mtd: rawnand: stm32_fmc2: add STM32 FMC2 NAND flash controller driver

The driver adds the support for the STMicroelectronics FMC2 NAND
Controller found on STM32MP SOCs.

This patch adds the polling mode, a basic mode that do not need
any DMA channels.

Only NAND_ECC_HW mode is actually supported.
The driver supports a maximum 8k page size.
The following ECC strength and step size are currently supported:
 - nand-ecc-strength = <8>, nand-ecc-step-size = <512> (BCH8)
 - nand-ecc-strength = <4>, nand-ecc-step-size = <512> (BCH4)
 - nand-ecc-strength = <1>, nand-ecc-step-size = <512> (Extended ECC
   based on Hamming)

This patch has been tested on Micron MT29F8G08ABACAH4.

Signed-off-by: Christophe Kerello <christophe.kerello@st.com>

3 files changed, 1104 insertions, 0 deletions

diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
index 7f76e5ecef..dc087ab641 100644
--- a/drivers/mtd/nand/raw/Kconfig
+++ b/drivers/mtd/nand/raw/Kconfig
@@ -256,6 +256,17 @@ config NAND_ZYNQ_USE_BOOTLOADER1_TIMINGS
 	  This flag prevent U-boot reconfigure NAND flash controller and reuse
 	  the NAND timing from 1st stage bootloader.
 
+config NAND_STM32_FMC2
+	bool "Support for NAND controller on STM32MP SoCs"
+	depends on ARCH_STM32MP
+	select SYS_NAND_SELF_INIT
+	imply CMD_NAND
+	help
+	  Enables support for NAND Flash chips on SoCs containing the FMC2
+	  NAND controller. This controller is found on STM32MP SoCs.
+	  The controller supports a maximum 8k page size and supports
+	  a maximum 8-bit correction error per sector of 512 bytes.
+
 comment "Generic NAND options"
 
 config SYS_NAND_BLOCK_SIZE
diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
index c61e3f3839..b10e718d15 100644
--- a/drivers/mtd/nand/raw/Makefile
+++ b/drivers/mtd/nand/raw/Makefile
@@ -65,6 +65,7 @@ obj-$(CONFIG_NAND_OMAP_ELM) += omap_elm.o
 obj-$(CONFIG_NAND_PLAT) += nand_plat.o
 obj-$(CONFIG_NAND_SUNXI) += sunxi_nand.o
 obj-$(CONFIG_NAND_ZYNQ) += zynq_nand.o
+obj-$(CONFIG_NAND_STM32_FMC2) += stm32_fmc2_nand.o
 
 else  # minimal SPL drivers
 
diff --git a/drivers/mtd/nand/raw/stm32_fmc2_nand.c b/drivers/mtd/nand/raw/stm32_fmc2_nand.c
new file mode 100644
index 0000000000..2bb749d7f7
--- /dev/null
+++ b/drivers/mtd/nand/raw/stm32_fmc2_nand.c
@@ -0,0 +1,1092 @@
+// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
+/*
+ * Copyright (C) STMicroelectronics 2019
+ * Author: Christophe Kerello <christophe.kerello@st.com>
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <nand.h>
+#include <reset.h>
+#include <linux/iopoll.h>
+#include <linux/ioport.h>
+
+/* Bad block marker length */
+#define FMC2_BBM_LEN			2
+
+/* ECC step size */
+#define FMC2_ECC_STEP_SIZE		512
+
+/* Command delay */
+#define FMC2_RB_DELAY_US		30
+
+/* Max chip enable */
+#define FMC2_MAX_CE			2
+
+/* Timings */
+#define FMC2_THIZ			1
+#define FMC2_TIO			8000
+#define FMC2_TSYNC			3000
+#define FMC2_PCR_TIMING_MASK		0xf
+#define FMC2_PMEM_PATT_TIMING_MASK	0xff
+
+/* FMC2 Controller Registers */
+#define FMC2_BCR1			0x0
+#define FMC2_PCR			0x80
+#define FMC2_SR				0x84
+#define FMC2_PMEM			0x88
+#define FMC2_PATT			0x8c
+#define FMC2_HECCR			0x94
+#define FMC2_BCHISR			0x254
+#define FMC2_BCHICR			0x258
+#define FMC2_BCHPBR1			0x260
+#define FMC2_BCHPBR2			0x264
+#define FMC2_BCHPBR3			0x268
+#define FMC2_BCHPBR4			0x26c
+#define FMC2_BCHDSR0			0x27c
+#define FMC2_BCHDSR1			0x280
+#define FMC2_BCHDSR2			0x284
+#define FMC2_BCHDSR3			0x288
+#define FMC2_BCHDSR4			0x28c
+
+/* Register: FMC2_BCR1 */
+#define FMC2_BCR1_FMC2EN		BIT(31)
+
+/* Register: FMC2_PCR */
+#define FMC2_PCR_PWAITEN		BIT(1)
+#define FMC2_PCR_PBKEN			BIT(2)
+#define FMC2_PCR_PWID_MASK		GENMASK(5, 4)
+#define FMC2_PCR_PWID(x)		(((x) & 0x3) << 4)
+#define FMC2_PCR_PWID_BUSWIDTH_8	0
+#define FMC2_PCR_PWID_BUSWIDTH_16	1
+#define FMC2_PCR_ECCEN			BIT(6)
+#define FMC2_PCR_ECCALG			BIT(8)
+#define FMC2_PCR_TCLR_MASK		GENMASK(12, 9)
+#define FMC2_PCR_TCLR(x)		(((x) & 0xf) << 9)
+#define FMC2_PCR_TCLR_DEFAULT		0xf
+#define FMC2_PCR_TAR_MASK		GENMASK(16, 13)
