stm32mp1: add sdmmc2 driver

This driver is for the STMicroelectronics sdmmc2 IP
which is in STM32MP1 SoC.
It uses the MMC framework, and can address either eMMC or SD-card.

Signed-off-by: Yann Gautier <yann.gautier@st.com>

1 files changed, 735 insertions, 0 deletions

diff --git a/drivers/st/mmc/stm32_sdmmc2.c b/drivers/st/mmc/stm32_sdmmc2.c
new file mode 100644
index 00000000..633a4250
--- /dev/null
+++ b/drivers/st/mmc/stm32_sdmmc2.c
@@ -0,0 +1,735 @@
+/*
+ * Copyright (c) 2018, STMicroelectronics - All Rights Reserved
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <arch_helpers.h>
+#include <assert.h>
+#include <debug.h>
+#include <delay_timer.h>
+#include <dt-bindings/clock/stm32mp1-clks.h>
+#include <dt-bindings/reset/stm32mp1-resets.h>
+#include <errno.h>
+#include <libfdt.h>
+#include <mmc.h>
+#include <mmio.h>
+#include <platform.h>
+#include <stm32_sdmmc2.h>
+#include <stm32mp1_clk.h>
+#include <stm32mp1_dt.h>
+#include <stm32mp1_rcc.h>
+#include <stm32mp1_reset.h>
+#include <string.h>
+#include <utils.h>
+
+/* Registers offsets */
+#define SDMMC_POWER			0x00U
+#define SDMMC_CLKCR			0x04U
+#define SDMMC_ARGR			0x08U
+#define SDMMC_CMDR			0x0CU
+#define SDMMC_RESPCMDR			0x10U
+#define SDMMC_RESP1R			0x14U
+#define SDMMC_RESP2R			0x18U
+#define SDMMC_RESP3R			0x1CU
+#define SDMMC_RESP4R			0x20U
+#define SDMMC_DTIMER			0x24U
+#define SDMMC_DLENR			0x28U
+#define SDMMC_DCTRLR			0x2CU
+#define SDMMC_DCNTR			0x30U
+#define SDMMC_STAR			0x34U
+#define SDMMC_ICR			0x38U
+#define SDMMC_MASKR			0x3CU
+#define SDMMC_ACKTIMER			0x40U
+#define SDMMC_IDMACTRLR			0x50U
+#define SDMMC_IDMABSIZER		0x54U
+#define SDMMC_IDMABASE0R		0x58U
+#define SDMMC_IDMABASE1R		0x5CU
+#define SDMMC_FIFOR			0x80U
+
+/* SDMMC power control register */
+#define SDMMC_POWER_PWRCTRL		GENMASK(1, 0)
+#define SDMMC_POWER_DIRPOL		BIT(4)
+
+/* SDMMC clock control register */
+#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_SELCLKRX_0		BIT(20)
+
+/* SDMMC command register */
+#define SDMMC_CMDR_CMDTRANS		BIT(6)
+#define SDMMC_CMDR_CMDSTOP		BIT(7)
+#define SDMMC_CMDR_WAITRESP		GENMASK(9, 8)
+#define SDMMC_CMDR_WAITRESP_SHORT	BIT(8)
+#define SDMMC_CMDR_WAITRESP_SHORT_NOCRC	BIT(9)
+#define SDMMC_CMDR_CPSMEN		BIT(12)
+
+/* SDMMC data control register */
+#define SDMMC_DCTRLR_DTEN		BIT(0)
+#define SDMMC_DCTRLR_DTDIR		BIT(1)
+#define SDMMC_DCTRLR_DTMODE		GENMASK(3, 2)
