mmc: cavium: Add core MMC driver for Cavium SOCs

This core driver will be used by a MIPS platform driver
or by an ARM64 PCI driver. The core driver implements the
mmc_host_ops and slot probe & remove functions.
Callbacks are provided to allow platform specific interrupt
enable and bus locking.

The host controller supports:
- up to 4 slots that can contain sd-cards or eMMC chips
- 1, 4 and 8 bit bus width
- SDR and DDR
- transfers up to 52 Mhz (might be less when multiple slots are used)
- DMA read/write
- multi-block read/write (but not stream mode)

Voltage is limited to 3.3v and shared for all slots (vmmc and vmmcq).

A global lock for all MMC devices is required because the host
controller is shared.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Steven J. Hill <steven.hill@cavium.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 982 insertions, 0 deletions

diff --git a/drivers/mmc/host/cavium.c b/drivers/mmc/host/cavium.c
new file mode 100644
index 000000000000..910e290579bf
--- /dev/null
+++ b/drivers/mmc/host/cavium.c
@@ -0,0 +1,982 @@
+/*
+ * Shared part of driver for MMC/SDHC controller on Cavium OCTEON and
+ * ThunderX SOCs.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2012-2017 Cavium Inc.
+ * Authors:
+ *   David Daney <david.daney@cavium.com>
+ *   Peter Swain <pswain@cavium.com>
+ *   Steven J. Hill <steven.hill@cavium.com>
+ *   Jan Glauber <jglauber@cavium.com>
+ */
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/dma-direction.h>
+#include <linux/dma-mapping.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/mmc/mmc.h>
+#include <linux/mmc/slot-gpio.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/scatterlist.h>
+#include <linux/time.h>
+
+#include "cavium.h"
+
+const char *cvm_mmc_irq_names[] = {
+	"MMC Buffer",
+	"MMC Command",
+	"MMC DMA",
+	"MMC Command Error",
+	"MMC DMA Error",
+	"MMC Switch",
+	"MMC Switch Error",
+	"MMC DMA int Fifo",
+	"MMC DMA int",
+};
+
+/*
+ * The Cavium MMC host hardware assumes that all commands have fixed
+ * command and response types.  These are correct if MMC devices are
+ * being used.  However, non-MMC devices like SD use command and
+ * response types that are unexpected by the host hardware.
+ *
+ * The command and response types can be overridden by supplying an
+ * XOR value that is applied to the type.  We calculate the XOR value
+ * from the values in this table and the flags passed from the MMC
+ * core.
+ */
+static struct cvm_mmc_cr_type cvm_mmc_cr_types[] = {
+	{0, 0},		/* CMD0 */
+	{0, 3},		/* CMD1 */
+	{0, 2},		/* CMD2 */
+	{0, 1},		/* CMD3 */
+	{0, 0},		/* CMD4 */
+	{0, 1},		/* CMD5 */
+	{0, 1},		/* CMD6 */
+	{0, 1},		/* CMD7 */
+	{1, 1},		/* CMD8 */
+	{0, 2},		/* CMD9 */
+	{0, 2},		/* CMD10 */
+	{1, 1},		/* CMD11 */
+	{0, 1},		/* CMD12 */
+	{0, 1},		/* CMD13 */
+	{1, 1},		/* CMD14 */
+	{0, 0},		/* CMD15 */
+	{0, 1},		/* CMD16 */
+	{1, 1},		/* CMD17 */
+	{1, 1},		/* CMD18 */
+	{3, 1},		/* CMD19 */
+	{2, 1},		/* CMD20 */
+	{0, 0},		/* CMD21 */
+	{0, 0},		/* CMD22 */
+	{0, 1},		/* CMD23 */
+	{2, 1},		/* CMD24 */
