/drivers/spi/stm32_qspi.c

/*
 * (C) Copyright 2016
 *
 * Michael Kurz, <michi.kurz@gmail.com>
 *
 * STM32 QSPI driver
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <malloc.h>
#include <spi.h>
#include <spi_flash.h>
#include <asm/io.h>
#include <dm.h>
#include <errno.h>
#include <asm/arch/stm32.h>
#include <asm/arch/stm32_defs.h>
#include <clk.h>

DECLARE_GLOBAL_DATA_PTR;

struct stm32_qspi_regs {
	u32 cr;		/* 0x00 */
	u32 dcr;	/* 0x04 */
	u32 sr;		/* 0x08 */
	u32 fcr;	/* 0x0C */
	u32 dlr;	/* 0x10 */
	u32 ccr;	/* 0x14 */
	u32 ar;		/* 0x18 */
	u32 abr;	/* 0x1C */
	u32 dr;		/* 0x20 */
	u32 psmkr;	/* 0x24 */
	u32 psmar;	/* 0x28 */
	u32 pir;	/* 0x2C */
	u32 lptr;	/* 0x30 */
};

/*
 * QUADSPI control register
 */
#define STM32_QSPI_CR_EN		BIT(0)
#define STM32_QSPI_CR_ABORT		BIT(1)
#define STM32_QSPI_CR_DMAEN		BIT(2)
#define STM32_QSPI_CR_TCEN		BIT(3)
#define STM32_QSPI_CR_SSHIFT		BIT(4)
#define STM32_QSPI_CR_DFM		BIT(6)
#define STM32_QSPI_CR_FSEL		BIT(7)
#define STM32_QSPI_CR_FTHRES_MASK	GENMASK(4, 0)
#define STM32_QSPI_CR_FTHRES_SHIFT	(8)
#define STM32_QSPI_CR_TEIE		BIT(16)
#define STM32_QSPI_CR_TCIE		BIT(17)
#define STM32_QSPI_CR_FTIE		BIT(18)
#define STM32_QSPI_CR_SMIE		BIT(19)
#define STM32_QSPI_CR_TOIE		BIT(20)
#define STM32_QSPI_CR_APMS		BIT(22)
#define STM32_QSPI_CR_PMM		BIT(23)
#define STM32_QSPI_CR_PRESCALER_MASK	GENMASK(7, 0)
#define STM32_QSPI_CR_PRESCALER_SHIFT	(24)

/*
 * QUADSPI device configuration register
 */
#define STM32_QSPI_DCR_CKMODE		BIT(0)
#define STM32_QSPI_DCR_CSHT_MASK	GENMASK(2, 0)
#define STM32_QSPI_DCR_CSHT_SHIFT	(8)
#define STM32_QSPI_DCR_FSIZE_MASK	GENMASK(4, 0)
#define STM32_QSPI_DCR_FSIZE_SHIFT	(16)

/*
 * QUADSPI status register
 */
#define STM32_QSPI_SR_TEF		BIT(0)
#define STM32_QSPI_SR_TCF		BIT(1)
#define STM32_QSPI_SR_FTF		BIT(2)
#define STM32_QSPI_SR_SMF		BIT(3)
#define STM32_QSPI_SR_TOF		BIT(4)
#define STM32_QSPI_SR_BUSY		BIT(5)
#define STM32_QSPI_SR_FLEVEL_MASK	GENMASK(5, 0)
#define STM32_QSPI_SR_FLEVEL_SHIFT	(8)

/*
 * QUADSPI flag clear register
 */
#define STM32_QSPI_FCR_CTEF		BIT(0)
#define STM32_QSPI_FCR_CTCF		BIT(1)
#define STM32_QSPI_FCR_CSMF		BIT(3)
#define STM32_QSPI_FCR_CTOF		BIT(4)

