drivers/ram/stm32_sdram.c - platform/external/u-boot - Gitiles

 /*
  * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
  * Author(s): Vikas Manocha, <vikas.manocha@st.com> for STMicroelectronics.
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */

 #include <common.h>
 #include <clk.h>
 #include <dm.h>
 #include <ram.h>
 #include <asm/io.h>

 DECLARE_GLOBAL_DATA_PTR;

 struct stm32_fmc_regs {
 	/* 0x0 */
 	u32 bcr1;	/* NOR/PSRAM Chip select control register 1 */
 	u32 btr1;	/* SRAM/NOR-Flash Chip select timing register 1 */
 	u32 bcr2;	/* NOR/PSRAM Chip select Control register 2 */
 	u32 btr2;	/* SRAM/NOR-Flash Chip select timing register 2 */
 	u32 bcr3;	/* NOR/PSRAMChip select Control register 3 */
 	u32 btr3;	/* SRAM/NOR-Flash Chip select timing register 3 */
 	u32 bcr4;	/* NOR/PSRAM Chip select Control register 4 */
 	u32 btr4;	/* SRAM/NOR-Flash Chip select timing register 4 */
 	u32 reserved1[24];

 	/* 0x80 */
 	u32 pcr;	/* NAND Flash control register */
 	u32 sr;		/* FIFO status and interrupt register */
 	u32 pmem;	/* Common memory space timing register */
 	u32 patt;	/* Attribute memory space timing registers  */
 	u32 reserved2[1];
 	u32 eccr;	/* ECC result registers */
 	u32 reserved3[27];

 	/* 0x104 */
 	u32 bwtr1;	/* SRAM/NOR-Flash write timing register 1 */
 	u32 reserved4[1];
 	u32 bwtr2;	/* SRAM/NOR-Flash write timing register 2 */
 	u32 reserved5[1];
 	u32 bwtr3;	/* SRAM/NOR-Flash write timing register 3 */
 	u32 reserved6[1];
 	u32 bwtr4;	/* SRAM/NOR-Flash write timing register 4 */
 	u32 reserved7[8];

 	/* 0x140 */
 	u32 sdcr1;	/* SDRAM Control register 1 */
 	u32 sdcr2;	/* SDRAM Control register 2 */
 	u32 sdtr1;	/* SDRAM Timing register 1 */
 	u32 sdtr2;	/* SDRAM Timing register 2 */
 	u32 sdcmr;	/* SDRAM Mode register */
 	u32 sdrtr;	/* SDRAM Refresh timing register */
 	u32 sdsr;	/* SDRAM Status register */
 };

 /*
  * NOR/PSRAM Control register BCR1
  * FMC controller Enable, only availabe for H7
  */
 #define FMC_BCR1_FMCEN		BIT(31)

 /* Control register SDCR */
 #define FMC_SDCR_RPIPE_SHIFT	13	/* RPIPE bit shift */
 #define FMC_SDCR_RBURST_SHIFT	12	/* RBURST bit shift */
 #define FMC_SDCR_SDCLK_SHIFT	10	/* SDRAM clock divisor shift */
 #define FMC_SDCR_WP_SHIFT	9	/* Write protection shift */
 #define FMC_SDCR_CAS_SHIFT	7	/* CAS latency shift */
 #define FMC_SDCR_NB_SHIFT	6	/* Number of banks shift */
 #define FMC_SDCR_MWID_SHIFT	4	/* Memory width shift */
 #define FMC_SDCR_NR_SHIFT	2	/* Number of row address bits shift */
 #define FMC_SDCR_NC_SHIFT	0	/* Number of col address bits shift */

 /* Timings register SDTR */
 #define FMC_SDTR_TMRD_SHIFT	0	/* Load mode register to active */
 #define FMC_SDTR_TXSR_SHIFT	4	/* Exit self-refresh time */
 #define FMC_SDTR_TRAS_SHIFT	8	/* Self-refresh time */
 #define FMC_SDTR_TRC_SHIFT	12	/* Row cycle delay */
 #define FMC_SDTR_TWR_SHIFT	16	/* Recovery delay */
 #define FMC_SDTR_TRP_SHIFT	20	/* Row precharge delay */
 #define FMC_SDTR_TRCD_SHIFT	24	/* Row-to-column delay */

