drivers/mmc/owl_mmc.c - u-boot - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (C) 2020 Amit Singh Tomar <amittomer25@gmail.com>
  *
  * Driver for SD/MMC controller present on Actions Semi S700/S900 SoC, based
  * on Linux Driver "drivers/mmc/host/owl-mmc.c".
  *
  * Though, there is a bit (BSEL, BUS or DMA Special Channel Selection) that
  * controls the data transfer from SDx_DAT register either using CPU AHB Bus
  * or DMA channel, but seems like, it only works correctly using external DMA
  * channel, and those special bits used in this driver is picked from vendor
  * source exclusively for MMC/SD.
  */
 #include <common.h>
 #include <clk.h>
 #include <cpu_func.h>
 #include <dm.h>
 #include <errno.h>
 #include <log.h>
 #include <mmc.h>
 #include <asm/io.h>
 #include <linux/bitops.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/iopoll.h>

 /*
  * SDC registers
  */
 #define OWL_REG_SD_EN			0x0000
 #define OWL_REG_SD_CTL			0x0004
 #define OWL_REG_SD_STATE		0x0008
 #define OWL_REG_SD_CMD			0x000c
 #define OWL_REG_SD_ARG			0x0010
 #define OWL_REG_SD_RSPBUF0		0x0014
 #define OWL_REG_SD_RSPBUF1		0x0018
 #define OWL_REG_SD_RSPBUF2		0x001c
 #define OWL_REG_SD_RSPBUF3		0x0020
 #define OWL_REG_SD_RSPBUF4		0x0024
 #define OWL_REG_SD_DAT			0x0028
 #define OWL_REG_SD_BLK_SIZE		0x002c
 #define OWL_REG_SD_BLK_NUM		0x0030
 #define OWL_REG_SD_BUF_SIZE		0x0034

 /* SD_EN Bits */
 #define OWL_SD_EN_RANE			BIT(31)
 #define OWL_SD_EN_RESE			BIT(10)
 #define OWL_SD_ENABLE			BIT(7)
 #define OWL_SD_EN_BSEL			BIT(6)
 #define OWL_SD_EN_DATAWID(x)		(((x) & 0x3) << 0)
 #define OWL_SD_EN_DATAWID_MASK		0x03

 /* SD_CTL Bits */
 #define OWL_SD_CTL_TOUTEN		BIT(31)
 #define OWL_SD_CTL_DELAY_MSK		GENMASK(23, 16)
 #define OWL_SD_CTL_RDELAY(x)		(((x) & 0xf) << 20)
 #define OWL_SD_CTL_WDELAY(x)		(((x) & 0xf) << 16)
 #define OWL_SD_CTL_TS			BIT(7)
 #define OWL_SD_CTL_LBE			BIT(6)
 #define OWL_SD_CTL_TM(x)		(((x) & 0xf) << 0)

 #define OWL_SD_DELAY_LOW_CLK		0x0f
 #define OWL_SD_DELAY_MID_CLK		0x0a
 #define OWL_SD_RDELAY_HIGH		0x08
 #define OWL_SD_WDELAY_HIGH		0x09

 /* SD_STATE Bits */
 #define OWL_SD_STATE_DAT0S		BIT(7)
 #define OWL_SD_STATE_CLNR		BIT(4)
 #define OWL_SD_STATE_CRC7ER		BIT(0)

 #define OWL_MMC_OCR			(MMC_VDD_32_33 | MMC_VDD_33_34 | \
 					 MMC_VDD_165_195)

 #define DATA_TRANSFER_TIMEOUT		3000000
 #define DMA_TRANSFER_TIMEOUT		5000000

 /*
  * Simple DMA transfer operations defines for MMC/SD card
  */
 #define SD_DMA_CHANNEL(base, channel)	((base) + 0x100 + 0x100 * (channel))

 #define DMA_MODE			0x0000
 #define DMA_SOURCE			0x0004
 #define DMA_DESTINATION			0x0008
 #define DMA_FRAME_LEN			0x000C
 #define DMA_FRAME_CNT			0x0010
 #define DMA_START			0x0024