/*
 * QUADSPI communication configuration register
 */
#define STM32_QSPI_CCR_DDRM		BIT(31)
#define STM32_QSPI_CCR_DHHC		BIT(30)
#define STM32_QSPI_CCR_SIOO		BIT(28)
#define STM32_QSPI_CCR_FMODE_SHIFT	(26)
#define STM32_QSPI_CCR_DMODE_SHIFT	(24)
#define STM32_QSPI_CCR_DCYC_SHIFT	(18)
#define STM32_QSPI_CCR_DCYC_MASK	GENMASK(4, 0)
#define STM32_QSPI_CCR_ABSIZE_SHIFT	(16)
#define STM32_QSPI_CCR_ABMODE_SHIFT	(14)
#define STM32_QSPI_CCR_ADSIZE_SHIFT	(12)
#define STM32_QSPI_CCR_ADMODE_SHIFT	(10)
#define STM32_QSPI_CCR_IMODE_SHIFT	(8)
#define STM32_QSPI_CCR_INSTRUCTION_MASK	GENMASK(7, 0)

enum STM32_QSPI_CCR_IMODE {
	STM32_QSPI_CCR_IMODE_NONE = 0,
	STM32_QSPI_CCR_IMODE_ONE_LINE = 1,
	STM32_QSPI_CCR_IMODE_TWO_LINE = 2,
	STM32_QSPI_CCR_IMODE_FOUR_LINE = 3,
};

enum STM32_QSPI_CCR_ADMODE {
	STM32_QSPI_CCR_ADMODE_NONE = 0,
	STM32_QSPI_CCR_ADMODE_ONE_LINE = 1,
	STM32_QSPI_CCR_ADMODE_TWO_LINE = 2,
	STM32_QSPI_CCR_ADMODE_FOUR_LINE = 3,
};

enum STM32_QSPI_CCR_ADSIZE {
	STM32_QSPI_CCR_ADSIZE_8BIT = 0,
	STM32_QSPI_CCR_ADSIZE_16BIT = 1,
	STM32_QSPI_CCR_ADSIZE_24BIT = 2,
	STM32_QSPI_CCR_ADSIZE_32BIT = 3,
};

enum STM32_QSPI_CCR_ABMODE {
	STM32_QSPI_CCR_ABMODE_NONE = 0,
	STM32_QSPI_CCR_ABMODE_ONE_LINE = 1,
	STM32_QSPI_CCR_ABMODE_TWO_LINE = 2,
	STM32_QSPI_CCR_ABMODE_FOUR_LINE = 3,
};

enum STM32_QSPI_CCR_ABSIZE {
	STM32_QSPI_CCR_ABSIZE_8BIT = 0,
	STM32_QSPI_CCR_ABSIZE_16BIT = 1,
	STM32_QSPI_CCR_ABSIZE_24BIT = 2,
	STM32_QSPI_CCR_ABSIZE_32BIT = 3,
};

enum STM32_QSPI_CCR_DMODE {
	STM32_QSPI_CCR_DMODE_NONE = 0,
	STM32_QSPI_CCR_DMODE_ONE_LINE = 1,
	STM32_QSPI_CCR_DMODE_TWO_LINE = 2,
	STM32_QSPI_CCR_DMODE_FOUR_LINE = 3,
};

enum STM32_QSPI_CCR_FMODE {
	STM32_QSPI_CCR_IND_WRITE = 0,
	STM32_QSPI_CCR_IND_READ = 1,
	STM32_QSPI_CCR_AUTO_POLL = 2,
	STM32_QSPI_CCR_MEM_MAP = 3,
};

/* default SCK frequency, unit: HZ */
#define STM32_QSPI_DEFAULT_SCK_FREQ 108000000

struct stm32_qspi_platdata {
	u32 base;
	u32 memory_map;
	u32 max_hz;
};

struct stm32_qspi_priv {
	struct stm32_qspi_regs *regs;
	ulong clock_rate;
	u32 max_hz;
	u32 mode;

	u32 command;
	u32 address;
	u32 dummycycles;
#define CMD_HAS_ADR	BIT(24)
#define CMD_HAS_DUMMY	BIT(25)
#define CMD_HAS_DATA	BIT(26)
};

static void _stm32_qspi_disable(struct stm32_qspi_priv *priv)
{
	clrbits_le32(&priv->regs->cr, STM32_QSPI_CR_EN);
}