 #define FMC_SDCMR_NRFS_SHIFT	5

 #define FMC_SDCMR_MODE_NORMAL		0
 #define FMC_SDCMR_MODE_START_CLOCK	1
 #define FMC_SDCMR_MODE_PRECHARGE	2
 #define FMC_SDCMR_MODE_AUTOREFRESH	3
 #define FMC_SDCMR_MODE_WRITE_MODE	4
 #define FMC_SDCMR_MODE_SELFREFRESH	5
 #define FMC_SDCMR_MODE_POWERDOWN	6

 #define FMC_SDCMR_BANK_1		BIT(4)
 #define FMC_SDCMR_BANK_2		BIT(3)

 #define FMC_SDCMR_MODE_REGISTER_SHIFT	9

 #define FMC_SDSR_BUSY			BIT(5)

 #define FMC_BUSY_WAIT(regs)	do { \
 		__asm__ __volatile__ ("dsb" : : : "memory"); \
 		while (regs->sdsr & FMC_SDSR_BUSY) \
 			; \
 	} while (0)

 struct stm32_sdram_control {
 	u8 no_columns;
 	u8 no_rows;
 	u8 memory_width;
 	u8 no_banks;
 	u8 cas_latency;
 	u8 sdclk;
 	u8 rd_burst;
 	u8 rd_pipe_delay;
 };

 struct stm32_sdram_timing {
 	u8 tmrd;
 	u8 txsr;
 	u8 tras;
 	u8 trc;
 	u8 trp;
 	u8 twr;
 	u8 trcd;
 };
 enum stm32_fmc_bank {
 	SDRAM_BANK1,
 	SDRAM_BANK2,
 	MAX_SDRAM_BANK,
 };

 enum stm32_fmc_family {
 	STM32F7_FMC,
 	STM32H7_FMC,
 };

 struct bank_params {
 	struct stm32_sdram_control *sdram_control;
 	struct stm32_sdram_timing *sdram_timing;
 	u32 sdram_ref_count;
 	enum stm32_fmc_bank target_bank;
 };

 struct stm32_sdram_params {
 	struct stm32_fmc_regs *base;
 	u8 no_sdram_banks;
 	struct bank_params bank_params[MAX_SDRAM_BANK];
 	enum stm32_fmc_family family;
 };

 #define SDRAM_MODE_BL_SHIFT	0
 #define SDRAM_MODE_CAS_SHIFT	4
 #define SDRAM_MODE_BL		0

 int stm32_sdram_init(struct udevice *dev)
 {
 	struct stm32_sdram_params *params = dev_get_platdata(dev);
 	struct stm32_sdram_control *control;
 	struct stm32_sdram_timing *timing;
 	struct stm32_fmc_regs *regs = params->base;
 	enum stm32_fmc_bank target_bank;
 	u32 ctb; /* SDCMR register: Command Target Bank */
 	u32 ref_count;
 	u8 i;

 	/* disable the FMC controller */
 	if (params->family == STM32H7_FMC)
 		clrbits_le32(&regs->bcr1, FMC_BCR1_FMCEN);

 	for (i = 0; i < params->no_sdram_banks; i++) {
 		control = params->bank_params[i].sdram_control;
 		timing = params->bank_params[i].sdram_timing;
 		target_bank = params->bank_params[i].target_bank;
 		ref_count = params->bank_params[i].sdram_ref_count;

 		writel(control->sdclk << FMC_SDCR_SDCLK_SHIFT
 			| control->cas_latency << FMC_SDCR_CAS_SHIFT
 			| control->no_banks << FMC_SDCR_NB_SHIFT
 			| control->memory_width << FMC_SDCR_MWID_SHIFT
 			| control->no_rows << FMC_SDCR_NR_SHIFT
 			| control->no_columns << FMC_SDCR_NC_SHIFT
 			| control->rd_pipe_delay << FMC_SDCR_RPIPE_SHIFT
 			| control->rd_burst << FMC_SDCR_RBURST_SHIFT,
 			&regs->sdcr1);

 		if (target_bank == SDRAM_BANK2)
 			writel(control->cas_latency << FMC_SDCR_CAS_SHIFT
 				| control->no_banks << FMC_SDCR_NB_SHIFT
 				| control->memory_width << FMC_SDCR_MWID_SHIFT
 				| control->no_rows << FMC_SDCR_NR_SHIFT
 				| control->no_columns << FMC_SDCR_NC_SHIFT,
 				&regs->sdcr2);