+	{2, 1},		/* CMD25 */
+	{2, 1},		/* CMD26 */
+	{2, 1},		/* CMD27 */
+	{0, 1},		/* CMD28 */
+	{0, 1},		/* CMD29 */
+	{1, 1},		/* CMD30 */
+	{1, 1},		/* CMD31 */
+	{0, 0},		/* CMD32 */
+	{0, 0},		/* CMD33 */
+	{0, 0},		/* CMD34 */
+	{0, 1},		/* CMD35 */
+	{0, 1},		/* CMD36 */
+	{0, 0},		/* CMD37 */
+	{0, 1},		/* CMD38 */
+	{0, 4},		/* CMD39 */
+	{0, 5},		/* CMD40 */
+	{0, 0},		/* CMD41 */
+	{2, 1},		/* CMD42 */
+	{0, 0},		/* CMD43 */
+	{0, 0},		/* CMD44 */
+	{0, 0},		/* CMD45 */
+	{0, 0},		/* CMD46 */
+	{0, 0},		/* CMD47 */
+	{0, 0},		/* CMD48 */
+	{0, 0},		/* CMD49 */
+	{0, 0},		/* CMD50 */
+	{0, 0},		/* CMD51 */
+	{0, 0},		/* CMD52 */
+	{0, 0},		/* CMD53 */
+	{0, 0},		/* CMD54 */
+	{0, 1},		/* CMD55 */
+	{0xff, 0xff},	/* CMD56 */
+	{0, 0},		/* CMD57 */
+	{0, 0},		/* CMD58 */
+	{0, 0},		/* CMD59 */
+	{0, 0},		/* CMD60 */
+	{0, 0},		/* CMD61 */
+	{0, 0},		/* CMD62 */
+	{0, 0}		/* CMD63 */
+};
+
+static struct cvm_mmc_cr_mods cvm_mmc_get_cr_mods(struct mmc_command *cmd)
+{
+	struct cvm_mmc_cr_type *cr;
+	u8 hardware_ctype, hardware_rtype;
+	u8 desired_ctype = 0, desired_rtype = 0;
+	struct cvm_mmc_cr_mods r;
+
+	cr = cvm_mmc_cr_types + (cmd->opcode & 0x3f);
+	hardware_ctype = cr->ctype;
+	hardware_rtype = cr->rtype;
+	if (cmd->opcode == MMC_GEN_CMD)
+		hardware_ctype = (cmd->arg & 1) ? 1 : 2;
+
+	switch (mmc_cmd_type(cmd)) {
+	case MMC_CMD_ADTC:
+		desired_ctype = (cmd->data->flags & MMC_DATA_WRITE) ? 2 : 1;
+		break;
+	case MMC_CMD_AC:
+	case MMC_CMD_BC:
+	case MMC_CMD_BCR:
+		desired_ctype = 0;
+		break;
+	}
+
+	switch (mmc_resp_type(cmd)) {
+	case MMC_RSP_NONE:
+		desired_rtype = 0;
+		break;
+	case MMC_RSP_R1:/* MMC_RSP_R5, MMC_RSP_R6, MMC_RSP_R7 */
+	case MMC_RSP_R1B:
+		desired_rtype = 1;
+		break;
+	case MMC_RSP_R2:
+		desired_rtype = 2;
+		break;
+	case MMC_RSP_R3: /* MMC_RSP_R4 */
+		desired_rtype = 3;
+		break;
+	}
+	r.ctype_xor = desired_ctype ^ hardware_ctype;
+	r.rtype_xor = desired_rtype ^ hardware_rtype;
+	return r;
+}
+
+static void check_switch_errors(struct cvm_mmc_host *host)
+{
+	u64 emm_switch;
+
+	emm_switch = readq(host->base + MIO_EMM_SWITCH(host));
+	if (emm_switch & MIO_EMM_SWITCH_ERR0)
+		dev_err(host->dev, "Switch power class error\n");
+	if (emm_switch & MIO_EMM_SWITCH_ERR1)
+		dev_err(host->dev, "Switch hs timing error\n");
+	if (emm_switch & MIO_EMM_SWITCH_ERR2)
+		dev_err(host->dev, "Switch bus width error\n");
+}
+
+static void clear_bus_id(u64 *reg)
+{
+	u64 bus_id_mask = GENMASK_ULL(61, 60);
+
+	*reg &= ~bus_id_mask;
+}
+
+static void set_bus_id(u64 *reg, int bus_id)
+{
+	clear_bus_id(reg);
+	*reg |= FIELD_PREP(GENMASK(61, 60), bus_id);
+}
+
+static int get_bus_id(u64 reg)
+{
+	return FIELD_GET(GENMASK_ULL(61, 60), reg);
+}
+
+/*
+ * We never set the switch_exe bit since that would interfere
+ * with the commands send by the MMC core.
+ */
+static void do_switch(struct cvm_mmc_host *host, u64 emm_switch)
+{
+	int retries = 100;
+	u64 rsp_sts;
+	int bus_id;
+
+	/*
+	 * Modes setting only taken from slot 0. Work around that hardware
+	 * issue by first switching to slot 0.
