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authorWolfgang Muees <wolfgang.mues@auerswald.de>2009-04-08 09:48:58 +0100
committerPierre Ossman <pierre@ossman.eu>2009-04-08 20:45:51 +0200
commitab5a643cf597f2214feb6ff7288c72589661bde1 (patch)
treeafa570e506d0b5eab61800d74bc3491dc3120664 /drivers/mmc/host
parenta8fe29d8bcdfbf85ba26c7f3522c4bdfbc83e71d (diff)
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.c150
1 files changed, 112 insertions, 38 deletions
diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c
index ed02ebd899d..f48349d18c9 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) {