mtd: nand: txx9ndfmc: transfer 512 byte at a time if possible

Using __nand_correct_data() helper function, this driver can read 512
byte (with 6 byte ECC) at a time.  This results minor performance
improvement.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/drivers/mtd/nand/txx9ndfmc.c b/drivers/mtd/nand/txx9ndfmc.c
index 488088e..73af832 100644 (file)
--- a/drivers/mtd/nand/txx9ndfmc.c
+++ b/drivers/mtd/nand/txx9ndfmc.c
@@ -189,18 +189,43 @@ static int txx9ndfmc_calculate_ecc(struct mtd_info *mtd, const uint8_t *dat,
                                   uint8_t *ecc_code)
 {
        struct platform_device *dev = mtd_to_platdev(mtd);
+       struct nand_chip *chip = mtd->priv;
+       int eccbytes;
        u32 mcr = txx9ndfmc_read(dev, TXX9_NDFMCR);
 
        mcr &= ~TXX9_NDFMCR_ECC_ALL;
        txx9ndfmc_write(dev, mcr | TXX9_NDFMCR_ECC_OFF, TXX9_NDFMCR);
        txx9ndfmc_write(dev, mcr | TXX9_NDFMCR_ECC_READ, TXX9_NDFMCR);
-       ecc_code[1] = txx9ndfmc_read(dev, TXX9_NDFDTR);
-       ecc_code[0] = txx9ndfmc_read(dev, TXX9_NDFDTR);
-       ecc_code[2] = txx9ndfmc_read(dev, TXX9_NDFDTR);
+       for (eccbytes = chip->ecc.bytes; eccbytes > 0; eccbytes -= 3) {
+               ecc_code[1] = txx9ndfmc_read(dev, TXX9_NDFDTR);
+               ecc_code[0] = txx9ndfmc_read(dev, TXX9_NDFDTR);
+               ecc_code[2] = txx9ndfmc_read(dev, TXX9_NDFDTR);
+               ecc_code += 3;
+       }
        txx9ndfmc_write(dev, mcr | TXX9_NDFMCR_ECC_OFF, TXX9_NDFMCR);
        return 0;
 }
 
+static int txx9ndfmc_correct_data(struct mtd_info *mtd, unsigned char *buf,
+               unsigned char *read_ecc, unsigned char *calc_ecc)
+{
+       struct nand_chip *chip = mtd->priv;
+       int eccsize;
+       int corrected = 0;
+       int stat;
+
+       for (eccsize = chip->ecc.size; eccsize > 0; eccsize -= 256) {
+               stat = __nand_correct_data(buf, read_ecc, calc_ecc, 256);
+               if (stat < 0)
+                       return stat;
+               corrected += stat;
+               buf += 256;
+               read_ecc += 3;
+               calc_ecc += 3;
+       }
+       return corrected;
+}
+
 static void txx9ndfmc_enable_hwecc(struct mtd_info *mtd, int mode)
 {
        struct platform_device *dev = mtd_to_platdev(mtd);
@@ -244,6 +269,22 @@ static void txx9ndfmc_initialize(struct platform_device *dev)
 #define TXX9NDFMC_NS_TO_CYC(gbusclk, ns) \
        DIV_ROUND_UP((ns) * DIV_ROUND_UP(gbusclk, 1000), 1000000)
 
+static int txx9ndfmc_nand_scan(struct mtd_info *mtd)
+{
+       struct nand_chip *chip = mtd->priv;
+       int ret;
+
+       ret = nand_scan_ident(mtd, 1);
+       if (!ret) {
+               if (mtd->writesize >= 512) {
+                       chip->ecc.size = mtd->writesize;
+                       chip->ecc.bytes = 3 * (mtd->writesize / 256);
+               }
+               ret = nand_scan_tail(mtd);
+       }
+       return ret;
+}
+
 static int __init txx9ndfmc_probe(struct platform_device *dev)
 {
        struct txx9ndfmc_platform_data *plat = dev->dev.platform_data;
@@ -321,9 +362,10 @@ static int __init txx9ndfmc_probe(struct platform_device *dev)
                chip->cmd_ctrl = txx9ndfmc_cmd_ctrl;
                chip->dev_ready = txx9ndfmc_dev_ready;
                chip->ecc.calculate = txx9ndfmc_calculate_ecc;
-               chip->ecc.correct = nand_correct_data;
+               chip->ecc.correct = txx9ndfmc_correct_data;
                chip->ecc.hwctl = txx9ndfmc_enable_hwecc;
                chip->ecc.mode = NAND_ECC_HW;
+               /* txx9ndfmc_nand_scan will overwrite ecc.size and ecc.bytes */
                chip->ecc.size = 256;
                chip->ecc.bytes = 3;
                chip->chip_delay = 100;
@@ -349,7 +391,7 @@ static int __init txx9ndfmc_probe(struct platform_device *dev)
                if (plat->wide_mask & (1 << i))
                        chip->options |= NAND_BUSWIDTH_16;
 
-               if (nand_scan(mtd, 1)) {
+               if (txx9ndfmc_nand_scan(mtd)) {
                        kfree(txx9_priv->mtdname);
                        kfree(txx9_priv);
                        continue;