+#define SDMMC_DCTRLR_DBLOCKSIZE_0	BIT(4)
+#define SDMMC_DCTRLR_DBLOCKSIZE_1	BIT(5)
+#define SDMMC_DCTRLR_DBLOCKSIZE_3	BIT(7)
+#define SDMMC_DCTRLR_DBLOCKSIZE		GENMASK(7, 4)
+#define SDMMC_DCTRLR_FIFORST		BIT(13)
+
+#define SDMMC_DCTRLR_CLEAR_MASK		(SDMMC_DCTRLR_DTEN | \
+					 SDMMC_DCTRLR_DTDIR | \
+					 SDMMC_DCTRLR_DTMODE | \
+					 SDMMC_DCTRLR_DBLOCKSIZE)
+#define SDMMC_DBLOCKSIZE_8		(SDMMC_DCTRLR_DBLOCKSIZE_0 | \
+					 SDMMC_DCTRLR_DBLOCKSIZE_1)
+#define SDMMC_DBLOCKSIZE_512		(SDMMC_DCTRLR_DBLOCKSIZE_0 | \
+					 SDMMC_DCTRLR_DBLOCKSIZE_3)
+
+/* SDMMC status register */
+#define SDMMC_STAR_CCRCFAIL		BIT(0)
+#define SDMMC_STAR_DCRCFAIL		BIT(1)
+#define SDMMC_STAR_CTIMEOUT		BIT(2)
+#define SDMMC_STAR_DTIMEOUT		BIT(3)
+#define SDMMC_STAR_TXUNDERR		BIT(4)
+#define SDMMC_STAR_RXOVERR		BIT(5)
+#define SDMMC_STAR_CMDREND		BIT(6)
+#define SDMMC_STAR_CMDSENT		BIT(7)
+#define SDMMC_STAR_DATAEND		BIT(8)
+#define SDMMC_STAR_DBCKEND		BIT(10)
+#define SDMMC_STAR_DPSMACT		BIT(11)
+#define SDMMC_STAR_RXFIFOHF		BIT(15)
+#define SDMMC_STAR_RXFIFOE		BIT(19)
+#define SDMMC_STAR_IDMATE		BIT(27)
+#define SDMMC_STAR_IDMABTC		BIT(28)
+
+/* SDMMC DMA control register */
+#define SDMMC_IDMACTRLR_IDMAEN		BIT(0)
+
+#define SDMMC_STATIC_FLAGS		(SDMMC_STAR_CCRCFAIL | \
+					 SDMMC_STAR_DCRCFAIL | \
+					 SDMMC_STAR_CTIMEOUT | \
+					 SDMMC_STAR_DTIMEOUT | \
+					 SDMMC_STAR_TXUNDERR | \
+					 SDMMC_STAR_RXOVERR  | \
+					 SDMMC_STAR_CMDREND  | \
+					 SDMMC_STAR_CMDSENT  | \
+					 SDMMC_STAR_DATAEND  | \
+					 SDMMC_STAR_DBCKEND  | \
+					 SDMMC_STAR_IDMATE   | \
+					 SDMMC_STAR_IDMABTC)
+
+#define TIMEOUT_10_MS			(plat_get_syscnt_freq2() / 100U)
+#define TIMEOUT_1_S			plat_get_syscnt_freq2()
+
+#define DT_SDMMC2_COMPAT		"st,stm32-sdmmc2"
+
+static void stm32_sdmmc2_init(void);
+static int stm32_sdmmc2_send_cmd_req(struct mmc_cmd *cmd);
+static int stm32_sdmmc2_send_cmd(struct mmc_cmd *cmd);
+static int stm32_sdmmc2_set_ios(unsigned int clk, unsigned int width);
+static int stm32_sdmmc2_prepare(int lba, uintptr_t buf, size_t size);
+static int stm32_sdmmc2_read(int lba, uintptr_t buf, size_t size);
+static int stm32_sdmmc2_write(int lba, uintptr_t buf, size_t size);
+
+static const struct mmc_ops stm32_sdmmc2_ops = {
+	.init		= stm32_sdmmc2_init,
+	.send_cmd	= stm32_sdmmc2_send_cmd,
+	.set_ios	= stm32_sdmmc2_set_ios,
+	.prepare	= stm32_sdmmc2_prepare,
