[PATCH v1 2/2] mci: add support for stm32mp sd/mmc controller

[Oleksij Rempel <o.rempel@pengutronix.de>]

This driver was ported from u-boot v2019.10.
Instead of devicetree compatible it is using ARM AMBA id. So, there is
no need to patch devicetree with different compatible as it was
implemented in u-boot.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
 drivers/mci/Kconfig        |   8 +
 drivers/mci/Makefile       |   1 +
 drivers/mci/stm32_sdmmc2.c | 680 +++++++++++++++++++++++++++++++++++++
 3 files changed, 689 insertions(+)
 create mode 100644 drivers/mci/stm32_sdmmc2.c

diff --git a/drivers/mci/Kconfig b/drivers/mci/Kconfig
index 08c8c84e8c..5b56031013 100644
--- a/drivers/mci/Kconfig
+++ b/drivers/mci/Kconfig
@@ -153,4 +153,12 @@ config MMC_SPI_CRC_ON
 	help
 	  Enable CRC protection for transfers
 
+config MCI_STM32_SDMMC2
+	bool "STMicroelectronics STM32H7 SD/MMC Host Controller support"
+	depends on ARM_AMBA
+	help
+	  This selects support for the SD/MMC controller on STM32H7 SoCs.
+	  If you have a board based on such a SoC and with a SD/MMC slot,
+	  say Y or M here.
+
 endif
diff --git a/drivers/mci/Makefile b/drivers/mci/Makefile
index 25a1d073dc..04c1287fee 100644
--- a/drivers/mci/Makefile
+++ b/drivers/mci/Makefile
@@ -14,3 +14,4 @@ obj-$(CONFIG_MCI_TEGRA)		+= tegra-sdmmc.o
 obj-$(CONFIG_MCI_SPI)		+= mci_spi.o
 obj-$(CONFIG_MCI_DW)		+= dw_mmc.o
 obj-$(CONFIG_MCI_MMCI)		+= mmci.o
+obj-$(CONFIG_MCI_STM32_SDMMC2)	+= stm32_sdmmc2.o
diff --git a/drivers/mci/stm32_sdmmc2.c b/drivers/mci/stm32_sdmmc2.c
new file mode 100644
index 0000000000..4fb3cbc6a5
--- /dev/null
+++ b/drivers/mci/stm32_sdmmc2.c
@@ -0,0 +1,680 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author(s): Patrice Chotard, <patrice.chotard@st.com> for STMicroelectronics.
+ */
+
+#include <common.h>
+#include <dma.h>
+#include <init.h>
+#include <linux/amba/bus.h>
+#include <linux/iopoll.h>
+#include <linux/log2.h>
+#include <linux/reset.h>
+#include <mci.h>
+
+#define DRIVER_NAME "stm32_sdmmc"
+
+/* SDMMC REGISTERS OFFSET */
+#define SDMMC_POWER		0x00	/* SDMMC power control             */
+#define SDMMC_CLKCR		0x04	/* SDMMC clock control             */
+#define SDMMC_ARG		0x08	/* SDMMC argument                  */
+#define SDMMC_CMD		0x0C	/* SDMMC command                   */
+#define SDMMC_RESP1		0x14	/* SDMMC response 1                */
+#define SDMMC_RESP2		0x18	/* SDMMC response 2                */
+#define SDMMC_RESP3		0x1C	/* SDMMC response 3                */
+#define SDMMC_RESP4		0x20	/* SDMMC response 4                */
+#define SDMMC_DTIMER		0x24	/* SDMMC data timer                */
