Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 706 insertions, 0 deletions

diff --git a/drivers/mmc/host/owl-mmc.c b/drivers/mmc/host/owl-mmc.c
new file mode 100644
index 000000000..8a40cf8a9
--- /dev/null
+++ b/drivers/mmc/host/owl-mmc.c
@@ -0,0 +1,706 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Actions Semi Owl SoCs SD/MMC driver
+ *
+ * Copyright (c) 2014 Actions Semi Inc.
+ * Copyright (c) 2019 Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+ *
+ * TODO: SDIO support
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-direction.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/slot-gpio.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/reset.h>
+#include <linux/spinlock.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_RAN_SEED(x)		(((x) & 0x3f) << 24)
+#define OWL_SD_EN_S18EN			BIT(12)
+#define OWL_SD_EN_RESE			BIT(10)
+#define OWL_SD_EN_DAT1_S		BIT(9)
+#define OWL_SD_EN_CLK_S			BIT(8)
+#define OWL_SD_ENABLE			BIT(7)
+#define OWL_SD_EN_BSEL			BIT(6)
+#define OWL_SD_EN_SDIOEN		BIT(3)
+#define OWL_SD_EN_DDREN			BIT(2)
+#define OWL_SD_EN_DATAWID(x)		(((x) & 0x3) << 0)
+
+/* SD_CTL Bits */
+#define OWL_SD_CTL_TOUTEN		BIT(31)
+#define OWL_SD_CTL_TOUTCNT(x)		(((x) & 0x7f) << 24)
+#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_CMDLEN		BIT(13)
+#define OWL_SD_CTL_SCC			BIT(12)
+#define OWL_SD_CTL_TCN(x)		(((x) & 0xf) << 8)
+#define OWL_SD_CTL_TS			BIT(7)
+#define OWL_SD_CTL_LBE			BIT(6)
+#define OWL_SD_CTL_C7EN			BIT(5)
+#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_DELAY_HIGH_CLK		0x09
+#define OWL_SD_RDELAY_DDR50		0x0a
+#define OWL_SD_WDELAY_DDR50		0x08
+
+/* SD_STATE Bits */
+#define OWL_SD_STATE_DAT1BS		BIT(18)
+#define OWL_SD_STATE_SDIOB_P		BIT(17)
+#define OWL_SD_STATE_SDIOB_EN		BIT(16)
+#define OWL_SD_STATE_TOUTE		BIT(15)
+#define OWL_SD_STATE_BAEP		BIT(14)
+#define OWL_SD_STATE_MEMRDY		BIT(12)
+#define OWL_SD_STATE_CMDS		BIT(11)
+#define OWL_SD_STATE_DAT1AS		BIT(10)
+#define OWL_SD_STATE_SDIOA_P		BIT(9)
+#define OWL_SD_STATE_SDIOA_EN		BIT(8)
+#define OWL_SD_STATE_DAT0S		BIT(7)
+#define OWL_SD_STATE_TEIE		BIT(6)
+#define OWL_SD_STATE_TEI		BIT(5)
+#define OWL_SD_STATE_CLNR		BIT(4)
+#define OWL_SD_STATE_CLC		BIT(3)
+#define OWL_SD_STATE_WC16ER		BIT(2)
+#define OWL_SD_STATE_RC16ER		BIT(1)
+#define OWL_SD_STATE_CRC7ER		BIT(0)
+
+#define OWL_CMD_TIMEOUT_MS		30000
+
+struct owl_mmc_host {
+	struct device *dev;
+	struct reset_control *reset;
+	void __iomem *base;
+	struct clk *clk;
+	struct completion sdc_complete;
+	spinlock_t lock;
+	int irq;
+	u32 clock;
+	bool ddr_50;
+
+	enum dma_data_direction dma_dir;
+	struct dma_chan *dma;
+	struct dma_async_tx_descriptor *desc;
+	struct dma_slave_config dma_cfg;
+	struct completion dma_complete;
+
+	struct mmc_host	*mmc;
+	struct mmc_request *mrq;
+	struct mmc_command *cmd;
+	struct mmc_data	*data;
+};
+
+static void owl_mmc_update_reg(void __iomem *reg, unsigned int val, bool state)
+{
+	unsigned int regval;
+
+	regval = readl(reg);
+
+	if (state)
+		regval |= val;
+	else
+		regval &= ~val;