+	.read		= stm32_sdmmc2_read,
+	.write		= stm32_sdmmc2_write,
+};
+
+static struct stm32_sdmmc2_params sdmmc2_params;
+
+#pragma weak plat_sdmmc2_use_dma
+bool plat_sdmmc2_use_dma(unsigned int instance, unsigned int memory)
+{
+	return false;
+}
+
+static void stm32_sdmmc2_init(void)
+{
+	uint32_t clock_div;
+	uintptr_t base = sdmmc2_params.reg_base;
+
+	clock_div = div_round_up(sdmmc2_params.clk_rate,
+				 STM32MP1_MMC_INIT_FREQ * 2);
+
+	mmio_write_32(base + SDMMC_CLKCR, SDMMC_CLKCR_HWFC_EN | clock_div |
+		      sdmmc2_params.negedge |
+		      sdmmc2_params.pin_ckin);
+
+	mmio_write_32(base + SDMMC_POWER,
+		      SDMMC_POWER_PWRCTRL | sdmmc2_params.dirpol);
+
+	mdelay(1);
+}
+
+static int stm32_sdmmc2_stop_transfer(void)
+{
+	struct mmc_cmd cmd_stop;
+
+	zeromem(&cmd_stop, sizeof(struct mmc_cmd));
+
+	cmd_stop.cmd_idx = MMC_CMD(12);
+	cmd_stop.resp_type = MMC_RESPONSE_R1B;
+
+	return stm32_sdmmc2_send_cmd(&cmd_stop);
+}
+
+static int stm32_sdmmc2_send_cmd_req(struct mmc_cmd *cmd)
+{
+	uint32_t flags_cmd, status;
+	uint32_t flags_data = 0;
+	int err = 0;
+	uintptr_t base = sdmmc2_params.reg_base;
+	unsigned int cmd_reg, arg_reg, start;
+
+	if (cmd == NULL) {
+		return -EINVAL;
+	}
+
+	flags_cmd = SDMMC_STAR_CTIMEOUT;
+	arg_reg = cmd->cmd_arg;
+
+	if ((mmio_read_32(base + SDMMC_CMDR) & SDMMC_CMDR_CPSMEN) != 0U) {
+		mmio_write_32(base + SDMMC_CMDR, 0);
+	}
+
+	cmd_reg = cmd->cmd_idx | SDMMC_CMDR_CPSMEN;
+
+	if (cmd->resp_type == 0U) {
+		flags_cmd |= SDMMC_STAR_CMDSENT;
+	}
+
+	if ((cmd->resp_type & MMC_RSP_48) != 0U) {
+		if ((cmd->resp_type & MMC_RSP_136) != 0U) {
+			flags_cmd |= SDMMC_STAR_CMDREND;
+			cmd_reg |= SDMMC_CMDR_WAITRESP;
+		} else if ((cmd->resp_type & MMC_RSP_CRC) != 0U) {
+			flags_cmd |= SDMMC_STAR_CMDREND | SDMMC_STAR_CCRCFAIL;
+			cmd_reg |= SDMMC_CMDR_WAITRESP_SHORT;
+		} else {
+			flags_cmd |= SDMMC_STAR_CMDREND;
+			cmd_reg |= SDMMC_CMDR_WAITRESP_SHORT_NOCRC;
+		}
+	}
+
+	switch (cmd->cmd_idx) {
+	case MMC_CMD(1):
+		arg_reg |= OCR_POWERUP;
+		break;
+	case MMC_CMD(8):
+		if (sdmmc2_params.device_info->mmc_dev_type == MMC_IS_EMMC) {
+			cmd_reg |= SDMMC_CMDR_CMDTRANS;
+		}
+		break;
+	case MMC_CMD(12):
+		cmd_reg |= SDMMC_CMDR_CMDSTOP;
+		break;
+	case MMC_CMD(17):
+	case MMC_CMD(18):
+		cmd_reg |= SDMMC_CMDR_CMDTRANS;
+		if (sdmmc2_params.use_dma) {
+			flags_data |= SDMMC_STAR_DCRCFAIL |
+				      SDMMC_STAR_DTIMEOUT |
