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Message-Id: <200904081048.58264.wolfgang.mues@auerswald.de>
Date: Wed, 8 Apr 2009 09:48:58 +0100
From: Wolfgang Mües <wolfgang.mues@...rswald.de>
To: Pierre Ossman <drzeus@...eus.cx>
Cc: "Andrew Morton" <akpm@...ux-foundation.org>,
"Matt Fleming" <matt@...sole-pimps.org>,
"David Brownell" <dbrownell@...rs.sourceforge.net>,
"Mike Frysinger" <vapier.adi@...il.com>,
linux-kernel@...r.kernel.org
Subject: [PATCH 7/7 revised] mmc_spi: support for non-byte-aligned cards
From: Wolfgang Muees <wolfgang.mues@...rswald.de>
o 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@...rswald.de>
---
diff -uprN 2_6_29_rc7_patch125346/drivers/mmc/host/mmc_spi.c 2_6_29_rc7_patch1253467/drivers/mmc/host/mmc_spi.c
--- 2_6_29_rc7_patch125346/drivers/mmc/host/mmc_spi.c 2009-04-07 15:59:54.000000000 +0200
+++ 2_6_29_rc7_patch1253467/drivers/mmc/host/mmc_spi.c 2009-04-07 17:19:21.000000000 +0200
@@ -254,6 +254,10 @@ static int mmc_spi_response_get(struct m
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 m
/* 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 m
}
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 *h
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 *h
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);
- }
-
- status = spi_sync(spi, &host->m);
-
- 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);
- }
-
- } else {
+ if (status < 0) {
dev_dbg(&spi->dev, "read error %02x (%d)\n", status, status);
+ return status;
+ }
- /* we've read extra garbage, timed out, etc */
- if (status < 0)
- return status;
+ /* 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_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);
+ }
- /* low four bits are an R2 subset, fifth seems to be
- * vendor specific ... map them all to generic error..
+ status = spi_sync(spi, &host->m);
+
+ 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 (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) {
---
regards
i. A. Wolfgang Mües
--
Auerswald GmbH & Co. KG
Hardware Development
Telefon: +49 (0)5306 9219 0
Telefax: +49 (0)5306 9219 94
E-Mail: Wolfgang.Mues@...rswald.de
Web: http://www.auerswald.de
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