static void _stm32_qspi_enable(struct stm32_qspi_priv *priv)
{
	setbits_le32(&priv->regs->cr, STM32_QSPI_CR_EN);
}

static void _stm32_qspi_wait_for_not_busy(struct stm32_qspi_priv *priv)
{
	while (readl(&priv->regs->sr) & STM32_QSPI_SR_BUSY)
		;
}

static void _stm32_qspi_wait_for_complete(struct stm32_qspi_priv *priv)
{
	while (!(readl(&priv->regs->sr) & STM32_QSPI_SR_TCF))
		;
}

static void _stm32_qspi_wait_for_ftf(struct stm32_qspi_priv *priv)
{
	while (!(readl(&priv->regs->sr) & STM32_QSPI_SR_FTF))
		;
}

static void _stm32_qspi_set_flash_size(struct stm32_qspi_priv *priv, u32 size)
{
	u32 fsize = fls(size) - 1;
	clrsetbits_le32(&priv->regs->dcr,
			STM32_QSPI_DCR_FSIZE_MASK << STM32_QSPI_DCR_FSIZE_SHIFT,
			fsize << STM32_QSPI_DCR_FSIZE_SHIFT);
}

static unsigned int _stm32_qspi_gen_ccr(struct stm32_qspi_priv *priv)
{
	unsigned int ccr_reg = 0;
	u8 imode, admode, dmode;
	u32 mode = priv->mode;
	u32 cmd = (priv->command & STM32_QSPI_CCR_INSTRUCTION_MASK);

	imode = STM32_QSPI_CCR_IMODE_ONE_LINE;
	admode = STM32_QSPI_CCR_ADMODE_ONE_LINE;

	if (mode & SPI_RX_QUAD) {
		dmode = STM32_QSPI_CCR_DMODE_FOUR_LINE;
		if (mode & SPI_TX_QUAD) {
			imode = STM32_QSPI_CCR_IMODE_FOUR_LINE;
			admode = STM32_QSPI_CCR_ADMODE_FOUR_LINE;
		}
	} else if (mode & SPI_RX_DUAL) {
		dmode = STM32_QSPI_CCR_DMODE_TWO_LINE;
		if (mode & SPI_TX_DUAL) {
			imode = STM32_QSPI_CCR_IMODE_TWO_LINE;
			admode = STM32_QSPI_CCR_ADMODE_TWO_LINE;
		}
	} else {
		dmode = STM32_QSPI_CCR_DMODE_ONE_LINE;
	}

	if (priv->command & CMD_HAS_DATA)
		ccr_reg |= (dmode << STM32_QSPI_CCR_DMODE_SHIFT);

	if (priv->command & CMD_HAS_DUMMY)
		ccr_reg |= ((priv->dummycycles & STM32_QSPI_CCR_DCYC_MASK)
				<< STM32_QSPI_CCR_DCYC_SHIFT);

	if (priv->command & CMD_HAS_ADR) {
		ccr_reg |= (STM32_QSPI_CCR_ADSIZE_24BIT
				<< STM32_QSPI_CCR_ADSIZE_SHIFT);
		ccr_reg |= (admode << STM32_QSPI_CCR_ADMODE_SHIFT);
	}
	ccr_reg |= (imode << STM32_QSPI_CCR_IMODE_SHIFT);
	ccr_reg |= cmd;
	return ccr_reg;
}

static void _stm32_qspi_enable_mmap(struct stm32_qspi_priv *priv,
		struct spi_flash *flash)
{
	priv->command = flash->read_cmd | CMD_HAS_ADR | CMD_HAS_DATA
			| CMD_HAS_DUMMY;
	priv->dummycycles = flash->dummy_byte * 8;

	unsigned int ccr_reg = _stm32_qspi_gen_ccr(priv);
	ccr_reg |= (STM32_QSPI_CCR_MEM_MAP << STM32_QSPI_CCR_FMODE_SHIFT);