+	 */
+	bus_id = get_bus_id(emm_switch);
+	clear_bus_id(&emm_switch);
+	writeq(emm_switch, host->base + MIO_EMM_SWITCH(host));
+
+	set_bus_id(&emm_switch, bus_id);
+	writeq(emm_switch, host->base + MIO_EMM_SWITCH(host));
+
+	/* wait for the switch to finish */
+	do {
+		rsp_sts = readq(host->base + MIO_EMM_RSP_STS(host));
+		if (!(rsp_sts & MIO_EMM_RSP_STS_SWITCH_VAL))
+			break;
+		udelay(10);
+	} while (--retries);
+
+	check_switch_errors(host);
+}
+
+static bool switch_val_changed(struct cvm_mmc_slot *slot, u64 new_val)
+{
+	/* Match BUS_ID, HS_TIMING, BUS_WIDTH, POWER_CLASS, CLK_HI, CLK_LO */
+	u64 match = 0x3001070fffffffffull;
+
+	return (slot->cached_switch & match) != (new_val & match);
+}
+
+static void set_wdog(struct cvm_mmc_slot *slot, unsigned int ns)
+{
+	u64 timeout;
+
+	if (!slot->clock)
+		return;
+
+	if (ns)
+		timeout = (slot->clock * ns) / NSEC_PER_SEC;
+	else
+		timeout = (slot->clock * 850ull) / 1000ull;
+	writeq(timeout, slot->host->base + MIO_EMM_WDOG(slot->host));
+}
+
+static void cvm_mmc_reset_bus(struct cvm_mmc_slot *slot)
+{
+	struct cvm_mmc_host *host = slot->host;
+	u64 emm_switch, wdog;
+
+	emm_switch = readq(slot->host->base + MIO_EMM_SWITCH(host));
+	emm_switch &= ~(MIO_EMM_SWITCH_EXE | MIO_EMM_SWITCH_ERR0 |
+			MIO_EMM_SWITCH_ERR1 | MIO_EMM_SWITCH_ERR2);
+	set_bus_id(&emm_switch, slot->bus_id);
+
+	wdog = readq(slot->host->base + MIO_EMM_WDOG(host));
+	do_switch(slot->host, emm_switch);
+
+	slot->cached_switch = emm_switch;
+
+	msleep(20);
+
+	writeq(wdog, slot->host->base + MIO_EMM_WDOG(host));
+}
+
+/* Switch to another slot if needed */
+static void cvm_mmc_switch_to(struct cvm_mmc_slot *slot)
+{
+	struct cvm_mmc_host *host = slot->host;
+	struct cvm_mmc_slot *old_slot;
+	u64 emm_sample, emm_switch;
+
+	if (slot->bus_id == host->last_slot)
+		return;
+
+	if (host->last_slot >= 0 && host->slot[host->last_slot]) {
+		old_slot = host->slot[host->last_slot];
+		old_slot->cached_switch = readq(host->base + MIO_EMM_SWITCH(host));
+		old_slot->cached_rca = readq(host->base + MIO_EMM_RCA(host));
+	}
+
+	writeq(slot->cached_rca, host->base + MIO_EMM_RCA(host));
+	emm_switch = slot->cached_switch;
+	set_bus_id(&emm_switch, slot->bus_id);
+	do_switch(host, emm_switch);
+
+	emm_sample = FIELD_PREP(MIO_EMM_SAMPLE_CMD_CNT, slot->cmd_cnt) |
+		     FIELD_PREP(MIO_EMM_SAMPLE_DAT_CNT, slot->dat_cnt);
+	writeq(emm_sample, host->base + MIO_EMM_SAMPLE(host));
+
+	host->last_slot = slot->bus_id;
+}
+
+static void do_read(struct cvm_mmc_host *host, struct mmc_request *req,
+		    u64 dbuf)
+{
+	struct sg_mapping_iter *smi = &host->smi;
+	int data_len = req->data->blocks * req->data->blksz;
+	int bytes_xfered, shift = -1;
+	u64 dat = 0;
+
+	/* Auto inc from offset zero */
+	writeq((0x10000 | (dbuf << 6)), host->base + MIO_EMM_BUF_IDX(host));
+
+	for (bytes_xfered = 0; bytes_xfered < data_len;) {
+		if (smi->consumed >= smi->length) {
+			if (!sg_miter_next(smi))
+				break;
+			smi->consumed = 0;
+		}
+
+		if (shift < 0) {
+			dat = readq(host->base + MIO_EMM_BUF_DAT(host));
+			shift = 56;
+		}
+
+		while (smi->consumed < smi->length && shift >= 0) {
+			((u8 *)smi->addr)[smi->consumed] = (dat >> shift) & 0xff;
+			bytes_xfered++;
+			smi->consumed++;
+			shift -= 8;
+		}
+	}
+
+	sg_miter_stop(smi);
+	req->data->bytes_xfered = bytes_xfered;
+	req->data->error = 0;
+}
+
+static void do_write(struct mmc_request *req)
+{
+	req->data->bytes_xfered = req->data->blocks * req->data->blksz;
+	req->data->error = 0;
+}
+
+static void set_cmd_response(struct cvm_mmc_host *host, struct mmc_request *req,
+			     u64 rsp_sts)
+{
+	u64 rsp_hi, rsp_lo;
+
+	if (!(rsp_sts & MIO_EMM_RSP_STS_RSP_VAL))
+		return;
+
+	rsp_lo = readq(host->base + MIO_EMM_RSP_LO(host));
+