+				      SDMMC_STAR_DATAEND |
+				      SDMMC_STAR_RXOVERR |
+				      SDMMC_STAR_IDMATE;
+		}
+		break;
+	case MMC_ACMD(41):
+		arg_reg |= OCR_3_2_3_3 | OCR_3_3_3_4;
+		break;
+	case MMC_ACMD(51):
+		cmd_reg |= SDMMC_CMDR_CMDTRANS;
+		if (sdmmc2_params.use_dma) {
+			flags_data |= SDMMC_STAR_DCRCFAIL |
+				      SDMMC_STAR_DTIMEOUT |
+				      SDMMC_STAR_DATAEND |
+				      SDMMC_STAR_RXOVERR |
+				      SDMMC_STAR_IDMATE |
+				      SDMMC_STAR_DBCKEND;
+		}
+		break;
+	default:
+		break;
+	}
+
+	if ((cmd->resp_type & MMC_RSP_BUSY) != 0U) {
+		mmio_write_32(base + SDMMC_DTIMER, UINT32_MAX);
+	}
+
+	mmio_write_32(base + SDMMC_ARGR, arg_reg);
+
+	mmio_write_32(base + SDMMC_CMDR, cmd_reg);
+
+	start = get_timer(0);
+
+	do {
+		status = mmio_read_32(base + SDMMC_STAR);
+
+		if (get_timer(start) > TIMEOUT_10_MS) {
+			err = -ETIMEDOUT;
+			ERROR("%s: timeout 10ms (cmd = %d,status = %x)\n",
+			      __func__, cmd->cmd_idx, status);
+			break;
+		}
+	} while ((status & flags_cmd) == 0U);
+
+	if (((status & (SDMMC_STAR_CTIMEOUT | SDMMC_STAR_CCRCFAIL)) != 0U) &&
+	    (err == 0)) {
+		if ((status & SDMMC_STAR_CTIMEOUT) != 0U) {
+			err = -ETIMEDOUT;
+			/*
+			 * Those timeouts can occur, and framework will handle
+			 * the retries. CMD8 is expected to return this timeout
+			 * for eMMC
+			 */
+			if (!((cmd->cmd_idx == MMC_CMD(1)) ||
+			      (cmd->cmd_idx == MMC_CMD(13)) ||
+			      ((cmd->cmd_idx == MMC_CMD(8)) &&
+			       (cmd->resp_type == MMC_RESPONSE_R7)))) {
+				ERROR("%s: CTIMEOUT (cmd = %d,status = %x)\n",
+				      __func__, cmd->cmd_idx, status);
+			}
+		} else {
+			err = -EIO;
+			ERROR("%s: CRCFAIL (cmd = %d,status = %x)\n",
+			      __func__, cmd->cmd_idx, status);
+		}
+	}
+
+	if (((cmd_reg & SDMMC_CMDR_WAITRESP) != 0U) && (err == 0)) {
+		if ((cmd->cmd_idx == MMC_CMD(9)) &&
+		    ((cmd_reg & SDMMC_CMDR_WAITRESP) == SDMMC_CMDR_WAITRESP)) {
+			/* Need to invert response to match CSD structure */
+			cmd->resp_data[0] = mmio_read_32(base + SDMMC_RESP4R);
+			cmd->resp_data[1] = mmio_read_32(base + SDMMC_RESP3R);
+			cmd->resp_data[2] = mmio_read_32(base + SDMMC_RESP2R);
+			cmd->resp_data[3] = mmio_read_32(base + SDMMC_RESP1R);
+		} else {
+			cmd->resp_data[0] = mmio_read_32(base + SDMMC_RESP1R);
+			if ((cmd_reg & SDMMC_CMDR_WAITRESP) ==
+			    SDMMC_CMDR_WAITRESP) {
+				cmd->resp_data[1] = mmio_read_32(base +