	_stm32_qspi_wait_for_not_busy(priv);

	writel(ccr_reg, &priv->regs->ccr);

	priv->dummycycles = 0;
}

static void _stm32_qspi_disable_mmap(struct stm32_qspi_priv *priv)
{
	setbits_le32(&priv->regs->cr, STM32_QSPI_CR_ABORT);
}

static void _stm32_qspi_set_xfer_length(struct stm32_qspi_priv *priv,
					u32 length)
{
	writel(length - 1, &priv->regs->dlr);
}

static void _stm32_qspi_start_xfer(struct stm32_qspi_priv *priv, u32 cr_reg)
{
	writel(cr_reg, &priv->regs->ccr);

	if (priv->command & CMD_HAS_ADR)
		writel(priv->address, &priv->regs->ar);
}

static int _stm32_qspi_xfer(struct stm32_qspi_priv *priv,
		struct spi_flash *flash, unsigned int bitlen,
		const u8 *dout, u8 *din, unsigned long flags)
{
	unsigned int words = bitlen / 8;

	if (flags & SPI_XFER_MMAP) {
		_stm32_qspi_enable_mmap(priv, flash);
		return 0;
	} else if (flags & SPI_XFER_MMAP_END) {
		_stm32_qspi_disable_mmap(priv);
		return 0;
	}

	if (bitlen == 0)
		return -1;

	if (bitlen % 8) {
		debug("spi_xfer: Non byte aligned SPI transfer\n");
		return -1;
	}

	if (dout && din) {
		debug("spi_xfer: QSPI cannot have data in and data out set\n");
		return -1;
	}

	if (!dout && (flags & SPI_XFER_BEGIN)) {
		debug("spi_xfer: QSPI transfer must begin with command\n");
		return -1;
	}

	if (dout) {
		if (flags & SPI_XFER_BEGIN) {
			/* data is command */
			priv->command = dout[0] | CMD_HAS_DATA;
			if (words >= 4) {
				/* address is here too */
				priv->address = (dout[1] << 16) |
						(dout[2] << 8) | dout[3];
				priv->command |= CMD_HAS_ADR;
			}

			if (words > 4) {
				/* rest is dummy bytes */
				priv->dummycycles = (words - 4) * 8;
				priv->command |= CMD_HAS_DUMMY;
			}

			if (flags & SPI_XFER_END) {
				/* command without data */
				priv->command &= ~(CMD_HAS_DATA);
			}
		}

		if (flags & SPI_XFER_END) {
			u32 ccr_reg = _stm32_qspi_gen_ccr(priv);
			ccr_reg |= STM32_QSPI_CCR_IND_WRITE
					<< STM32_QSPI_CCR_FMODE_SHIFT;

			_stm32_qspi_wait_for_not_busy(priv);

			if (priv->command & CMD_HAS_DATA)
				_stm32_qspi_set_xfer_length(priv, words);

			_stm32_qspi_start_xfer(priv, ccr_reg);

			debug("%s: write: ccr:0x%08x adr:0x%08x\n",
			      __func__, priv->regs->ccr, priv->regs->ar);

			if (priv->command & CMD_HAS_DATA) {
				_stm32_qspi_wait_for_ftf(priv);

				debug("%s: words:%d data:", __func__, words);

				int i = 0;
				while (words > i) {
					writeb(dout[i], &priv->regs->dr);
					debug("%02x ", dout[i]);
					i++;
				}
				debug("\n");

				_stm32_qspi_wait_for_complete(priv);
			} else {
				_stm32_qspi_wait_for_not_busy(priv);
			}
		}
	} else if (din) {
		u32 ccr_reg = _stm32_qspi_gen_ccr(priv);
		ccr_reg |= STM32_QSPI_CCR_IND_READ
				<< STM32_QSPI_CCR_FMODE_SHIFT;

		_stm32_qspi_wait_for_not_busy(priv);

		_stm32_qspi_set_xfer_length(priv, words);