+
+	writel(regval, reg);
+}
+
+static irqreturn_t owl_irq_handler(int irq, void *devid)
+{
+	struct owl_mmc_host *owl_host = devid;
+	unsigned long flags;
+	u32 state;
+
+	spin_lock_irqsave(&owl_host->lock, flags);
+
+	state = readl(owl_host->base + OWL_REG_SD_STATE);
+	if (state & OWL_SD_STATE_TEI) {
+		state = readl(owl_host->base + OWL_REG_SD_STATE);
+		state |= OWL_SD_STATE_TEI;
+		writel(state, owl_host->base + OWL_REG_SD_STATE);
+		complete(&owl_host->sdc_complete);
+	}
+
+	spin_unlock_irqrestore(&owl_host->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+static void owl_mmc_finish_request(struct owl_mmc_host *owl_host)
+{
+	struct mmc_request *mrq = owl_host->mrq;
+	struct mmc_data *data = mrq->data;
+
+	/* Should never be NULL */
+	WARN_ON(!mrq);
+
+	owl_host->mrq = NULL;
+
+	if (data)
+		dma_unmap_sg(owl_host->dma->device->dev, data->sg, data->sg_len,
+			     owl_host->dma_dir);
+
+	/* Finally finish request */
+	mmc_request_done(owl_host->mmc, mrq);
+}
+
+static void owl_mmc_send_cmd(struct owl_mmc_host *owl_host,
+			     struct mmc_command *cmd,
+			     struct mmc_data *data)
+{
+	unsigned long timeout;
+	u32 mode, state, resp[2];
+	u32 cmd_rsp_mask = 0;
+
+	init_completion(&owl_host->sdc_complete);
+
+	switch (mmc_resp_type(cmd)) {
+	case MMC_RSP_NONE:
+		mode = OWL_SD_CTL_TM(0);
+		break;
+
+	case 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);
+		}
+		cmd_rsp_mask = OWL_SD_STATE_CLNR | OWL_SD_STATE_CRC7ER;
+
+		break;
+
+	case MMC_RSP_R1B:
+		mode = OWL_SD_CTL_TM(3);
+		cmd_rsp_mask = OWL_SD_STATE_CLNR | OWL_SD_STATE_CRC7ER;
+		break;
+
+	case MMC_RSP_R2:
+		mode = OWL_SD_CTL_TM(2);
+		cmd_rsp_mask = OWL_SD_STATE_CLNR | OWL_SD_STATE_CRC7ER;
+		break;
+
+	case MMC_RSP_R3:
+		mode = OWL_SD_CTL_TM(1);
+		cmd_rsp_mask = OWL_SD_STATE_CLNR;
+		break;
+
+	default:
+		dev_warn(owl_host->dev, "Unknown MMC command\n");
+		cmd->error = -EINVAL;
+		return;
+	}
+
+	/* Keep current WDELAY and RDELAY */
+	mode |= (readl(owl_host->base + OWL_REG_SD_CTL) & (0xff << 16));
+
+	/* Start to send corresponding command type */
+	writel(cmd->arg, owl_host->base + OWL_REG_SD_ARG);
+	writel(cmd->opcode, owl_host->base + OWL_REG_SD_CMD);
+
+	/* Set LBE to send clk at the end of last read block */
+	if (data) {
+		mode |= (OWL_SD_CTL_TS | OWL_SD_CTL_LBE | 0x64000000);
+	} else {
+		mode &= ~(OWL_SD_CTL_TOUTEN | OWL_SD_CTL_LBE);
+		mode |= OWL_SD_CTL_TS;
+	}
+
+	owl_host->cmd = cmd;
+
+	/* Start transfer */
+	writel(mode, owl_host->base + OWL_REG_SD_CTL);
+
+	if (data)
+		return;
+
+	timeout = msecs_to_jiffies(cmd->busy_timeout ? cmd->busy_timeout :
+		OWL_CMD_TIMEOUT_MS);
+
+	if (!wait_for_completion_timeout(&owl_host->sdc_complete, timeout)) {
+		dev_err(owl_host->dev, "CMD interrupt timeout\n");
+		cmd->error = -ETIMEDOUT;
+		return;
+	}
+
+	state = readl(owl_host->base + OWL_REG_SD_STATE);
+	if (mmc_resp_type(cmd) & MMC_RSP_PRESENT) {
+		if (cmd_rsp_mask & state) {
+			if (state & OWL_SD_STATE_CLNR) {
+				dev_err(owl_host->dev, "Error CMD_NO_RSP\n");
+				cmd->error = -EILSEQ;
