Commit af517150 authored by David Brownell's avatar David Brownell Committed by Pierre Ossman
Browse files

MMC core learns about SPI 



Teach the MMC/SD/SDIO core about using SPI mode.

 - Use mmc_host_is_spi() so enumeration works through SPI signaling
   and protocols, not just the native versions.

 - Provide the SPI response type flags with each request issued,
   including requests from the new lock/unlock code.

 - Understand that cmd->resp[0] and mmc_get_status() results for SPI
   return different values than for "native" MMC/SD protocol; this
   affects resetting, checking card lock status, and some others.

 - Understand that some commands act a bit differently ... notably:
     * OP_COND command doesn't return the OCR
     * APP_CMD status doesn't have an R1_APP_CMD analogue

Those changes required some new and updated primitives:

 - Provide utilities to access two SPI-only requests, and one
   request that wasn't previously needed:
     * mmc_spi_read_ocr() ... SPI only
     * mmc_spi_set_crc() ... SPI only (override by module parm)
     * mmc_send_cid() ... for use without broadcast mode

 - Updated internal routines:
     * Previous mmc_send_csd() modified into mmc_send_cxd_native();
       it uses native "R2" responses, which include 16 bytes of data.
     * Previous mmc_send_ext_csd() becomes new mmc_send_cxd_data()
       helper for command-and-data access
     * Bugfix to that mmc_send_cxd_data() code:  dma-to-stack is
       unsafe/nonportable, so kmalloc a bounce buffer instead.

 - Modified mmc_send_ext_csd() now uses mmc_send_cxd_data() helper

 - Modified mmc_send_csd(), and new mmc_spi_send_cid(), routines use
   those helper routines based on whether they're native or SPI

The newest categories of cards supported by the MMC stack aren't expected
to work yet with SPI:  MMC or SD cards with over 4GB data, and SDIO.
All those cards support SPI mode, so eventually they should work too.

Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarPierre Ossman <drzeus@drzeus.cx>
parent 7213d175

drivers/mmc/core/bus.c

+18 −6
Original line number Diff line number Diff line
@@ -243,10 +243,17 @@ int mmc_add_card(struct mmc_card *card) 
		break;

	}



	if (mmc_host_is_spi(card->host)) {

		printk(KERN_INFO "%s: new %s%s card on SPI\n",

			mmc_hostname(card->host),

			mmc_card_highspeed(card) ? "high speed " : "",

			type);

	} else {

		printk(KERN_INFO "%s: new %s%s card at address %04x\n",

			mmc_hostname(card->host),

			mmc_card_highspeed(card) ? "high speed " : "",

			type, card->rca);

	}



	card->dev.uevent_suppress = 1;
@@ -278,8 +285,13 @@ int mmc_add_card(struct mmc_card *card) 
void mmc_remove_card(struct mmc_card *card)

{

	if (mmc_card_present(card)) {

		if (mmc_host_is_spi(card->host)) {

			printk(KERN_INFO "%s: SPI card removed\n",

				mmc_hostname(card->host));

		} else {

			printk(KERN_INFO "%s: card %04x removed\n",

				mmc_hostname(card->host), card->rca);

		}



		if (card->host->bus_ops->sysfs_remove)

			card->host->bus_ops->sysfs_remove(card->host, card);

drivers/mmc/core/core.c

+24 −4
Original line number Diff line number Diff line
@@ -41,6 +41,14 @@ extern int mmc_attach_sdio(struct mmc_host *host, u32 ocr); 


static struct workqueue_struct *workqueue;



/*

 * Enabling software CRCs on the data blocks can be a significant (30%)

 * performance cost, and for other reasons may not always be desired.

 * So we allow it it to be disabled.

 */

int use_spi_crc = 1;

module_param(use_spi_crc, bool, 0);



/*

 * Internal function. Schedule delayed work in the MMC work queue.