+#define SDMMC_DLEN		0x28	/* SDMMC data length               */
+#define SDMMC_DCTRL		0x2C	/* SDMMC data control              */
+#define SDMMC_DCOUNT		0x30	/* SDMMC data counter              */
+#define SDMMC_STA		0x34	/* SDMMC status                    */
+#define SDMMC_ICR		0x38	/* SDMMC interrupt clear           */
+#define SDMMC_MASK		0x3C	/* SDMMC mask                      */
+#define SDMMC_IDMACTRL		0x50	/* SDMMC DMA control               */
+#define SDMMC_IDMABASE0		0x58	/* SDMMC DMA buffer 0 base address */
+
+/* SDMMC_POWER register */
+#define SDMMC_POWER_PWRCTRL_MASK	GENMASK(1, 0)
+#define SDMMC_POWER_PWRCTRL_OFF		0
+#define SDMMC_POWER_PWRCTRL_CYCLE	2
+#define SDMMC_POWER_PWRCTRL_ON		3
+#define SDMMC_POWER_VSWITCH		BIT(2)
+#define SDMMC_POWER_VSWITCHEN		BIT(3)
+#define SDMMC_POWER_DIRPOL		BIT(4)
+
+/* SDMMC_CLKCR register */
+#define SDMMC_CLKCR_CLKDIV		GENMASK(9, 0)
+#define SDMMC_CLKCR_CLKDIV_MAX		SDMMC_CLKCR_CLKDIV
+#define SDMMC_CLKCR_PWRSAV		BIT(12)
+#define SDMMC_CLKCR_WIDBUS_4		BIT(14)
+#define SDMMC_CLKCR_WIDBUS_8		BIT(15)
+#define SDMMC_CLKCR_NEGEDGE		BIT(16)
+#define SDMMC_CLKCR_HWFC_EN		BIT(17)
+#define SDMMC_CLKCR_DDR			BIT(18)
+#define SDMMC_CLKCR_BUSSPEED		BIT(19)
+#define SDMMC_CLKCR_SELCLKRX_MASK	GENMASK(21, 20)
+#define SDMMC_CLKCR_SELCLKRX_CK		0
+#define SDMMC_CLKCR_SELCLKRX_CKIN	BIT(20)
+#define SDMMC_CLKCR_SELCLKRX_FBCK	BIT(21)
+
+/* SDMMC_CMD register */
+#define SDMMC_CMD_CMDINDEX		GENMASK(5, 0)
+#define SDMMC_CMD_CMDTRANS		BIT(6)
+#define SDMMC_CMD_CMDSTOP		BIT(7)
+#define SDMMC_CMD_WAITRESP		GENMASK(9, 8)
+#define SDMMC_CMD_WAITRESP_0		BIT(8)
+#define SDMMC_CMD_WAITRESP_1		BIT(9)
+#define SDMMC_CMD_WAITINT		BIT(10)
+#define SDMMC_CMD_WAITPEND		BIT(11)
+#define SDMMC_CMD_CPSMEN		BIT(12)
+#define SDMMC_CMD_DTHOLD		BIT(13)
+#define SDMMC_CMD_BOOTMODE		BIT(14)
+#define SDMMC_CMD_BOOTEN		BIT(15)
+#define SDMMC_CMD_CMDSUSPEND		BIT(16)
+
+/* SDMMC_DCTRL register */
+#define SDMMC_DCTRL_DTEN		BIT(0)
+#define SDMMC_DCTRL_DTDIR		BIT(1)
+#define SDMMC_DCTRL_DTMODE		GENMASK(3, 2)
+#define SDMMC_DCTRL_DBLOCKSIZE		GENMASK(7, 4)
+#define SDMMC_DCTRL_DBLOCKSIZE_SHIFT	4
+#define SDMMC_DCTRL_RWSTART		BIT(8)
+#define SDMMC_DCTRL_RWSTOP		BIT(9)
+#define SDMMC_DCTRL_RWMOD		BIT(10)
+#define SDMMC_DCTRL_SDMMCEN		BIT(11)
+#define SDMMC_DCTRL_BOOTACKEN		BIT(12)
+#define SDMMC_DCTRL_FIFORST		BIT(13)
+
+/* SDMMC_STA register */
+#define SDMMC_STA_CCRCFAIL		BIT(0)
+#define SDMMC_STA_DCRCFAIL		BIT(1)
+#define SDMMC_STA_CTIMEOUT		BIT(2)
+#define SDMMC_STA_DTIMEOUT		BIT(3)
+#define SDMMC_STA_TXUNDERR		BIT(4)