+#define FMC2_PCR_TAR(x)			(((x) & 0xf) << 13)
+#define FMC2_PCR_TAR_DEFAULT		0xf
+#define FMC2_PCR_ECCSS_MASK		GENMASK(19, 17)
+#define FMC2_PCR_ECCSS(x)		(((x) & 0x7) << 17)
+#define FMC2_PCR_ECCSS_512		1
+#define FMC2_PCR_ECCSS_2048		3
+#define FMC2_PCR_BCHECC			BIT(24)
+#define FMC2_PCR_WEN			BIT(25)
+
+/* Register: FMC2_SR */
+#define FMC2_SR_NWRF			BIT(6)
+
+/* Register: FMC2_PMEM */
+#define FMC2_PMEM_MEMSET(x)		(((x) & 0xff) << 0)
+#define FMC2_PMEM_MEMWAIT(x)		(((x) & 0xff) << 8)
+#define FMC2_PMEM_MEMHOLD(x)		(((x) & 0xff) << 16)
+#define FMC2_PMEM_MEMHIZ(x)		(((x) & 0xff) << 24)
+#define FMC2_PMEM_DEFAULT		0x0a0a0a0a
+
+/* Register: FMC2_PATT */
+#define FMC2_PATT_ATTSET(x)		(((x) & 0xff) << 0)
+#define FMC2_PATT_ATTWAIT(x)		(((x) & 0xff) << 8)
+#define FMC2_PATT_ATTHOLD(x)		(((x) & 0xff) << 16)
+#define FMC2_PATT_ATTHIZ(x)		(((x) & 0xff) << 24)
+#define FMC2_PATT_DEFAULT		0x0a0a0a0a
+
+/* Register: FMC2_BCHISR */
+#define FMC2_BCHISR_DERF		BIT(1)
+#define FMC2_BCHISR_EPBRF		BIT(4)
+
+/* Register: FMC2_BCHICR */
+#define FMC2_BCHICR_CLEAR_IRQ		GENMASK(4, 0)
+
+/* Register: FMC2_BCHDSR0 */
+#define FMC2_BCHDSR0_DUE		BIT(0)
+#define FMC2_BCHDSR0_DEF		BIT(1)
+#define FMC2_BCHDSR0_DEN_MASK		GENMASK(7, 4)
+#define FMC2_BCHDSR0_DEN_SHIFT		4
+
+/* Register: FMC2_BCHDSR1 */
+#define FMC2_BCHDSR1_EBP1_MASK		GENMASK(12, 0)
+#define FMC2_BCHDSR1_EBP2_MASK		GENMASK(28, 16)
+#define FMC2_BCHDSR1_EBP2_SHIFT		16
+
+/* Register: FMC2_BCHDSR2 */
+#define FMC2_BCHDSR2_EBP3_MASK		GENMASK(12, 0)
+#define FMC2_BCHDSR2_EBP4_MASK		GENMASK(28, 16)
+#define FMC2_BCHDSR2_EBP4_SHIFT		16
+
+/* Register: FMC2_BCHDSR3 */
+#define FMC2_BCHDSR3_EBP5_MASK		GENMASK(12, 0)
+#define FMC2_BCHDSR3_EBP6_MASK		GENMASK(28, 16)
+#define FMC2_BCHDSR3_EBP6_SHIFT		16
+
+/* Register: FMC2_BCHDSR4 */
+#define FMC2_BCHDSR4_EBP7_MASK		GENMASK(12, 0)
+#define FMC2_BCHDSR4_EBP8_MASK		GENMASK(28, 16)
+#define FMC2_BCHDSR4_EBP8_SHIFT		16
+
+#define FMC2_NSEC_PER_SEC		1000000000L
+
+enum stm32_fmc2_ecc {
+	FMC2_ECC_HAM = 1,
+	FMC2_ECC_BCH4 = 4,
+	FMC2_ECC_BCH8 = 8
+};
+
+struct stm32_fmc2_timings {
+	u8 tclr;
+	u8 tar;
+	u8 thiz;
+	u8 twait;
+	u8 thold_mem;
+	u8 tset_mem;
+	u8 thold_att;
+	u8 tset_att;
+};
+
+struct stm32_fmc2_nand {
+	struct nand_chip chip;
+	struct stm32_fmc2_timings timings;
+	int ncs;
+	int cs_used[FMC2_MAX_CE];
+};
+
+static inline struct stm32_fmc2_nand *to_fmc2_nand(struct nand_chip *chip)
+{
+	return container_of(chip, struct stm32_fmc2_nand, chip);
+}
+
+struct stm32_fmc2_nfc {
+	struct nand_hw_control base;
+	struct stm32_fmc2_nand nand;
+	struct nand_ecclayout ecclayout;
+	void __iomem *io_base;
+	void __iomem *data_base[FMC2_MAX_CE];
+	void __iomem *cmd_base[FMC2_MAX_CE];
+	void __iomem *addr_base[FMC2_MAX_CE];
+	struct clk clk;
+
+	u8 cs_assigned;
+	int cs_sel;
+};
+
+static inline struct stm32_fmc2_nfc *to_stm32_nfc(struct nand_hw_control *base)
+{
+	return container_of(base, struct stm32_fmc2_nfc, base);
+}
+
+/* Timings configuration */
+static void stm32_fmc2_timings_init(struct nand_chip *chip)
+{
+	struct stm32_fmc2_nfc *fmc2 = to_stm32_nfc(chip->controller);
+	struct stm32_fmc2_nand *nand = to_fmc2_nand(chip);
+	struct stm32_fmc2_timings *timings = &nand->timings;
+	u32 pcr = readl(fmc2->io_base + FMC2_PCR);
+	u32 pmem, patt;
+
+	/* Set tclr/tar timings */
+	pcr &= ~FMC2_PCR_TCLR_MASK;
+	pcr |= FMC2_PCR_TCLR(timings->tclr);
+	pcr &= ~FMC2_PCR_TAR_MASK;
+	pcr |= FMC2_PCR_TAR(timings->tar);
+
+	/* Set tset/twait/thold/thiz timings in common bank */
+	pmem = FMC2_PMEM_MEMSET(timings->tset_mem);
+	pmem |= FMC2_PMEM_MEMWAIT(timings->twait);
+	pmem |= FMC2_PMEM_MEMHOLD(timings->thold_mem);
+	pmem |= FMC2_PMEM_MEMHIZ(timings->thiz);
+
+	/* Set tset/twait/thold/thiz timings in attribut bank */
+	patt = FMC2_PATT_ATTSET(timings->tset_att);
+	patt |= FMC2_PATT_ATTWAIT(timings->twait);
+	patt |= FMC2_PATT_ATTHOLD(timings->thold_att);
+	patt |= FMC2_PATT_ATTHIZ(timings->thiz);
+
+	writel(pcr, fmc2->io_base + FMC2_PCR);
+	writel(pmem, fmc2->io_base + FMC2_PMEM);