+				return;
+			}
+
+			if (state & OWL_SD_STATE_CRC7ER) {
+				dev_err(owl_host->dev, "Error CMD_RSP_CRC\n");
+				cmd->error = -EILSEQ;
+				return;
+			}
+		}
+
+		if (mmc_resp_type(cmd) & MMC_RSP_136) {
+			cmd->resp[3] = readl(owl_host->base + OWL_REG_SD_RSPBUF0);
+			cmd->resp[2] = readl(owl_host->base + OWL_REG_SD_RSPBUF1);
+			cmd->resp[1] = readl(owl_host->base + OWL_REG_SD_RSPBUF2);
+			cmd->resp[0] = readl(owl_host->base + OWL_REG_SD_RSPBUF3);
+		} else {
+			resp[0] = readl(owl_host->base + OWL_REG_SD_RSPBUF0);
+			resp[1] = readl(owl_host->base + OWL_REG_SD_RSPBUF1);
+			cmd->resp[0] = resp[1] << 24 | resp[0] >> 8;
+			cmd->resp[1] = resp[1] >> 8;
+		}
+	}
+}
+
+static void owl_mmc_dma_complete(void *param)
+{
+	struct owl_mmc_host *owl_host = param;
+	struct mmc_data *data = owl_host->data;
+
+	if (data)
+		complete(&owl_host->dma_complete);
+}
+
+static int owl_mmc_prepare_data(struct owl_mmc_host *owl_host,
+				struct mmc_data *data)
+{
+	u32 total;
+
+	owl_mmc_update_reg(owl_host->base + OWL_REG_SD_EN, OWL_SD_EN_BSEL,
+			   true);
+	writel(data->blocks, owl_host->base + OWL_REG_SD_BLK_NUM);
+	writel(data->blksz, owl_host->base + OWL_REG_SD_BLK_SIZE);
+	total = data->blksz * data->blocks;
+
+	if (total < 512)
+		writel(total, owl_host->base + OWL_REG_SD_BUF_SIZE);
+	else
+		writel(512, owl_host->base + OWL_REG_SD_BUF_SIZE);
+
+	if (data->flags & MMC_DATA_WRITE) {
+		owl_host->dma_dir = DMA_TO_DEVICE;
+		owl_host->dma_cfg.direction = DMA_MEM_TO_DEV;
+	} else {
+		owl_host->dma_dir = DMA_FROM_DEVICE;
+		owl_host->dma_cfg.direction = DMA_DEV_TO_MEM;
+	}
+
+	dma_map_sg(owl_host->dma->device->dev, data->sg,
+		   data->sg_len, owl_host->dma_dir);
+
+	dmaengine_slave_config(owl_host->dma, &owl_host->dma_cfg);
+	owl_host->desc = dmaengine_prep_slave_sg(owl_host->dma, data->sg,
+						 data->sg_len,
+						 owl_host->dma_cfg.direction,
+						 DMA_PREP_INTERRUPT |
+						 DMA_CTRL_ACK);
+	if (!owl_host->desc) {
+		dev_err(owl_host->dev, "Can't prepare slave sg\n");
+		return -EBUSY;
+	}
+
+	owl_host->data = data;
+
+	owl_host->desc->callback = owl_mmc_dma_complete;
+	owl_host->desc->callback_param = (void *)owl_host;
+	data->error = 0;
+
+	return 0;
+}
+
+static void owl_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+	struct owl_mmc_host *owl_host = mmc_priv(mmc);
+	struct mmc_data *data = mrq->data;
+	int ret;
+
+	owl_host->mrq = mrq;
+	if (mrq->data) {
+		ret = owl_mmc_prepare_data(owl_host, data);
+		if (ret < 0) {
+			data->error = ret;
+			goto err_out;
+		}
+
+		init_completion(&owl_host->dma_complete);
+		dmaengine_submit(owl_host->desc);
+		dma_async_issue_pending(owl_host->dma);
+	}
+
+	owl_mmc_send_cmd(owl_host, mrq->cmd, data);
+
+	if (data) {
+		if (!wait_for_completion_timeout(&owl_host->sdc_complete,
+						 10 * HZ)) {
+			dev_err(owl_host->dev, "CMD interrupt timeout\n");
+			mrq->cmd->error = -ETIMEDOUT;
+			dmaengine_terminate_all(owl_host->dma);
+			goto err_out;
+		}
+
+		if (!wait_for_completion_timeout(&owl_host->dma_complete,
