[PATCH v4 1/2] mtd: rawnand: Add support for manufacturer specific suspend/resume operation

[Mason Yang]

Patch nand_suspend() & nand_resume() to let manufacturers overwrite
suspend/resume operations.

Signed-off-by: Mason Yang <masonccyang@xxxxxxxxxxx>
Reviewed-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
---
 drivers/mtd/nand/raw/nand_base.c | 17 +++++++++++++----
 include/linux/mtd/rawnand.h      |  4 ++++
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index f64e3b6..bde17a3 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -4321,16 +4321,22 @@ static int nand_block_markbad(struct mtd_info *mtd, loff_t ofs)
 /**
  * nand_suspend - [MTD Interface] Suspend the NAND flash
  * @mtd: MTD device structure
+ *
+ * Returns 0 for success or negative error code otherwise.
  */
 static int nand_suspend(struct mtd_info *mtd)
 {
 	struct nand_chip *chip = mtd_to_nand(mtd);
+	int ret = 0;
 
 	mutex_lock(&chip->lock);
-	chip->suspended = 1;
+	if (chip->suspend)
+		ret = chip->suspend(chip);
+	if (!ret)
+		chip->suspended = 1;
 	mutex_unlock(&chip->lock);
 
-	return 0;
+	return ret;
 }
 
 /**
@@ -4342,11 +4348,14 @@ static void nand_resume(struct mtd_info *mtd)
 	struct nand_chip *chip = mtd_to_nand(mtd);
 
 	mutex_lock(&chip->lock);
-	if (chip->suspended)
+	if (chip->suspended) {
+		if (chip->resume)
+			chip->resume(chip);
 		chip->suspended = 0;
-	else
+	} else {
 		pr_err("%s called for a chip which is not in suspended state\n",
 			__func__);
+	}
 	mutex_unlock(&chip->lock);
 }
 
diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
index 4ab9bcc..b3dccb9 100644
--- a/include/linux/mtd/rawnand.h
+++ b/include/linux/mtd/rawnand.h
@@ -1064,6 +1064,8 @@ struct nand_legacy {
  * @lock:		lock protecting the suspended field. Also used to
  *			serialize accesses to the NAND device.
  * @suspended:		set to 1 when the device is suspended, 0 when it's not.
+ * @suspend:		[REPLACEABLE] specific NAND device suspend operation
+ * @resume:		[REPLACEABLE] specific NAND device resume operation
  * @bbt:		[INTERN] bad block table pointer
  * @bbt_td:		[REPLACEABLE] bad block table descriptor for flash
  *			lookup.
@@ -1117,6 +1119,8 @@ struct nand_chip {
 
 	struct mutex lock;
 	unsigned int suspended : 1;
+	int (*suspend)(struct nand_chip *chip);
+	void (*resume)(struct nand_chip *chip);
 
 	uint8_t *oob_poi;
 	struct nand_controller *controller;
-- 
1.9.1