+	writel(patt, fmc2->io_base + FMC2_PATT);
+}
+
+/* Controller configuration */
+static void stm32_fmc2_setup(struct nand_chip *chip)
+{
+	struct stm32_fmc2_nfc *fmc2 = to_stm32_nfc(chip->controller);
+	u32 pcr = readl(fmc2->io_base + FMC2_PCR);
+
+	/* Configure ECC algorithm (default configuration is Hamming) */
+	pcr &= ~FMC2_PCR_ECCALG;
+	pcr &= ~FMC2_PCR_BCHECC;
+	if (chip->ecc.strength == FMC2_ECC_BCH8) {
+		pcr |= FMC2_PCR_ECCALG;
+		pcr |= FMC2_PCR_BCHECC;
+	} else if (chip->ecc.strength == FMC2_ECC_BCH4) {
+		pcr |= FMC2_PCR_ECCALG;
+	}
+
+	/* Set buswidth */
+	pcr &= ~FMC2_PCR_PWID_MASK;
+	if (chip->options & NAND_BUSWIDTH_16)
+		pcr |= FMC2_PCR_PWID(FMC2_PCR_PWID_BUSWIDTH_16);
+
+	/* Set ECC sector size */
+	pcr &= ~FMC2_PCR_ECCSS_MASK;
+	pcr |= FMC2_PCR_ECCSS(FMC2_PCR_ECCSS_512);
+
+	writel(pcr, fmc2->io_base + FMC2_PCR);
+}
+
+/* Select target */
+static void stm32_fmc2_select_chip(struct mtd_info *mtd, int chipnr)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct stm32_fmc2_nfc *fmc2 = to_stm32_nfc(chip->controller);
+	struct stm32_fmc2_nand *nand = to_fmc2_nand(chip);
+
+	if (chipnr < 0 || chipnr >= nand->ncs)
+		return;
+
+	if (nand->cs_used[chipnr] == fmc2->cs_sel)
+		return;
+
+	fmc2->cs_sel = nand->cs_used[chipnr];
+	chip->IO_ADDR_R = fmc2->data_base[fmc2->cs_sel];
+	chip->IO_ADDR_W = fmc2->data_base[fmc2->cs_sel];
+
+	/* FMC2 setup routine */
+	stm32_fmc2_setup(chip);
+
+	/* Apply timings */
+	stm32_fmc2_timings_init(chip);
+}
+
+/* Set bus width to 16-bit or 8-bit */
+static void stm32_fmc2_set_buswidth_16(struct stm32_fmc2_nfc *fmc2, bool set)
+{
+	u32 pcr = readl(fmc2->io_base + FMC2_PCR);
+
+	pcr &= ~FMC2_PCR_PWID_MASK;
+	if (set)
+		pcr |= FMC2_PCR_PWID(FMC2_PCR_PWID_BUSWIDTH_16);
+	writel(pcr, fmc2->io_base + FMC2_PCR);
+}
+
+/* Enable/disable ECC */
+static void stm32_fmc2_set_ecc(struct stm32_fmc2_nfc *fmc2, bool enable)
+{
+	u32 pcr = readl(fmc2->io_base + FMC2_PCR);
+
+	pcr &= ~FMC2_PCR_ECCEN;
+	if (enable)
+		pcr |= FMC2_PCR_ECCEN;
+	writel(pcr, fmc2->io_base + FMC2_PCR);
+}
+
+/* Clear irq sources in case of bch is used */
+static inline void stm32_fmc2_clear_bch_irq(struct stm32_fmc2_nfc *fmc2)
+{
+	writel(FMC2_BCHICR_CLEAR_IRQ, fmc2->io_base + FMC2_BCHICR);
+}
+
+/* Send command and address cycles */
+static void stm32_fmc2_cmd_ctrl(struct mtd_info *mtd, int cmd,
+				unsigned int ctrl)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct stm32_fmc2_nfc *fmc2 = to_stm32_nfc(chip->controller);
+
+	if (cmd == NAND_CMD_NONE)
+		return;
+
+	if (ctrl & NAND_CLE) {
+		writeb(cmd, fmc2->cmd_base[fmc2->cs_sel]);
+		return;
+	}
+
+	writeb(cmd, fmc2->addr_base[fmc2->cs_sel]);
+}
+
+/*
+ * Enable ECC logic and reset syndrome/parity bits previously calculated
+ * Syndrome/parity bits is cleared by setting the ECCEN bit to 0
+ */
+static void stm32_fmc2_hwctl(struct mtd_info *mtd, int mode)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct stm32_fmc2_nfc *fmc2 = to_stm32_nfc(chip->controller);
+
+	stm32_fmc2_set_ecc(fmc2, false);
+
+	if (chip->ecc.strength != FMC2_ECC_HAM) {
+		u32 pcr = readl(fmc2->io_base + FMC2_PCR);
+
+		if (mode == NAND_ECC_WRITE)
+			pcr |= FMC2_PCR_WEN;
+		else
+			pcr &= ~FMC2_PCR_WEN;
+		writel(pcr, fmc2->io_base + FMC2_PCR);
+
+		stm32_fmc2_clear_bch_irq(fmc2);
+	}
+
+	stm32_fmc2_set_ecc(fmc2, true);
+}
+
+/*
+ * ECC Hamming calculation
+ * ECC is 3 bytes for 512 bytes of data (supports error correction up to
+ * max of 1-bit)
+ */
+static int stm32_fmc2_ham_calculate(struct mtd_info *mtd, const u8 *data,
+				    u8 *ecc)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct stm32_fmc2_nfc *fmc2 = to_stm32_nfc(chip->controller);
+	u32 heccr, sr;
+	int ret;
+
+	ret = readl_poll_timeout(fmc2->io_base + FMC2_SR, sr,
+				 sr & FMC2_SR_NWRF, 10000);
+	if (ret < 0) {
+		pr_err("Ham timeout\n");
+		return ret;
+	}
+
+	heccr = readl(fmc2->io_base + FMC2_HECCR);
+
+	ecc[0] = heccr;
+	ecc[1] = heccr >> 8;
+	ecc[2] = heccr >> 16;
+
+	/* Disable ecc */
+	stm32_fmc2_set_ecc(fmc2, false);
+
+	return 0;
+}