+						 5 * HZ)) {
+			dev_err(owl_host->dev, "DMA interrupt timeout\n");
+			mrq->cmd->error = -ETIMEDOUT;
+			dmaengine_terminate_all(owl_host->dma);
+			goto err_out;
+		}
+
+		if (data->stop)
+			owl_mmc_send_cmd(owl_host, data->stop, NULL);
+
+		data->bytes_xfered = data->blocks * data->blksz;
+	}
+
+err_out:
+	owl_mmc_finish_request(owl_host);
+}
+
+static int owl_mmc_set_clk_rate(struct owl_mmc_host *owl_host,
+				unsigned int rate)
+{
+	unsigned long clk_rate;
+	int ret;
+	u32 reg;
+
+	reg = readl(owl_host->base + OWL_REG_SD_CTL);
+	reg &= ~OWL_SD_CTL_DELAY_MSK;
+
+	/* Set RDELAY and WDELAY based on the clock */
+	if (rate <= 1000000) {
+		writel(reg | OWL_SD_CTL_RDELAY(OWL_SD_DELAY_LOW_CLK) |
+		       OWL_SD_CTL_WDELAY(OWL_SD_DELAY_LOW_CLK),
+		       owl_host->base + OWL_REG_SD_CTL);
+	} else if ((rate > 1000000) && (rate <= 26000000)) {
+		writel(reg | OWL_SD_CTL_RDELAY(OWL_SD_DELAY_MID_CLK) |
+		       OWL_SD_CTL_WDELAY(OWL_SD_DELAY_MID_CLK),
+		       owl_host->base + OWL_REG_SD_CTL);
+	} else if ((rate > 26000000) && (rate <= 52000000) && !owl_host->ddr_50) {
+		writel(reg | OWL_SD_CTL_RDELAY(OWL_SD_DELAY_HIGH_CLK) |
+		       OWL_SD_CTL_WDELAY(OWL_SD_DELAY_HIGH_CLK),
+		       owl_host->base + OWL_REG_SD_CTL);
+	/* DDR50 mode has special delay chain */
+	} else if ((rate > 26000000) && (rate <= 52000000) && owl_host->ddr_50) {
+		writel(reg | OWL_SD_CTL_RDELAY(OWL_SD_RDELAY_DDR50) |
+		       OWL_SD_CTL_WDELAY(OWL_SD_WDELAY_DDR50),
+		       owl_host->base + OWL_REG_SD_CTL);
+	} else {
+		dev_err(owl_host->dev, "SD clock rate not supported\n");
+		return -EINVAL;
+	}
+
+	clk_rate = clk_round_rate(owl_host->clk, rate << 1);
+	ret = clk_set_rate(owl_host->clk, clk_rate);
+
+	return ret;
+}
+
+static void owl_mmc_set_clk(struct owl_mmc_host *owl_host, struct mmc_ios *ios)
+{
+	if (!ios->clock)
+		return;
+
+	owl_host->clock = ios->clock;
+	owl_mmc_set_clk_rate(owl_host, ios->clock);
+}
+
+static void owl_mmc_set_bus_width(struct owl_mmc_host *owl_host,
+				  struct mmc_ios *ios)
+{
+	u32 reg;
+
+	reg = readl(owl_host->base + OWL_REG_SD_EN);
+	reg &= ~0x03;
+	switch (ios->bus_width) {
+	case MMC_BUS_WIDTH_1:
+		break;
+	case MMC_BUS_WIDTH_4:
+		reg |= OWL_SD_EN_DATAWID(1);
+		break;
+	case MMC_BUS_WIDTH_8:
+		reg |= OWL_SD_EN_DATAWID(2);
+		break;
+	}
+
+	writel(reg, owl_host->base + OWL_REG_SD_EN);
+}
+
+static void owl_mmc_ctr_reset(struct owl_mmc_host *owl_host)
+{
+	reset_control_assert(owl_host->reset);
+	udelay(20);
+	reset_control_deassert(owl_host->reset);
+}
+
+static void owl_mmc_power_on(struct owl_mmc_host *owl_host)
+{
+	u32 mode;
+
+	init_completion(&owl_host->sdc_complete);
+
+	/* Enable transfer end IRQ */
+	owl_mmc_update_reg(owl_host->base + OWL_REG_SD_STATE,
+		       OWL_SD_STATE_TEIE, true);
+
+	/* Send init clk */
+	mode = (readl(owl_host->base + OWL_REG_SD_CTL) & (0xff << 16));
+	mode |= OWL_SD_CTL_TS | OWL_SD_CTL_TCN(5) | OWL_SD_CTL_TM(8);
+	writel(mode, owl_host->base + OWL_REG_SD_CTL);
+
+	if (!wait_for_completion_timeout(&owl_host->sdc_complete, HZ)) {
