drivers/spi/ti_qspi.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * TI QSPI driver
 *
 * Copyright (C) 2013, Texas Instruments, Incorporated
 */

#include <cpu_func.h>
#include <log.h>
#include <asm/cache.h>
#include <asm/global_data.h>
#include <asm/io.h>
#include <asm/arch/omap.h>
#include <malloc.h>
#include <spi.h>
#include <spi-mem.h>
#include <dm.h>
#include <asm/gpio.h>
#include <asm/omap_gpio.h>
#include <asm/omap_common.h>
#include <asm/ti-common/ti-edma3.h>
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <regmap.h>
#include <syscon.h>

DECLARE_GLOBAL_DATA_PTR;

/* ti qpsi register bit masks */
#define QSPI_TIMEOUT                    2000000
/* AM4372: QSPI gets SPI_GCLK from PRCM unit as PER_CLKOUTM2 divided by 4. */
#define QSPI_FCLK                       (192000000 / 4)
#define QSPI_DRA7XX_FCLK                76800000
#define QSPI_WLEN_MAX_BITS		128
#define QSPI_WLEN_MAX_BYTES		(QSPI_WLEN_MAX_BITS >> 3)
#define QSPI_WLEN_MASK			QSPI_WLEN(QSPI_WLEN_MAX_BITS)
/* clock control */
#define QSPI_CLK_EN                     BIT(31)
#define QSPI_CLK_DIV_MAX                0xffff
/* command */
#define QSPI_EN_CS(n)                   (n << 28)
#define QSPI_WLEN(n)                    ((n-1) << 19)
#define QSPI_3_PIN                      BIT(18)
#define QSPI_RD_SNGL                    BIT(16)
#define QSPI_WR_SNGL                    (2 << 16)
#define QSPI_INVAL                      (4 << 16)
#define QSPI_RD_QUAD                    (7 << 16)
/* device control */
#define QSPI_CKPHA(n)                   (1 << (2 + n*8))
#define QSPI_CSPOL(n)                   (1 << (1 + n*8))
#define QSPI_CKPOL(n)                   (1 << (n*8))
/* status */
#define QSPI_WC                         BIT(1)
#define QSPI_BUSY                       BIT(0)
#define QSPI_WC_BUSY                    (QSPI_WC | QSPI_BUSY)
#define QSPI_XFER_DONE                  QSPI_WC
#define MM_SWITCH                       0x01
#define MEM_CS(cs)                      ((cs + 1) << 8)
#define MEM_CS_UNSELECT                 0xfffff8ff

#define QSPI_SETUP0_READ_NORMAL         (0x0 << 12)
#define QSPI_SETUP0_READ_DUAL           (0x1 << 12)
#define QSPI_SETUP0_READ_QUAD           (0x3 << 12)
#define QSPI_SETUP0_ADDR_SHIFT		(8)
#define QSPI_SETUP0_DBITS_SHIFT		(10)

#define TI_QSPI_SETUP_REG(priv, cs)	(&(priv)->base->setup0 + (cs))

/* ti qspi register set */
struct ti_qspi_regs {
	u32 pid;
	u32 pad0[3];
	u32 sysconfig;
	u32 pad1[3];
	u32 int_stat_raw;
	u32 int_stat_en;
	u32 int_en_set;
	u32 int_en_ctlr;
	u32 intc_eoi;
	u32 pad2[3];
	u32 clk_ctrl;
	u32 dc;
	u32 cmd;
	u32 status;
	u32 data;
	u32 setup0;
	u32 setup1;
	u32 setup2;
	u32 setup3;
	u32 memswitch;
	u32 data1;
	u32 data2;
	u32 data3;
};

/* ti qspi priv */
struct ti_qspi_priv {
	void *memory_map;
	size_t mmap_size;
	uint max_hz;
	u32 num_cs;
	struct ti_qspi_regs *base;
	void *ctrl_mod_mmap;
	ulong fclk;
	unsigned int mode;
	u32 cmd;
	u32 dc;
};

static int ti_qspi_set_speed(struct udevice *bus, uint hz)
{
	struct ti_qspi_priv *priv = dev_get_priv(bus);
	uint clk_div;

	if (!hz)
		clk_div = 0;
	else
		clk_div = DIV_ROUND_UP(priv->fclk, hz) - 1;