+
+static int stm32_fmc2_ham_correct(struct mtd_info *mtd, u8 *dat,
+				  u8 *read_ecc, u8 *calc_ecc)
+{
+	u8 bit_position = 0, b0, b1, b2;
+	u32 byte_addr = 0, b;
+	u32 i, shifting = 1;
+
+	/* Indicate which bit and byte is faulty (if any) */
+	b0 = read_ecc[0] ^ calc_ecc[0];
+	b1 = read_ecc[1] ^ calc_ecc[1];
+	b2 = read_ecc[2] ^ calc_ecc[2];
+	b = b0 | (b1 << 8) | (b2 << 16);
+
+	/* No errors */
+	if (likely(!b))
+		return 0;
+
+	/* Calculate bit position */
+	for (i = 0; i < 3; i++) {
+		switch (b % 4) {
+		case 2:
+			bit_position += shifting;
+		case 1:
+			break;
+		default:
+			return -EBADMSG;
+		}
+		shifting <<= 1;
+		b >>= 2;
+	}
+
+	/* Calculate byte position */
+	shifting = 1;
+	for (i = 0; i < 9; i++) {
+		switch (b % 4) {
+		case 2:
+			byte_addr += shifting;
+		case 1:
+			break;
+		default:
+			return -EBADMSG;
+		}
+		shifting <<= 1;
+		b >>= 2;
+	}
+
+	/* Flip the bit */
+	dat[byte_addr] ^= (1 << bit_position);
+
+	return 1;
+}
+
+/*
+ * ECC BCH calculation and correction
+ * ECC is 7/13 bytes for 512 bytes of data (supports error correction up to
+ * max of 4-bit/8-bit)
+ */
+
+static int stm32_fmc2_bch_calculate(struct mtd_info *mtd, const u8 *data,
+				    u8 *ecc)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct stm32_fmc2_nfc *fmc2 = to_stm32_nfc(chip->controller);
+	u32 bchpbr, bchisr;
+	int ret;
+
+	/* Wait until the BCH code is ready */
+	ret = readl_poll_timeout(fmc2->io_base + FMC2_BCHISR, bchisr,
+				 bchisr & FMC2_BCHISR_EPBRF, 10000);
+	if (ret < 0) {
+		pr_err("Bch timeout\n");
+		return ret;
+	}
+
+	/* Read parity bits */
+	bchpbr = readl(fmc2->io_base + FMC2_BCHPBR1);
+	ecc[0] = bchpbr;
+	ecc[1] = bchpbr >> 8;
+	ecc[2] = bchpbr >> 16;
+	ecc[3] = bchpbr >> 24;
+
+	bchpbr = readl(fmc2->io_base + FMC2_BCHPBR2);
+	ecc[4] = bchpbr;
+	ecc[5] = bchpbr >> 8;
+	ecc[6] = bchpbr >> 16;
+
+	if (chip->ecc.strength == FMC2_ECC_BCH8) {
+		ecc[7] = bchpbr >> 24;
+
+		bchpbr = readl(fmc2->io_base + FMC2_BCHPBR3);
+		ecc[8] = bchpbr;
+		ecc[9] = bchpbr >> 8;
+		ecc[10] = bchpbr >> 16;
+		ecc[11] = bchpbr >> 24;
+
+		bchpbr = readl(fmc2->io_base + FMC2_BCHPBR4);
+		ecc[12] = bchpbr;
+	}
+
+	/* Disable ecc */
+	stm32_fmc2_set_ecc(fmc2, false);
+
+	return 0;
+}
+
+/* BCH algorithm correction */
+static int stm32_fmc2_bch_correct(struct mtd_info *mtd, u8 *dat,
+				  u8 *read_ecc, u8 *calc_ecc)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct stm32_fmc2_nfc *fmc2 = to_stm32_nfc(chip->controller);
+	u32 bchdsr0, bchdsr1, bchdsr2, bchdsr3, bchdsr4, bchisr;
+	u16 pos[8];
+	int i, ret, den, eccsize = chip->ecc.size;
+	unsigned int nb_errs = 0;
+
+	/* Wait until the decoding error is ready */
+	ret = readl_poll_timeout(fmc2->io_base + FMC2_BCHISR, bchisr,
+				 bchisr & FMC2_BCHISR_DERF, 10000);
+	if (ret < 0) {
+		pr_err("Bch timeout\n");
+		return ret;
+	}
+
+	bchdsr0 = readl(fmc2->io_base + FMC2_BCHDSR0);
+	bchdsr1 = readl(fmc2->io_base + FMC2_BCHDSR1);
+	bchdsr2 = readl(fmc2->io_base + FMC2_BCHDSR2);
+	bchdsr3 = readl(fmc2->io_base + FMC2_BCHDSR3);
+	bchdsr4 = readl(fmc2->io_base + FMC2_BCHDSR4);
+
+	/* Disable ECC */
+	stm32_fmc2_set_ecc(fmc2, false);
+
+	/* No errors found */
+	if (likely(!(bchdsr0 & FMC2_BCHDSR0_DEF)))
+		return 0;
+
+	/* Too many errors detected */
+	if (unlikely(bchdsr0 & FMC2_BCHDSR0_DUE))
+		return -EBADMSG;
+
+	pos[0] = bchdsr1 & FMC2_BCHDSR1_EBP1_MASK;
+	pos[1] = (bchdsr1 & FMC2_BCHDSR1_EBP2_MASK) >> FMC2_BCHDSR1_EBP2_SHIFT;
+	pos[2] = bchdsr2 & FMC2_BCHDSR2_EBP3_MASK;
+	pos[3] = (bchdsr2 & FMC2_BCHDSR2_EBP4_MASK) >> FMC2_BCHDSR2_EBP4_SHIFT;
+	pos[4] = bchdsr3 & FMC2_BCHDSR3_EBP5_MASK;
+	pos[5] = (bchdsr3 & FMC2_BCHDSR3_EBP6_MASK) >> FMC2_BCHDSR3_EBP6_SHIFT;
+	pos[6] = bchdsr4 & FMC2_BCHDSR4_EBP7_MASK;
+	pos[7] = (bchdsr4 & FMC2_BCHDSR4_EBP8_MASK) >> FMC2_BCHDSR4_EBP8_SHIFT;
+
+	den = (bchdsr0 & FMC2_BCHDSR0_DEN_MASK) >> FMC2_BCHDSR0_DEN_SHIFT;
+	for (i = 0; i < den; i++) {
+		if (pos[i] < eccsize * 8) {
+			__change_bit(pos[i], (unsigned long *)dat);
+			nb_errs++;
+		}
+	}
+
+	return nb_errs;