+		dev_err(owl_host->dev, "CMD interrupt timeout\n");
+		return;
+	}
+}
+
+static void owl_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	struct owl_mmc_host *owl_host = mmc_priv(mmc);
+
+	switch (ios->power_mode) {
+	case MMC_POWER_UP:
+		dev_dbg(owl_host->dev, "Powering card up\n");
+
+		/* Reset the SDC controller to clear all previous states */
+		owl_mmc_ctr_reset(owl_host);
+		clk_prepare_enable(owl_host->clk);
+		writel(OWL_SD_ENABLE | OWL_SD_EN_RESE,
+		       owl_host->base + OWL_REG_SD_EN);
+
+		break;
+
+	case MMC_POWER_ON:
+		dev_dbg(owl_host->dev, "Powering card on\n");
+		owl_mmc_power_on(owl_host);
+
+		break;
+
+	case MMC_POWER_OFF:
+		dev_dbg(owl_host->dev, "Powering card off\n");
+		clk_disable_unprepare(owl_host->clk);
+
+		return;
+
+	default:
+		dev_dbg(owl_host->dev, "Ignoring unknown card power state\n");
+		break;
+	}
+
+	if (ios->clock != owl_host->clock)
+		owl_mmc_set_clk(owl_host, ios);
+
+	owl_mmc_set_bus_width(owl_host, ios);
+
+	/* Enable DDR mode if requested */
+	if (ios->timing == MMC_TIMING_UHS_DDR50) {
+		owl_host->ddr_50 = 1;
+		owl_mmc_update_reg(owl_host->base + OWL_REG_SD_EN,
+			       OWL_SD_EN_DDREN, true);
+	} else {
+		owl_host->ddr_50 = 0;
+	}
+}
+
+static int owl_mmc_start_signal_voltage_switch(struct mmc_host *mmc,
+					       struct mmc_ios *ios)
+{
+	struct owl_mmc_host *owl_host = mmc_priv(mmc);
+
+	/* It is enough to change the pad ctrl bit for voltage switch */
+	switch (ios->signal_voltage) {
+	case MMC_SIGNAL_VOLTAGE_330:
+		owl_mmc_update_reg(owl_host->base + OWL_REG_SD_EN,
+			       OWL_SD_EN_S18EN, false);
+		break;
+	case MMC_SIGNAL_VOLTAGE_180:
+		owl_mmc_update_reg(owl_host->base + OWL_REG_SD_EN,
+			       OWL_SD_EN_S18EN, true);
+		break;
+	default:
+		return -ENOTSUPP;
+	}
+
+	return 0;
+}
+
+static const struct mmc_host_ops owl_mmc_ops = {
+	.request	= owl_mmc_request,
+	.set_ios	= owl_mmc_set_ios,
+	.get_ro		= mmc_gpio_get_ro,
+	.get_cd		= mmc_gpio_get_cd,
+	.start_signal_voltage_switch = owl_mmc_start_signal_voltage_switch,
+};
+
+static int owl_mmc_probe(struct platform_device *pdev)
+{
+	struct owl_mmc_host *owl_host;
+	struct mmc_host *mmc;
+	struct resource *res;
+	int ret;
+
+	mmc = mmc_alloc_host(sizeof(struct owl_mmc_host), &pdev->dev);
+	if (!mmc) {
+		dev_err(&pdev->dev, "mmc alloc host failed\n");
+		return -ENOMEM;
+	}
+	platform_set_drvdata(pdev, mmc);
+
+	owl_host = mmc_priv(mmc);
+	owl_host->dev = &pdev->dev;
+	owl_host->mmc = mmc;
+	spin_lock_init(&owl_host->lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	owl_host->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(owl_host->base)) {
+		dev_err(&pdev->dev, "Failed to remap registers\n");
+		ret = PTR_ERR(owl_host->base);
+		goto err_free_host;
+	}
+
+	owl_host->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(owl_host->clk)) {
+		dev_err(&pdev->dev, "No clock defined\n");
+		ret = PTR_ERR(owl_host->clk);
+		goto err_free_host;
+	}
+
+	owl_host->reset = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+	if (IS_ERR(owl_host->reset)) {