 		writel(timing->trcd << FMC_SDTR_TRCD_SHIFT
 			| timing->trp << FMC_SDTR_TRP_SHIFT
 			| timing->twr << FMC_SDTR_TWR_SHIFT
 			| timing->trc << FMC_SDTR_TRC_SHIFT
 			| timing->tras << FMC_SDTR_TRAS_SHIFT
 			| timing->txsr << FMC_SDTR_TXSR_SHIFT
 			| timing->tmrd << FMC_SDTR_TMRD_SHIFT,
 			&regs->sdtr1);

 		if (target_bank == SDRAM_BANK2)
 			writel(timing->trcd << FMC_SDTR_TRCD_SHIFT
 				| timing->trp << FMC_SDTR_TRP_SHIFT
 				| timing->twr << FMC_SDTR_TWR_SHIFT
 				| timing->trc << FMC_SDTR_TRC_SHIFT
 				| timing->tras << FMC_SDTR_TRAS_SHIFT
 				| timing->txsr << FMC_SDTR_TXSR_SHIFT
 				| timing->tmrd << FMC_SDTR_TMRD_SHIFT,
 				&regs->sdtr2);

 		if (target_bank == SDRAM_BANK1)
 			ctb = FMC_SDCMR_BANK_1;
 		else
 			ctb = FMC_SDCMR_BANK_2;

 		writel(ctb | FMC_SDCMR_MODE_START_CLOCK, &regs->sdcmr);
 		udelay(200);	/* 200 us delay, page 10, "Power-Up" */
 		FMC_BUSY_WAIT(regs);

 		writel(ctb | FMC_SDCMR_MODE_PRECHARGE, &regs->sdcmr);
 		udelay(100);
 		FMC_BUSY_WAIT(regs);

 		writel((ctb | FMC_SDCMR_MODE_AUTOREFRESH | 7 << FMC_SDCMR_NRFS_SHIFT),
 		       &regs->sdcmr);
 		udelay(100);
 		FMC_BUSY_WAIT(regs);

 		writel(ctb | (SDRAM_MODE_BL << SDRAM_MODE_BL_SHIFT
 		       | control->cas_latency << SDRAM_MODE_CAS_SHIFT)
 		       << FMC_SDCMR_MODE_REGISTER_SHIFT | FMC_SDCMR_MODE_WRITE_MODE,
 		       &regs->sdcmr);
 		udelay(100);
 		FMC_BUSY_WAIT(regs);

 		writel(ctb | FMC_SDCMR_MODE_NORMAL, &regs->sdcmr);
 		FMC_BUSY_WAIT(regs);

 		/* Refresh timer */
 		writel(ref_count << 1, &regs->sdrtr);
 	}

 	/* enable the FMC controller */
 	if (params->family == STM32H7_FMC)
 		setbits_le32(&regs->bcr1, FMC_BCR1_FMCEN);

 	return 0;
 }

 static int stm32_fmc_ofdata_to_platdata(struct udevice *dev)
 {
 	struct stm32_sdram_params *params = dev_get_platdata(dev);
 	struct bank_params *bank_params;
 	ofnode bank_node;
 	char *bank_name;
 	u8 bank = 0;

 	dev_for_each_subnode(bank_node, dev) {
 		/* extract the bank index from DT */
 		bank_name = (char *)ofnode_get_name(bank_node);
 		strsep(&bank_name, "@");
 		if (!bank_name) {
 			pr_err("missing sdram bank index");
 			return -EINVAL;
 		}

 		bank_params = &params->bank_params[bank];
 		strict_strtoul(bank_name, 10,
 			       (long unsigned int *)&bank_params->target_bank);

 		if (bank_params->target_bank >= MAX_SDRAM_BANK) {
 			pr_err("Found bank %d , but only bank 0 and 1 are supported",
 			      bank_params->target_bank);
 			return -EINVAL;
 		}

 		debug("Find bank %s %u\n", bank_name, bank_params->target_bank);

 		params->bank_params[bank].sdram_control =
 			(struct stm32_sdram_control *)
 			 ofnode_read_u8_array_ptr(bank_node,
 						  "st,sdram-control",
 						  sizeof(struct stm32_sdram_control));

 		if (!params->bank_params[bank].sdram_control) {
 			pr_err("st,sdram-control not found for %s",
 			      ofnode_get_name(bank_node));
 			return -EINVAL;
 		}