+}
+
+static int stm32_fmc2_read_page(struct mtd_info *mtd,
+				struct nand_chip *chip, u8 *buf,
+				int oob_required, int page)
+{
+	int i, s, stat, eccsize = chip->ecc.size;
+	int eccbytes = chip->ecc.bytes;
+	int eccsteps = chip->ecc.steps;
+	int eccstrength = chip->ecc.strength;
+	u8 *p = buf;
+	u8 *ecc_calc = chip->buffers->ecccalc;
+	u8 *ecc_code = chip->buffers->ecccode;
+	unsigned int max_bitflips = 0;
+
+	for (i = mtd->writesize + FMC2_BBM_LEN, s = 0; s < eccsteps;
+	     s++, i += eccbytes, p += eccsize) {
+		chip->ecc.hwctl(mtd, NAND_ECC_READ);
+
+		/* Read the nand page sector (512 bytes) */
+		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, s * eccsize, -1);
+		chip->read_buf(mtd, p, eccsize);
+
+		/* Read the corresponding ECC bytes */
+		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, i, -1);
+		chip->read_buf(mtd, ecc_code, eccbytes);
+
+		/* Correct the data */
+		stat = chip->ecc.correct(mtd, p, ecc_code, ecc_calc);
+		if (stat == -EBADMSG)
+			/* Check for empty pages with bitflips */
+			stat = nand_check_erased_ecc_chunk(p, eccsize,
+							   ecc_code, eccbytes,
+							   NULL, 0,
+							   eccstrength);
+
+		if (stat < 0) {
+			mtd->ecc_stats.failed++;
+		} else {
+			mtd->ecc_stats.corrected += stat;
+			max_bitflips = max_t(unsigned int, max_bitflips, stat);
+		}
+	}
+
+	/* Read oob */
+	if (oob_required) {
+		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, mtd->writesize, -1);
+		chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
+	}
+
+	return max_bitflips;
+}
+
+/* Controller initialization */
+static void stm32_fmc2_init(struct stm32_fmc2_nfc *fmc2)
+{
+	u32 pcr = readl(fmc2->io_base + FMC2_PCR);
+	u32 bcr1 = readl(fmc2->io_base + FMC2_BCR1);
+
+	/* Set CS used to undefined */
+	fmc2->cs_sel = -1;
+
+	/* Enable wait feature and nand flash memory bank */
+	pcr |= FMC2_PCR_PWAITEN;
+	pcr |= FMC2_PCR_PBKEN;
+
+	/* Set buswidth to 8 bits mode for identification */
+	pcr &= ~FMC2_PCR_PWID_MASK;
+
+	/* ECC logic is disabled */
+	pcr &= ~FMC2_PCR_ECCEN;
+
+	/* Default mode */
+	pcr &= ~FMC2_PCR_ECCALG;
+	pcr &= ~FMC2_PCR_BCHECC;
+	pcr &= ~FMC2_PCR_WEN;
+
+	/* Set default ECC sector size */
+	pcr &= ~FMC2_PCR_ECCSS_MASK;
+	pcr |= FMC2_PCR_ECCSS(FMC2_PCR_ECCSS_2048);
+
+	/* Set default tclr/tar timings */
+	pcr &= ~FMC2_PCR_TCLR_MASK;
+	pcr |= FMC2_PCR_TCLR(FMC2_PCR_TCLR_DEFAULT);
+	pcr &= ~FMC2_PCR_TAR_MASK;
+	pcr |= FMC2_PCR_TAR(FMC2_PCR_TAR_DEFAULT);
+
+	/* Enable FMC2 controller */
+	bcr1 |= FMC2_BCR1_FMC2EN;
+
+	writel(bcr1, fmc2->io_base + FMC2_BCR1);
+	writel(pcr, fmc2->io_base + FMC2_PCR);
+	writel(FMC2_PMEM_DEFAULT, fmc2->io_base + FMC2_PMEM);
+	writel(FMC2_PATT_DEFAULT, fmc2->io_base + FMC2_PATT);
+}
+
+/* Controller timings */
+static void stm32_fmc2_calc_timings(struct nand_chip *chip,
+				    const struct nand_sdr_timings *sdrt)
+{
+	struct stm32_fmc2_nfc *fmc2 = to_stm32_nfc(chip->controller);
+	struct stm32_fmc2_nand *nand = to_fmc2_nand(chip);
+	struct stm32_fmc2_timings *tims = &nand->timings;
+	unsigned long hclk = clk_get_rate(&fmc2->clk);
+	unsigned long hclkp = FMC2_NSEC_PER_SEC / (hclk / 1000);
+	int tar, tclr, thiz, twait, tset_mem, tset_att, thold_mem, thold_att;
+
+	tar = hclkp;
+	if (tar < sdrt->tAR_min)
+		tar = sdrt->tAR_min;
+	tims->tar = DIV_ROUND_UP(tar, hclkp) - 1;
+	if (tims->tar > FMC2_PCR_TIMING_MASK)
+		tims->tar = FMC2_PCR_TIMING_MASK;
+
+	tclr = hclkp;
+	if (tclr < sdrt->tCLR_min)
+		tclr = sdrt->tCLR_min;
+	tims->tclr = DIV_ROUND_UP(tclr, hclkp) - 1;
+	if (tims->tclr > FMC2_PCR_TIMING_MASK)
+		tims->tclr = FMC2_PCR_TIMING_MASK;
+
+	tims->thiz = FMC2_THIZ;
+	thiz = (tims->thiz + 1) * hclkp;
+
+	/*
+	 * tWAIT > tRP
+	 * tWAIT > tWP
+	 * tWAIT > tREA + tIO
+	 */
+	twait = hclkp;
+	if (twait < sdrt->tRP_min)
+		twait = sdrt->tRP_min;
+	if (twait < sdrt->tWP_min)
+		twait = sdrt->tWP_min;
+	if (twait < sdrt->tREA_max + FMC2_TIO)
+		twait = sdrt->tREA_max + FMC2_TIO;
+	tims->twait = DIV_ROUND_UP(twait, hclkp);
+	if (tims->twait == 0)
+		tims->twait = 1;
