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mtd: atmel_nand: optimize read/write buffer functions 

For PIO NAND access functions, we use the features of the SMC:
- no need to take into account the NAND bus width: SMC will deal with this
- use of an IO memcpy on the NAND chip-select space is able to generate
  proper SMC behavior.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Artem Bityutskiy <dedekind1@gmail.com>
This commit is contained in:
Nicolas Ferre 2011-07-04 16:17:53 +02:00 committed by Artem Bityutskiy
parent 57b078a09b
commit fb5427508a
1 changed files with 4 additions and 41 deletions
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45
drivers/mtd/nand/atmel_nand.c
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@ -161,37 +161,6 @@ static int atmel_nand_device_ready(struct mtd_info *mtd)
!!host->board->rdy_pin_active_low;
}
/*
* Minimal-overhead PIO for data access.
*/
static void atmel_read_buf8(struct mtd_info *mtd, u8 *buf, int len)
{
struct nand_chip *nand_chip = mtd->priv;
__raw_readsb(nand_chip->IO_ADDR_R, buf, len);
}
static void atmel_read_buf16(struct mtd_info *mtd, u8 *buf, int len)
{
struct nand_chip *nand_chip = mtd->priv;
__raw_readsw(nand_chip->IO_ADDR_R, buf, len / 2);
}
static void atmel_write_buf8(struct mtd_info *mtd, const u8 *buf, int len)
{
struct nand_chip *nand_chip = mtd->priv;
__raw_writesb(nand_chip->IO_ADDR_W, buf, len);
}
static void atmel_write_buf16(struct mtd_info *mtd, const u8 *buf, int len)
{
struct nand_chip *nand_chip = mtd->priv;
__raw_writesw(nand_chip->IO_ADDR_W, buf, len / 2);
}
static void dma_complete_func(void *completion)
{
complete(completion);
@ -266,33 +235,27 @@ err_buf:
static void atmel_read_buf(struct mtd_info *mtd, u8 *buf, int len)
{
struct nand_chip *chip = mtd->priv;
struct atmel_nand_host *host = chip->priv;
if (use_dma && len > mtd->oobsize)
/* only use DMA for bigger than oob size: better performances */
if (atmel_nand_dma_op(mtd, buf, len, 1) == 0)
return;
if (host->board->bus_width_16)
atmel_read_buf16(mtd, buf, len);
else
atmel_read_buf8(mtd, buf, len);
/* if no DMA operation possible, use PIO */
memcpy_fromio(buf, chip->IO_ADDR_R, len);
}
static void atmel_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
{
struct nand_chip *chip = mtd->priv;
struct atmel_nand_host *host = chip->priv;
if (use_dma && len > mtd->oobsize)
/* only use DMA for bigger than oob size: better performances */
if (atmel_nand_dma_op(mtd, (void *)buf, len, 0) == 0)
return;
if (host->board->bus_width_16)
atmel_write_buf16(mtd, buf, len);
else
atmel_write_buf8(mtd, buf, len);
/* if no DMA operation possible, use PIO */
memcpy_toio(chip->IO_ADDR_W, buf, len);
}
/*