 		params->bank_params[bank].sdram_timing =
 			(struct stm32_sdram_timing *)
 			 ofnode_read_u8_array_ptr(bank_node,
 						  "st,sdram-timing",
 						  sizeof(struct stm32_sdram_timing));

 		if (!params->bank_params[bank].sdram_timing) {
 			pr_err("st,sdram-timing not found for %s",
 			      ofnode_get_name(bank_node));
 			return -EINVAL;
 		}


 		bank_params->sdram_ref_count = ofnode_read_u32_default(bank_node,
 						"st,sdram-refcount", 8196);
 		bank++;
 	}

 	params->no_sdram_banks = bank;
 	debug("%s, no of banks = %d\n", __func__, params->no_sdram_banks);

 	return 0;
 }

 static int stm32_fmc_probe(struct udevice *dev)
 {
 	struct stm32_sdram_params *params = dev_get_platdata(dev);
 	int ret;
 	fdt_addr_t addr;

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

 	params->base = (struct stm32_fmc_regs *)addr;
 	params->family = dev_get_driver_data(dev);

 #ifdef CONFIG_CLK
 	struct clk clk;

 	ret = clk_get_by_index(dev, 0, &clk);
 	if (ret < 0)
 		return ret;

 	ret = clk_enable(&clk);

 	if (ret) {
 		dev_err(dev, "failed to enable clock\n");
 		return ret;
 	}
 #endif
 	ret = stm32_sdram_init(dev);
 	if (ret)
 		return ret;

 	return 0;
 }

 static int stm32_fmc_get_info(struct udevice *dev, struct ram_info *info)
 {
 	return 0;
 }

 static struct ram_ops stm32_fmc_ops = {
 	.get_info = stm32_fmc_get_info,
 };

 static const struct udevice_id stm32_fmc_ids[] = {
 	{ .compatible = "st,stm32-fmc", .data = STM32F7_FMC },
 	{ .compatible = "st,stm32h7-fmc", .data = STM32H7_FMC },
 	{ }
 };

 U_BOOT_DRIVER(stm32_fmc) = {
 	.name = "stm32_fmc",
 	.id = UCLASS_RAM,
 	.of_match = stm32_fmc_ids,
 	.ops = &stm32_fmc_ops,
 	.ofdata_to_platdata = stm32_fmc_ofdata_to_platdata,
 	.probe = stm32_fmc_probe,
 	.platdata_auto_alloc_size = sizeof(struct stm32_sdram_params),
 };
	/*
	* Copyright (C) 2017, STMicroelectronics - All Rights Reserved
	* Author(s): Vikas Manocha, <vikas.manocha@st.com> for STMicroelectronics.
	*
	* SPDX-License-Identifier: GPL-2.0+
	*/

	#include <common.h>
	#include <clk.h>
	#include <dm.h>
	#include <ram.h>
	#include <asm/io.h>

	DECLARE_GLOBAL_DATA_PTR;

	struct stm32_fmc_regs {
	/* 0x0 */
	u32 bcr1; /* NOR/PSRAM Chip select control register 1 */
	u32 btr1; /* SRAM/NOR-Flash Chip select timing register 1 */
	u32 bcr2; /* NOR/PSRAM Chip select Control register 2 */
	u32 btr2; /* SRAM/NOR-Flash Chip select timing register 2 */
	u32 bcr3; /* NOR/PSRAMChip select Control register 3 */
	u32 btr3; /* SRAM/NOR-Flash Chip select timing register 3 */
	u32 bcr4; /* NOR/PSRAM Chip select Control register 4 */
	u32 btr4; /* SRAM/NOR-Flash Chip select timing register 4 */
	u32 reserved1[24];

	/* 0x80 */
	u32 pcr; /* NAND Flash control register */
	u32 sr; /* FIFO status and interrupt register */
	u32 pmem; /* Common memory space timing register */
	u32 patt; /* Attribute memory space timing registers */
	u32 reserved2[1];
	u32 eccr; /* ECC result registers */
	u32 reserved3[27];

	/* 0x104 */
	u32 bwtr1; /* SRAM/NOR-Flash write timing register 1 */
	u32 reserved4[1];
	u32 bwtr2; /* SRAM/NOR-Flash write timing register 2 */
	u32 reserved5[1];
	u32 bwtr3; /* SRAM/NOR-Flash write timing register 3 */
	u32 reserved6[1];
	u32 bwtr4; /* SRAM/NOR-Flash write timing register 4 */
	u32 reserved7[8];