 /* DMAx_MODE */
 #define DMA_MODE_ST(x)			(((x) & 0x3) << 8)
 #define DMA_MODE_ST_DEV			DMA_MODE_ST(0)
 #define DMA_MODE_DT(x)			(((x) & 0x3) << 10)
 #define DMA_MODE_DT_DCU			DMA_MODE_DT(2)
 #define DMA_MODE_SAM(x)			(((x) & 0x3) << 16)
 #define DMA_MODE_SAM_CONST		DMA_MODE_SAM(0)
 #define DMA_MODE_DAM(x)			(((x) & 0x3) << 18)
 #define DMA_MODE_DAM_INC		DMA_MODE_DAM(1)

 #define DMA_ENABLE			0x1

 struct owl_mmc_plat {
 	struct mmc_config cfg;
 	struct mmc mmc;
 };

 struct owl_mmc_priv {
 	void *reg_base;
 	void *dma_channel;
 	struct clk clk;
 	unsigned int clock;	  /* Current clock */
 	unsigned int dma_drq;	  /* Trigger Source */
 };

 static void owl_dma_config(struct owl_mmc_priv *priv, unsigned int src,
 			   unsigned int dst, unsigned int len)
 {
 	unsigned int mode = priv->dma_drq;

 	/* Set Source and Destination adderess mode */
 	mode |= (DMA_MODE_ST_DEV | DMA_MODE_SAM_CONST | DMA_MODE_DT_DCU |
 			DMA_MODE_DAM_INC);

 	writel(mode, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_MODE);
 	writel(src, SD_DMA_CHANNEL(priv->dma_channel, 0)  + DMA_SOURCE);
 	writel(dst, SD_DMA_CHANNEL(priv->dma_channel, 0)  + DMA_DESTINATION);
 	writel(len, SD_DMA_CHANNEL(priv->dma_channel, 0)  + DMA_FRAME_LEN);
 	writel(0x1, SD_DMA_CHANNEL(priv->dma_channel, 0)  + DMA_FRAME_CNT);
 }

 static void owl_mmc_prepare_data(struct owl_mmc_priv *priv,
 				 struct mmc_data *data)
 {
 	unsigned int total;
 	u32 buf = 0;

 	setbits_le32(priv->reg_base + OWL_REG_SD_EN, OWL_SD_EN_BSEL);

 	writel(data->blocks, priv->reg_base + OWL_REG_SD_BLK_NUM);
 	writel(data->blocksize, priv->reg_base + OWL_REG_SD_BLK_SIZE);
 	total = data->blocksize * data->blocks;

 	if (total < 512)
 		writel(total, priv->reg_base + OWL_REG_SD_BUF_SIZE);
 	else
 		writel(512, priv->reg_base + OWL_REG_SD_BUF_SIZE);

 	/* DMA STOP */
 	writel(0x0, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_START);

 	if (data) {
 		if (data->flags == MMC_DATA_READ) {
 			buf = (ulong) (data->dest);
 			owl_dma_config(priv, (ulong) priv->reg_base +
 				       OWL_REG_SD_DAT, buf, total);
 			invalidate_dcache_range(buf, buf + total);
 		} else {
 			buf = (ulong) (data->src);
 			owl_dma_config(priv, buf, (ulong) priv->reg_base +
 				       OWL_REG_SD_DAT, total);
 			flush_dcache_range(buf, buf + total);
 		}
 		/* DMA START */
 		writel(0x1, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_START);
 	}
 }

 static int owl_mmc_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
 			    struct mmc_data *data)
 {
 	struct owl_mmc_priv *priv = dev_get_priv(dev);
 	unsigned int cmd_rsp_mask, mode, reg;
 	int ret;

 	setbits_le32(priv->reg_base + OWL_REG_SD_EN, OWL_SD_ENABLE);