+								 SDMMC_RESP2R);
+				cmd->resp_data[2] = mmio_read_32(base +
+								 SDMMC_RESP3R);
+				cmd->resp_data[3] = mmio_read_32(base +
+								 SDMMC_RESP4R);
+			}
+		}
+	}
+
+	if ((flags_data == 0U) || (err != 0)) {
+		if (flags_data != 0U) {
+			mmio_clrbits_32(base + SDMMC_CMDR, SDMMC_CMDR_CMDTRANS);
+		}
+
+		mmio_write_32(base + SDMMC_ICR, SDMMC_STATIC_FLAGS);
+
+		if ((err != 0) && (flags_data != 0U)) {
+			return stm32_sdmmc2_stop_transfer();
+		}
+
+		return err;
+	}
+
+	start = get_timer(0);
+
+	do {
+		status = mmio_read_32(base + SDMMC_STAR);
+
+		if (get_timer(start) > TIMEOUT_10_MS) {
+			ERROR("%s: timeout 10ms (cmd = %d,status = %x)\n",
+			      __func__, cmd->cmd_idx, status);
+			err = -ETIMEDOUT;
+			break;
+		}
+	} while ((status & flags_data) == 0U);
+
+	if ((status & (SDMMC_STAR_DTIMEOUT | SDMMC_STAR_DCRCFAIL |
+		       SDMMC_STAR_TXUNDERR | SDMMC_STAR_RXOVERR |
+		       SDMMC_STAR_IDMATE)) != 0U) {
+		ERROR("%s: Error flag (cmd = %d,status = %x)\n", __func__,
+		      cmd->cmd_idx, status);
+		err = -EIO;
+	}
+
+	mmio_write_32(base + SDMMC_ICR, SDMMC_STATIC_FLAGS);
+	mmio_clrbits_32(base + SDMMC_CMDR, SDMMC_CMDR_CMDTRANS);
+
+	if (err != 0) {
+		return stm32_sdmmc2_stop_transfer();
+	}
+
+	return err;
+}
+
+static int stm32_sdmmc2_send_cmd(struct mmc_cmd *cmd)
+{
+	int8_t retry;
+	int err = 0;
+
+	assert(cmd != NULL);
+
+	for (retry = 0; retry <= 3; retry++) {
+		err = stm32_sdmmc2_send_cmd_req(cmd);
+		if (err == 0) {
+			return err;
+		}
+
+		if ((cmd->cmd_idx == MMC_CMD(1)) ||
+		    (cmd->cmd_idx == MMC_CMD(13))) {
+			return 0; /* Retry managed by framework */
+		}
+
+		/* Command 8 is expected to fail for eMMC */
+		if (!(cmd->cmd_idx == MMC_CMD(8))) {
+			WARN(" CMD%d, Retry: %d, Error: %d\n",
+			     cmd->cmd_idx, retry, err);
+		}
+
+		udelay(10);
+	}
+
+	return err;
+}
+
+static int stm32_sdmmc2_set_ios(unsigned int clk, unsigned int width)
+{
+	uintptr_t base = sdmmc2_params.reg_base;
+	uint32_t bus_cfg = 0;
+	uint32_t clock_div, max_freq;
+	uint32_t clk_rate = sdmmc2_params.clk_rate;
+	uint32_t max_bus_freq = sdmmc2_params.device_info->max_bus_freq;
+
+	switch (width) {
+	case MMC_BUS_WIDTH_1:
+		break;
+	case MMC_BUS_WIDTH_4:
+		bus_cfg |= SDMMC_CLKCR_WIDBUS_4;
+		break;
+	case MMC_BUS_WIDTH_8:
+		bus_cfg |= SDMMC_CLKCR_WIDBUS_8;
+		break;
+	default:
+		panic();
+		break;
+	}
+
