev, bootparam->shutdown_status);
 	bootparam->shutdown_status = 0;
-	if (MIC_SHUTTING_DOWN != mdev->state)
+
+	/*
+	 * if state is MIC_SUSPENDED, OSPM suspend is in progress. We do not
+	 * change the state here so as to prevent users from booting the card
+	 * during and after the suspend operation.
+	 */
+	if (MIC_SHUTTING_DOWN != mdev->state &&
+	    MIC_SUSPENDED != mdev->state)
 		mic_set_state(mdev, MIC_SHUTTING_DOWN);
 	mutex_unlock(&mdev->mic_mutex);
 }
@@ -183,3 +194,106 @@ void mic_reset_trigger_work(struct work_struct *work)
 
 	mic_stop(mdev, false);
 }
+
+/**
+ * mic_complete_resume - Complete MIC Resume after an OSPM suspend/hibernate
+ * event.
+ * @mdev: pointer to mic_device instance
+ *
+ * RETURNS: None.
+ */
+void mic_complete_resume(struct mic_device *mdev)
+{
+	if (mdev->state != MIC_SUSPENDED) {
+		dev_warn(mdev->sdev->parent, "state %d should be %d\n",
+			 mdev->state, MIC_SUSPENDED);
+		return;
+	}
+
+	/* Make sure firmware is ready */
+	if (!mdev->ops->is_fw_ready(mdev))
+		mic_stop(mdev, true);
+
+	mutex_lock(&mdev->mic_mutex);
+	mic_set_state(mdev, MIC_OFFLINE);
+	mutex_unlock(&mdev->mic_mutex);
+}
+
+/**
+ * mic_prepare_suspend - Handle suspend notification for the MIC device.
+ * @mdev: pointer to mic_device instance
+ *
+ * RETURNS: None.
+ */
+void mic_prepare_suspend(struct mic_device *mdev)
+{
+	int rc;
+
+#define MIC_SUSPEND_TIMEOUT (60 * HZ)
+
+	mutex_lock(&mdev->mic_mutex);
+	switch (mdev->state) {
+	case MIC_OFFLINE:
+		/*
+		 * Card is already offline. Set state to MIC_SUSPENDED
+		 * to prevent users from booting the card.
+		 */
+		mic_set_state(mdev, MIC_SUSPENDED);
+		mutex_unlock(&mdev->mic_mutex);
+		break;
+	case MIC_ONLINE:
+		/*
+		 * Card is online. Set state to MIC_SUSPENDING and notify
+		 * MIC user space daemon which will issue card
+		 * shutdown and reset.
+		 */
+		mic_set_state(mdev, MIC_SUSPENDING);
+		mutex_unlock(&mdev->mic_mutex);
+		rc = wait_for_completion_timeout(&mdev->reset_wait,
+						MIC_SUSPEND_TIMEOUT);
+		/* Force reset the card if the shutdown completion timed out */
+		if (!rc) {
+			mutex_lock(&mdev->mic_mutex);
+			mic_set_state(mdev, MIC_SUSPENDED);
+			mutex_unlock(&mdev->mic_mutex);
+			mic_stop(mdev, true);
+		}
+		break;
+	case MIC_SHUTTING_DOWN:
+		/*
+		 * Card is shutting down. Set state to MIC_SUSPENDED
+		 * to prevent further boot of the card.
+		 */
+		mic_set_state(mdev, MIC_SUSPENDED);
+		mutex_unlock(&mdev->mic_mutex);
+		rc = wait_for_completion_timeout(&mdev->reset_wait,
+						MIC_SUSPEND_TIMEOUT);
+		/* Force reset the card if the shutdown completion timed out */
+		if (!rc)
+			mic_stop(mdev, true);
+		break;
+	default:
+		mutex_unlock(&mdev->mic_mutex);
+		break;
+	}
+}
+
+/**
+ * mic_suspend - Initiate MIC suspend. Suspend merely issues card shutdown.
+ * @mdev: pointer to mic_device instance
+ *
+ * RETURNS: None.
+ */
+void mic_suspend(struct mic_device *mdev)
+{
+	struct mic_bootparam *bootparam = mdev->dp;
+	s8 db = bootparam->h2c_shutdown_db;
+
+	mutex_lock(&mdev->mic_mutex);
+	if (MIC_SUSPENDING == mdev->state && db != -1) {
+		bootparam->shutdown_card = 1;
+		mdev->ops->send_intr(mdev, db);
+		mic_set_state(mdev, MIC_SUSPENDED);
+	}
+	mutex_unlock(&mdev->mic_mutex);
+}