[RFC 44/47] mtd: nand: stm_nand_bch: MTD read and write (BCH)

Lee Jones
2014-03-25T08:22:05Z

MTD interfaces: Standard set of callbacks for MTD functionality.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
drivers/mtd/nand/stm_nand_bch.c | 54 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 54 insertions(+)

diff --git a/drivers/mtd/nand/stm_nand_bch.c b/drivers/mtd/nand/stm_nand_bch.c
index bcaed32..f5b0a00 100644
--- a/drivers/mtd/nand/stm_nand_bch.c
+++ b/drivers/mtd/nand/stm_nand_bch.c
@@ -1226,6 +1226,58 @@ static int bch_load_bbt(struct nandi_controller *nandi,
}

/*
+ * MTD Interface: Standard set of callbacks for MTD functionality
+ */
+static int bch_mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
+ size_t *retlen, uint8_t *buf)
+{
+ struct nand_chip *chip = mtd->priv;
+ struct nandi_controller *nandi = chip->priv;
+ int ret;
+
+ dev_dbg(nandi->dev, "%s: %llu @ 0x%012llx\n", __func__,
+ (unsigned long long)len, from);
+
+ nand_get_device(mtd, FL_READING);
+
+ ret = bch_read(nandi, from, len, retlen, buf);
+
+ nand_release_device(mtd);
+
+ return ret;
+}
+
+static int bch_mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
+ size_t *retlen, const uint8_t *buf)
+{
+ struct nand_chip *chip = mtd->priv;
+ struct nandi_controller *nandi = chip->priv;
+ uint32_t page_mask = mtd->writesize - 1;
+ int ret;
+
+ dev_dbg(nandi->dev, "%s: %llu @ 0x%012llx\n", __func__,
+ (unsigned long long)len, to);
+
+ if ((to & page_mask) || (len & page_mask)) {
+ dev_err(nandi->dev, "attempt to write non-page-aligned data\n");
+ return -EINVAL;
+ }
+
+ nand_get_device(mtd, FL_WRITING);
+
+ if (flex_check_wp(nandi)) {
+ dev_dbg(nandi->dev, "device is write-protected\n");
+ return -EIO;
+ }
+
+ ret = bch_write(nandi, to, len, retlen, buf);
+
+ nand_release_device(mtd);
+
+ return ret;
+}
+
+/*
* Helper function for mtd_read_oob(): handles multi-page transfers
* and mapping between BCH sectors and MTD page+OOB data.
*/
@@ -1701,6 +1753,8 @@ static void nandi_set_mtd_defaults(struct nandi_controller *nandi,
mtd->oobavail = 0;
mtd->subpage_sft = 0;

+ mtd->_read = bch_mtd_read;
+ mtd->_write = bch_mtd_write;
mtd->_erase = bch_mtd_erase;
mtd->_read_oob = bch_mtd_read_oob;
mtd->_write_oob = bch_mtd_write_oob;
--
1.8.3.2