Extend m25p80_read allowing to read in chunks in case the SPI HW has a max supported message size.
Signed-off-by: Heiner Kallweit <[email protected]> --- drivers/mtd/devices/m25p80.c | 39 ++++++++++++++++++++++++++++++++++----- 1 file changed, 34 insertions(+), 5 deletions(-) diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c index c9c3b7f..df4c510 100644 --- a/drivers/mtd/devices/m25p80.c +++ b/drivers/mtd/devices/m25p80.c @@ -115,11 +115,7 @@ static inline unsigned int m25p80_rx_nbits(struct spi_nor *nor) } } -/* - * Read an address range from the nor chip. The address range - * may be any size provided it is within the physical boundaries. - */ -static int m25p80_read(struct spi_nor *nor, loff_t from, size_t len, +static int _m25p80_read(struct spi_nor *nor, loff_t from, size_t len, size_t *retlen, u_char *buf) { struct m25p *flash = nor->priv; @@ -153,6 +149,39 @@ static int m25p80_read(struct spi_nor *nor, loff_t from, size_t len, } /* + * Read an address range from the nor chip. The address range + * may be any size provided it is within the physical boundaries. + */ +static int m25p80_read(struct spi_nor *nor, loff_t from, size_t len, + size_t *retlen, u_char *buf) +{ + struct m25p *flash = nor->priv; + size_t cmd_len, xfer_len, max_len; + int ret = 0; + + /* convert the dummy cycles to the number of bytes */ + cmd_len = m25p_cmdsz(nor) + nor->read_dummy / 8; + + max_len = flash->spi->master->max_msg_size ?: SIZE_MAX; + + if (unlikely(max_len < cmd_len)) + return -EINVAL; + + max_len -= cmd_len; + + while (len) { + xfer_len = min(len, max_len); + ret = _m25p80_read(nor, from, xfer_len, retlen, buf); + if (ret < 0) + break; + from += xfer_len; + len -= xfer_len; + } + + return ret; +} + +/* * board specific setup should have ensured the SPI clock used here * matches what the READ command supports, at least until this driver * understands FAST_READ (for clocks over 25 MHz). -- 2.6.2 -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