 */
@@ -71,6 +79,11 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq) 
	struct mmc_command *cmd = mrq->cmd;

	int err = cmd->error;



	if (err && cmd->retries && mmc_host_is_spi(host)) {

		if (cmd->resp[0] & R1_SPI_ILLEGAL_COMMAND)

			cmd->retries = 0;

	}



	if (err && cmd->retries) {

		pr_debug("%s: req failed (CMD%u): %d, retrying...\n",

			mmc_hostname(host), cmd->opcode, err);
@@ -453,8 +466,13 @@ static void mmc_power_up(struct mmc_host *host) 
	int bit = fls(host->ocr_avail) - 1;



	host->ios.vdd = bit;

	host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;

	if (mmc_host_is_spi(host)) {

		host->ios.chip_select = MMC_CS_HIGH;

		host->ios.bus_mode = MMC_BUSMODE_PUSHPULL;

	} else {

		host->ios.chip_select = MMC_CS_DONTCARE;

		host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;

	}

	host->ios.power_mode = MMC_POWER_UP;

	host->ios.bus_width = MMC_BUS_WIDTH_1;

	host->ios.timing = MMC_TIMING_LEGACY;
@@ -481,8 +499,10 @@ static void mmc_power_off(struct mmc_host *host) 
{

	host->ios.clock = 0;

	host->ios.vdd = 0;

	if (!mmc_host_is_spi(host)) {

		host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;

		host->ios.chip_select = MMC_CS_DONTCARE;

	}

	host->ios.power_mode = MMC_POWER_OFF;

	host->ios.bus_width = MMC_BUS_WIDTH_1;

	host->ios.timing = MMC_TIMING_LEGACY;

drivers/mmc/core/core.h

+2 −0
Original line number Diff line number Diff line
@@ -48,5 +48,7 @@ void mmc_rescan(struct work_struct *work); 
void mmc_start_host(struct mmc_host *host);

void mmc_stop_host(struct mmc_host *host);



extern int use_spi_crc;



#endif

drivers/mmc/core/mmc.c

+37 −13
Original line number Diff line number Diff line
@@ -165,8 +165,6 @@ static int mmc_read_ext_csd(struct mmc_card *card) 


	BUG_ON(!card);



	err = -EIO;



	if (card->csd.mmca_vsn < CSD_SPEC_VER_4)

		return 0;
@@ -279,9 +277,21 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, 
	if (err)

		goto err;



	/*

	 * For SPI, enable CRC as appropriate.

	 */

	if (mmc_host_is_spi(host)) {

		err = mmc_spi_set_crc(host, use_spi_crc);

		if (err)

			goto err;

	}



	/*

	 * Fetch CID from card.

	 */

	if (mmc_host_is_spi(host))

		err = mmc_send_cid(host, cid);

	else

		err = mmc_all_send_cid(host, cid);

	if (err)

		goto err;
@@ -309,13 +319,15 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, 
	}



	/*

	 * Set card RCA.

	 * For native busses:  set card RCA and quit open drain mode.

	 */

	if (!mmc_host_is_spi(host)) {

		err = mmc_set_relative_addr(card);

		if (err)

			goto free_card;



		mmc_set_bus_mode(host, MMC_BUSMODE_PUSHPULL);

	}



	if (!oldcard) {

		/*
@@ -336,13 +348,15 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, 
	/*

	 * Select card, as all following commands rely on that.

	 */

	if (!mmc_host_is_spi(host)) {

		err = mmc_select_card(card);

		if (err)

			goto free_card;

	}



	if (!oldcard) {

		/*

		 * Fetch and process extened CSD.

		 * Fetch and process extended CSD.

		 */

		err = mmc_read_ext_csd(card);

		if (err)
@@ -502,6 +516,7 @@ static void mmc_suspend(struct mmc_host *host) 
	BUG_ON(!host->card);



	mmc_claim_host(host);

	if (!mmc_host_is_spi(host))

		mmc_deselect_cards(host);

	host->card->state &= ~MMC_STATE_HIGHSPEED;

	mmc_release_host(host);
@@ -562,6 +577,15 @@ int mmc_attach_mmc(struct mmc_host *host, u32 ocr) 


	mmc_attach_bus(host, &mmc_ops);



	/*

	 * We need to get OCR a different way for SPI.

	 */

	if (mmc_host_is_spi(host)) {

		err = mmc_spi_read_ocr(host, 1, &ocr);

		if (err)

			goto err;

	}



	/*

	 * Sanity check the voltages that the card claims to

	 * support.

drivers/mmc/core/mmc_ops.c

+135 −31
Original line number Diff line number Diff line
@@ -63,23 +63,36 @@ int mmc_go_idle(struct mmc_host *host) 
	int err;

	struct mmc_command cmd;



	/*

	 * Non-SPI hosts need to prevent chipselect going active during

	 * GO_IDLE; that would put chips into SPI mode.  Remind them of

	 * that in case of hardware that won't pull up DAT3/nCS otherwise.