+		dev_err(&pdev->dev, "Could not get reset control\n");
+		ret = PTR_ERR(owl_host->reset);
+		goto err_free_host;
+	}
+
+	mmc->ops		= &owl_mmc_ops;
+	mmc->max_blk_count	= 512;
+	mmc->max_blk_size	= 512;
+	mmc->max_segs		= 256;
+	mmc->max_seg_size	= 262144;
+	mmc->max_req_size	= 262144;
+	/* 100kHz ~ 52MHz */
+	mmc->f_min		= 100000;
+	mmc->f_max		= 52000000;
+	mmc->caps	       |= MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED |
+				  MMC_CAP_4_BIT_DATA;
+	mmc->caps2		= (MMC_CAP2_BOOTPART_NOACC | MMC_CAP2_NO_SDIO);
+	mmc->ocr_avail		= MMC_VDD_32_33 | MMC_VDD_33_34 |
+				  MMC_VDD_165_195;
+
+	ret = mmc_of_parse(mmc);
+	if (ret)
+		goto err_free_host;
+
+	pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
+	pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
+	owl_host->dma = dma_request_chan(&pdev->dev, "mmc");
+	if (IS_ERR(owl_host->dma)) {
+		dev_err(owl_host->dev, "Failed to get external DMA channel.\n");
+		ret = PTR_ERR(owl_host->dma);
+		goto err_free_host;
+	}
+
+	dev_info(&pdev->dev, "Using %s for DMA transfers\n",
+		 dma_chan_name(owl_host->dma));
+
+	owl_host->dma_cfg.src_addr = res->start + OWL_REG_SD_DAT;
+	owl_host->dma_cfg.dst_addr = res->start + OWL_REG_SD_DAT;
+	owl_host->dma_cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	owl_host->dma_cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	owl_host->dma_cfg.device_fc = false;
+
+	owl_host->irq = platform_get_irq(pdev, 0);
+	if (owl_host->irq < 0) {
+		ret = owl_host->irq;
+		goto err_release_channel;
+	}
+
+	ret = devm_request_irq(&pdev->dev, owl_host->irq, owl_irq_handler,
+			       0, dev_name(&pdev->dev), owl_host);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request irq %d\n",
+			owl_host->irq);
+		goto err_release_channel;
+	}
+
+	ret = mmc_add_host(mmc);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to add host\n");
+		goto err_release_channel;
+	}
+
+	dev_dbg(&pdev->dev, "Owl MMC Controller Initialized\n");
+
+	return 0;
+
+err_release_channel:
+	dma_release_channel(owl_host->dma);
+err_free_host:
+	mmc_free_host(mmc);
+
+	return ret;
+}
+
+static int owl_mmc_remove(struct platform_device *pdev)
+{
+	struct mmc_host	*mmc = platform_get_drvdata(pdev);
+	struct owl_mmc_host *owl_host = mmc_priv(mmc);
+
+	mmc_remove_host(mmc);
+	disable_irq(owl_host->irq);
+	dma_release_channel(owl_host->dma);
+	mmc_free_host(mmc);
+
+	return 0;
+}
+
+static const struct of_device_id owl_mmc_of_match[] = {
+	{.compatible = "actions,owl-mmc",},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, owl_mmc_of_match);
+
+static struct platform_driver owl_mmc_driver = {
+	.driver = {
+		.name	= "owl_mmc",
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.of_match_table = owl_mmc_of_match,
+	},
+	.probe		= owl_mmc_probe,
+	.remove		= owl_mmc_remove,
+};
+module_platform_driver(owl_mmc_driver);
+
+MODULE_DESCRIPTION("Actions Semi Owl SoCs SD/MMC Driver");
+MODULE_AUTHOR("Actions Semi");
+MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
+MODULE_LICENSE("GPL");