	/* truncate clk_div value to QSPI_CLK_DIV_MAX */
	if (clk_div > QSPI_CLK_DIV_MAX)
		clk_div = QSPI_CLK_DIV_MAX;

	debug("ti_spi_set_speed: hz: %d, clock divider %d\n", hz, clk_div);

	/* disable SCLK */
	writel(readl(&priv->base->clk_ctrl) & ~QSPI_CLK_EN,
	       &priv->base->clk_ctrl);
	/* enable SCLK and program the clk divider */
	writel(QSPI_CLK_EN | clk_div, &priv->base->clk_ctrl);

	return 0;
}

static void ti_qspi_cs_deactivate(struct ti_qspi_priv *priv)
{
	writel(priv->cmd | QSPI_INVAL, &priv->base->cmd);
	/* dummy readl to ensure bus sync */
	readl(&priv->base->cmd);
}

static void ti_qspi_ctrl_mode_mmap(void *ctrl_mod_mmap, int cs, bool enable)
{
	u32 val;

	val = readl(ctrl_mod_mmap);
	if (enable)
		val |= MEM_CS(cs);
	else
		val &= MEM_CS_UNSELECT;
	writel(val, ctrl_mod_mmap);
}

static int ti_qspi_xfer(struct udevice *dev, unsigned int bitlen,
			const void *dout, void *din, unsigned long flags)
{
	struct dm_spi_slave_plat *slave = dev_get_parent_plat(dev);
	struct ti_qspi_priv *priv;
	struct udevice *bus;
	uint words = bitlen >> 3; /* fixed 8-bit word length */
	const uchar *txp = dout;
	uchar *rxp = din;
	uint status;
	int timeout;
	unsigned int cs = slave->cs;

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

	if (cs > priv->num_cs) {
		debug("invalid qspi chip select\n");
		return -EINVAL;
	}

	if (bitlen == 0)
		return -1;

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

	/* Setup command reg */
	priv->cmd = 0;
	priv->cmd |= QSPI_WLEN(8);
	priv->cmd |= QSPI_EN_CS(cs);
	if (priv->mode & SPI_3WIRE)
		priv->cmd |= QSPI_3_PIN;
	priv->cmd |= 0xfff;

	while (words) {
		u8 xfer_len = 0;

		if (txp) {
			u32 cmd = priv->cmd;

			if (words >= QSPI_WLEN_MAX_BYTES) {
				u32 *txbuf = (u32 *)txp;
				u32 data;

				data = cpu_to_be32(*txbuf++);
				writel(data, &priv->base->data3);
				data = cpu_to_be32(*txbuf++);
				writel(data, &priv->base->data2);
				data = cpu_to_be32(*txbuf++);
				writel(data, &priv->base->data1);
				data = cpu_to_be32(*txbuf++);
				writel(data, &priv->base->data);
				cmd &= ~QSPI_WLEN_MASK;
				cmd |= QSPI_WLEN(QSPI_WLEN_MAX_BITS);
				xfer_len = QSPI_WLEN_MAX_BYTES;
			} else {
				writeb(*txp, &priv->base->data);
				xfer_len = 1;
			}
			debug("tx cmd %08x dc %08x\n",
			      cmd | QSPI_WR_SNGL, priv->dc);
			writel(cmd | QSPI_WR_SNGL, &priv->base->cmd);
			status = readl(&priv->base->status);
			timeout = QSPI_TIMEOUT;
			while ((status & QSPI_WC_BUSY) != QSPI_XFER_DONE) {
				if (--timeout < 0) {
					printf("spi_xfer: TX timeout!\n");
					return -1;
				}
				status = readl(&priv->base->status);
			}
			txp += xfer_len;
			debug("tx done, status %08x\n", status);
		}
		if (rxp) {
			debug("rx cmd %08x dc %08x\n",
			      ((u32)(priv->cmd | QSPI_RD_SNGL)), priv->dc);
			writel(priv->cmd | QSPI_RD_SNGL, &priv->base->cmd);
			status = readl(&priv->base->status);
			timeout = QSPI_TIMEOUT;
			while ((status & QSPI_WC_BUSY) != QSPI_XFER_DONE) {
				if (--timeout < 0) {
					printf("spi_xfer: RX timeout!\n");
					return -1;
				}
				status = readl(&priv->base->status);
			}
			*rxp++ = readl(&priv->base->data);
			xfer_len = 1;
			debug("rx done, status %08x, read %02x\n",
			      status, *(rxp-1));
		}
		words -= xfer_len;
	}

