[MTD] OneNAND: Power Management (PM) support
Kyungmin Park [Thu, 29 Sep 2005 02:55:31 +0000 (03:55 +0100)]
Add suspend/resume

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

drivers/mtd/onenand/onenand_base.c
include/linux/mtd/onenand.h

index 75d7578..a002d40 100644 (file)
@@ -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;
index 5802308..afaa634 100644 (file)
@@ -36,6 +36,7 @@ typedef enum {
        FL_SYNCING,
        FL_UNLOCKING,
        FL_LOCKING,
+       FL_PM_SUSPENDED,
 } onenand_state_t;
 
 /**