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Subject[PATCH 3/3] txx9ndfmc: Transfer 512 byte at a time if possible
Date
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>
---
drivers/mtd/nand/txx9ndfmc.c | 52 +++++++++++++++++++++++++++++++++++++----
1 files changed, 47 insertions(+), 5 deletions(-)

diff --git a/drivers/mtd/nand/txx9ndfmc.c b/drivers/mtd/nand/txx9ndfmc.c
index 488088e..73af832 100644
--- 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;
--
1.5.6.5


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