+	else if (tims->twait > FMC2_PMEM_PATT_TIMING_MASK)
+		tims->twait = FMC2_PMEM_PATT_TIMING_MASK;
+
+	/*
+	 * tSETUP_MEM > tCS - tWAIT
+	 * tSETUP_MEM > tALS - tWAIT
+	 * tSETUP_MEM > tDS - (tWAIT - tHIZ)
+	 */
+	tset_mem = hclkp;
+	if (sdrt->tCS_min > twait && (tset_mem < sdrt->tCS_min - twait))
+		tset_mem = sdrt->tCS_min - twait;
+	if (sdrt->tALS_min > twait && (tset_mem < sdrt->tALS_min - twait))
+		tset_mem = sdrt->tALS_min - twait;
+	if (twait > thiz && (sdrt->tDS_min > twait - thiz) &&
+	    (tset_mem < sdrt->tDS_min - (twait - thiz)))
+		tset_mem = sdrt->tDS_min - (twait - thiz);
+	tims->tset_mem = DIV_ROUND_UP(tset_mem, hclkp);
+	if (tims->tset_mem == 0)
+		tims->tset_mem = 1;
+	else if (tims->tset_mem > FMC2_PMEM_PATT_TIMING_MASK)
+		tims->tset_mem = FMC2_PMEM_PATT_TIMING_MASK;
+
+	/*
+	 * tHOLD_MEM > tCH
+	 * tHOLD_MEM > tREH - tSETUP_MEM
+	 * tHOLD_MEM > max(tRC, tWC) - (tSETUP_MEM + tWAIT)
+	 */
+	thold_mem = hclkp;
+	if (thold_mem < sdrt->tCH_min)
+		thold_mem = sdrt->tCH_min;
+	if (sdrt->tREH_min > tset_mem &&
+	    (thold_mem < sdrt->tREH_min - tset_mem))
+		thold_mem = sdrt->tREH_min - tset_mem;
+	if ((sdrt->tRC_min > tset_mem + twait) &&
+	    (thold_mem < sdrt->tRC_min - (tset_mem + twait)))
+		thold_mem = sdrt->tRC_min - (tset_mem + twait);
+	if ((sdrt->tWC_min > tset_mem + twait) &&
+	    (thold_mem < sdrt->tWC_min - (tset_mem + twait)))
+		thold_mem = sdrt->tWC_min - (tset_mem + twait);
+	tims->thold_mem = DIV_ROUND_UP(thold_mem, hclkp);
+	if (tims->thold_mem == 0)
+		tims->thold_mem = 1;
+	else if (tims->thold_mem > FMC2_PMEM_PATT_TIMING_MASK)
+		tims->thold_mem = FMC2_PMEM_PATT_TIMING_MASK;
+
+	/*
+	 * tSETUP_ATT > tCS - tWAIT
+	 * tSETUP_ATT > tCLS - tWAIT
+	 * tSETUP_ATT > tALS - tWAIT
+	 * tSETUP_ATT > tRHW - tHOLD_MEM
+	 * tSETUP_ATT > tDS - (tWAIT - tHIZ)
+	 */
+	tset_att = hclkp;
+	if (sdrt->tCS_min > twait && (tset_att < sdrt->tCS_min - twait))
+		tset_att = sdrt->tCS_min - twait;
+	if (sdrt->tCLS_min > twait && (tset_att < sdrt->tCLS_min - twait))
+		tset_att = sdrt->tCLS_min - twait;
+	if (sdrt->tALS_min > twait && (tset_att < sdrt->tALS_min - twait))
+		tset_att = sdrt->tALS_min - twait;
+	if (sdrt->tRHW_min > thold_mem &&
+	    (tset_att < sdrt->tRHW_min - thold_mem))
+		tset_att = sdrt->tRHW_min - thold_mem;
+	if (twait > thiz && (sdrt->tDS_min > twait - thiz) &&
+	    (tset_att < sdrt->tDS_min - (twait - thiz)))
+		tset_att = sdrt->tDS_min - (twait - thiz);
+	tims->tset_att = DIV_ROUND_UP(tset_att, hclkp);
+	if (tims->tset_att == 0)
+		tims->tset_att = 1;
+	else if (tims->tset_att > FMC2_PMEM_PATT_TIMING_MASK)
+		tims->tset_att = FMC2_PMEM_PATT_TIMING_MASK;
+
+	/*
+	 * tHOLD_ATT > tALH
+	 * tHOLD_ATT > tCH
+	 * tHOLD_ATT > tCLH
+	 * tHOLD_ATT > tCOH
+	 * tHOLD_ATT > tDH
+	 * tHOLD_ATT > tWB + tIO + tSYNC - tSETUP_MEM
+	 * tHOLD_ATT > tADL - tSETUP_MEM
+	 * tHOLD_ATT > tWH - tSETUP_MEM
+	 * tHOLD_ATT > tWHR - tSETUP_MEM
+	 * tHOLD_ATT > tRC - (tSETUP_ATT + tWAIT)
+	 * tHOLD_ATT > tWC - (tSETUP_ATT + tWAIT)
+	 */
+	thold_att = hclkp;
+	if (thold_att < sdrt->tALH_min)
+		thold_att = sdrt->tALH_min;
+	if (thold_att < sdrt->tCH_min)
+		thold_att = sdrt->tCH_min;
+	if (thold_att < sdrt->tCLH_min)
+		thold_att = sdrt->tCLH_min;
+	if (thold_att < sdrt->tCOH_min)
+		thold_att = sdrt->tCOH_min;
+	if (thold_att < sdrt->tDH_min)
+		thold_att = sdrt->tDH_min;
+	if ((sdrt->tWB_max + FMC2_TIO + FMC2_TSYNC > tset_mem) &&
+	    (thold_att < sdrt->tWB_max + FMC2_TIO + FMC2_TSYNC - tset_mem))
+		thold_att = sdrt->tWB_max + FMC2_TIO + FMC2_TSYNC - tset_mem;
+	if (sdrt->tADL_min > tset_mem &&
+	    (thold_att < sdrt->tADL_min - tset_mem))
+		thold_att = sdrt->tADL_min - tset_mem;
+	if (sdrt->tWH_min > tset_mem &&
+	    (thold_att < sdrt->tWH_min - tset_mem))
+		thold_att = sdrt->tWH_min - tset_mem;
+	if (sdrt->tWHR_min > tset_mem &&
+	    (thold_att < sdrt->tWHR_min - tset_mem))
+		thold_att = sdrt->tWHR_min - tset_mem;
+	if ((sdrt->tRC_min > tset_att + twait) &&
+	    (thold_att < sdrt->tRC_min - (tset_att + twait)))
+		thold_att = sdrt->tRC_min - (tset_att + twait);
