diff options
author | Wolfgang Muees <wolfgang.mues@auerswald.de> | 2009-04-08 08:48:58 (GMT) |
---|---|---|
committer | Pierre Ossman <pierre@ossman.eu> | 2009-04-08 18:45:51 (GMT) |
commit | ab5a643cf597f2214feb6ff7288c72589661bde1 (patch) | |
tree | afa570e506d0b5eab61800d74bc3491dc3120664 /drivers/mmc/host | |
parent | a8fe29d8bcdfbf85ba26c7f3522c4bdfbc83e71d (diff) | |
download | linux-fsl-qoriq-ab5a643cf597f2214feb6ff7288c72589661bde1.tar.xz |
mmc_spi: support for non-byte-aligned cards
A very large subset of SD cards in the market send their
responses and data non-byte-aligned. So add logic to the
mmc spi driver to handle this mess.
Signed-off-by: Wolfgang Muees <wolfgang.mues@auerswald.de>
Signed-off-by: Pierre Ossman <pierre@ossman.eu>
Diffstat (limited to 'drivers/mmc/host')
-rw-r--r-- | drivers/mmc/host/mmc_spi.c | 150 |
1 files changed, 112 insertions, 38 deletions
diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c index ed02ebd..f48349d 100644 --- a/drivers/mmc/host/mmc_spi.c +++ b/drivers/mmc/host/mmc_spi.c @@ -254,6 +254,10 @@ static int mmc_spi_response_get(struct mmc_spi_host *host, u8 *cp = host->data->status; u8 *end = cp + host->t.len; int value = 0; + int bitshift; + u8 leftover = 0; + unsigned short rotator; + int i; char tag[32]; snprintf(tag, sizeof(tag), " ... CMD%d response SPI_%s", @@ -271,9 +275,8 @@ static int mmc_spi_response_get(struct mmc_spi_host *host, /* Data block reads (R1 response types) may need more data... */ if (cp == end) { - unsigned i; - cp = host->data->status; + end = cp+1; /* Card sends N(CR) (== 1..8) bytes of all-ones then one * status byte ... and we already scanned 2 bytes. @@ -298,20 +301,34 @@ static int mmc_spi_response_get(struct mmc_spi_host *host, } checkstatus: - if (*cp & 0x80) { - dev_dbg(&host->spi->dev, "%s: INVALID RESPONSE, %02x\n", - tag, *cp); - value = -EBADR; - goto done; + bitshift = 0; + if (*cp & 0x80) { + /* Houston, we have an ugly card with a bit-shifted response */ + rotator = *cp++ << 8; + /* read the next byte */ + if (cp == end) { + value = mmc_spi_readbytes(host, 1); + if (value < 0) + goto done; + cp = host->data->status; + end = cp+1; + } + rotator |= *cp++; + while (rotator & 0x8000) { + bitshift++; + rotator <<= 1; + } + cmd->resp[0] = rotator >> 8; + leftover = rotator; + } else { + cmd->resp[0] = *cp++; } - - cmd->resp[0] = *cp++; cmd->error = 0; /* Status byte: the entire seven-bit R1 response. */ if (cmd->resp[0] != 0) { if ((R1_SPI_PARAMETER | R1_SPI_ADDRESS - | R1_SPI_ILLEGAL_COMMAND) + | R1_SPI_ILLEGAL_COMMAND) & cmd->resp[0]) value = -EINVAL; else if (R1_SPI_COM_CRC & cmd->resp[0]) @@ -339,12 +356,45 @@ checkstatus: * SPI R5 == R1 + data byte; IO_RW_DIRECT */ case MMC_RSP_SPI_R2: - cmd->resp[0] |= *cp << 8; + /* read the next byte */ + if (cp == end) { + value = mmc_spi_readbytes(host, 1); + if (value < 0) + goto done; + cp = host->data->status; + end = cp+1; + } + if (bitshift) { + rotator = leftover << 8; + rotator |= *cp << bitshift; + cmd->resp[0] |= (rotator & 0xFF00); + } else { + cmd->resp[0] |= *cp << 8; + } break; /* SPI R3, R4, or R7 == R1 + 4 bytes */ case MMC_RSP_SPI_R3: - cmd->resp[1] = get_unaligned_be32(cp); + rotator = leftover << 8; + cmd->resp[1] = 0; + for (i = 0; i < 4; i++) { + cmd->resp[1] <<= 8; + /* read the next byte */ + if (cp == end) { + value = mmc_spi_readbytes(host, 1); + if (value < 0) + goto done; + cp = host->data->status; + end = cp+1; + } + if (bitshift) { + rotator |= *cp++ << bitshift; + cmd->resp[1] |= (rotator >> 8); + rotator <<= 8; + } else { + cmd->resp[1] |= *cp++; + } + } break; /* SPI R1 == just one status byte */ @@ -725,6 +775,8 @@ mmc_spi_readblock(struct mmc_spi_host *host, struct spi_transfer *t, struct spi_device *spi = host->spi; int status; struct scratch *scratch = host->data; + unsigned int bitshift; + u8 leftover; /* At least one SD card sends an all-zeroes byte when N(CX) * applies, before the all-ones bytes ... just cope with that. @@ -736,38 +788,60 @@ mmc_spi_readblock(struct mmc_spi_host *host, struct spi_transfer *t, if (status == 0xff || status == 0) status = mmc_spi_readtoken(host, timeout); - if (status == SPI_TOKEN_SINGLE) { - if (host->dma_dev) { - dma_sync_single_for_device(host->dma_dev, - host->data_dma, sizeof(*scratch), - DMA_BIDIRECTIONAL); - dma_sync_single_for_device(host->dma_dev, - t->rx_dma, t->len, - DMA_FROM_DEVICE); - } + if (status < 0) { + dev_dbg(&spi->dev, "read error %02x (%d)\n", status, status); + return status; + } - status = spi_sync(spi, &host->m); + /* The token may be bit-shifted... + * the first 0-bit precedes the data stream. + */ + bitshift = 7; + while (status & 0x80) { + status <<= 1; + bitshift--; + } + leftover = status << 1; - if (host->dma_dev) { - dma_sync_single_for_cpu(host->dma_dev, - host->data_dma, sizeof(*scratch), - DMA_BIDIRECTIONAL); - dma_sync_single_for_cpu(host->dma_dev, - t->rx_dma, t->len, - DMA_FROM_DEVICE); - } + if (host->dma_dev) { + dma_sync_single_for_device(host->dma_dev, + host->data_dma, sizeof(*scratch), + DMA_BIDIRECTIONAL); + dma_sync_single_for_device(host->dma_dev, + t->rx_dma, t->len, + DMA_FROM_DEVICE); + } - } else { - dev_dbg(&spi->dev, "read error %02x (%d)\n", status, status); + status = spi_sync(spi, &host->m); - /* we've read extra garbage, timed out, etc */ - if (status < 0) - return status; + if (host->dma_dev) { + dma_sync_single_for_cpu(host->dma_dev, + host->data_dma, sizeof(*scratch), + DMA_BIDIRECTIONAL); + dma_sync_single_for_cpu(host->dma_dev, + t->rx_dma, t->len, + DMA_FROM_DEVICE); + } - /* low four bits are an R2 subset, fifth seems to be - * vendor specific ... map them all to generic error.. + if (bitshift) { + /* Walk through the data and the crc and do + * all the magic to get byte-aligned data. */ - return -EIO; + u8 *cp = t->rx_buf; + unsigned int len; + unsigned int bitright = 8 - bitshift; + u8 temp; + for (len = t->len; len; len--) { + temp = *cp; + *cp++ = leftover | (temp >> bitshift); + leftover = temp << bitright; + } + cp = (u8 *) &scratch->crc_val; + temp = *cp; + *cp++ = leftover | (temp >> bitshift); + leftover = temp << bitright; + temp = *cp; + *cp = leftover | (temp >> bitshift); } if (host->mmc->use_spi_crc) { |