 	/* setup response */
 	mode = 0;
 	if (cmd->resp_type != MMC_RSP_NONE)
 		cmd_rsp_mask = OWL_SD_STATE_CLNR | OWL_SD_STATE_CRC7ER;
 	if (cmd->resp_type == MMC_RSP_R1) {
 		if (data) {
 			if (data->flags == MMC_DATA_READ)
 				mode |= OWL_SD_CTL_TM(4);
 			else
 				mode |= OWL_SD_CTL_TM(5);
 		} else
 			mode |= OWL_SD_CTL_TM(1);
 	} else if (cmd->resp_type == MMC_RSP_R2) {
 			mode = OWL_SD_CTL_TM(2);
 	} else if (cmd->resp_type == MMC_RSP_R1b) {
 			mode = OWL_SD_CTL_TM(3);
 	} else if (cmd->resp_type == MMC_RSP_R3) {
 			cmd_rsp_mask = OWL_SD_STATE_CLNR;
 			mode = OWL_SD_CTL_TM(1);
 	}

 	mode |= (readl(priv->reg_base + OWL_REG_SD_CTL) & (0xff << 16));

 	/* setup command */
 	writel(cmd->cmdidx, priv->reg_base + OWL_REG_SD_CMD);
 	writel(cmd->cmdarg, priv->reg_base + OWL_REG_SD_ARG);

 	/* Set LBE to send clk at the end of last read block */
 	if (data)
 		mode |= (OWL_SD_CTL_TS | OWL_SD_CTL_LBE | 0xE4000000);
 	else
 		mode |= OWL_SD_CTL_TS;

 	if (data)
 		owl_mmc_prepare_data(priv, data);

 	/* Start transfer */
 	writel(mode, priv->reg_base + OWL_REG_SD_CTL);

 	ret = readl_poll_timeout(priv->reg_base + OWL_REG_SD_CTL, reg,
 				 !(reg & OWL_SD_CTL_TS), DATA_TRANSFER_TIMEOUT);

 	if (ret == -ETIMEDOUT) {
 		debug("error: transferred data timeout\n");
 		return ret;
 	}

 	reg = readl(priv->reg_base + OWL_REG_SD_STATE) & cmd_rsp_mask;
 	if (cmd->resp_type & MMC_RSP_PRESENT) {
 		if (reg & OWL_SD_STATE_CLNR) {
 			printf("Error CMD_NO_RSP\n");
 			return -1;
 		}

 		if (reg & OWL_SD_STATE_CRC7ER) {
 			printf("Error CMD_RSP_CRC\n");
 			return -1;
 		}

 		if (cmd->resp_type & MMC_RSP_136) {
 			cmd->response[3] = readl(priv->reg_base + OWL_REG_SD_RSPBUF0);
 			cmd->response[2] = readl(priv->reg_base + OWL_REG_SD_RSPBUF1);
 			cmd->response[1] = readl(priv->reg_base + OWL_REG_SD_RSPBUF2);
 			cmd->response[0] = readl(priv->reg_base + OWL_REG_SD_RSPBUF3);
 		} else {
 			u32 rsp[2];

 			rsp[0] = readl(priv->reg_base + OWL_REG_SD_RSPBUF0);
 			rsp[1] = readl(priv->reg_base + OWL_REG_SD_RSPBUF1);
 			cmd->response[0] = rsp[1] << 24 | rsp[0] >> 8;
 			cmd->response[1] = rsp[1] >> 8;
 		}
 	}

 	if (data) {
 		ret = readl_poll_timeout(SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_START,
 					 reg, !(reg & DMA_ENABLE), DMA_TRANSFER_TIMEOUT);

 		if (ret == -ETIMEDOUT) {
 			debug("error: DMA transfer timeout\n");
 			return ret;
 		}

 		/* DMA STOP */
 		writel(0x0, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_START);
 		/* Transmission STOP */
 		while (readl(priv->reg_base + OWL_REG_SD_CTL) & OWL_SD_CTL_TS)
 			clrbits_le32(priv->reg_base + OWL_REG_SD_CTL,
 					OWL_SD_CTL_TS);
 	}

 	return 0;
 }

 static int owl_mmc_clk_set(struct owl_mmc_priv *priv, int rate)
 {
 	u32 reg, wdelay, rdelay;

 	reg = readl(priv->reg_base + OWL_REG_SD_CTL);
 	reg &= ~OWL_SD_CTL_DELAY_MSK;

