[MTD NAND] Allow override of page read and write functions.

- allow high-level nand_write_page() function to be overridden
- likewise low-level write_page_raw() and read_page_raw() functions
- Clean up the abuse of chip->ecc.{write,read}_page() with MTD_OOB_RAW

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index e1e81a9543e8581ea3e16d48bd03ffd3599bed40..baece61169f4933af73704779143ddbaf21c08f7 100644 (file)
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -990,7 +990,10 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
                        }
 
                        /* Now read the page into the buffer */
-                       ret = chip->ecc.read_page(mtd, chip, bufpoi);
+                       if (unlikely(ops->mode == MTD_OOB_RAW))
+                               ret = chip->ecc.read_page_raw(mtd, chip, bufpoi);
+                       else
+                               ret = chip->ecc.read_page(mtd, chip, bufpoi);
                        if (ret < 0)
                                break;
 
@@ -1323,8 +1326,6 @@ static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
 static int nand_read_oob(struct mtd_info *mtd, loff_t from,
                         struct mtd_oob_ops *ops)
 {
-       int (*read_page)(struct mtd_info *mtd, struct nand_chip *chip,
-                        uint8_t *buf) = NULL;
        struct nand_chip *chip = mtd->priv;
        int ret = -ENOTSUPP;
 
@@ -1342,12 +1343,7 @@ static int nand_read_oob(struct mtd_info *mtd, loff_t from,
        switch(ops->mode) {
        case MTD_OOB_PLACE:
        case MTD_OOB_AUTO:
-               break;
-
        case MTD_OOB_RAW:
-               /* Replace the read_page algorithm temporary */
-               read_page = chip->ecc.read_page;
-               chip->ecc.read_page = nand_read_page_raw;
                break;
 
        default:
@@ -1359,8 +1355,6 @@ static int nand_read_oob(struct mtd_info *mtd, loff_t from,
        else
                ret = nand_do_read_ops(mtd, from, ops);
 
-       if (unlikely(ops->mode == MTD_OOB_RAW))
-               chip->ecc.read_page = read_page;
  out:
        nand_release_device(mtd);
        return ret;
@@ -1479,7 +1473,7 @@ static void nand_write_page_syndrome(struct mtd_info *mtd,
 }
 
 /**
- * nand_write_page - [INTERNAL] write one page
+ * nand_write_page - [REPLACEABLE] write one page
  * @mtd:       MTD device structure
  * @chip:      NAND chip descriptor
  * @buf:       the data to write
@@ -1487,13 +1481,16 @@ static void nand_write_page_syndrome(struct mtd_info *mtd,
  * @cached:    cached programming
  */
 static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
-                          const uint8_t *buf, int page, int cached)
+                          const uint8_t *buf, int page, int cached, int raw)
 {
        int status;
 
        chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
 
-       chip->ecc.write_page(mtd, chip, buf);
+       if (unlikely(raw))
+               chip->ecc.write_page_raw(mtd, chip, buf);
+       else
+               chip->ecc.write_page(mtd, chip, buf);
 
        /*
         * Cached progamming disabled for now, Not sure if its worth the
@@ -1636,7 +1633,8 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
                if (unlikely(oob))
                        oob = nand_fill_oob(chip, oob, ops);
 
-               ret = nand_write_page(mtd, chip, buf, page, cached);
+               ret = chip->write_page(mtd, chip, buf, page, cached,
+                                      (ops->mode == MTD_OOB_RAW));
                if (ret)
                        break;
 
@@ -1769,8 +1767,6 @@ static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
 static int nand_write_oob(struct mtd_info *mtd, loff_t to,
                          struct mtd_oob_ops *ops)
 {
-       void (*write_page)(struct mtd_info *mtd, struct nand_chip *chip,
-                         const uint8_t *buf) = NULL;
        struct nand_chip *chip = mtd->priv;
        int ret = -ENOTSUPP;
 
