Exemplo n.º 1
0
static char *maptype(struct mmc_command *cmd)
{
	switch (mmc_spi_resp_type(cmd)) {
	case MMC_RSP_SPI_R1:	return "R1";
	case MMC_RSP_SPI_R1B:	return "R1B";
	case MMC_RSP_SPI_R2:	return "R2/R5";
	case MMC_RSP_SPI_R3:	return "R3/R4/R7";
	default:		return "?";
	}
}
Exemplo n.º 2
0
/* return zero, else negative errno after setting cmd->error */
static int mmc_spi_response_get(struct mmc_spi_host *host,
		struct mmc_command *cmd, int cs_on)
{
	u8	*cp = host->data->status;
	u8	*end = cp + host->t.len;
	int	value = 0;
	char	tag[32];

	snprintf(tag, sizeof(tag), "  ... CMD%d response SPI_%s",
		cmd->opcode, maptype(cmd));

	/* Except for data block reads, the whole response will already
	 * be stored in the scratch buffer.  It's somewhere after the
	 * command and the first byte we read after it.  We ignore that
	 * first byte.  After STOP_TRANSMISSION command it may include
	 * two data bits, but otherwise it's all ones.
	 */
	cp += 8;
	while (cp < end && *cp == 0xff)
		cp++;

	/* Data block reads (R1 response types) may need more data... */
	if (cp == end) {
		unsigned	i;

		cp = host->data->status;

		/* Card sends N(CR) (== 1..8) bytes of all-ones then one
		 * status byte ... and we already scanned 2 bytes.
		 *
		 * REVISIT block read paths use nasty byte-at-a-time I/O
		 * so it can always DMA directly into the target buffer.
		 * It'd probably be better to memcpy() the first chunk and
		 * avoid extra i/o calls...
		 */
		for (i = 2; i < 9; i++) {
			value = mmc_spi_readbytes(host, 1);
			if (value < 0)
				goto done;
			if (*cp != 0xff)
				goto checkstatus;
		}
		value = -ETIMEDOUT;
		goto done;
	}

checkstatus:
	if (*cp & 0x80) {
		dev_dbg(&host->spi->dev, "%s: INVALID RESPONSE, %02x\n",
					tag, *cp);
		value = -EBADR;
		goto done;
	}

	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)
				& cmd->resp[0])
			value = -EINVAL;
		else if (R1_SPI_COM_CRC & cmd->resp[0])
			value = -EILSEQ;
		else if ((R1_SPI_ERASE_SEQ | R1_SPI_ERASE_RESET)
				& cmd->resp[0])
			value = -EIO;
		/* else R1_SPI_IDLE, "it's resetting" */
	}

	switch (mmc_spi_resp_type(cmd)) {

	/* SPI R1B == R1 + busy; STOP_TRANSMISSION (for multiblock reads)
	 * and less-common stuff like various erase operations.
	 */
	case MMC_RSP_SPI_R1B:
		/* maybe we read all the busy tokens already */
		while (cp < end && *cp == 0)
			cp++;
		if (cp == end)
			mmc_spi_wait_unbusy(host, r1b_timeout);
		break;

	/* SPI R2 == R1 + second status byte; SEND_STATUS
	 * SPI R5 == R1 + data byte; IO_RW_DIRECT
	 */
	case MMC_RSP_SPI_R2:
		cmd->resp[0] |= *cp << 8;
		break;

	/* SPI R3, R4, or R7 == R1 + 4 bytes */
	case MMC_RSP_SPI_R3:
		cmd->resp[1] = be32_to_cpu(get_unaligned((u32 *)cp));
		break;

	/* SPI R1 == just one status byte */
	case MMC_RSP_SPI_R1:
		break;

	default:
		dev_dbg(&host->spi->dev, "bad response type %04x\n",
				mmc_spi_resp_type(cmd));
		if (value >= 0)
			value = -EINVAL;
		goto done;
	}

	if (value < 0)
		dev_dbg(&host->spi->dev, "%s: resp %04x %08x\n",
			tag, cmd->resp[0], cmd->resp[1]);

	/* disable chipselect on errors and some success cases */
	if (value >= 0 && cs_on)
		return value;
done:
	if (value < 0)
		cmd->error = value;
	mmc_cs_off(host);
	return value;
}