+#define SDMMC_STA_RXOVERR		BIT(5)
+#define SDMMC_STA_CMDREND		BIT(6)
+#define SDMMC_STA_CMDSENT		BIT(7)
+#define SDMMC_STA_DATAEND		BIT(8)
+#define SDMMC_STA_DHOLD			BIT(9)
+#define SDMMC_STA_DBCKEND		BIT(10)
+#define SDMMC_STA_DABORT		BIT(11)
+#define SDMMC_STA_DPSMACT		BIT(12)
+#define SDMMC_STA_CPSMACT		BIT(13)
+#define SDMMC_STA_TXFIFOHE		BIT(14)
+#define SDMMC_STA_RXFIFOHF		BIT(15)
+#define SDMMC_STA_TXFIFOF		BIT(16)
+#define SDMMC_STA_RXFIFOF		BIT(17)
+#define SDMMC_STA_TXFIFOE		BIT(18)
+#define SDMMC_STA_RXFIFOE		BIT(19)
+#define SDMMC_STA_BUSYD0		BIT(20)
+#define SDMMC_STA_BUSYD0END		BIT(21)
+#define SDMMC_STA_SDMMCIT		BIT(22)
+#define SDMMC_STA_ACKFAIL		BIT(23)
+#define SDMMC_STA_ACKTIMEOUT		BIT(24)
+#define SDMMC_STA_VSWEND		BIT(25)
+#define SDMMC_STA_CKSTOP		BIT(26)
+#define SDMMC_STA_IDMATE		BIT(27)
+#define SDMMC_STA_IDMABTC		BIT(28)
+
+/* SDMMC_ICR register */
+#define SDMMC_ICR_CCRCFAILC		BIT(0)
+#define SDMMC_ICR_DCRCFAILC		BIT(1)
+#define SDMMC_ICR_CTIMEOUTC		BIT(2)
+#define SDMMC_ICR_DTIMEOUTC		BIT(3)
+#define SDMMC_ICR_TXUNDERRC		BIT(4)
+#define SDMMC_ICR_RXOVERRC		BIT(5)
+#define SDMMC_ICR_CMDRENDC		BIT(6)
+#define SDMMC_ICR_CMDSENTC		BIT(7)
+#define SDMMC_ICR_DATAENDC		BIT(8)
+#define SDMMC_ICR_DHOLDC		BIT(9)
+#define SDMMC_ICR_DBCKENDC		BIT(10)
+#define SDMMC_ICR_DABORTC		BIT(11)
+#define SDMMC_ICR_BUSYD0ENDC		BIT(21)
+#define SDMMC_ICR_SDMMCITC		BIT(22)
+#define SDMMC_ICR_ACKFAILC		BIT(23)
+#define SDMMC_ICR_ACKTIMEOUTC		BIT(24)
+#define SDMMC_ICR_VSWENDC		BIT(25)
+#define SDMMC_ICR_CKSTOPC		BIT(26)
+#define SDMMC_ICR_IDMATEC		BIT(27)
+#define SDMMC_ICR_IDMABTCC		BIT(28)
+#define SDMMC_ICR_STATIC_FLAGS		((GENMASK(28, 21)) | (GENMASK(11, 0)))
+
+/* SDMMC_MASK register */
+#define SDMMC_MASK_CCRCFAILIE		BIT(0)
+#define SDMMC_MASK_DCRCFAILIE		BIT(1)
+#define SDMMC_MASK_CTIMEOUTIE		BIT(2)
+#define SDMMC_MASK_DTIMEOUTIE		BIT(3)
+#define SDMMC_MASK_TXUNDERRIE		BIT(4)
+#define SDMMC_MASK_RXOVERRIE		BIT(5)
+#define SDMMC_MASK_CMDRENDIE		BIT(6)
+#define SDMMC_MASK_CMDSENTIE		BIT(7)
+#define SDMMC_MASK_DATAENDIE		BIT(8)
+#define SDMMC_MASK_DHOLDIE		BIT(9)
+#define SDMMC_MASK_DBCKENDIE		BIT(10)
+#define SDMMC_MASK_DABORTIE		BIT(11)
+#define SDMMC_MASK_TXFIFOHEIE		BIT(14)
+#define SDMMC_MASK_RXFIFOHFIE		BIT(15)
+#define SDMMC_MASK_RXFIFOFIE		BIT(17)
+#define SDMMC_MASK_TXFIFOEIE		BIT(18)
+#define SDMMC_MASK_BUSYD0ENDIE		BIT(21)
+#define SDMMC_MASK_SDMMCITIE		BIT(22)
+#define SDMMC_MASK_ACKFAILIE		BIT(23)
+#define SDMMC_MASK_ACKTIMEOUTIE		BIT(24)
+#define SDMMC_MASK_VSWENDIE		BIT(25)
+#define SDMMC_MASK_CKSTOPIE		BIT(26)
+#define SDMMC_MASK_IDMABTCIE		BIT(28)