		_stm32_qspi_start_xfer(priv, ccr_reg);

		debug("%s: read: ccr:0x%08x adr:0x%08x len:%d\n", __func__,
		      priv->regs->ccr, priv->regs->ar, priv->regs->dlr);

		debug("%s: data:", __func__);

		int i = 0;
		while (words > i) {
			din[i] = readb(&priv->regs->dr);
			debug("%02x ", din[i]);
			i++;
		}
		debug("\n");
	}

	return 0;
}

static int stm32_qspi_ofdata_to_platdata(struct udevice *bus)
{
	struct fdt_resource res_regs, res_mem;
	struct stm32_qspi_platdata *plat = bus->platdata;
	const void *blob = gd->fdt_blob;
	int node = dev_of_offset(bus);
	int ret;

	ret = fdt_get_named_resource(blob, node, "reg", "reg-names",
				     "QuadSPI", &res_regs);
	if (ret) {
		debug("Error: can't get regs base addresses(ret = %d)!\n", ret);
		return -ENOMEM;
	}
	ret = fdt_get_named_resource(blob, node, "reg", "reg-names",
				     "QuadSPI-memory", &res_mem);
	if (ret) {
		debug("Error: can't get mmap base address(ret = %d)!\n", ret);
		return -ENOMEM;
	}

	plat->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency",
					STM32_QSPI_DEFAULT_SCK_FREQ);

	plat->base = res_regs.start;
	plat->memory_map = res_mem.start;

	debug("%s: regs=<0x%x> mapped=<0x%x>, max-frequency=%d\n",
	      __func__,
	      plat->base,
	      plat->memory_map,
	      plat->max_hz
	      );

	return 0;
}

static int stm32_qspi_probe(struct udevice *bus)
{
	struct stm32_qspi_platdata *plat = dev_get_platdata(bus);
	struct stm32_qspi_priv *priv = dev_get_priv(bus);
	struct dm_spi_bus *dm_spi_bus;

	dm_spi_bus = bus->uclass_priv;

	dm_spi_bus->max_hz = plat->max_hz;

	priv->regs = (struct stm32_qspi_regs *)(uintptr_t)plat->base;

	priv->max_hz = plat->max_hz;

#ifdef CONFIG_CLK
	int ret;
	struct clk clk;
	ret = clk_get_by_index(bus, 0, &clk);
	if (ret < 0)
		return ret;

	ret = clk_enable(&clk);

	if (ret) {
		dev_err(bus, "failed to enable clock\n");
		return ret;
	}

	priv->clock_rate = clk_get_rate(&clk);
	if (priv->clock_rate < 0) {
		clk_disable(&clk);
		return priv->clock_rate;
	}

#endif

	setbits_le32(&priv->regs->cr, STM32_QSPI_CR_SSHIFT);

	return 0;
}

static int stm32_qspi_remove(struct udevice *bus)
{
	return 0;
}

static int stm32_qspi_claim_bus(struct udevice *dev)
{
	struct stm32_qspi_priv *priv;
	struct udevice *bus;
	struct spi_flash *flash;

	bus = dev->parent;
	priv = dev_get_priv(bus);
	flash = dev_get_uclass_priv(dev);

	_stm32_qspi_set_flash_size(priv, flash->size);

	_stm32_qspi_enable(priv);

	return 0;
}

static int stm32_qspi_release_bus(struct udevice *dev)
{
	struct stm32_qspi_priv *priv;
	struct udevice *bus;

	bus = dev->parent;
	priv = dev_get_priv(bus);

	_stm32_qspi_disable(priv);

	return 0;
}

static int stm32_qspi_xfer(struct udevice *dev, unsigned int bitlen,
		const void *dout, void *din, unsigned long flags)
{
	struct stm32_qspi_priv *priv;
	struct udevice *bus;
	struct spi_flash *flash;

	bus = dev->parent;
	priv = dev_get_priv(bus);
	flash = dev_get_uclass_priv(dev);

	return _stm32_qspi_xfer(priv, flash, bitlen, (const u8 *)dout,
				(u8 *)din, flags);
}

static int stm32_qspi_set_speed(struct udevice *bus, uint speed)
{
	struct stm32_qspi_platdata *plat = bus->platdata;
	struct stm32_qspi_priv *priv = dev_get_priv(bus);

	if (speed > plat->max_hz)
		speed = plat->max_hz;

	u32 qspi_clk = priv->clock_rate;
	u32 prescaler = 255;
	if (speed > 0) {
		prescaler = DIV_ROUND_UP(qspi_clk, speed) - 1;
		if (prescaler > 255)
			prescaler = 255;
		else if (prescaler < 0)
			prescaler = 0;
	}

	u32 csht = DIV_ROUND_UP((5 * qspi_clk) / (prescaler + 1), 100000000);
	csht = (csht - 1) & STM32_QSPI_DCR_CSHT_MASK;