+	switch (FIELD_GET(MIO_EMM_RSP_STS_RSP_TYPE, rsp_sts)) {
+	case 1:
+	case 3:
+		req->cmd->resp[0] = (rsp_lo >> 8) & 0xffffffff;
+		req->cmd->resp[1] = 0;
+		req->cmd->resp[2] = 0;
+		req->cmd->resp[3] = 0;
+		break;
+	case 2:
+		req->cmd->resp[3] = rsp_lo & 0xffffffff;
+		req->cmd->resp[2] = (rsp_lo >> 32) & 0xffffffff;
+		rsp_hi = readq(host->base + MIO_EMM_RSP_HI(host));
+		req->cmd->resp[1] = rsp_hi & 0xffffffff;
+		req->cmd->resp[0] = (rsp_hi >> 32) & 0xffffffff;
+		break;
+	}
+}
+
+static int get_dma_dir(struct mmc_data *data)
+{
+	return (data->flags & MMC_DATA_WRITE) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+}
+
+static int finish_dma_single(struct cvm_mmc_host *host, struct mmc_data *data)
+{
+	data->bytes_xfered = data->blocks * data->blksz;
+	data->error = 0;
+	return 1;
+}
+
+static int finish_dma(struct cvm_mmc_host *host, struct mmc_data *data)
+{
+	return finish_dma_single(host, data);
+}
+
+static int check_status(u64 rsp_sts)
+{
+	if (rsp_sts & MIO_EMM_RSP_STS_RSP_BAD_STS ||
+	    rsp_sts & MIO_EMM_RSP_STS_RSP_CRC_ERR ||
+	    rsp_sts & MIO_EMM_RSP_STS_BLK_CRC_ERR)
+		return -EILSEQ;
+	if (rsp_sts & MIO_EMM_RSP_STS_RSP_TIMEOUT ||
+	    rsp_sts & MIO_EMM_RSP_STS_BLK_TIMEOUT)
+		return -ETIMEDOUT;
+	if (rsp_sts & MIO_EMM_RSP_STS_DBUF_ERR)
+		return -EIO;
+	return 0;
+}
+
+/* Try to clean up failed DMA. */
+static void cleanup_dma(struct cvm_mmc_host *host, u64 rsp_sts)
+{
+	u64 emm_dma;
+
+	emm_dma = readq(host->base + MIO_EMM_DMA(host));
+	emm_dma |= FIELD_PREP(MIO_EMM_DMA_VAL, 1) |
+		   FIELD_PREP(MIO_EMM_DMA_DAT_NULL, 1);
+	set_bus_id(&emm_dma, get_bus_id(rsp_sts));
+	writeq(emm_dma, host->base + MIO_EMM_DMA(host));
+}
+
+irqreturn_t cvm_mmc_interrupt(int irq, void *dev_id)
+{
+	struct cvm_mmc_host *host = dev_id;
+	struct mmc_request *req;
+	unsigned long flags = 0;
+	u64 emm_int, rsp_sts;
+	bool host_done;
+
+	if (host->need_irq_handler_lock)
+		spin_lock_irqsave(&host->irq_handler_lock, flags);
+	else
+		__acquire(&host->irq_handler_lock);
+
+	/* Clear interrupt bits (write 1 clears ). */
+	emm_int = readq(host->base + MIO_EMM_INT(host));
+	writeq(emm_int, host->base + MIO_EMM_INT(host));
+
+	if (emm_int & MIO_EMM_INT_SWITCH_ERR)
+		check_switch_errors(host);
+
+	req = host->current_req;
+	if (!req)
+		goto out;
+
+	rsp_sts = readq(host->base + MIO_EMM_RSP_STS(host));
+	/*
+	 * dma_val set means DMA is still in progress. Don't touch
+	 * the request and wait for the interrupt indicating that
+	 * the DMA is finished.
+	 */
+	if ((rsp_sts & MIO_EMM_RSP_STS_DMA_VAL) && host->dma_active)
+		goto out;
+
+	if (!host->dma_active && req->data &&
+	    (emm_int & MIO_EMM_INT_BUF_DONE)) {
+		unsigned int type = (rsp_sts >> 7) & 3;
+
+		if (type == 1)
+			do_read(host, req, rsp_sts & MIO_EMM_RSP_STS_DBUF);
+		else if (type == 2)
+			do_write(req);
+	}
+
+	host_done = emm_int & MIO_EMM_INT_CMD_DONE ||
+		    emm_int & MIO_EMM_INT_DMA_DONE ||
+		    emm_int & MIO_EMM_INT_CMD_ERR  ||
+		    emm_int & MIO_EMM_INT_DMA_ERR;
+
+	if (!(host_done && req->done))
+		goto no_req_done;
+
+	req->cmd->error = check_status(rsp_sts);
+
+	if (host->dma_active && req->data)
+		if (!finish_dma(host, req->data))
+			goto no_req_done;
+
+	set_cmd_response(host, req, rsp_sts);
+	if ((emm_int & MIO_EMM_INT_DMA_ERR) &&
+	    (rsp_sts & MIO_EMM_RSP_STS_DMA_PEND))
+		cleanup_dma(host, rsp_sts);
+
+	host->current_req = NULL;
+	req->done(req);
+
+no_req_done:
+	if (host->dmar_fixup_done)
+		host->dmar_fixup_done(host);
+	if (host_done)
+		host->release_bus(host);
+out:
+	if (host->need_irq_handler_lock)
+		spin_unlock_irqrestore(&host->irq_handler_lock, flags);
+	else
+		__release(&host->irq_handler_lock);
+	return IRQ_RETVAL(emm_int != 0);
+}
+
+/*
+ * Program DMA_CFG and if needed DMA_ADR.