+
+/* SDMMC_IDMACTRL register */
+#define SDMMC_IDMACTRL_IDMAEN		BIT(0)
+
+#define SDMMC_CMD_TIMEOUT		0xFFFFFFFF
+#define SDMMC_BUSYD0END_TIMEOUT_US	2000000
+
+#define IS_RISING_EDGE(reg) ((reg) & SDMMC_CLKCR_NEGEDGE ? 0 : 1)
+
+struct stm32_sdmmc2_priv {
+	void __iomem *base;
+	struct mci_host mci;
+	struct device_d	*dev;
+	struct clk *clk;
+	struct reset_control *reset_ctl;
+	u32 clk_reg_msk;
+	u32 pwr_reg_msk;
+};
+
+struct stm32_sdmmc2_ctx {
+	u32 cache_start;
+	u32 cache_end;
+	u32 data_length;
+	bool dpsm_abort;
+};
+
+#define to_mci_host(mci)	container_of(mci, struct stm32_sdmmc2_priv, mci)
+
+static void stm32_sdmmc2_start_data(struct stm32_sdmmc2_priv *priv,
+				    struct mci_data *data,
+				    struct stm32_sdmmc2_ctx *ctx)
+{
+	unsigned int num_bytes = data->blocks * data->blocksize;
+	u32 data_ctrl, idmabase0;
+
+	/* Configure the SDMMC DPSM (Data Path State Machine) */
+	data_ctrl = (__ilog2_u32(data->blocksize) <<
+		     SDMMC_DCTRL_DBLOCKSIZE_SHIFT) &
+		    SDMMC_DCTRL_DBLOCKSIZE;
+
+	if (data->flags & MMC_DATA_READ) {
+		data_ctrl |= SDMMC_DCTRL_DTDIR;
+		idmabase0 = (u32)data->dest;
+	} else {
+		idmabase0 = (u32)data->src;
+	}
+
+	/* Set the SDMMC DataLength value */
+	writel(ctx->data_length, priv->base + SDMMC_DLEN);
+
+	/* Write to SDMMC DCTRL */
+	writel(data_ctrl, priv->base + SDMMC_DCTRL);
+
+	if (data->flags & MMC_DATA_WRITE)
+		dma_sync_single_for_device((unsigned long)idmabase0,
+					   num_bytes, DMA_TO_DEVICE);
+	else
+		dma_sync_single_for_device((unsigned long)idmabase0,
+					   num_bytes, DMA_FROM_DEVICE);
+
+	/* Enable internal DMA */
+	writel(idmabase0, priv->base + SDMMC_IDMABASE0);
+	writel(SDMMC_IDMACTRL_IDMAEN, priv->base + SDMMC_IDMACTRL);
+}
+
+static void stm32_sdmmc2_start_cmd(struct stm32_sdmmc2_priv *priv,
+				   struct mci_cmd *cmd, u32 cmd_param,
+				   struct stm32_sdmmc2_ctx *ctx)
+{
+	u32 timeout = 0;
+
+	if (readl(priv->base + SDMMC_CMD) & SDMMC_CMD_CPSMEN)
+		writel(0, priv->base + SDMMC_CMD);
+
+	cmd_param |= cmd->cmdidx | SDMMC_CMD_CPSMEN;
+	if (cmd->resp_type & MMC_RSP_PRESENT) {
+		if (cmd->resp_type & MMC_RSP_136)
+			cmd_param |= SDMMC_CMD_WAITRESP;
+		else if (cmd->resp_type & MMC_RSP_CRC)
+			cmd_param |= SDMMC_CMD_WAITRESP_0;
+		else
+			cmd_param |= SDMMC_CMD_WAITRESP_1;
+	}
+
+	/*
+	 * SDMMC_DTIME must be set in two case:
+	 * - on data transfert.
+	 * - on busy request.
+	 * If not done or too short, the dtimeout flag occurs and DPSM stays
+	 * enabled/busy and waits for abort (stop transmission cmd).
+	 * Next data command is not possible whereas DPSM is activated.