+	if ((sdrt->tWC_min > tset_att + twait) &&
+	    (thold_att < sdrt->tWC_min - (tset_att + twait)))
+		thold_att = sdrt->tWC_min - (tset_att + twait);
+	tims->thold_att = DIV_ROUND_UP(thold_att, hclkp);
+	if (tims->thold_att == 0)
+		tims->thold_att = 1;
+	else if (tims->thold_att > FMC2_PMEM_PATT_TIMING_MASK)
+		tims->thold_att = FMC2_PMEM_PATT_TIMING_MASK;
+}
+
+static int stm32_fmc2_setup_interface(struct mtd_info *mtd, int chipnr,
+				      const struct nand_data_interface *conf)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	const struct nand_sdr_timings *sdrt;
+
+	sdrt = nand_get_sdr_timings(conf);
+	if (IS_ERR(sdrt))
+		return PTR_ERR(sdrt);
+
+	if (chipnr == NAND_DATA_IFACE_CHECK_ONLY)
+		return 0;
+
+	stm32_fmc2_calc_timings(chip, sdrt);
+
+	/* Apply timings */
+	stm32_fmc2_timings_init(chip);
+
+	return 0;
+}
+
+/* NAND callbacks setup */
+static void stm32_fmc2_nand_callbacks_setup(struct nand_chip *chip)
+{
+	chip->ecc.hwctl = stm32_fmc2_hwctl;
+
+	/*
+	 * Specific callbacks to read/write a page depending on
+	 * the algo used (Hamming, BCH).
+	 */
+	if (chip->ecc.strength == FMC2_ECC_HAM) {
+		/* Hamming is used */
+		chip->ecc.calculate = stm32_fmc2_ham_calculate;
+		chip->ecc.correct = stm32_fmc2_ham_correct;
+		chip->ecc.bytes = chip->options & NAND_BUSWIDTH_16 ? 4 : 3;
+		chip->ecc.options |= NAND_ECC_GENERIC_ERASED_CHECK;
+		return;
+	}
+
+	/* BCH is used */
+	chip->ecc.read_page = stm32_fmc2_read_page;
+	chip->ecc.calculate = stm32_fmc2_bch_calculate;
+	chip->ecc.correct = stm32_fmc2_bch_correct;
+
+	if (chip->ecc.strength == FMC2_ECC_BCH8)
+		chip->ecc.bytes = chip->options & NAND_BUSWIDTH_16 ? 14 : 13;
+	else
+		chip->ecc.bytes = chip->options & NAND_BUSWIDTH_16 ? 8 : 7;
+}
+
+/* FMC2 caps */
+static int stm32_fmc2_calc_ecc_bytes(int step_size, int strength)
+{
+	/* Hamming */
+	if (strength == FMC2_ECC_HAM)
+		return 4;
+
+	/* BCH8 */
+	if (strength == FMC2_ECC_BCH8)
+		return 14;
+
+	/* BCH4 */
+	return 8;
+}
+
+NAND_ECC_CAPS_SINGLE(stm32_fmc2_ecc_caps, stm32_fmc2_calc_ecc_bytes,
+		     FMC2_ECC_STEP_SIZE,
+		     FMC2_ECC_HAM, FMC2_ECC_BCH4, FMC2_ECC_BCH8);
+
+/* FMC2 probe */
+static int stm32_fmc2_parse_child(struct stm32_fmc2_nfc *fmc2,
+				  ofnode node)
+{
+	struct stm32_fmc2_nand *nand = &fmc2->nand;
+	u32 cs[FMC2_MAX_CE];
+	int ret, i;
+
+	if (!ofnode_get_property(node, "reg", &nand->ncs))
+		return -EINVAL;
+
+	nand->ncs /= sizeof(u32);
+	if (!nand->ncs) {
+		pr_err("Invalid reg property size\n");
+		return -EINVAL;
+	}
+
+	ret = ofnode_read_u32_array(node, "reg", cs, nand->ncs);
+	if (ret < 0) {
+		pr_err("Could not retrieve reg property\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < nand->ncs; i++) {
+		if (cs[i] > FMC2_MAX_CE) {
+			pr_err("Invalid reg value: %d\n",
+			       nand->cs_used[i]);
+			return -EINVAL;
+		}
+
+		if (fmc2->cs_assigned & BIT(cs[i])) {
+			pr_err("Cs already assigned: %d\n",
+			       nand->cs_used[i]);
+			return -EINVAL;
+		}
+
+		fmc2->cs_assigned |= BIT(cs[i]);
+		nand->cs_used[i] = cs[i];
+	}
+
+	nand->chip.flash_node = ofnode_to_offset(node);
+
+	return 0;
+}
+
+static int stm32_fmc2_parse_dt(struct udevice *dev,
+			       struct stm32_fmc2_nfc *fmc2)
+{
+	ofnode child;
+	int ret, nchips = 0;
+
+	dev_for_each_subnode(child, dev)
+		nchips++;
+
+	if (!nchips) {
+		pr_err("NAND chip not defined\n");
+		return -EINVAL;
+	}
+
+	if (nchips > 1) {
+		pr_err("Too many NAND chips defined\n");
+		return -EINVAL;
+	}
+
+	dev_for_each_subnode(child, dev) {
+		ret = stm32_fmc2_parse_child(fmc2, child);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int stm32_fmc2_probe(struct udevice *dev)
+{
+	struct stm32_fmc2_nfc *fmc2 = dev_get_priv(dev);
+	struct stm32_fmc2_nand *nand = &fmc2->nand;
+	struct nand_chip *chip = &nand->chip;
+	struct mtd_info *mtd = &chip->mtd;
+	struct nand_ecclayout *ecclayout;
+	struct resource resource;
+	struct reset_ctl reset;
+	int oob_index, chip_cs, mem_region, ret, i;
+
+	spin_lock_init(&fmc2->controller.lock);