+ * Returns 0 on error, DMA address otherwise.
+ */
+static u64 prepare_dma_single(struct cvm_mmc_host *host, struct mmc_data *data)
+{
+	u64 dma_cfg, addr;
+	int count, rw;
+
+	count = dma_map_sg(host->dev, data->sg, data->sg_len,
+			   get_dma_dir(data));
+	if (!count)
+		return 0;
+
+	rw = (data->flags & MMC_DATA_WRITE) ? 1 : 0;
+	dma_cfg = FIELD_PREP(MIO_EMM_DMA_CFG_EN, 1) |
+		  FIELD_PREP(MIO_EMM_DMA_CFG_RW, rw);
+#ifdef __LITTLE_ENDIAN
+	dma_cfg |= FIELD_PREP(MIO_EMM_DMA_CFG_ENDIAN, 1);
+#endif
+	dma_cfg |= FIELD_PREP(MIO_EMM_DMA_CFG_SIZE,
+			      (sg_dma_len(&data->sg[0]) / 8) - 1);
+
+	addr = sg_dma_address(&data->sg[0]);
+	if (!host->big_dma_addr)
+		dma_cfg |= FIELD_PREP(MIO_EMM_DMA_CFG_ADR, addr);
+	writeq(dma_cfg, host->dma_base + MIO_EMM_DMA_CFG(host));
+
+	pr_debug("[%s] sg_dma_len: %u  total sg_elem: %d\n",
+		 (rw) ? "W" : "R", sg_dma_len(&data->sg[0]), count);
+
+	if (host->big_dma_addr)
+		writeq(addr, host->dma_base + MIO_EMM_DMA_ADR(host));
+	return addr;
+}
+
+static u64 prepare_dma(struct cvm_mmc_host *host, struct mmc_data *data)
+{
+	return prepare_dma_single(host, data);
+}
+
+static u64 prepare_ext_dma(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+	struct cvm_mmc_slot *slot = mmc_priv(mmc);
+	u64 emm_dma;
+
+	emm_dma = FIELD_PREP(MIO_EMM_DMA_VAL, 1) |
+		  FIELD_PREP(MIO_EMM_DMA_SECTOR,
+			     (mrq->data->blksz == 512) ? 1 : 0) |
+		  FIELD_PREP(MIO_EMM_DMA_RW,
+			     (mrq->data->flags & MMC_DATA_WRITE) ? 1 : 0) |
+		  FIELD_PREP(MIO_EMM_DMA_BLOCK_CNT, mrq->data->blocks) |
+		  FIELD_PREP(MIO_EMM_DMA_CARD_ADDR, mrq->cmd->arg);
+	set_bus_id(&emm_dma, slot->bus_id);
+
+	if (mmc_card_mmc(mmc->card) || (mmc_card_sd(mmc->card) &&
+	    (mmc->card->scr.cmds & SD_SCR_CMD23_SUPPORT)))
+		emm_dma |= FIELD_PREP(MIO_EMM_DMA_MULTI, 1);
+
+	pr_debug("[%s] blocks: %u  multi: %d\n",
+		(emm_dma & MIO_EMM_DMA_RW) ? "W" : "R",
+		 mrq->data->blocks, (emm_dma & MIO_EMM_DMA_MULTI) ? 1 : 0);
+	return emm_dma;
+}
+
+static void cvm_mmc_dma_request(struct mmc_host *mmc,
+				struct mmc_request *mrq)
+{
+	struct cvm_mmc_slot *slot = mmc_priv(mmc);
+	struct cvm_mmc_host *host = slot->host;
+	struct mmc_data *data;
+	u64 emm_dma, addr;
+
+	if (!mrq->data || !mrq->data->sg || !mrq->data->sg_len ||
+	    !mrq->stop || mrq->stop->opcode != MMC_STOP_TRANSMISSION) {
+		dev_err(&mmc->card->dev,
+			"Error: cmv_mmc_dma_request no data\n");
+		goto error;
+	}
+
+	cvm_mmc_switch_to(slot);
+
+	data = mrq->data;
+	pr_debug("DMA request  blocks: %d  block_size: %d  total_size: %d\n",
+		 data->blocks, data->blksz, data->blocks * data->blksz);
+	if (data->timeout_ns)
+		set_wdog(slot, data->timeout_ns);
+
+	WARN_ON(host->current_req);
+	host->current_req = mrq;
+
+	emm_dma = prepare_ext_dma(mmc, mrq);
+	addr = prepare_dma(host, data);
+	if (!addr) {
+		dev_err(host->dev, "prepare_dma failed\n");
+		goto error;
+	}
+
+	host->dma_active = true;
+	host->int_enable(host, MIO_EMM_INT_CMD_ERR | MIO_EMM_INT_DMA_DONE |
+			 MIO_EMM_INT_DMA_ERR);
+
+	if (host->dmar_fixup)
+		host->dmar_fixup(host, mrq->cmd, data, addr);
+
+	/*
+	 * If we have a valid SD card in the slot, we set the response
+	 * bit mask to check for CRC errors and timeouts only.