	/* 0x140 */
	u32 sdcr1; /* SDRAM Control register 1 */
	u32 sdcr2; /* SDRAM Control register 2 */
	u32 sdtr1; /* SDRAM Timing register 1 */
	u32 sdtr2; /* SDRAM Timing register 2 */
	u32 sdcmr; /* SDRAM Mode register */
	u32 sdrtr; /* SDRAM Refresh timing register */
	u32 sdsr; /* SDRAM Status register */
	};

	/*
	* NOR/PSRAM Control register BCR1
	* FMC controller Enable, only availabe for H7
	*/
	#define FMC_BCR1_FMCEN BIT(31)

	/* Control register SDCR */
	#define FMC_SDCR_RPIPE_SHIFT 13 /* RPIPE bit shift */
	#define FMC_SDCR_RBURST_SHIFT 12 /* RBURST bit shift */
	#define FMC_SDCR_SDCLK_SHIFT 10 /* SDRAM clock divisor shift */
	#define FMC_SDCR_WP_SHIFT 9 /* Write protection shift */
	#define FMC_SDCR_CAS_SHIFT 7 /* CAS latency shift */
	#define FMC_SDCR_NB_SHIFT 6 /* Number of banks shift */
	#define FMC_SDCR_MWID_SHIFT 4 /* Memory width shift */
	#define FMC_SDCR_NR_SHIFT 2 /* Number of row address bits shift */
	#define FMC_SDCR_NC_SHIFT 0 /* Number of col address bits shift */

	/* Timings register SDTR */
	#define FMC_SDTR_TMRD_SHIFT 0 /* Load mode register to active */
	#define FMC_SDTR_TXSR_SHIFT 4 /* Exit self-refresh time */
	#define FMC_SDTR_TRAS_SHIFT 8 /* Self-refresh time */
	#define FMC_SDTR_TRC_SHIFT 12 /* Row cycle delay */
	#define FMC_SDTR_TWR_SHIFT 16 /* Recovery delay */
	#define FMC_SDTR_TRP_SHIFT 20 /* Row precharge delay */
	#define FMC_SDTR_TRCD_SHIFT 24 /* Row-to-column delay */

	#define FMC_SDCMR_NRFS_SHIFT 5

	#define FMC_SDCMR_MODE_NORMAL 0
	#define FMC_SDCMR_MODE_START_CLOCK 1
	#define FMC_SDCMR_MODE_PRECHARGE 2
	#define FMC_SDCMR_MODE_AUTOREFRESH 3
	#define FMC_SDCMR_MODE_WRITE_MODE 4
	#define FMC_SDCMR_MODE_SELFREFRESH 5
	#define FMC_SDCMR_MODE_POWERDOWN 6

	#define FMC_SDCMR_BANK_1 BIT(4)
	#define FMC_SDCMR_BANK_2 BIT(3)

	#define FMC_SDCMR_MODE_REGISTER_SHIFT 9

	#define FMC_SDSR_BUSY BIT(5)

	#define FMC_BUSY_WAIT(regs) do { \
	__asm__ __volatile__ ("dsb" : : : "memory"); \
	while (regs->sdsr & FMC_SDSR_BUSY) \
	; \
	} while (0)

	struct stm32_sdram_control {
	u8 no_columns;
	u8 no_rows;
	u8 memory_width;
	u8 no_banks;
	u8 cas_latency;
	u8 sdclk;
	u8 rd_burst;
	u8 rd_pipe_delay;
	};

	struct stm32_sdram_timing {
	u8 tmrd;
	u8 txsr;
	u8 tras;
	u8 trc;
	u8 trp;
	u8 twr;
	u8 trcd;
	};
	enum stm32_fmc_bank {
	SDRAM_BANK1,
	SDRAM_BANK2,
	MAX_SDRAM_BANK,
	};

	enum stm32_fmc_family {
	STM32F7_FMC,
	STM32H7_FMC,
	};

	struct bank_params {
	struct stm32_sdram_control *sdram_control;
	struct stm32_sdram_timing *sdram_timing;
	u32 sdram_ref_count;
	enum stm32_fmc_bank target_bank;
	};

	struct stm32_sdram_params {
	struct stm32_fmc_regs *base;
	u8 no_sdram_banks;
	struct bank_params bank_params[MAX_SDRAM_BANK];
	enum stm32_fmc_family family;
	};