+	init_waitqueue_head(&fmc2->controller.wq);
+
+	ret = stm32_fmc2_parse_dt(dev, fmc2);
+	if (ret)
+		return ret;
+
+	/* Get resources */
+	ret = dev_read_resource(dev, 0, &resource);
+	if (ret) {
+		pr_err("Resource io_base not found");
+		return ret;
+	}
+	fmc2->io_base = (void __iomem *)resource.start;
+
+	for (chip_cs = 0, mem_region = 1; chip_cs < FMC2_MAX_CE;
+	     chip_cs++, mem_region += 3) {
+		if (!(fmc2->cs_assigned & BIT(chip_cs)))
+			continue;
+
+		ret = dev_read_resource(dev, mem_region, &resource);
+		if (ret) {
+			pr_err("Resource data_base not found for cs%d",
+			       chip_cs);
+			return ret;
+		}
+		fmc2->data_base[chip_cs] = (void __iomem *)resource.start;
+
+		ret = dev_read_resource(dev, mem_region + 1, &resource);
+		if (ret) {
+			pr_err("Resource cmd_base not found for cs%d",
+			       chip_cs);
+			return ret;
+		}
+		fmc2->cmd_base[chip_cs] = (void __iomem *)resource.start;
+
+		ret = dev_read_resource(dev, mem_region + 2, &resource);
+		if (ret) {
+			pr_err("Resource addr_base not found for cs%d",
+			       chip_cs);
+			return ret;
+		}
+		fmc2->addr_base[chip_cs] = (void __iomem *)resource.start;
+	}
+
+	/* Enable the clock */
+	ret = clk_get_by_index(dev, 0, &fmc2->clk);
+	if (ret)
+		return ret;
+
+	ret = clk_enable(&fmc2->clk);
+	if (ret)
+		return ret;
+
+	/* Reset */
+	ret = reset_get_by_index(dev, 0, &reset);
+	if (!ret) {
+		reset_assert(&reset);
+		udelay(2);
+		reset_deassert(&reset);
+	}
+
+	/* FMC2 init routine */
+	stm32_fmc2_init(fmc2);
+
+	chip->controller = &fmc2->base;
+	chip->select_chip = stm32_fmc2_select_chip;
+	chip->setup_data_interface = stm32_fmc2_setup_interface;
+	chip->cmd_ctrl = stm32_fmc2_cmd_ctrl;
+	chip->chip_delay = FMC2_RB_DELAY_US;
+	chip->options |= NAND_BUSWIDTH_AUTO | NAND_NO_SUBPAGE_WRITE |
+			 NAND_USE_BOUNCE_BUFFER;
+
+	/* Default ECC settings */
+	chip->ecc.mode = NAND_ECC_HW;
+	chip->ecc.size = FMC2_ECC_STEP_SIZE;
+	chip->ecc.strength = FMC2_ECC_BCH8;
+
+	/* Scan to find existence of the device */
+	ret = nand_scan_ident(mtd, nand->ncs, NULL);
+	if (ret)
+		return ret;
+
+	/*
+	 * Only NAND_ECC_HW mode is actually supported
+	 * Hamming => ecc.strength = 1
+	 * BCH4 => ecc.strength = 4
+	 * BCH8 => ecc.strength = 8
+	 * ECC sector size = 512
+	 */
+	if (chip->ecc.mode != NAND_ECC_HW) {
+		pr_err("Nand_ecc_mode is not well defined in the DT\n");
+		return -EINVAL;
+	}
+
+	ret = nand_check_ecc_caps(chip, &stm32_fmc2_ecc_caps,
+				  mtd->oobsize - FMC2_BBM_LEN);
+	if (ret) {
+		pr_err("No valid ECC settings set\n");
+		return ret;
+	}
+
+	if (chip->bbt_options & NAND_BBT_USE_FLASH)
+		chip->bbt_options |= NAND_BBT_NO_OOB;
+
+	/* NAND callbacks setup */
+	stm32_fmc2_nand_callbacks_setup(chip);
+
+	/* Define ECC layout */
+	ecclayout = &fmc2->ecclayout;
+	ecclayout->eccbytes = chip->ecc.bytes *
+			      (mtd->writesize / chip->ecc.size);
+	oob_index = FMC2_BBM_LEN;
+	for (i = 0; i < ecclayout->eccbytes; i++, oob_index++)
+		ecclayout->eccpos[i] = oob_index;
+	ecclayout->oobfree->offset = oob_index;
+	ecclayout->oobfree->length = mtd->oobsize - ecclayout->oobfree->offset;
+	chip->ecc.layout = ecclayout;
+
+	/* Configure bus width to 16-bit */
+	if (chip->options & NAND_BUSWIDTH_16)
+		stm32_fmc2_set_buswidth_16(fmc2, true);
+
+	/* Scan the device to fill MTD data-structures */
+	ret = nand_scan_tail(mtd);
+	if (ret)
+		return ret;
+
+	return nand_register(0, mtd);
+}
+
+static const struct udevice_id stm32_fmc2_match[] = {
+	{ .compatible = "st,stm32mp15-fmc2" },
+	{ /* Sentinel */ }
+};
+
+U_BOOT_DRIVER(stm32_fmc2_nand) = {
+	.name = "stm32_fmc2_nand",
+	.id = UCLASS_MTD,
+	.of_match = stm32_fmc2_match,
+	.probe = stm32_fmc2_probe,
+	.priv_auto_alloc_size = sizeof(struct stm32_fmc2_nfc),
+};
+
+void board_nand_init(void)
+{
+	struct udevice *dev;
+	int ret;
+
+	ret = uclass_get_device_by_driver(UCLASS_MTD,
+					  DM_GET_DRIVER(stm32_fmc2_nand),
+					  &dev);
+	if (ret && ret != -ENODEV)
+		pr_err("Failed to initialize STM32 FMC2 NAND controller. (error %d)\n",
+		       ret);
+}