[MTD] OneNAND: Power Management (PM) support

Add suspend/resume

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

2 files changed, 34 insertions, 3 deletions

diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index 75d757882697..a002d4025b29 100644
--- a/drivers/mtd/onenand/onenand_base.c
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -505,7 +505,7 @@ static int onenand_update_bufferram(struct mtd_info *mtd, loff_t addr,
  *
  * Get the device and lock it for exclusive access
  */
-static void onenand_get_device(struct mtd_info *mtd, int new_state)
+static int onenand_get_device(struct mtd_info *mtd, int new_state)
 {
         struct onenand_chip *this = mtd->priv;
         DECLARE_WAITQUEUE(wait, current);
@@ -520,12 +520,18 @@ static void onenand_get_device(struct mtd_info *mtd, int new_state)
                         spin_unlock(&this->chip_lock);
                         break;
                 }
+                if (new_state == FL_PM_SUSPENDED) {
+                        spin_unlock(&this->chip_lock);
+                        return (this->state == FL_PM_SUSPENDED) ? 0 : -EAGAIN;
+                }
                 set_current_state(TASK_UNINTERRUPTIBLE);
                 add_wait_queue(&this->wq, &wait);
                 spin_unlock(&this->chip_lock);
                 schedule();
                 remove_wait_queue(&this->wq, &wait);
         }
+
+        return 0;
 }
 
 /**
@@ -1440,6 +1446,30 @@ static int onenand_probe(struct mtd_info *mtd)
         return 0;
 }
 
+/**
+ * onenand_suspend - [MTD Interface] Suspend the OneNAND flash
+ * @param mtd           MTD device structure
+ */
+static int onenand_suspend(struct mtd_info *mtd)
+{
+        return onenand_get_device(mtd, FL_PM_SUSPENDED);
+}
+
+/**
+ * onenand_resume - [MTD Interface] Resume the OneNAND flash
+ * @param mtd           MTD device structure
+ */
+static void onenand_resume(struct mtd_info *mtd)
+{
+        struct onenand_chip *this = mtd->priv;
+
+        if (this->state == FL_PM_SUSPENDED)
+                onenand_release_device(mtd);
+        else
+                printk(KERN_ERR "resume() called for the chip which is not"
+                                "in suspended state\n");
+}
+
 
 /**
  * onenand_scan - [OneNAND Interface] Scan for the OneNAND device
@@ -1527,8 +1557,8 @@ int onenand_scan(struct mtd_info *mtd, int maxchips)
         mtd->sync = onenand_sync;
         mtd->lock = NULL;
         mtd->unlock = onenand_unlock;
-        mtd->suspend = NULL;
-        mtd->resume = NULL;
+        mtd->suspend = onenand_suspend;
+        mtd->resume = onenand_resume;
         mtd->block_isbad = onenand_block_isbad;
         mtd->block_markbad = onenand_block_markbad;
         mtd->owner = THIS_MODULE;
diff --git a/include/linux/mtd/onenand.h b/include/linux/mtd/onenand.h
index 58023082320a..afaa6342aa7f 100644
--- a/include/linux/mtd/onenand.h
+++ b/include/linux/mtd/onenand.h
@@ -36,6 +36,7 @@ typedef enum {
         FL_SYNCING,
         FL_UNLOCKING,
         FL_LOCKING,
+        FL_PM_SUSPENDED,
 } onenand_state_t;
 
 /**