mtd: nand: Provide nand_cleanup() function to free NAND related resources

Provide a nand_cleanup() function to free all nand related resources
without unregistering the mtd device.
This should allow drivers to call mtd_device_unregister() and handle
its return value and still being able to cleanup all nand related
resources.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Daniel Walter <dwalter@sigma-star.at>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

drivers/mtd/nand/nand_base.c

@@ -4799,19 +4799,15 @@ int nand_scan(struct mtd_info *mtd, int maxchips)
 EXPORT_SYMBOL(nand_scan);
 
 /**
- * nand_release - [NAND Interface] Free resources held by the NAND device
- * @mtd: MTD device structure
+ * nand_cleanup - [NAND Interface] Free resources held by the NAND device
+ * @chip: NAND chip object
  */
-void nand_release(struct mtd_info *mtd)
+void nand_cleanup(struct nand_chip *chip)
 {
-	struct nand_chip *chip = mtd_to_nand(mtd);
-
 	if (chip->ecc.mode == NAND_ECC_SOFT &&
 	    chip->ecc.algo == NAND_ECC_BCH)
 		nand_bch_free((struct nand_bch_control *)chip->ecc.priv);
 
-	mtd_device_unregister(mtd);
-
 	nand_release_data_interface(chip);
 
 	/* Free bad block table memory */
@@ -4824,6 +4820,18 @@ void nand_release(struct mtd_info *mtd)
 			& NAND_BBT_DYNAMICSTRUCT)
 		kfree(chip->badblock_pattern);
 }
+EXPORT_SYMBOL_GPL(nand_cleanup);
+
+/**
+ * nand_release - [NAND Interface] Unregister the MTD device and free resources
+ *		  held by the NAND device
+ * @mtd: MTD device structure
+ */
+void nand_release(struct mtd_info *mtd)
+{
+	mtd_device_unregister(mtd);
+	nand_cleanup(mtd_to_nand(mtd));
+}
 EXPORT_SYMBOL_GPL(nand_release);
 
 MODULE_LICENSE("GPL");

include/linux/mtd/nand.h

@@ -38,7 +38,7 @@ int nand_scan_ident(struct mtd_info *mtd, int max_chips,
 			   struct nand_flash_dev *table);
 int nand_scan_tail(struct mtd_info *mtd);
 
-/* Free resources held by the NAND device */
+/* Unregister the MTD device and free resources held by the NAND device */
 void nand_release(struct mtd_info *mtd);
 
 /* Internal helper for board drivers which need to override command function */
@@ -1186,4 +1186,7 @@ int nand_read_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
 /* Reset and initialize a NAND device */
 int nand_reset(struct nand_chip *chip);
 
+/* Free resources held by the NAND device */
+void nand_cleanup(struct nand_chip *chip);
+
 #endif /* __LINUX_MTD_NAND_H */