	#define SDRAM_MODE_BL_SHIFT 0
	#define SDRAM_MODE_CAS_SHIFT 4
	#define SDRAM_MODE_BL 0

	int stm32_sdram_init(struct udevice *dev)
	{
	struct stm32_sdram_params *params = dev_get_platdata(dev);
	struct stm32_sdram_control *control;
	struct stm32_sdram_timing *timing;
	struct stm32_fmc_regs *regs = params->base;
	enum stm32_fmc_bank target_bank;
	u32 ctb; /* SDCMR register: Command Target Bank */
	u32 ref_count;
	u8 i;

	/* disable the FMC controller */
	if (params->family == STM32H7_FMC)
	clrbits_le32(&regs->bcr1, FMC_BCR1_FMCEN);

	for (i = 0; i < params->no_sdram_banks; i++) {
	control = params->bank_params[i].sdram_control;
	timing = params->bank_params[i].sdram_timing;
	target_bank = params->bank_params[i].target_bank;
	ref_count = params->bank_params[i].sdram_ref_count;

	writel(control->sdclk << FMC_SDCR_SDCLK_SHIFT
	\| control->cas_latency << FMC_SDCR_CAS_SHIFT
	\| control->no_banks << FMC_SDCR_NB_SHIFT
	\| control->memory_width << FMC_SDCR_MWID_SHIFT
	\| control->no_rows << FMC_SDCR_NR_SHIFT
	\| control->no_columns << FMC_SDCR_NC_SHIFT
	\| control->rd_pipe_delay << FMC_SDCR_RPIPE_SHIFT
	\| control->rd_burst << FMC_SDCR_RBURST_SHIFT,
	&regs->sdcr1);

	if (target_bank == SDRAM_BANK2)
	writel(control->cas_latency << FMC_SDCR_CAS_SHIFT
	\| control->no_banks << FMC_SDCR_NB_SHIFT
	\| control->memory_width << FMC_SDCR_MWID_SHIFT
	\| control->no_rows << FMC_SDCR_NR_SHIFT
	\| control->no_columns << FMC_SDCR_NC_SHIFT,
	&regs->sdcr2);

	writel(timing->trcd << FMC_SDTR_TRCD_SHIFT
	\| timing->trp << FMC_SDTR_TRP_SHIFT
	\| timing->twr << FMC_SDTR_TWR_SHIFT
	\| timing->trc << FMC_SDTR_TRC_SHIFT
	\| timing->tras << FMC_SDTR_TRAS_SHIFT
	\| timing->txsr << FMC_SDTR_TXSR_SHIFT
	\| timing->tmrd << FMC_SDTR_TMRD_SHIFT,
	&regs->sdtr1);

	if (target_bank == SDRAM_BANK2)
	writel(timing->trcd << FMC_SDTR_TRCD_SHIFT
	\| timing->trp << FMC_SDTR_TRP_SHIFT
	\| timing->twr << FMC_SDTR_TWR_SHIFT
	\| timing->trc << FMC_SDTR_TRC_SHIFT
	\| timing->tras << FMC_SDTR_TRAS_SHIFT
	\| timing->txsr << FMC_SDTR_TXSR_SHIFT
	\| timing->tmrd << FMC_SDTR_TMRD_SHIFT,
	&regs->sdtr2);

	if (target_bank == SDRAM_BANK1)
	ctb = FMC_SDCMR_BANK_1;
	else
	ctb = FMC_SDCMR_BANK_2;

	writel(ctb \| FMC_SDCMR_MODE_START_CLOCK, &regs->sdcmr);
	udelay(200); /* 200 us delay, page 10, "Power-Up" */
	FMC_BUSY_WAIT(regs);

	writel(ctb \| FMC_SDCMR_MODE_PRECHARGE, &regs->sdcmr);
	udelay(100);
	FMC_BUSY_WAIT(regs);

	writel((ctb \| FMC_SDCMR_MODE_AUTOREFRESH \| 7 << FMC_SDCMR_NRFS_SHIFT),
	&regs->sdcmr);
	udelay(100);
	FMC_BUSY_WAIT(regs);

	writel(ctb \| (SDRAM_MODE_BL << SDRAM_MODE_BL_SHIFT
	\| control->cas_latency << SDRAM_MODE_CAS_SHIFT)
	<< FMC_SDCMR_MODE_REGISTER_SHIFT \| FMC_SDCMR_MODE_WRITE_MODE,
	&regs->sdcmr);
	udelay(100);
	FMC_BUSY_WAIT(regs);

	writel(ctb \| FMC_SDCMR_MODE_NORMAL, &regs->sdcmr);
	FMC_BUSY_WAIT(regs);