 	/* Set RDELAY and WDELAY based on the clock */
 	if (rate <= 1000000)
 		rdelay = wdelay = OWL_SD_DELAY_LOW_CLK;
 	else if ((rate > 1000000) && (rate <= 26000000))
 		rdelay = wdelay = OWL_SD_DELAY_MID_CLK;
 	else if ((rate > 26000000) && (rate <= 52000000)) {
 		rdelay = OWL_SD_RDELAY_HIGH;
 		wdelay = OWL_SD_WDELAY_HIGH;
 	} else {
 		debug("SD clock rate not supported\n");
 		return -EINVAL;
 	}

 	writel(reg | OWL_SD_CTL_RDELAY(rdelay) | OWL_SD_CTL_WDELAY(wdelay),
 	       priv->reg_base + OWL_REG_SD_CTL);

 	return 0;
 }

 static int owl_mmc_set_ios(struct udevice *dev)
 {
 	struct owl_mmc_priv *priv = dev_get_priv(dev);
 	struct owl_mmc_plat *plat = dev_get_plat(dev);
 	struct mmc *mmc = &plat->mmc;
 	u32 reg, ret;

 	if (mmc->clock != priv->clock) {
 		priv->clock = mmc->clock;
 		ret = owl_mmc_clk_set(priv, mmc->clock);
 		if (IS_ERR_VALUE(ret))
 			return ret;

 		ret = clk_set_rate(&priv->clk, mmc->clock);
 		if (IS_ERR_VALUE(ret))
 			return ret;
 	}

 	if (mmc->clk_disable)
 		ret = clk_disable(&priv->clk);
 	else
 		ret = clk_enable(&priv->clk);
 	if (ret)
 		return ret;

 	/* Set the Bus width */
 	reg = readl(priv->reg_base + OWL_REG_SD_EN);
 	reg &= ~OWL_SD_EN_DATAWID_MASK;
 	if (mmc->bus_width == 8)
 		reg |= OWL_SD_EN_DATAWID(2);
 	else if (mmc->bus_width == 4)
 		reg |= OWL_SD_EN_DATAWID(1);

 	writel(reg, priv->reg_base + OWL_REG_SD_EN);

 	return 0;
 }

 static const struct dm_mmc_ops owl_mmc_ops = {
 	.send_cmd       = owl_mmc_send_cmd,
 	.set_ios        = owl_mmc_set_ios,
 };

 static int owl_mmc_probe(struct udevice *dev)
 {
 	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
 	struct owl_mmc_plat *plat = dev_get_plat(dev);
 	struct owl_mmc_priv *priv = dev_get_priv(dev);
 	struct mmc_config *cfg = &plat->cfg;
 	struct ofnode_phandle_args args;
 	int ret;
 	fdt_addr_t addr;

 	cfg->name = dev->name;
 	cfg->voltages = OWL_MMC_OCR;
 	cfg->f_min = 400000;
 	cfg->f_max = 52000000;
 	cfg->b_max = 512;
 	cfg->host_caps = MMC_MODE_HS | MMC_MODE_HS_52MHz;

 	ret = mmc_of_parse(dev, cfg);
 	if (ret)
 		return ret;

 	addr = dev_read_addr(dev);
 	if (addr == FDT_ADDR_T_NONE)
 		return -EINVAL;

 	priv->reg_base = (void *)addr;

 	ret = dev_read_phandle_with_args(dev, "dmas", "#dma-cells", 0, 0,
 					 &args);
 	if (ret)
 		return ret;

 	priv->dma_channel = (void *)ofnode_get_addr(args.node);
 	priv->dma_drq	  = args.args[0];

 	ret = clk_get_by_index(dev, 0, &priv->clk);
 	if (ret) {
 		debug("clk_get_by_index() failed: %d\n", ret);
 		return ret;
 	}

 	upriv->mmc = &plat->mmc;

 	return 0;
 }

 static int owl_mmc_bind(struct udevice *dev)
 {
 	struct owl_mmc_plat *plat = dev_get_plat(dev);

 	return mmc_bind(dev, &plat->mmc, &plat->cfg);
 }

 static const struct udevice_id owl_mmc_ids[] = {
 	{ .compatible = "actions,s700-mmc" },
 	{ .compatible = "actions,owl-mmc" },
 	{ }
 };

