mmc_spi: support for non-byte-aligned cards (ab5a643c) · Commits · e / devices / android_kernel_oneplus_sm8150

drivers/mmc/host/mmc_spi.c

+112 −38

Original line number	Original line	Diff line number	Diff line
	@@ -254,6 +254,10 @@ static int mmc_spi_response_get(struct mmc_spi_host *host,
	u8 *cp = host->data->status;		u8 *cp = host->data->status;
	u8 *end = cp + host->t.len;		u8 *end = cp + host->t.len;
	int value = 0;		int value = 0;
			int bitshift;
			u8 leftover = 0;
			unsigned short rotator;
			int i;
	char tag[32];		char tag[32];

	snprintf(tag, sizeof(tag), " ... CMD%d response SPI_%s",		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... */		/* Data block reads (R1 response types) may need more data... */
	if (cp == end) {		if (cp == end) {
	unsigned i;

	cp = host->data->status;		cp = host->data->status;
			end = cp+1;

	/* Card sends N(CR) (== 1..8) bytes of all-ones then one		/* Card sends N(CR) (== 1..8) bytes of all-ones then one
	* status byte ... and we already scanned 2 bytes.		* status byte ... and we already scanned 2 bytes.
	@@ -298,14 +301,28 @@ static int mmc_spi_response_get(struct mmc_spi_host *host,
	}		}

	checkstatus:		checkstatus:
			bitshift = 0;
	if (*cp & 0x80) {		if (*cp & 0x80) {
	dev_dbg(&host->spi->dev, "%s: INVALID RESPONSE, %02x\n",		/* Houston, we have an ugly card with a bit-shifted response */
	tag, *cp);		rotator = *cp++ << 8;
	value = -EBADR;		/* read the next byte */
			if (cp == end) {
			value = mmc_spi_readbytes(host, 1);
			if (value < 0)
	goto done;		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;		cmd->error = 0;

	/* Status byte: the entire seven-bit R1 response. */		/* Status byte: the entire seven-bit R1 response. */
	@@ -339,12 +356,45 @@ static int mmc_spi_response_get(struct mmc_spi_host *host,
	* SPI R5 == R1 + data byte; IO_RW_DIRECT		* SPI R5 == R1 + data byte; IO_RW_DIRECT
	*/		*/
	case MMC_RSP_SPI_R2:		case MMC_RSP_SPI_R2:
			/* 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;		cmd->resp[0] \|= *cp << 8;
			}
	break;		break;

	/* SPI R3, R4, or R7 == R1 + 4 bytes */		/* SPI R3, R4, or R7 == R1 + 4 bytes */
	case MMC_RSP_SPI_R3:		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;		break;

	/* SPI R1 == just one status byte */		/* 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;		struct spi_device *spi = host->spi;
	int status;		int status;
	struct scratch *scratch = host->data;		struct scratch *scratch = host->data;
			unsigned int bitshift;
			u8 leftover;

	/* At least one SD card sends an all-zeroes byte when N(CX)		/* At least one SD card sends an all-zeroes byte when N(CX)
	* applies, before the all-ones bytes ... just cope with that.		* applies, before the all-ones bytes ... just cope with that.
	@@ -736,7 +788,21 @@ mmc_spi_readblock(struct mmc_spi_host host, struct spi_transfer t,
	if (status == 0xff \|\| status == 0)		if (status == 0xff \|\| status == 0)
	status = mmc_spi_readtoken(host, timeout);		status = mmc_spi_readtoken(host, timeout);

	if (status == SPI_TOKEN_SINGLE) {		if (status < 0) {
			dev_dbg(&spi->dev, "read error %02x (%d)\n", status, status);
			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) {		if (host->dma_dev) {
	dma_sync_single_for_device(host->dma_dev,		dma_sync_single_for_device(host->dma_dev,
	host->data_dma, sizeof(*scratch),		host->data_dma, sizeof(*scratch),
	@@ -757,17 +823,25 @@ mmc_spi_readblock(struct mmc_spi_host host, struct spi_transfer t,
	DMA_FROM_DEVICE);		DMA_FROM_DEVICE);
	}		}

	} else {		if (bitshift) {
	dev_dbg(&spi->dev, "read error %02x (%d)\n", status, status);		/* Walk through the data and the crc and do
			* all the magic to get byte-aligned data.
	/* we've read extra garbage, timed out, etc */
	if (status < 0)
	return status;

	/* low four bits are an R2 subset, fifth seems to be
	* vendor specific ... map them all to generic error..
	*/		*/
	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) {		if (host->mmc->use_spi_crc) {