	 *

	 * SPI hosts ignore ios.chip_select; it's managed according to

	 * rules that must accomodate non-MMC slaves which this layer

	 * won't even know about.

	 */

	if (!mmc_host_is_spi(host)) {

		mmc_set_chip_select(host, MMC_CS_HIGH);



		mmc_delay(1);

	}



	memset(&cmd, 0, sizeof(struct mmc_command));



	cmd.opcode = MMC_GO_IDLE_STATE;

	cmd.arg = 0;

	cmd.flags = MMC_RSP_NONE | MMC_CMD_BC;

	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_NONE | MMC_CMD_BC;



	err = mmc_wait_for_cmd(host, &cmd, 0);



	mmc_delay(1);



	if (!mmc_host_is_spi(host)) {

		mmc_set_chip_select(host, MMC_CS_DONTCARE);



		mmc_delay(1);

	}



	host->use_spi_crc = 0;



	return err;

}
@@ -94,23 +107,33 @@ int mmc_send_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr) 
	memset(&cmd, 0, sizeof(struct mmc_command));



	cmd.opcode = MMC_SEND_OP_COND;

	cmd.arg = ocr;

	cmd.flags = MMC_RSP_R3 | MMC_CMD_BCR;

	cmd.arg = mmc_host_is_spi(host) ? 0 : ocr;

	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R3 | MMC_CMD_BCR;



	for (i = 100; i; i--) {

		err = mmc_wait_for_cmd(host, &cmd, 0);

		if (err)

			break;



		if (cmd.resp[0] & MMC_CARD_BUSY || ocr == 0)

		/* if we're just probing, do a single pass */

		if (ocr == 0)

			break;



		/* otherwise wait until reset completes */

		if (mmc_host_is_spi(host)) {

			if (!(cmd.resp[0] & R1_SPI_IDLE))

				break;

		} else {

			if (cmd.resp[0] & MMC_CARD_BUSY)

				break;

		}



		err = -ETIMEDOUT;



		mmc_delay(10);

	}



	if (rocr)

	if (rocr && !mmc_host_is_spi(host))

		*rocr = cmd.resp[0];



	return err;
@@ -160,40 +183,46 @@ int mmc_set_relative_addr(struct mmc_card *card) 
	return 0;

}



int mmc_send_csd(struct mmc_card *card, u32 *csd)

static int

mmc_send_cxd_native(struct mmc_host *host, u32 arg, u32 *cxd, int opcode)

{

	int err;

	struct mmc_command cmd;



	BUG_ON(!card);

	BUG_ON(!card->host);

	BUG_ON(!csd);

	BUG_ON(!host);

	BUG_ON(!cxd);



	memset(&cmd, 0, sizeof(struct mmc_command));



	cmd.opcode = MMC_SEND_CSD;

	cmd.arg = card->rca << 16;

	cmd.opcode = opcode;

	cmd.arg = arg;

	cmd.flags = MMC_RSP_R2 | MMC_CMD_AC;



	err = mmc_wait_for_cmd(card->host, &cmd, MMC_CMD_RETRIES);

	err = mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);

	if (err)

		return err;



	memcpy(csd, cmd.resp, sizeof(u32) * 4);

	memcpy(cxd, cmd.resp, sizeof(u32) * 4);



	return 0;

}



int mmc_send_ext_csd(struct mmc_card *card, u8 *ext_csd)

static int

mmc_send_cxd_data(struct mmc_card *card, struct mmc_host *host,

		u32 opcode, void *buf, unsigned len)

{

	struct mmc_request mrq;

	struct mmc_command cmd;

	struct mmc_data data;

	struct scatterlist sg;

	void *data_buf;



	BUG_ON(!card);

	BUG_ON(!card->host);

	BUG_ON(!ext_csd);

	/* dma onto stack is unsafe/nonportable, but callers to this

	 * routine normally provide temporary on-stack buffers ...