+	if (sdmmc2_params.device_info->mmc_dev_type == MMC_IS_EMMC) {
+		if (max_bus_freq >= 52000000U) {
+			max_freq = STM32MP1_EMMC_HIGH_SPEED_MAX_FREQ;
+		} else {
+			max_freq = STM32MP1_EMMC_NORMAL_SPEED_MAX_FREQ;
+		}
+	} else {
+		if (max_bus_freq >= 50000000U) {
+			max_freq = STM32MP1_SD_HIGH_SPEED_MAX_FREQ;
+		} else {
+			max_freq = STM32MP1_SD_NORMAL_SPEED_MAX_FREQ;
+		}
+	}
+
+	clock_div = div_round_up(clk_rate, max_freq * 2);
+
+	mmio_write_32(base + SDMMC_CLKCR,
+		      SDMMC_CLKCR_HWFC_EN | clock_div | bus_cfg |
+		      sdmmc2_params.negedge |
+		      sdmmc2_params.pin_ckin);
+
+	return 0;
+}
+
+static int stm32_sdmmc2_prepare(int lba, uintptr_t buf, size_t size)
+{
+	struct mmc_cmd cmd;
+	int ret;
+	uintptr_t base = sdmmc2_params.reg_base;
+	uint32_t data_ctrl = SDMMC_DCTRLR_DTDIR;
+
+	if (size == 8U) {
+		data_ctrl |= SDMMC_DBLOCKSIZE_8;
+	} else {
+		data_ctrl |= SDMMC_DBLOCKSIZE_512;
+	}
+
+	sdmmc2_params.use_dma = plat_sdmmc2_use_dma(base, buf);
+
+	if (sdmmc2_params.use_dma) {
+		inv_dcache_range(buf, size);
+	}
+
+	/* Prepare CMD 16*/
+	mmio_write_32(base + SDMMC_DTIMER, UINT32_MAX);
+
+	mmio_write_32(base + SDMMC_DLENR, 0);
+
+	mmio_clrsetbits_32(base + SDMMC_DCTRLR,
+			   SDMMC_DCTRLR_CLEAR_MASK, SDMMC_DCTRLR_DTDIR);
+
+	zeromem(&cmd, sizeof(struct mmc_cmd));
+
+	cmd.cmd_idx = MMC_CMD(16);
+	if (size > MMC_BLOCK_SIZE) {
+		cmd.cmd_arg = MMC_BLOCK_SIZE;
+	} else {
+		cmd.cmd_arg = size;
+	}
+
+	cmd.resp_type = MMC_RESPONSE_R1;
+
+	ret = stm32_sdmmc2_send_cmd(&cmd);
+	if (ret != 0) {
+		ERROR("CMD16 failed\n");
+		return ret;
+	}
+
+	/* Prepare data command */
+	mmio_write_32(base + SDMMC_DTIMER, UINT32_MAX);
+
+	mmio_write_32(base + SDMMC_DLENR, size);
+
+	if (sdmmc2_params.use_dma) {
+		mmio_write_32(base + SDMMC_IDMACTRLR,
+			      SDMMC_IDMACTRLR_IDMAEN);
+		mmio_write_32(base + SDMMC_IDMABASE0R, buf);
+
+		flush_dcache_range(buf, size);
+	}
+
+	mmio_clrsetbits_32(base + SDMMC_DCTRLR,
+			   SDMMC_DCTRLR_CLEAR_MASK,
+			   data_ctrl);
+
+	return 0;
+}
+
+static int stm32_sdmmc2_read(int lba, uintptr_t buf, size_t size)
+{
+	uint32_t error_flags = SDMMC_STAR_RXOVERR | SDMMC_STAR_DCRCFAIL |
+			       SDMMC_STAR_DTIMEOUT;
+	uint32_t flags = error_flags | SDMMC_STAR_DATAEND;
+	uint32_t status;
+	uint32_t *buffer;
+	uintptr_t base = sdmmc2_params.reg_base;
+	uintptr_t fifo_reg = base + SDMMC_FIFOR;
+	unsigned int start;
+	int ret;
+
