diff options
Diffstat (limited to 'drivers/mmc/host/mmc_spi.c')
| -rw-r--r-- | drivers/mmc/host/mmc_spi.c | 29 |
1 files changed, 24 insertions, 5 deletions
diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c index f48349d18c9..a461017ce5c 100644 --- a/drivers/mmc/host/mmc_spi.c +++ b/drivers/mmc/host/mmc_spi.c @@ -97,6 +97,14 @@ */ #define r1b_timeout (HZ * 3) +/* One of the critical speed parameters is the amount of data which may + * be transfered in one command. If this value is too low, the SD card + * controller has to do multiple partial block writes (argggh!). With + * today (2008) SD cards there is little speed gain if we transfer more + * than 64 KBytes at a time. So use this value until there is any indication + * that we should do more here. + */ +#define MMC_SPI_BLOCKSATONCE 128 /****************************************************************************/ @@ -327,15 +335,16 @@ checkstatus: /* Status byte: the entire seven-bit R1 response. */ if (cmd->resp[0] != 0) { - if ((R1_SPI_PARAMETER | R1_SPI_ADDRESS - | R1_SPI_ILLEGAL_COMMAND) + if ((R1_SPI_PARAMETER | R1_SPI_ADDRESS) & cmd->resp[0]) - value = -EINVAL; + value = -EFAULT; /* Bad address */ + else if (R1_SPI_ILLEGAL_COMMAND & cmd->resp[0]) + value = -ENOSYS; /* Function not implemented */ else if (R1_SPI_COM_CRC & cmd->resp[0]) - value = -EILSEQ; + value = -EILSEQ; /* Illegal byte sequence */ else if ((R1_SPI_ERASE_SEQ | R1_SPI_ERASE_RESET) & cmd->resp[0]) - value = -EIO; + value = -EIO; /* I/O error */ /* else R1_SPI_IDLE, "it's resetting" */ } @@ -1304,6 +1313,12 @@ static int mmc_spi_probe(struct spi_device *spi) struct mmc_spi_host *host; int status; + /* We rely on full duplex transfers, mostly to reduce + * per-transfer overheads (by making fewer transfers). + */ + if (spi->master->flags & SPI_MASTER_HALF_DUPLEX) + return -EINVAL; + /* MMC and SD specs only seem to care that sampling is on the * rising edge ... meaning SPI modes 0 or 3. So either SPI mode * should be legit. We'll use mode 0 since the steady state is 0, @@ -1366,6 +1381,10 @@ static int mmc_spi_probe(struct spi_device *spi) mmc->ops = &mmc_spi_ops; mmc->max_blk_size = MMC_SPI_BLOCKSIZE; + mmc->max_hw_segs = MMC_SPI_BLOCKSATONCE; + mmc->max_phys_segs = MMC_SPI_BLOCKSATONCE; + mmc->max_req_size = MMC_SPI_BLOCKSATONCE * MMC_SPI_BLOCKSIZE; + mmc->max_blk_count = MMC_SPI_BLOCKSATONCE; mmc->caps = MMC_CAP_SPI; |