	 */

	data_buf = kmalloc(len, GFP_KERNEL);

	if (data_buf == NULL)

		return -ENOMEM;



	memset(&mrq, 0, sizeof(struct mmc_request));

	memset(&cmd, 0, sizeof(struct mmc_command));
@@ -202,21 +231,31 @@ int mmc_send_ext_csd(struct mmc_card *card, u8 *ext_csd) 
	mrq.cmd = &cmd;

	mrq.data = &data;



	cmd.opcode = MMC_SEND_EXT_CSD;

	cmd.opcode = opcode;

	cmd.arg = 0;

	cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;



	data.blksz = 512;

	/* NOTE HACK:  the MMC_RSP_SPI_R1 is always correct here, but we

	 * rely on callers to never use this with "native" calls for reading

	 * CSD or CID.  Native versions of those commands use the R2 type,

	 * not R1 plus a data block.

	 */

	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;



	data.blksz = len;

	data.blocks = 1;

	data.flags = MMC_DATA_READ;

	data.sg = &sg;

	data.sg_len = 1;



	sg_init_one(&sg, ext_csd, 512);

	sg_init_one(&sg, data_buf, len);



	if (card)

		mmc_set_data_timeout(&data, card);



	mmc_wait_for_req(card->host, &mrq);

	mmc_wait_for_req(host, &mrq);



	memcpy(buf, data_buf, len);

	kfree(data_buf);



	if (cmd.error)

		return cmd.error;
@@ -226,6 +265,67 @@ int mmc_send_ext_csd(struct mmc_card *card, u8 *ext_csd) 
	return 0;

}



int mmc_send_csd(struct mmc_card *card, u32 *csd)

{

	if (!mmc_host_is_spi(card->host))

		return mmc_send_cxd_native(card->host, card->rca << 16,

				csd, MMC_SEND_CSD);



	return mmc_send_cxd_data(card, card->host, MMC_SEND_CSD, csd, 16);

}



int mmc_send_cid(struct mmc_host *host, u32 *cid)

{

	if (!mmc_host_is_spi(host)) {

		if (!host->card)

			return -EINVAL;

		return mmc_send_cxd_native(host, host->card->rca << 16,

				cid, MMC_SEND_CID);

	}



	return mmc_send_cxd_data(NULL, host, MMC_SEND_CID, cid, 16);

}



int mmc_send_ext_csd(struct mmc_card *card, u8 *ext_csd)

{

	return mmc_send_cxd_data(card, card->host, MMC_SEND_EXT_CSD,

			ext_csd, 512);

}



int mmc_spi_read_ocr(struct mmc_host *host, int highcap, u32 *ocrp)

{

	struct mmc_command cmd;

	int err;



	memset(&cmd, 0, sizeof(struct mmc_command));



	cmd.opcode = MMC_SPI_READ_OCR;

	cmd.arg = highcap ? (1 << 30) : 0;

	cmd.flags = MMC_RSP_SPI_R3;



	err = mmc_wait_for_cmd(host, &cmd, 0);



	*ocrp = cmd.resp[1];

	return err;

}



int mmc_spi_set_crc(struct mmc_host *host, int use_crc)

{

	struct mmc_command cmd;

	int err;



	memset(&cmd, 0, sizeof(struct mmc_command));



	cmd.opcode = MMC_SPI_CRC_ON_OFF;

	cmd.flags = MMC_RSP_SPI_R1;

	cmd.arg = use_crc;



	err = mmc_wait_for_cmd(host, &cmd, 0);

	if (!err)

		host->use_spi_crc = use_crc;

	return err;

}



int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value)

{

	int err;
@@ -241,7 +341,7 @@ int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value) 
		  (index << 16) |

		  (value << 8) |

		  set;

	cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;

	cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;



	err = mmc_wait_for_cmd(card->host, &cmd, MMC_CMD_RETRIES);

	if (err)
@@ -261,13 +361,17 @@ int mmc_send_status(struct mmc_card *card, u32 *status) 
	memset(&cmd, 0, sizeof(struct mmc_command));



	cmd.opcode = MMC_SEND_STATUS;

	if (!mmc_host_is_spi(card->host))

		cmd.arg = card->rca << 16;

	cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;

	cmd.flags = MMC_RSP_SPI_R2 | MMC_RSP_R1 | MMC_CMD_AC;



	err = mmc_wait_for_cmd(card->host, &cmd, MMC_CMD_RETRIES);

	if (err)

		return err;



	/* NOTE: callers are required to understand the difference

	 * between "native" and SPI format status words!

	 */

	if (status)

		*status = cmd.resp[0];

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