+	/* Assert buf is 4 bytes aligned */
+	assert((buf & GENMASK(1, 0)) == 0U);
+
+	buffer = (uint32_t *)buf;
+
+	if (sdmmc2_params.use_dma) {
+		inv_dcache_range(buf, size);
+
+		return 0;
+	}
+
+	if (size <= MMC_BLOCK_SIZE) {
+		flags |= SDMMC_STAR_DBCKEND;
+	}
+
+	start = get_timer(0);
+
+	do {
+		status = mmio_read_32(base + SDMMC_STAR);
+
+		if ((status & error_flags) != 0U) {
+			ERROR("%s: Read error (status = %x)\n", __func__,
+			      status);
+			mmio_write_32(base + SDMMC_DCTRLR,
+				      SDMMC_DCTRLR_FIFORST);
+
+			mmio_write_32(base + SDMMC_ICR,
+				      SDMMC_STATIC_FLAGS);
+
+			ret = stm32_sdmmc2_stop_transfer();
+			if (ret != 0) {
+				return ret;
+			}
+
+			return -EIO;
+		}
+
+		if (get_timer(start) > TIMEOUT_1_S) {
+			ERROR("%s: timeout 1s (status = %x)\n",
+			      __func__, status);
+			mmio_write_32(base + SDMMC_ICR,
+				      SDMMC_STATIC_FLAGS);
+
+			ret = stm32_sdmmc2_stop_transfer();
+			if (ret != 0) {
+				return ret;
+			}
+
+			return -ETIMEDOUT;
+		}
+
+		if (size < (8U * sizeof(uint32_t))) {
+			if ((mmio_read_32(base + SDMMC_DCNTR) > 0U) &&
+			    ((status & SDMMC_STAR_RXFIFOE) == 0U)) {
+				*buffer = mmio_read_32(fifo_reg);
+				buffer++;
+			}
+		} else if ((status & SDMMC_STAR_RXFIFOHF) != 0U) {
+			uint32_t count;
+
+			/* Read data from SDMMC Rx FIFO */
+			for (count = 0; count < 8U; count++) {
+				*buffer = mmio_read_32(fifo_reg);
+				buffer++;
+			}
+		}
+	} while ((status & flags) == 0U);
+
+	mmio_write_32(base + SDMMC_ICR, SDMMC_STATIC_FLAGS);
+
+	if ((status & SDMMC_STAR_DPSMACT) != 0U) {
+		WARN("%s: DPSMACT=1, send stop\n", __func__);
+		return stm32_sdmmc2_stop_transfer();
+	}
+
+	return 0;
+}
+
+static int stm32_sdmmc2_write(int lba, uintptr_t buf, size_t size)
+{
+	return 0;
+}
+
+static int stm32_sdmmc2_dt_get_config(void)
+{
+	int sdmmc_node;
+	void *fdt = NULL;
+	const fdt32_t *cuint;
+
+	if (fdt_get_address(&fdt) == 0) {
+		return -FDT_ERR_NOTFOUND;
+	}
+
+	if (fdt == NULL) {
+		return -FDT_ERR_NOTFOUND;
+	}
+
+	sdmmc_node = fdt_node_offset_by_compatible(fdt, -1, DT_SDMMC2_COMPAT);
+
+	while (sdmmc_node != -FDT_ERR_NOTFOUND) {
+		cuint = fdt_getprop(fdt, sdmmc_node, "reg", NULL);
+		if (cuint == NULL) {
+			continue;
+		}
+
+		if (fdt32_to_cpu(*cuint) == sdmmc2_params.reg_base) {
+			break;
+		}
+
+		sdmmc_node = fdt_node_offset_by_compatible(fdt, sdmmc_node,
+							   DT_SDMMC2_COMPAT);
+	}
+