+	 */
+	if (ctx->data_length) {
+		timeout = SDMMC_CMD_TIMEOUT;
+	} else {
+		writel(0, priv->base + SDMMC_DCTRL);
+
+		if (cmd->resp_type & MMC_RSP_BUSY)
+			timeout = SDMMC_CMD_TIMEOUT;
+	}
+
+	/* Set the SDMMC Data TimeOut value */
+	writel(timeout, priv->base + SDMMC_DTIMER);
+
+	/* Clear flags */
+	writel(SDMMC_ICR_STATIC_FLAGS, priv->base + SDMMC_ICR);
+
+	/* Set SDMMC argument value */
+	writel(cmd->cmdarg, priv->base + SDMMC_ARG);
+
+	/* Set SDMMC command parameters */
+	writel(cmd_param, priv->base + SDMMC_CMD);
+}
+
+static int stm32_sdmmc2_end_cmd(struct stm32_sdmmc2_priv *priv,
+				struct mci_cmd *cmd,
+				struct stm32_sdmmc2_ctx *ctx)
+{
+	u32 mask = SDMMC_STA_CTIMEOUT;
+	u32 status;
+	int ret;
+
+	if (cmd->resp_type & MMC_RSP_PRESENT) {
+		mask |= SDMMC_STA_CMDREND;
+		if (cmd->resp_type & MMC_RSP_CRC)
+			mask |= SDMMC_STA_CCRCFAIL;
+	} else {
+		mask |= SDMMC_STA_CMDSENT;
+	}
+
+	/* Polling status register */
+	ret = readl_poll_timeout(priv->base + SDMMC_STA, status, status & mask,
+				 1000000);
+
+	if (ret < 0) {
+		dev_err(priv->dev, "%s: timeout reading SDMMC_STA register\n",
+			__func__);
+		ctx->dpsm_abort = true;
+		return ret;
+	}
+
+	/* Check status */
+	if (status & SDMMC_STA_CTIMEOUT) {
+		dev_err(priv->dev, "%s: error SDMMC_STA_CTIMEOUT (0x%x) for cmd %d\n",
+			__func__, status, cmd->cmdidx);
+		ctx->dpsm_abort = true;
+		return -ETIMEDOUT;
+	}
+
+	if (status & SDMMC_STA_CCRCFAIL && cmd->resp_type & MMC_RSP_CRC) {
+		dev_err(priv->dev, "%s: error SDMMC_STA_CCRCFAIL (0x%x) for cmd %d\n",
+			__func__, status, cmd->cmdidx);
+		ctx->dpsm_abort = true;
+		return -EILSEQ;
+	}
+
+	if (status & SDMMC_STA_CMDREND && cmd->resp_type & MMC_RSP_PRESENT) {
+		cmd->response[0] = readl(priv->base + SDMMC_RESP1);
+		if (cmd->resp_type & MMC_RSP_136) {
+			cmd->response[1] = readl(priv->base + SDMMC_RESP2);
+			cmd->response[2] = readl(priv->base + SDMMC_RESP3);
+			cmd->response[3] = readl(priv->base + SDMMC_RESP4);
+		}
+
+		/* Wait for BUSYD0END flag if busy status is detected */
+		if (cmd->resp_type & MMC_RSP_BUSY &&
+		    status & SDMMC_STA_BUSYD0) {
+			mask = SDMMC_STA_DTIMEOUT | SDMMC_STA_BUSYD0END;
+
+			/* Polling status register */
+			ret = readl_poll_timeout(priv->base + SDMMC_STA,
+						 status, status & mask,
+						 SDMMC_BUSYD0END_TIMEOUT_US);
+
+			if (ret < 0) {
+				dev_err(priv->dev, "%s: timeout reading SDMMC_STA\n",
+					__func__);
+				ctx->dpsm_abort = true;
+				return ret;
+			}
+
+			if (status & SDMMC_STA_DTIMEOUT) {
+				dev_err(priv->dev, "%s: error SDMMC_STA_DTIMEOUT (0x%x)\n",
+					__func__, status);
+				ctx->dpsm_abort = true;
+				return -ETIMEDOUT;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int stm32_sdmmc2_end_data(struct stm32_sdmmc2_priv *priv,