+	 * Otherwise, use the default power reset value.
+	 */
+	if (mmc->card && mmc_card_sd(mmc->card))
+		writeq(0x00b00000ull, host->base + MIO_EMM_STS_MASK(host));
+	else
+		writeq(0xe4390080ull, host->base + MIO_EMM_STS_MASK(host));
+	writeq(emm_dma, host->base + MIO_EMM_DMA(host));
+	return;
+
+error:
+	mrq->cmd->error = -EINVAL;
+	if (mrq->done)
+		mrq->done(mrq);
+	host->release_bus(host);
+}
+
+static void do_read_request(struct cvm_mmc_host *host, struct mmc_request *mrq)
+{
+	sg_miter_start(&host->smi, mrq->data->sg, mrq->data->sg_len,
+		       SG_MITER_ATOMIC | SG_MITER_TO_SG);
+}
+
+static void do_write_request(struct cvm_mmc_host *host, struct mmc_request *mrq)
+{
+	unsigned int data_len = mrq->data->blocks * mrq->data->blksz;
+	struct sg_mapping_iter *smi = &host->smi;
+	unsigned int bytes_xfered;
+	int shift = 56;
+	u64 dat = 0;
+
+	/* Copy data to the xmit buffer before issuing the command. */
+	sg_miter_start(smi, mrq->data->sg, mrq->data->sg_len, SG_MITER_FROM_SG);
+
+	/* Auto inc from offset zero, dbuf zero */
+	writeq(0x10000ull, host->base + MIO_EMM_BUF_IDX(host));
+
+	for (bytes_xfered = 0; bytes_xfered < data_len;) {
+		if (smi->consumed >= smi->length) {
+			if (!sg_miter_next(smi))
+				break;
+			smi->consumed = 0;
+		}
+
+		while (smi->consumed < smi->length && shift >= 0) {
+			dat |= ((u8 *)smi->addr)[smi->consumed] << shift;
+			bytes_xfered++;
+			smi->consumed++;
+			shift -= 8;
+		}
+
+		if (shift < 0) {
+			writeq(dat, host->base + MIO_EMM_BUF_DAT(host));
+			shift = 56;
+			dat = 0;
+		}
+	}
+	sg_miter_stop(smi);
+}
+
+static void cvm_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+	struct cvm_mmc_slot *slot = mmc_priv(mmc);
+	struct cvm_mmc_host *host = slot->host;
+	struct mmc_command *cmd = mrq->cmd;
+	struct cvm_mmc_cr_mods mods;
+	u64 emm_cmd, rsp_sts;
+	int retries = 100;
+
+	/*
+	 * Note about locking:
+	 * All MMC devices share the same bus and controller. Allow only a
+	 * single user of the bootbus/MMC bus at a time. The lock is acquired
+	 * on all entry points from the MMC layer.
+	 *
+	 * For requests the lock is only released after the completion
+	 * interrupt!
+	 */
+	host->acquire_bus(host);
+
+	if (cmd->opcode == MMC_READ_MULTIPLE_BLOCK ||
+	    cmd->opcode == MMC_WRITE_MULTIPLE_BLOCK)
+		return cvm_mmc_dma_request(mmc, mrq);
+
+	cvm_mmc_switch_to(slot);
+
+	mods = cvm_mmc_get_cr_mods(cmd);
+
+	WARN_ON(host->current_req);
+	host->current_req = mrq;
+
+	if (cmd->data) {
+		if (cmd->data->flags & MMC_DATA_READ)
+			do_read_request(host, mrq);
+		else
+			do_write_request(host, mrq);
+
+		if (cmd->data->timeout_ns)
+			set_wdog(slot, cmd->data->timeout_ns);
+	} else
+		set_wdog(slot, 0);
+
+	host->dma_active = false;
+	host->int_enable(host, MIO_EMM_INT_CMD_DONE | MIO_EMM_INT_CMD_ERR);
+
+	emm_cmd = FIELD_PREP(MIO_EMM_CMD_VAL, 1) |
+		  FIELD_PREP(MIO_EMM_CMD_CTYPE_XOR, mods.ctype_xor) |
+		  FIELD_PREP(MIO_EMM_CMD_RTYPE_XOR, mods.rtype_xor) |
+		  FIELD_PREP(MIO_EMM_CMD_IDX, cmd->opcode) |
+		  FIELD_PREP(MIO_EMM_CMD_ARG, cmd->arg);
+	set_bus_id(&emm_cmd, slot->bus_id);
+	if (mmc_cmd_type(cmd) == MMC_CMD_ADTC)
+		emm_cmd |= FIELD_PREP(MIO_EMM_CMD_OFFSET,
+				64 - ((cmd->data->blocks * cmd->data->blksz) / 8));
+
+	writeq(0, host->base + MIO_EMM_STS_MASK(host));
+
+retry:
+	rsp_sts = readq(host->base + MIO_EMM_RSP_STS(host));
+	if (rsp_sts & MIO_EMM_RSP_STS_DMA_VAL ||
+	    rsp_sts & MIO_EMM_RSP_STS_CMD_VAL ||