 U_BOOT_DRIVER(owl_mmc_drv) = {
 	.name           = "owl_mmc",
 	.id             = UCLASS_MMC,
 	.of_match       = owl_mmc_ids,
 	.bind           = owl_mmc_bind,
 	.probe          = owl_mmc_probe,
 	.ops            = &owl_mmc_ops,
 	.plat_auto      = sizeof(struct owl_mmc_plat),
 	.priv_auto      = sizeof(struct owl_mmc_priv),
 };
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* Copyright (C) 2020 Amit Singh Tomar <amittomer25@gmail.com>
	*
	* Driver for SD/MMC controller present on Actions Semi S700/S900 SoC, based
	* on Linux Driver "drivers/mmc/host/owl-mmc.c".
	*
	* Though, there is a bit (BSEL, BUS or DMA Special Channel Selection) that
	* controls the data transfer from SDx_DAT register either using CPU AHB Bus
	* or DMA channel, but seems like, it only works correctly using external DMA
	* channel, and those special bits used in this driver is picked from vendor
	* source exclusively for MMC/SD.
	*/
	#include <common.h>
	#include <clk.h>
	#include <cpu_func.h>
	#include <dm.h>
	#include <errno.h>
	#include <log.h>
	#include <mmc.h>
	#include <asm/io.h>
	#include <linux/bitops.h>
	#include <linux/delay.h>
	#include <linux/err.h>
	#include <linux/iopoll.h>

	/*
	* SDC registers
	*/
	#define OWL_REG_SD_EN 0x0000
	#define OWL_REG_SD_CTL 0x0004
	#define OWL_REG_SD_STATE 0x0008
	#define OWL_REG_SD_CMD 0x000c
	#define OWL_REG_SD_ARG 0x0010
	#define OWL_REG_SD_RSPBUF0 0x0014
	#define OWL_REG_SD_RSPBUF1 0x0018
	#define OWL_REG_SD_RSPBUF2 0x001c
	#define OWL_REG_SD_RSPBUF3 0x0020
	#define OWL_REG_SD_RSPBUF4 0x0024
	#define OWL_REG_SD_DAT 0x0028
	#define OWL_REG_SD_BLK_SIZE 0x002c
	#define OWL_REG_SD_BLK_NUM 0x0030
	#define OWL_REG_SD_BUF_SIZE 0x0034

	/* SD_EN Bits */
	#define OWL_SD_EN_RANE BIT(31)
	#define OWL_SD_EN_RESE BIT(10)
	#define OWL_SD_ENABLE BIT(7)
	#define OWL_SD_EN_BSEL BIT(6)
	#define OWL_SD_EN_DATAWID(x) (((x) & 0x3) << 0)
	#define OWL_SD_EN_DATAWID_MASK 0x03

	/* SD_CTL Bits */
	#define OWL_SD_CTL_TOUTEN BIT(31)
	#define OWL_SD_CTL_DELAY_MSK GENMASK(23, 16)
	#define OWL_SD_CTL_RDELAY(x) (((x) & 0xf) << 20)
	#define OWL_SD_CTL_WDELAY(x) (((x) & 0xf) << 16)
	#define OWL_SD_CTL_TS BIT(7)
	#define OWL_SD_CTL_LBE BIT(6)
	#define OWL_SD_CTL_TM(x) (((x) & 0xf) << 0)

	#define OWL_SD_DELAY_LOW_CLK 0x0f
	#define OWL_SD_DELAY_MID_CLK 0x0a
	#define OWL_SD_RDELAY_HIGH 0x08
	#define OWL_SD_WDELAY_HIGH 0x09

	/* SD_STATE Bits */
	#define OWL_SD_STATE_DAT0S BIT(7)
	#define OWL_SD_STATE_CLNR BIT(4)
	#define OWL_SD_STATE_CRC7ER BIT(0)

	#define OWL_MMC_OCR (MMC_VDD_32_33 \| MMC_VDD_33_34 \| \
	MMC_VDD_165_195)

	#define DATA_TRANSFER_TIMEOUT 3000000
	#define DMA_TRANSFER_TIMEOUT 5000000

	/*
	* Simple DMA transfer operations defines for MMC/SD card
	*/
	#define SD_DMA_CHANNEL(base, channel) ((base) + 0x100 + 0x100 * (channel))