	/* Terminate frame */
	if (flags & SPI_XFER_END)
		ti_qspi_cs_deactivate(priv);

	return 0;
}

/* TODO: control from sf layer to here through dm-spi */
static void ti_qspi_copy_mmap(void *data, void *offset, size_t len)
{
#if defined(CONFIG_TI_EDMA3) && !defined(CONFIG_DMA)
	unsigned int			addr = (unsigned int) (data);
	unsigned int			edma_slot_num = 1;

	/* Invalidate the area, so no writeback into the RAM races with DMA */
	invalidate_dcache_range(addr, addr + roundup(len, ARCH_DMA_MINALIGN));

	/* enable edma3 clocks */
	enable_edma3_clocks();

	/* Call edma3 api to do actual DMA transfer	*/
	edma3_transfer(EDMA3_BASE, edma_slot_num, data, offset, len);

	/* disable edma3 clocks */
	disable_edma3_clocks();
#else
	memcpy_fromio(data, offset, len);
#endif

	*((unsigned int *)offset) += len;
}

static void ti_qspi_setup_mmap_read(struct ti_qspi_priv *priv, int cs,
				    u8 opcode, u8 data_nbits, u8 addr_width,
				    u8 dummy_bytes)
{
	u32 memval = opcode;

	switch (data_nbits) {
	case 4:
		memval |= QSPI_SETUP0_READ_QUAD;
		break;
	case 2:
		memval |= QSPI_SETUP0_READ_DUAL;
		break;
	default:
		memval |= QSPI_SETUP0_READ_NORMAL;
		break;
	}

	memval |= ((addr_width - 1) << QSPI_SETUP0_ADDR_SHIFT |
		   dummy_bytes << QSPI_SETUP0_DBITS_SHIFT);

	writel(memval, TI_QSPI_SETUP_REG(priv, cs));
}

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

	priv->dc = 0;
	if (mode & SPI_CPHA)
		priv->dc |= QSPI_CKPHA(0);
	if (mode & SPI_CPOL)
		priv->dc |= QSPI_CKPOL(0);
	if (mode & SPI_CS_HIGH)
		priv->dc |= QSPI_CSPOL(0);

	return 0;
}

static int ti_qspi_exec_mem_op(struct spi_slave *slave,
			       const struct spi_mem_op *op)
{
	struct dm_spi_slave_plat *slave_plat;
	struct ti_qspi_priv *priv;
	struct udevice *bus;
	u32 from = 0;
	int ret = 0;

	bus = slave->dev->parent;
	priv = dev_get_priv(bus);
	slave_plat = dev_get_parent_plat(slave->dev);

	/* Only optimize read path. */
	if (!op->data.nbytes || op->data.dir != SPI_MEM_DATA_IN ||
	    !op->addr.nbytes || op->addr.nbytes > 4)
		return -ENOTSUPP;

	/* Address exceeds MMIO window size, fall back to regular mode. */
	from = op->addr.val;
	if (from + op->data.nbytes > priv->mmap_size)
		return -ENOTSUPP;

	ti_qspi_setup_mmap_read(priv, slave_plat->cs, op->cmd.opcode,
				op->data.buswidth, op->addr.nbytes,
				op->dummy.nbytes);

	ti_qspi_copy_mmap((void *)op->data.buf.in,
			  (void *)priv->memory_map + from, op->data.nbytes);

	return ret;
}

static int ti_qspi_claim_bus(struct udevice *dev)
{
	struct dm_spi_slave_plat *slave_plat = dev_get_parent_plat(dev);
	struct ti_qspi_priv *priv;
	struct udevice *bus;

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

	if (slave_plat->cs > priv->num_cs) {
		debug("invalid qspi chip select\n");
		return -EINVAL;
	}

	writel(MM_SWITCH, &priv->base->memswitch);
	if (priv->ctrl_mod_mmap)
		ti_qspi_ctrl_mode_mmap(priv->ctrl_mod_mmap,
				       slave_plat->cs, true);

	writel(priv->dc, &priv->base->dc);
	writel(0, &priv->base->cmd);
	writel(0, &priv->base->data);

	priv->dc <<= slave_plat->cs * 8;
	writel(priv->dc, &priv->base->dc);

	return 0;
}

static int ti_qspi_release_bus(struct udevice *dev)
{
	struct dm_spi_slave_plat *slave_plat = dev_get_parent_plat(dev);
	struct ti_qspi_priv *priv;
	struct udevice *bus;