	_stm32_qspi_wait_for_not_busy(priv);

	clrsetbits_le32(&priv->regs->cr,
			STM32_QSPI_CR_PRESCALER_MASK <<
			STM32_QSPI_CR_PRESCALER_SHIFT,
			prescaler << STM32_QSPI_CR_PRESCALER_SHIFT);


	clrsetbits_le32(&priv->regs->dcr,
			STM32_QSPI_DCR_CSHT_MASK << STM32_QSPI_DCR_CSHT_SHIFT,
			csht << STM32_QSPI_DCR_CSHT_SHIFT);

	debug("%s: regs=%p, speed=%d\n", __func__, priv->regs,
	      (qspi_clk / (prescaler + 1)));

	return 0;
}

static int stm32_qspi_set_mode(struct udevice *bus, uint mode)
{
	struct stm32_qspi_priv *priv = dev_get_priv(bus);

	_stm32_qspi_wait_for_not_busy(priv);

	if ((mode & SPI_CPHA) && (mode & SPI_CPOL))
		setbits_le32(&priv->regs->dcr, STM32_QSPI_DCR_CKMODE);
	else if (!(mode & SPI_CPHA) && !(mode & SPI_CPOL))
		clrbits_le32(&priv->regs->dcr, STM32_QSPI_DCR_CKMODE);
	else
		return -ENODEV;

	if (mode & SPI_CS_HIGH)
		return -ENODEV;

	if (mode & SPI_RX_QUAD)
		priv->mode |= SPI_RX_QUAD;
	else if (mode & SPI_RX_DUAL)
		priv->mode |= SPI_RX_DUAL;
	else
		priv->mode &= ~(SPI_RX_QUAD | SPI_RX_DUAL);

	if (mode & SPI_TX_QUAD)
		priv->mode |= SPI_TX_QUAD;
	else if (mode & SPI_TX_DUAL)
		priv->mode |= SPI_TX_DUAL;
	else
		priv->mode &= ~(SPI_TX_QUAD | SPI_TX_DUAL);

	debug("%s: regs=%p, mode=%d rx: ", __func__, priv->regs, mode);

	if (mode & SPI_RX_QUAD)
		debug("quad, tx: ");
	else if (mode & SPI_RX_DUAL)
		debug("dual, tx: ");
	else
		debug("single, tx: ");

	if (mode & SPI_TX_QUAD)
		debug("quad\n");
	else if (mode & SPI_TX_DUAL)
		debug("dual\n");
	else
		debug("single\n");

	return 0;
}

static const struct dm_spi_ops stm32_qspi_ops = {
	.claim_bus	= stm32_qspi_claim_bus,
	.release_bus	= stm32_qspi_release_bus,
	.xfer		= stm32_qspi_xfer,
	.set_speed	= stm32_qspi_set_speed,
	.set_mode	= stm32_qspi_set_mode,
};

static const struct udevice_id stm32_qspi_ids[] = {
	{ .compatible = "st,stm32-qspi" },
	{ }
};

U_BOOT_DRIVER(stm32_qspi) = {
	.name	= "stm32_qspi",
	.id	= UCLASS_SPI,
	.of_match = stm32_qspi_ids,
	.ops	= &stm32_qspi_ops,
	.ofdata_to_platdata = stm32_qspi_ofdata_to_platdata,
	.platdata_auto_alloc_size = sizeof(struct stm32_qspi_platdata),
	.priv_auto_alloc_size = sizeof(struct stm32_qspi_priv),
	.probe	= stm32_qspi_probe,
	.remove = stm32_qspi_remove,
};