	#define DMA_MODE 0x0000
	#define DMA_SOURCE 0x0004
	#define DMA_DESTINATION 0x0008
	#define DMA_FRAME_LEN 0x000C
	#define DMA_FRAME_CNT 0x0010
	#define DMA_START 0x0024

	/* DMAx_MODE */
	#define DMA_MODE_ST(x) (((x) & 0x3) << 8)
	#define DMA_MODE_ST_DEV DMA_MODE_ST(0)
	#define DMA_MODE_DT(x) (((x) & 0x3) << 10)
	#define DMA_MODE_DT_DCU DMA_MODE_DT(2)
	#define DMA_MODE_SAM(x) (((x) & 0x3) << 16)
	#define DMA_MODE_SAM_CONST DMA_MODE_SAM(0)
	#define DMA_MODE_DAM(x) (((x) & 0x3) << 18)
	#define DMA_MODE_DAM_INC DMA_MODE_DAM(1)

	#define DMA_ENABLE 0x1

	struct owl_mmc_plat {
	struct mmc_config cfg;
	struct mmc mmc;
	};

	struct owl_mmc_priv {
	void *reg_base;
	void *dma_channel;
	struct clk clk;
	unsigned int clock; /* Current clock */
	unsigned int dma_drq; /* Trigger Source */
	};

	static void owl_dma_config(struct owl_mmc_priv *priv, unsigned int src,
	unsigned int dst, unsigned int len)
	{
	unsigned int mode = priv->dma_drq;

	/* Set Source and Destination adderess mode */
	mode \|= (DMA_MODE_ST_DEV \| DMA_MODE_SAM_CONST \| DMA_MODE_DT_DCU \|
	DMA_MODE_DAM_INC);

	writel(mode, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_MODE);
	writel(src, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_SOURCE);
	writel(dst, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_DESTINATION);
	writel(len, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_FRAME_LEN);
	writel(0x1, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_FRAME_CNT);
	}

	static void owl_mmc_prepare_data(struct owl_mmc_priv *priv,
	struct mmc_data *data)
	{
	unsigned int total;
	u32 buf = 0;

	setbits_le32(priv->reg_base + OWL_REG_SD_EN, OWL_SD_EN_BSEL);

	writel(data->blocks, priv->reg_base + OWL_REG_SD_BLK_NUM);
	writel(data->blocksize, priv->reg_base + OWL_REG_SD_BLK_SIZE);
	total = data->blocksize * data->blocks;

	if (total < 512)
	writel(total, priv->reg_base + OWL_REG_SD_BUF_SIZE);
	else
	writel(512, priv->reg_base + OWL_REG_SD_BUF_SIZE);

	/* DMA STOP */
	writel(0x0, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_START);

	if (data) {
	if (data->flags == MMC_DATA_READ) {
	buf = (ulong) (data->dest);
	owl_dma_config(priv, (ulong) priv->reg_base +
	OWL_REG_SD_DAT, buf, total);
	invalidate_dcache_range(buf, buf + total);
	} else {
	buf = (ulong) (data->src);
	owl_dma_config(priv, buf, (ulong) priv->reg_base +
	OWL_REG_SD_DAT, total);
	flush_dcache_range(buf, buf + total);
	}
	/* DMA START */
	writel(0x1, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_START);
	}
	}

	static int owl_mmc_send_cmd(struct udevice dev, struct mmc_cmd cmd,
	struct mmc_data *data)
	{
	struct owl_mmc_priv *priv = dev_get_priv(dev);
	unsigned int cmd_rsp_mask, mode, reg;
	int ret;

	setbits_le32(priv->reg_base + OWL_REG_SD_EN, OWL_SD_ENABLE);