+	if (sdmmc_node == -FDT_ERR_NOTFOUND) {
+		return -FDT_ERR_NOTFOUND;
+	}
+
+	if (fdt_check_status(sdmmc_node) == 0) {
+		return -FDT_ERR_NOTFOUND;
+	}
+
+	if (dt_set_pinctrl_config(sdmmc_node) != 0) {
+		return -FDT_ERR_BADVALUE;
+	}
+
+	cuint = fdt_getprop(fdt, sdmmc_node, "clocks", NULL);
+	if (cuint == NULL) {
+		return -FDT_ERR_NOTFOUND;
+	}
+
+	cuint++;
+	sdmmc2_params.clock_id = fdt32_to_cpu(*cuint);
+
+	cuint = fdt_getprop(fdt, sdmmc_node, "resets", NULL);
+	if (cuint == NULL) {
+		return -FDT_ERR_NOTFOUND;
+	}
+
+	cuint++;
+	sdmmc2_params.reset_id = fdt32_to_cpu(*cuint);
+
+	if ((fdt_getprop(fdt, sdmmc_node, "st,pin-ckin", NULL)) != NULL) {
+		sdmmc2_params.pin_ckin = SDMMC_CLKCR_SELCLKRX_0;
+	}
+
+	if ((fdt_getprop(fdt, sdmmc_node, "st,dirpol", NULL)) != NULL) {
+		sdmmc2_params.dirpol = SDMMC_POWER_DIRPOL;
+	}
+
+	if ((fdt_getprop(fdt, sdmmc_node, "st,negedge", NULL)) != NULL) {
+		sdmmc2_params.negedge = SDMMC_CLKCR_NEGEDGE;
+	}
+
+	cuint = fdt_getprop(fdt, sdmmc_node, "bus-width", NULL);
+	if (cuint != NULL) {
+		switch (fdt32_to_cpu(*cuint)) {
+		case 4:
+			sdmmc2_params.bus_width = MMC_BUS_WIDTH_4;
+			break;
+
+		case 8:
+			sdmmc2_params.bus_width = MMC_BUS_WIDTH_8;
+			break;
+
+		default:
+			break;
+		}
+	}
+
+	return 0;
+}
+
+unsigned long long stm32_sdmmc2_mmc_get_device_size(void)
+{
+	return sdmmc2_params.device_info->device_size;
+}
+
+int stm32_sdmmc2_mmc_init(struct stm32_sdmmc2_params *params)
+{
+	int ret;
+
+	assert((params != NULL) &&
+	       ((params->reg_base & MMC_BLOCK_MASK) == 0U) &&
+	       ((params->bus_width == MMC_BUS_WIDTH_1) ||
+		(params->bus_width == MMC_BUS_WIDTH_4) ||
+		(params->bus_width == MMC_BUS_WIDTH_8)));
+
+	memcpy(&sdmmc2_params, params, sizeof(struct stm32_sdmmc2_params));
+
+	if (stm32_sdmmc2_dt_get_config() != 0) {
+		ERROR("%s: DT error\n", __func__);
+		return -ENOMEM;
+	}
+
+	ret = stm32mp1_clk_enable(sdmmc2_params.clock_id);
+	if (ret != 0) {
+		ERROR("%s: clock %d failed\n", __func__,
+		      sdmmc2_params.clock_id);
+		return ret;
+	}
+
+	stm32mp1_reset_assert(sdmmc2_params.reset_id);
+	udelay(2);
+	stm32mp1_reset_deassert(sdmmc2_params.reset_id);
+	mdelay(1);
+
+	sdmmc2_params.clk_rate = stm32mp1_clk_get_rate(sdmmc2_params.clock_id);
+
+	return mmc_init(&stm32_sdmmc2_ops, sdmmc2_params.clk_rate,
+			sdmmc2_params.bus_width, sdmmc2_params.flags,
+			sdmmc2_params.device_info);
+}