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

	writel(~MM_SWITCH, &priv->base->memswitch);
	if (priv->ctrl_mod_mmap)
		ti_qspi_ctrl_mode_mmap(priv->ctrl_mod_mmap,
				       slave_plat->cs, false);

	writel(0, &priv->base->dc);
	writel(0, &priv->base->cmd);
	writel(0, &priv->base->data);
	writel(0, TI_QSPI_SETUP_REG(priv, slave_plat->cs));

	return 0;
}

static int ti_qspi_probe(struct udevice *bus)
{
	struct ti_qspi_priv *priv = dev_get_priv(bus);

	priv->fclk = dev_get_driver_data(bus);

	return 0;
}

static void *map_syscon_chipselects(struct udevice *bus)
{
#if CONFIG_IS_ENABLED(SYSCON)
	struct udevice *syscon;
	struct regmap *regmap;
	const fdt32_t *cell;
	int len, err;

	err = uclass_get_device_by_phandle(UCLASS_SYSCON, bus,
					   "syscon-chipselects", &syscon);
	if (err) {
		debug("%s: unable to find syscon device (%d)\n", __func__,
		      err);
		return NULL;
	}

	regmap = syscon_get_regmap(syscon);
	if (IS_ERR(regmap)) {
		debug("%s: unable to find regmap (%ld)\n", __func__,
		      PTR_ERR(regmap));
		return NULL;
	}

	cell = fdt_getprop(gd->fdt_blob, dev_of_offset(bus),
			   "syscon-chipselects", &len);
	if (len < 2*sizeof(fdt32_t)) {
		debug("%s: offset not available\n", __func__);
		return NULL;
	}

	return fdtdec_get_number(cell + 1, 1) + regmap_get_range(regmap, 0);
#else
	fdt_addr_t addr;
	addr = devfdt_get_addr_index(bus, 2);
	return (addr == FDT_ADDR_T_NONE) ? NULL :
		map_physmem(addr, 0, MAP_NOCACHE);
#endif
}

static int ti_qspi_of_to_plat(struct udevice *bus)
{
	struct ti_qspi_priv *priv = dev_get_priv(bus);
	const void *blob = gd->fdt_blob;
	int node = dev_of_offset(bus);
	fdt_addr_t mmap_addr;
	fdt_addr_t mmap_size;

	priv->ctrl_mod_mmap = map_syscon_chipselects(bus);
	priv->base = map_physmem(dev_read_addr(bus),
				 sizeof(struct ti_qspi_regs), MAP_NOCACHE);
	mmap_addr = devfdt_get_addr_size_index(bus, 1, &mmap_size);
	priv->memory_map = map_physmem(mmap_addr, mmap_size, MAP_NOCACHE);
	priv->mmap_size = mmap_size;

	priv->max_hz = dev_read_u32_default(bus, "spi-max-frequency", 0);
	if (!priv->max_hz) {
		debug("Error: Max frequency missing\n");
		return -ENODEV;
	}
	priv->num_cs = fdtdec_get_int(blob, node, "num-cs", 4);

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

	return 0;
}

static const struct spi_controller_mem_ops ti_qspi_mem_ops = {
	.exec_op = ti_qspi_exec_mem_op,
};

static const struct dm_spi_ops ti_qspi_ops = {
	.claim_bus	= ti_qspi_claim_bus,
	.release_bus	= ti_qspi_release_bus,
	.xfer		= ti_qspi_xfer,
	.set_speed	= ti_qspi_set_speed,
	.set_mode	= ti_qspi_set_mode,
	.mem_ops        = &ti_qspi_mem_ops,
};

static const struct udevice_id ti_qspi_ids[] = {
	{ .compatible = "ti,dra7xxx-qspi",	.data = QSPI_DRA7XX_FCLK},
	{ .compatible = "ti,am4372-qspi",	.data = QSPI_FCLK},
	{ }
};

U_BOOT_DRIVER(ti_qspi) = {
	.name	= "ti_qspi",
	.id	= UCLASS_SPI,
	.of_match = ti_qspi_ids,
	.ops	= &ti_qspi_ops,
	.of_to_plat = ti_qspi_of_to_plat,
	.priv_auto	= sizeof(struct ti_qspi_priv),
	.probe	= ti_qspi_probe,
};