	/* setup response */
	mode = 0;
	if (cmd->resp_type != MMC_RSP_NONE)
	cmd_rsp_mask = OWL_SD_STATE_CLNR \| OWL_SD_STATE_CRC7ER;
	if (cmd->resp_type == MMC_RSP_R1) {
	if (data) {
	if (data->flags == MMC_DATA_READ)
	mode \|= OWL_SD_CTL_TM(4);
	else
	mode \|= OWL_SD_CTL_TM(5);
	} else
	mode \|= OWL_SD_CTL_TM(1);
	} else if (cmd->resp_type == MMC_RSP_R2) {
	mode = OWL_SD_CTL_TM(2);
	} else if (cmd->resp_type == MMC_RSP_R1b) {
	mode = OWL_SD_CTL_TM(3);
	} else if (cmd->resp_type == MMC_RSP_R3) {
	cmd_rsp_mask = OWL_SD_STATE_CLNR;
	mode = OWL_SD_CTL_TM(1);
	}

	mode \|= (readl(priv->reg_base + OWL_REG_SD_CTL) & (0xff << 16));

	/* setup command */
	writel(cmd->cmdidx, priv->reg_base + OWL_REG_SD_CMD);
	writel(cmd->cmdarg, priv->reg_base + OWL_REG_SD_ARG);

	/* Set LBE to send clk at the end of last read block */
	if (data)
	mode \|= (OWL_SD_CTL_TS \| OWL_SD_CTL_LBE \| 0xE4000000);
	else
	mode \|= OWL_SD_CTL_TS;

	if (data)
	owl_mmc_prepare_data(priv, data);

	/* Start transfer */
	writel(mode, priv->reg_base + OWL_REG_SD_CTL);

	ret = readl_poll_timeout(priv->reg_base + OWL_REG_SD_CTL, reg,
	!(reg & OWL_SD_CTL_TS), DATA_TRANSFER_TIMEOUT);

	if (ret == -ETIMEDOUT) {
	debug("error: transferred data timeout\n");
	return ret;
	}

	reg = readl(priv->reg_base + OWL_REG_SD_STATE) & cmd_rsp_mask;
	if (cmd->resp_type & MMC_RSP_PRESENT) {
	if (reg & OWL_SD_STATE_CLNR) {
	printf("Error CMD_NO_RSP\n");
	return -1;
	}

	if (reg & OWL_SD_STATE_CRC7ER) {
	printf("Error CMD_RSP_CRC\n");
	return -1;
	}

	if (cmd->resp_type & MMC_RSP_136) {
	cmd->response[3] = readl(priv->reg_base + OWL_REG_SD_RSPBUF0);
	cmd->response[2] = readl(priv->reg_base + OWL_REG_SD_RSPBUF1);
	cmd->response[1] = readl(priv->reg_base + OWL_REG_SD_RSPBUF2);
	cmd->response[0] = readl(priv->reg_base + OWL_REG_SD_RSPBUF3);
	} else {
	u32 rsp[2];

	rsp[0] = readl(priv->reg_base + OWL_REG_SD_RSPBUF0);
	rsp[1] = readl(priv->reg_base + OWL_REG_SD_RSPBUF1);
	cmd->response[0] = rsp[1] << 24 \| rsp[0] >> 8;
	cmd->response[1] = rsp[1] >> 8;
	}
	}

	if (data) {
	ret = readl_poll_timeout(SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_START,
	reg, !(reg & DMA_ENABLE), DMA_TRANSFER_TIMEOUT);

	if (ret == -ETIMEDOUT) {
	debug("error: DMA transfer timeout\n");
	return ret;
	}

	/* DMA STOP */
	writel(0x0, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_START);
	/* Transmission STOP */
	while (readl(priv->reg_base + OWL_REG_SD_CTL) & OWL_SD_CTL_TS)
	clrbits_le32(priv->reg_base + OWL_REG_SD_CTL,
	OWL_SD_CTL_TS);
	}

	return 0;
	}

	static int owl_mmc_clk_set(struct owl_mmc_priv *priv, int rate)
	{
	u32 reg, wdelay, rdelay;

	reg = readl(priv->reg_base + OWL_REG_SD_CTL);
	reg &= ~OWL_SD_CTL_DELAY_MSK;