+				 struct mci_cmd *cmd,
+				 struct mci_data *data,
+				 struct stm32_sdmmc2_ctx *ctx)
+{
+	u32 mask = SDMMC_STA_DCRCFAIL | SDMMC_STA_DTIMEOUT |
+		   SDMMC_STA_IDMATE | SDMMC_STA_DATAEND;
+	unsigned int num_bytes = data->blocks * data->blocksize;
+	u32 status;
+
+	if (data->flags & MMC_DATA_READ)
+		mask |= SDMMC_STA_RXOVERR;
+	else
+		mask |= SDMMC_STA_TXUNDERR;
+
+	status = readl(priv->base + SDMMC_STA);
+	while (!(status & mask))
+		status = readl(priv->base + SDMMC_STA);
+
+	if (data->flags & MMC_DATA_WRITE)
+		dma_sync_single_for_cpu((unsigned long)data->src,
+					num_bytes, DMA_TO_DEVICE);
+	else
+		dma_sync_single_for_cpu((unsigned long)data->dest,
+					num_bytes, DMA_FROM_DEVICE);
+
+	if (status & SDMMC_STA_DCRCFAIL) {
+		dev_err(priv->dev, "%s: error SDMMC_STA_DCRCFAIL (0x%x) for cmd %d\n",
+			__func__, status, cmd->cmdidx);
+		if (readl(priv->base + SDMMC_DCOUNT))
+			ctx->dpsm_abort = true;
+		return -EILSEQ;
+	}
+
+	if (status & SDMMC_STA_DTIMEOUT) {
+		dev_err(priv->dev, "%s: error SDMMC_STA_DTIMEOUT (0x%x) for cmd %d\n",
+			__func__, status, cmd->cmdidx);
+		ctx->dpsm_abort = true;
+		return -ETIMEDOUT;
+	}
+
+	if (status & SDMMC_STA_TXUNDERR) {
+		dev_err(priv->dev, "%s: error SDMMC_STA_TXUNDERR (0x%x) for cmd %d\n",
+			__func__, status, cmd->cmdidx);
+		ctx->dpsm_abort = true;
+		return -EIO;
+	}
+
+	if (status & SDMMC_STA_RXOVERR) {
+		dev_err(priv->dev, "%s: error SDMMC_STA_RXOVERR (0x%x) for cmd %d\n",
+			__func__, status, cmd->cmdidx);
+		ctx->dpsm_abort = true;
+		return -EIO;
+	}
+
+	if (status & SDMMC_STA_IDMATE) {
+		dev_err(priv->dev, "%s: error SDMMC_STA_IDMATE (0x%x) for cmd %d\n",
+			__func__, status, cmd->cmdidx);
+		ctx->dpsm_abort = true;
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int stm32_sdmmc2_send_cmd(struct mci_host *mci, struct mci_cmd *cmd,
+				 struct mci_data *data)
+{
+	struct stm32_sdmmc2_priv *priv = to_mci_host(mci);
+	struct stm32_sdmmc2_ctx ctx;
+	u32 cmdat = data ? SDMMC_CMD_CMDTRANS : 0;
+	int ret, retry = 3;
+
+retry_cmd:
+	ctx.data_length = 0;
+	ctx.dpsm_abort = false;
+
+	if (data) {
+		ctx.data_length = data->blocks * data->blocksize;
+		stm32_sdmmc2_start_data(priv, data, &ctx);
+	}
+
+	stm32_sdmmc2_start_cmd(priv, cmd, cmdat, &ctx);
+
+	dev_dbg(priv->dev, "%s: send cmd %d data: 0x%x @ 0x%x\n", __func__,
+		cmd->cmdidx, data ? ctx.data_length : 0, (unsigned int)data);
+
+	ret = stm32_sdmmc2_end_cmd(priv, cmd, &ctx);
+
+	if (data && !ret)
+		ret = stm32_sdmmc2_end_data(priv, cmd, data, &ctx);
+
+	/* Clear flags */
+	writel(SDMMC_ICR_STATIC_FLAGS, priv->base + SDMMC_ICR);
+	if (data)
+		writel(0x0, priv->base + SDMMC_IDMACTRL);
+
+	/*
+	 * To stop Data Path State Machine, a stop_transmission command
+	 * shall be send on cmd or data errors.