+	    rsp_sts & MIO_EMM_RSP_STS_SWITCH_VAL ||
+	    rsp_sts & MIO_EMM_RSP_STS_DMA_PEND) {
+		udelay(10);
+		if (--retries)
+			goto retry;
+	}
+	if (!retries)
+		dev_err(host->dev, "Bad status: %llx before command write\n", rsp_sts);
+	writeq(emm_cmd, host->base + MIO_EMM_CMD(host));
+}
+
+static void cvm_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	struct cvm_mmc_slot *slot = mmc_priv(mmc);
+	struct cvm_mmc_host *host = slot->host;
+	int clk_period = 0, power_class = 10, bus_width = 0;
+	u64 clock, emm_switch;
+
+	host->acquire_bus(host);
+	cvm_mmc_switch_to(slot);
+
+	/* Set the power state */
+	switch (ios->power_mode) {
+	case MMC_POWER_ON:
+		break;
+
+	case MMC_POWER_OFF:
+		cvm_mmc_reset_bus(slot);
+		if (host->global_pwr_gpiod)
+			host->set_shared_power(host, 0);
+		else
+			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
+		break;
+
+	case MMC_POWER_UP:
+		if (host->global_pwr_gpiod)
+			host->set_shared_power(host, 1);
+		else
+			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
+		break;
+	}
+
+	/* Convert bus width to HW definition */
+	switch (ios->bus_width) {
+	case MMC_BUS_WIDTH_8:
+		bus_width = 2;
+		break;
+	case MMC_BUS_WIDTH_4:
+		bus_width = 1;
+		break;
+	case MMC_BUS_WIDTH_1:
+		bus_width = 0;
+		break;
+	}
+
+	/* Change the clock frequency. */
+	clock = ios->clock;
+	if (clock > 52000000)
+		clock = 52000000;
+	slot->clock = clock;
+
+	if (clock)
+		clk_period = (host->sys_freq + clock - 1) / (2 * clock);
+
+	emm_switch = FIELD_PREP(MIO_EMM_SWITCH_HS_TIMING,
+				(ios->timing == MMC_TIMING_MMC_HS)) |
+		     FIELD_PREP(MIO_EMM_SWITCH_BUS_WIDTH, bus_width) |
+		     FIELD_PREP(MIO_EMM_SWITCH_POWER_CLASS, power_class) |
+		     FIELD_PREP(MIO_EMM_SWITCH_CLK_HI, clk_period) |
+		     FIELD_PREP(MIO_EMM_SWITCH_CLK_LO, clk_period);
+	set_bus_id(&emm_switch, slot->bus_id);
+
+	if (!switch_val_changed(slot, emm_switch))
+		goto out;
+
+	set_wdog(slot, 0);
+	do_switch(host, emm_switch);
+	slot->cached_switch = emm_switch;
+out:
+	host->release_bus(host);
+}
+
+static const struct mmc_host_ops cvm_mmc_ops = {
+	.request        = cvm_mmc_request,
+	.set_ios        = cvm_mmc_set_ios,
+	.get_ro		= mmc_gpio_get_ro,
+	.get_cd		= mmc_gpio_get_cd,
+};
+
+static void cvm_mmc_set_clock(struct cvm_mmc_slot *slot, unsigned int clock)
+{
+	struct mmc_host *mmc = slot->mmc;
+
+	clock = min(clock, mmc->f_max);
+	clock = max(clock, mmc->f_min);
+	slot->clock = clock;
+}
+
+static int cvm_mmc_init_lowlevel(struct cvm_mmc_slot *slot)
+{
+	struct cvm_mmc_host *host = slot->host;
+	u64 emm_switch;
+
+	/* Enable this bus slot. */
+	host->emm_cfg |= (1ull << slot->bus_id);
+	writeq(host->emm_cfg, slot->host->base + MIO_EMM_CFG(host));
+	udelay(10);
+
+	/* Program initial clock speed and power. */
+	cvm_mmc_set_clock(slot, slot->mmc->f_min);
+	emm_switch = FIELD_PREP(MIO_EMM_SWITCH_POWER_CLASS, 10);
+	emm_switch |= FIELD_PREP(MIO_EMM_SWITCH_CLK_HI,
+				 (host->sys_freq / slot->clock) / 2);
+	emm_switch |= FIELD_PREP(MIO_EMM_SWITCH_CLK_LO,
+				 (host->sys_freq / slot->clock) / 2);
+
+	/* Make the changes take effect on this bus slot. */
+	set_bus_id(&emm_switch, slot->bus_id);
+	do_switch(host, emm_switch);
+
+	slot->cached_switch = emm_switch;
+
+	/*
+	 * Set watchdog timeout value and default reset value
+	 * for the mask register. Finally, set the CARD_RCA
+	 * bit so that we can get the card address relative
+	 * to the CMD register for CMD7 transactions.
