[U-Boot] [PATCH 05/22] mtd: nand: Create a NAND reset function

[Masahiro Yamada]

From: Sascha Hauer <s.hauer at pengutronix.de>

When NAND devices are resetted some initialization may have to be done,
like for example they have to be configured for the timing mode that
shall be used. To get a common place where this initialization can be
implemented create a nand_reset() function. This currently only issues
a NAND_CMD_RESET to the NAND device. The places issuing this command
manually are replaced with a call to nand_reset().

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
[Linux commit: 2f94abfe35b210e7711af9202a3dcfc9e779219a]
Signed-off-by: Masahiro Yamada <yamada.masahiro at socionext.com>

---

 drivers/mtd/nand/nand_base.c | 21 ++++++++++++++++++---
 include/linux/mtd/nand.h     |  4 ++++
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 18f4169..77da6fa 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -902,6 +902,21 @@ static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip)
 }
 
 /**
+ * nand_reset - Reset and initialize a NAND device
+ * @chip: The NAND chip
+ *
+ * Returns 0 for success or negative error code otherwise
+ */
+int nand_reset(struct nand_chip *chip)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
+
+	return 0;
+}
+
+/**
  * nand_check_erased_buf - check if a buffer contains (almost) only 0xff data
  * @buf: buffer to test
  * @len: buffer length
@@ -2591,7 +2606,7 @@ static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
 	 * if we don't do this. I have no clue why, but I seem to have 'fixed'
 	 * it in the doc2000 driver in August 1999.  dwmw2.
 	 */
-	chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
+	nand_reset(chip);
 
 	/* Check, if it is write protected */
 	if (nand_check_wp(mtd)) {
@@ -3612,7 +3627,7 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
 	 * Reset the chip, required by some chips (e.g. Micron MT29FxGxxxxx)
 	 * after power-up.
 	 */
-	chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
+	nand_reset(chip);
 
 	/* Send the command for reading device ID */
 	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
@@ -3873,7 +3888,7 @@ int nand_scan_ident(struct mtd_info *mtd, int maxchips,
 	for (i = 1; i < maxchips; i++) {
 		chip->select_chip(mtd, i);
 		/* See comment in nand_get_flash_type for reset */
-		chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
+		nand_reset(chip);
 		/* Send the command for reading device ID */
 		chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
 		/* Read manufacturer and device IDs */
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 3facbbd..df00fd1 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -1115,4 +1115,8 @@ int nand_check_erased_ecc_chunk(void *data, int datalen,
 				void *ecc, int ecclen,
 				void *extraoob, int extraooblen,
 				int threshold);
+
+/* Reset and initialize a NAND device */
+int nand_reset(struct nand_chip *chip);
+
 #endif /* __LINUX_MTD_NAND_H */
-- 
2.7.4