+	 */
+	if (ctx.dpsm_abort && cmd->cmdidx != MMC_CMD_STOP_TRANSMISSION) {
+		struct mci_cmd stop_cmd;
+
+		stop_cmd.cmdidx = MMC_CMD_STOP_TRANSMISSION;
+		stop_cmd.cmdarg = 0;
+		stop_cmd.resp_type = MMC_RSP_R1b;
+
+		dev_dbg(priv->dev, "%s: send STOP command to abort dpsm treatments\n",
+			__func__);
+
+		ctx.data_length = 0;
+
+		stm32_sdmmc2_start_cmd(priv, &stop_cmd,
+				       SDMMC_CMD_CMDSTOP, &ctx);
+		stm32_sdmmc2_end_cmd(priv, &stop_cmd, &ctx);
+
+		writel(SDMMC_ICR_STATIC_FLAGS, priv->base + SDMMC_ICR);
+	}
+
+	if (ret != -ETIMEDOUT && ret != 0 && retry) {
+		dev_warn(priv->dev, "%s: cmd %d failed, retrying ...\n",
+			 __func__, cmd->cmdidx);
+		retry--;
+		goto retry_cmd;
+	}
+
+	dev_dbg(priv->dev, "%s: end for CMD %d, ret = %d\n", __func__,
+		cmd->cmdidx, ret);
+
+	return ret;
+}
+
+/*
+ * Reset the SDMMC with the RCC.SDMMCxRST register bit.
+ * This will reset the SDMMC to the reset state and the CPSM and DPSM
+ * to the Idle state. SDMMC is disabled, Signals Hiz.
+ */
+static int stm32_sdmmc2_reset(struct mci_host *mci, struct device_d *mci_dev)
+{
+	struct stm32_sdmmc2_priv *priv = to_mci_host(mci);
+
+	reset_control_assert(priv->reset_ctl);
+	udelay(2);
+	reset_control_deassert(priv->reset_ctl);
+
+	/* init the needed SDMMC register after reset */
+	writel(priv->pwr_reg_msk, priv->base + SDMMC_POWER);
+
+	return 0;
+}
+
+/*
+ * Set the SDMMC in power-cycle state.
+ * This will make that the SDMMC_D[7:0],
+ * SDMMC_CMD and SDMMC_CK are driven low, to prevent the card from being
+ * supplied through the signal lines.
+ */
+static void stm32_sdmmc2_pwrcycle(struct stm32_sdmmc2_priv *priv)
+{
+	if ((readl(priv->base + SDMMC_POWER) & SDMMC_POWER_PWRCTRL_MASK) ==
+	    SDMMC_POWER_PWRCTRL_CYCLE)
+		return;
+
+	stm32_sdmmc2_reset(&priv->mci, priv->dev);
+	writel(SDMMC_POWER_PWRCTRL_CYCLE | priv->pwr_reg_msk,
+	       priv->base + SDMMC_POWER);
+}
+
+/*
+ * set the SDMMC state Power-on: the card is clocked
+ * manage the SDMMC state control:
+ * Reset => Power-Cycle => Power-Off => Power
+ *    PWRCTRL=10     PWCTRL=00    PWCTRL=11
+ */
+static void stm32_sdmmc2_pwron(struct stm32_sdmmc2_priv *priv)
+{
+	u32 pwrctrl =
+		readl(priv->base + SDMMC_POWER) &  SDMMC_POWER_PWRCTRL_MASK;
+
+	if (pwrctrl == SDMMC_POWER_PWRCTRL_ON)
+		return;
+
+	/* warning: same PWRCTRL value after reset and for power-off state
+	 * it is the reset state here = the only managed by the driver
+	 */
+	if (pwrctrl == SDMMC_POWER_PWRCTRL_OFF) {
+		writel(SDMMC_POWER_PWRCTRL_CYCLE | priv->pwr_reg_msk,
+		       priv->base + SDMMC_POWER);
+	}
+
+	/*
+	 * the remaining case is SDMMC_POWER_PWRCTRL_CYCLE
+	 * switch to Power-Off state: SDMCC disable, signals drive 1
+	 */
+	writel(SDMMC_POWER_PWRCTRL_OFF | priv->pwr_reg_msk,
+	       priv->base + SDMMC_POWER);
+
+	/* After the 1ms delay set the SDMMC to power-on */
+	mdelay(1);
+	writel(SDMMC_POWER_PWRCTRL_ON | priv->pwr_reg_msk,
+	       priv->base + SDMMC_POWER);
+
+	/* during the first 74 SDMMC_CK cycles the SDMMC is still disabled. */