+	 */
+	set_wdog(slot, 0);
+	writeq(0xe4390080ull, host->base + MIO_EMM_STS_MASK(host));
+	writeq(1, host->base + MIO_EMM_RCA(host));
+	return 0;
+}
+
+static int cvm_mmc_of_parse(struct device *dev, struct cvm_mmc_slot *slot)
+{
+	u32 id, cmd_skew = 0, dat_skew = 0, bus_width = 0;
+	struct device_node *node = dev->of_node;
+	struct mmc_host *mmc = slot->mmc;
+	u64 clock_period;
+	int ret;
+
+	ret = of_property_read_u32(node, "reg", &id);
+	if (ret) {
+		dev_err(dev, "Missing or invalid reg property on %s\n",
+			of_node_full_name(node));
+		return ret;
+	}
+
+	if (id >= CAVIUM_MAX_MMC || slot->host->slot[id]) {
+		dev_err(dev, "Invalid reg property on %s\n",
+			of_node_full_name(node));
+		return -EINVAL;
+	}
+
+	mmc->supply.vmmc = devm_regulator_get_optional(dev, "vmmc");
+	if (IS_ERR(mmc->supply.vmmc)) {
+		if (PTR_ERR(mmc->supply.vmmc) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		/*
+		 * Legacy Octeon firmware has no regulator entry, fall-back to
+		 * a hard-coded voltage to get a sane OCR.
+		 */
+		mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
+	} else {
+		ret = mmc_regulator_get_ocrmask(mmc->supply.vmmc);
+		if (ret > 0)
+			mmc->ocr_avail = ret;
+	}
+
+	/* Common MMC bindings */
+	ret = mmc_of_parse(mmc);
+	if (ret)
+		return ret;
+
+	/* Set bus width */
+	if (!(mmc->caps & (MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA))) {
+		of_property_read_u32(node, "cavium,bus-max-width", &bus_width);
+		if (bus_width == 8)
+			mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA;
+		else if (bus_width == 4)
+			mmc->caps |= MMC_CAP_4_BIT_DATA;
+	}
+
+	/* Set maximum and minimum frequency */
+	if (!mmc->f_max)
+		of_property_read_u32(node, "spi-max-frequency", &mmc->f_max);
+	if (!mmc->f_max || mmc->f_max > 52000000)
+		mmc->f_max = 52000000;
+	mmc->f_min = 400000;
+
+	/* Sampling register settings, period in picoseconds */
+	clock_period = 1000000000000ull / slot->host->sys_freq;
+	of_property_read_u32(node, "cavium,cmd-clk-skew", &cmd_skew);
+	of_property_read_u32(node, "cavium,dat-clk-skew", &dat_skew);
+	slot->cmd_cnt = (cmd_skew + clock_period / 2) / clock_period;
+	slot->dat_cnt = (dat_skew + clock_period / 2) / clock_period;
+
+	return id;
+}
+
+int cvm_mmc_of_slot_probe(struct device *dev, struct cvm_mmc_host *host)
+{
+	struct cvm_mmc_slot *slot;
+	struct mmc_host *mmc;
+	int ret, id;
+
+	mmc = mmc_alloc_host(sizeof(struct cvm_mmc_slot), dev);
+	if (!mmc)
+		return -ENOMEM;
+
+	slot = mmc_priv(mmc);
+	slot->mmc = mmc;
+	slot->host = host;
+
+	ret = cvm_mmc_of_parse(dev, slot);
+	if (ret < 0)
+		goto error;
+	id = ret;
+
+	/* Set up host parameters */
+	mmc->ops = &cvm_mmc_ops;
+
+	mmc->caps |= MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED |
+		     MMC_CAP_ERASE | MMC_CAP_CMD23 | MMC_CAP_POWER_OFF_CARD;
+
+	mmc->max_segs = 1;
+
+	/* DMA size field can address up to 8 MB */
+	mmc->max_seg_size = 8 * 1024 * 1024;
+	mmc->max_req_size = mmc->max_seg_size;
+	/* External DMA is in 512 byte blocks */
+	mmc->max_blk_size = 512;
+	/* DMA block count field is 15 bits */
+	mmc->max_blk_count = 32767;
+
+	slot->clock = mmc->f_min;
+	slot->bus_id = id;
+	slot->cached_rca = 1;
+
+	host->acquire_bus(host);
+	host->slot[id] = slot;
+	cvm_mmc_switch_to(slot);
+	cvm_mmc_init_lowlevel(slot);
+	host->release_bus(host);
+
+	ret = mmc_add_host(mmc);
+	if (ret) {
+		dev_err(dev, "mmc_add_host() returned %d\n", ret);
+		slot->host->slot[id] = NULL;
+		goto error;
+	}
+	return 0;
+
+error:
+	mmc_free_host(slot->mmc);
+	return ret;
+}
+
+int cvm_mmc_of_slot_remove(struct cvm_mmc_slot *slot)
+{
+	mmc_remove_host(slot->mmc);
+	slot->host->slot[slot->bus_id] = NULL;
+	mmc_free_host(slot->mmc);
+	return 0;
+}