	/* Set RDELAY and WDELAY based on the clock */
	if (rate <= 1000000)
	rdelay = wdelay = OWL_SD_DELAY_LOW_CLK;
	else if ((rate > 1000000) && (rate <= 26000000))
	rdelay = wdelay = OWL_SD_DELAY_MID_CLK;
	else if ((rate > 26000000) && (rate <= 52000000)) {
	rdelay = OWL_SD_RDELAY_HIGH;
	wdelay = OWL_SD_WDELAY_HIGH;
	} else {
	debug("SD clock rate not supported\n");
	return -EINVAL;
	}

	writel(reg \| OWL_SD_CTL_RDELAY(rdelay) \| OWL_SD_CTL_WDELAY(wdelay),
	priv->reg_base + OWL_REG_SD_CTL);

	return 0;
	}

	static int owl_mmc_set_ios(struct udevice *dev)
	{
	struct owl_mmc_priv *priv = dev_get_priv(dev);
	struct owl_mmc_plat *plat = dev_get_plat(dev);
	struct mmc *mmc = &plat->mmc;
	u32 reg, ret;

	if (mmc->clock != priv->clock) {
	priv->clock = mmc->clock;
	ret = owl_mmc_clk_set(priv, mmc->clock);
	if (IS_ERR_VALUE(ret))
	return ret;

	ret = clk_set_rate(&priv->clk, mmc->clock);
	if (IS_ERR_VALUE(ret))
	return ret;
	}

	if (mmc->clk_disable)
	ret = clk_disable(&priv->clk);
	else
	ret = clk_enable(&priv->clk);
	if (ret)
	return ret;

	/* Set the Bus width */
	reg = readl(priv->reg_base + OWL_REG_SD_EN);
	reg &= ~OWL_SD_EN_DATAWID_MASK;
	if (mmc->bus_width == 8)
	reg \|= OWL_SD_EN_DATAWID(2);
	else if (mmc->bus_width == 4)
	reg \|= OWL_SD_EN_DATAWID(1);

	writel(reg, priv->reg_base + OWL_REG_SD_EN);

	return 0;
	}

	static const struct dm_mmc_ops owl_mmc_ops = {
	.send_cmd = owl_mmc_send_cmd,
	.set_ios = owl_mmc_set_ios,
	};

	static int owl_mmc_probe(struct udevice *dev)
	{
	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
	struct owl_mmc_plat *plat = dev_get_plat(dev);
	struct owl_mmc_priv *priv = dev_get_priv(dev);
	struct mmc_config *cfg = &plat->cfg;
	struct ofnode_phandle_args args;
	int ret;
	fdt_addr_t addr;

	cfg->name = dev->name;
	cfg->voltages = OWL_MMC_OCR;
	cfg->f_min = 400000;
	cfg->f_max = 52000000;
	cfg->b_max = 512;
	cfg->host_caps = MMC_MODE_HS \| MMC_MODE_HS_52MHz;

	ret = mmc_of_parse(dev, cfg);
	if (ret)
	return ret;

	addr = dev_read_addr(dev);
	if (addr == FDT_ADDR_T_NONE)
	return -EINVAL;

	priv->reg_base = (void *)addr;

	ret = dev_read_phandle_with_args(dev, "dmas", "#dma-cells", 0, 0,
	&args);
	if (ret)
	return ret;

	priv->dma_channel = (void *)ofnode_get_addr(args.node);
	priv->dma_drq = args.args[0];

	ret = clk_get_by_index(dev, 0, &priv->clk);
	if (ret) {
	debug("clk_get_by_index() failed: %d\n", ret);
	return ret;
	}

	upriv->mmc = &plat->mmc;

	return 0;
	}

	static int owl_mmc_bind(struct udevice *dev)
	{
	struct owl_mmc_plat *plat = dev_get_plat(dev);

	return mmc_bind(dev, &plat->mmc, &plat->cfg);
	}

	static const struct udevice_id owl_mmc_ids[] = {
	{ .compatible = "actions,s700-mmc" },
	{ .compatible = "actions,owl-mmc" },
	{ }
	};

	U_BOOT_DRIVER(owl_mmc_drv) = {
	.name = "owl_mmc",
	.id = UCLASS_MMC,
	.of_match = owl_mmc_ids,
	.bind = owl_mmc_bind,
	.probe = owl_mmc_probe,
	.ops = &owl_mmc_ops,
	.plat_auto = sizeof(struct owl_mmc_plat),
	.priv_auto = sizeof(struct owl_mmc_priv),
	};