+}
+
+static void stm32_sdmmc2_set_ios(struct mci_host *mci, struct mci_ios *ios)
+{
+	struct stm32_sdmmc2_priv *priv = to_mci_host(mci);
+	u32 desired = mci->clock;
+	u32 sys_clock = clk_get_rate(priv->clk);
+	u32 clk = 0;
+
+	dev_dbg(priv->dev, "%s: bus_with = %d, clock = %d\n", __func__,
+		mci->bus_width, mci->clock);
+
+	if (mci->clock)
+		stm32_sdmmc2_pwron(priv);
+	else
+		stm32_sdmmc2_pwrcycle(priv);
+
+	/*
+	 * clk_div = 0 => command and data generated on SDMMCCLK falling edge
+	 * clk_div > 0 and NEGEDGE = 0 => command and data generated on
+	 * SDMMCCLK rising edge
+	 * clk_div > 0 and NEGEDGE = 1 => command and data generated on
+	 * SDMMCCLK falling edge
+	 */
+	if (desired && (sys_clock > desired ||
+			IS_RISING_EDGE(priv->clk_reg_msk))) {
+		clk = DIV_ROUND_UP(sys_clock, 2 * desired);
+		if (clk > SDMMC_CLKCR_CLKDIV_MAX)
+			clk = SDMMC_CLKCR_CLKDIV_MAX;
+	}
+
+	if (mci->bus_width == 4)
+		clk |= SDMMC_CLKCR_WIDBUS_4;
+	if (mci->bus_width == 8)
+		clk |= SDMMC_CLKCR_WIDBUS_8;
+
+	writel(clk | priv->clk_reg_msk | SDMMC_CLKCR_HWFC_EN,
+	       priv->base + SDMMC_CLKCR);
+}
+
+static int stm32_sdmmc2_probe(struct amba_device *adev,
+			      const struct amba_id *id)
+{
+	struct device_d *dev = &adev->dev;
+	struct device_node *np = dev->device_node;
+	struct stm32_sdmmc2_priv *priv;
+	struct mci_host *mci;
+	int ret;
+
+	priv = xzalloc(sizeof(*priv));
+
+	priv->base = amba_get_mem_region(adev);
+	priv->dev = dev;
+
+	mci = &priv->mci;
+	mci->send_cmd = stm32_sdmmc2_send_cmd,
+	mci->set_ios = stm32_sdmmc2_set_ios,
+	mci->init = stm32_sdmmc2_reset;
+	mci->hw_dev = dev;
+
+	priv->clk = clk_get(dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		ret = PTR_ERR(priv->clk);
+		goto priv_free;
+	}
+
+	ret = clk_enable(priv->clk);
+	if (ret)
+		goto priv_free;
+
+	if (of_get_property(np, "st,neg-edge", NULL))
+		priv->clk_reg_msk |= SDMMC_CLKCR_NEGEDGE;
+	if (of_get_property(np, "st,sig-dir", NULL))
+		priv->pwr_reg_msk |= SDMMC_POWER_DIRPOL;
+	if (of_get_property(np, "st,use-ckin", NULL))
+		priv->clk_reg_msk |= SDMMC_CLKCR_SELCLKRX_CKIN;
+
+	priv->reset_ctl = reset_control_get(dev, NULL);
+	if (IS_ERR(priv->reset_ctl))
+		priv->reset_ctl = NULL;
+
+	mci->f_min = 400000;
+	/* f_max is taken from kernel v5.3 variant_stm32_sdmmc */
+	mci->f_max = 208000000;
+	mci->voltages = MMC_VDD_32_33 | MMC_VDD_33_34 | MMC_VDD_165_195;
+
+	return mci_register(&priv->mci);
+
+priv_free:
+	free(priv);
+
+	return ret;
+}
+
+static struct amba_id stm32_sdmmc2_ids[] = {
+	/* ST Micro STM32MP157C */
+	{
+		.id     = 0x10153180,
+		.mask	= 0xf0ffffff,
+	},
+	{ 0, 0 },
+};
+
+static struct amba_driver stm32_sdmmc2_driver = {
+	.drv		= {
+		.name	= DRIVER_NAME,
+	},
+	.probe		= stm32_sdmmc2_probe,
+	.id_table	= stm32_sdmmc2_ids,
+};
+
+static int stm32_sdmmc2_init(void)
+{
+	amba_driver_register(&stm32_sdmmc2_driver);
+	return 0;
+}
+device_initcall(stm32_sdmmc2_init);
-- 
2.23.0


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