@@ -1788,12 +1784,7 @@ static int nand_write_oob(struct mtd_info *mtd, loff_t to,
        switch(ops->mode) {
        case MTD_OOB_PLACE:
        case MTD_OOB_AUTO:
-               break;
-
        case MTD_OOB_RAW:
-               /* Replace the write_page algorithm temporary */
-               write_page = chip->ecc.write_page;
-               chip->ecc.write_page = nand_write_page_raw;
                break;
 
        default:
@@ -1805,8 +1796,6 @@ static int nand_write_oob(struct mtd_info *mtd, loff_t to,
        else
                ret = nand_do_write_ops(mtd, to, ops);
 
-       if (unlikely(ops->mode == MTD_OOB_RAW))
-               chip->ecc.write_page = write_page;
  out:
        nand_release_device(mtd);
        return ret;
@@ -2383,10 +2372,18 @@ int nand_scan_tail(struct mtd_info *mtd)
                }
        }
 
+       if (!chip->write_page)
+               chip->write_page = nand_write_page;
+
        /*
         * check ECC mode, default to software if 3byte/512byte hardware ECC is
         * selected and we have 256 byte pagesize fallback to software ECC
         */
+       if (!chip->ecc.read_page_raw)
+               chip->ecc.read_page_raw = nand_read_page_raw;
+       if (!chip->ecc.write_page_raw)
+               chip->ecc.write_page_raw = nand_write_page_raw;
+
        switch (chip->ecc.mode) {
        case NAND_ECC_HW:
                /* Use standard hwecc read page function ? */
@@ -2444,6 +2441,7 @@ int nand_scan_tail(struct mtd_info *mtd)
                chip->ecc.size = mtd->writesize;
                chip->ecc.bytes = 0;
                break;
+
        default:
                printk(KERN_WARNING "Invalid NAND_ECC_MODE %d\n",
                       chip->ecc.mode);

diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index cd4fe9ae8622197ca5b6d637588fc4a2f2019728..2bcbcc896835c53b752df6f2d486006b2162b25d 100644 (file)
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -235,6 +235,8 @@ struct nand_hw_control {
  *             be provided if an hardware ECC is available
  * @calculate: function for ecc calculation or readback from ecc hardware
  * @correct:   function for ecc correction, matching to ecc generator (sw/hw)
+ * @read_page_raw:     function to read a raw page without ECC
+ * @write_page_raw:    function to write a raw page without ECC
  * @read_page: function to read a page according to the ecc generator requirements
  * @write_page:        function to write a page according to the ecc generator requirements
  * @read_oob:  function to read chip OOB data
@@ -256,6 +258,12 @@ struct nand_ecc_ctrl {
        int                     (*correct)(struct mtd_info *mtd, uint8_t *dat,
                                           uint8_t *read_ecc,
                                           uint8_t *calc_ecc);
+       int                     (*read_page_raw)(struct mtd_info *mtd,
+                                                struct nand_chip *chip,
+                                                uint8_t *buf);
+       void                    (*write_page_raw)(struct mtd_info *mtd,
+                                                 struct nand_chip *chip,
+                                                 const uint8_t *buf);
        int                     (*read_page)(struct mtd_info *mtd,
                                             struct nand_chip *chip,
                                             uint8_t *buf);
@@ -344,6 +352,7 @@ struct nand_buffers {
  * @priv:              [OPTIONAL] pointer to private chip date
  * @errstat:           [OPTIONAL] hardware specific function to perform additional error status checks
  *                     (determine if errors are correctable)
+ * @write_page         [REPLACEABLE] High-level page write function
  */
 
 struct nand_chip {
@@ -366,6 +375,8 @@ struct nand_chip {
        void            (*erase_cmd)(struct mtd_info *mtd, int page);
        int             (*scan_bbt)(struct mtd_info *mtd);
        int             (*errstat)(struct mtd_info *mtd, struct nand_chip *this, int state, int status, int page);
+       int             (*write_page)(struct mtd_info *mtd, struct nand_chip *chip,
+                                     const uint8_t *buf, int page, int cached, int raw);
 
        int             chip_delay;
        unsigned int    options;