	/* Refresh timer */
	writel(ref_count << 1, &regs->sdrtr);
	}

	/* enable the FMC controller */
	if (params->family == STM32H7_FMC)
	setbits_le32(&regs->bcr1, FMC_BCR1_FMCEN);

	return 0;
	}

	static int stm32_fmc_ofdata_to_platdata(struct udevice *dev)
	{
	struct stm32_sdram_params *params = dev_get_platdata(dev);
	struct bank_params *bank_params;
	ofnode bank_node;
	char *bank_name;
	u8 bank = 0;

	dev_for_each_subnode(bank_node, dev) {
	/* extract the bank index from DT */
	bank_name = (char *)ofnode_get_name(bank_node);
	strsep(&bank_name, "@");
	if (!bank_name) {
	pr_err("missing sdram bank index");
	return -EINVAL;
	}

	bank_params = &params->bank_params[bank];
	strict_strtoul(bank_name, 10,
	(long unsigned int *)&bank_params->target_bank);

	if (bank_params->target_bank >= MAX_SDRAM_BANK) {
	pr_err("Found bank %d , but only bank 0 and 1 are supported",
	bank_params->target_bank);
	return -EINVAL;
	}

	debug("Find bank %s %u\n", bank_name, bank_params->target_bank);

	params->bank_params[bank].sdram_control =
	(struct stm32_sdram_control *)
	ofnode_read_u8_array_ptr(bank_node,
	"st,sdram-control",
	sizeof(struct stm32_sdram_control));

	if (!params->bank_params[bank].sdram_control) {
	pr_err("st,sdram-control not found for %s",
	ofnode_get_name(bank_node));
	return -EINVAL;
	}


	params->bank_params[bank].sdram_timing =
	(struct stm32_sdram_timing *)
	ofnode_read_u8_array_ptr(bank_node,
	"st,sdram-timing",
	sizeof(struct stm32_sdram_timing));

	if (!params->bank_params[bank].sdram_timing) {
	pr_err("st,sdram-timing not found for %s",
	ofnode_get_name(bank_node));
	return -EINVAL;
	}


	bank_params->sdram_ref_count = ofnode_read_u32_default(bank_node,
	"st,sdram-refcount", 8196);
	bank++;
	}

	params->no_sdram_banks = bank;
	debug("%s, no of banks = %d\n", __func__, params->no_sdram_banks);

	return 0;
	}

	static int stm32_fmc_probe(struct udevice *dev)
	{
	struct stm32_sdram_params *params = dev_get_platdata(dev);
	int ret;
	fdt_addr_t addr;

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

	params->base = (struct stm32_fmc_regs *)addr;
	params->family = dev_get_driver_data(dev);

	#ifdef CONFIG_CLK
	struct clk clk;

	ret = clk_get_by_index(dev, 0, &clk);
	if (ret < 0)
	return ret;

	ret = clk_enable(&clk);

	if (ret) {
	dev_err(dev, "failed to enable clock\n");
	return ret;
	}
	#endif
	ret = stm32_sdram_init(dev);
	if (ret)
	return ret;

	return 0;
	}

	static int stm32_fmc_get_info(struct udevice dev, struct ram_info info)
	{
	return 0;
	}

	static struct ram_ops stm32_fmc_ops = {
	.get_info = stm32_fmc_get_info,
	};

	static const struct udevice_id stm32_fmc_ids[] = {
	{ .compatible = "st,stm32-fmc", .data = STM32F7_FMC },
	{ .compatible = "st,stm32h7-fmc", .data = STM32H7_FMC },
	{ }
	};

	U_BOOT_DRIVER(stm32_fmc) = {
	.name = "stm32_fmc",
	.id = UCLASS_RAM,
	.of_match = stm32_fmc_ids,
	.ops = &stm32_fmc_ops,
	.ofdata_to_platdata = stm32_fmc_ofdata_to_platdata,
	.probe = stm32_fmc_probe,
	.platdata_auto_alloc_size = sizeof(struct stm32_sdram_params),
	};