drivers/spi/ftssp010_spi.c - github/trini/u-boot - Gitiles

 /*
  * (C) Copyright 2013
  * Faraday Technology Corporation. <http://www.faraday-tech.com/tw/>
  * Kuo-Jung Su <dantesu@gmail.com>
  *
  * SPDX-License-Identifier:     GPL-2.0+
  */

 #include <common.h>
 #include <linux/compat.h>
 #include <asm/io.h>
 #include <malloc.h>
 #include <spi.h>

 #ifndef CONFIG_FTSSP010_BASE_LIST
 #define CONFIG_FTSSP010_BASE_LIST   { CONFIG_FTSSP010_BASE }
 #endif

 #ifndef CONFIG_FTSSP010_GPIO_BASE
 #define CONFIG_FTSSP010_GPIO_BASE   0
 #endif

 #ifndef CONFIG_FTSSP010_GPIO_LIST
 #define CONFIG_FTSSP010_GPIO_LIST   { CONFIG_FTSSP010_GPIO_BASE }
 #endif

 #ifndef CONFIG_FTSSP010_CLOCK
 #define CONFIG_FTSSP010_CLOCK       clk_get_rate("SSP");
 #endif

 #ifndef CONFIG_FTSSP010_TIMEOUT
 #define CONFIG_FTSSP010_TIMEOUT     100
 #endif

 /* FTSSP010 chip registers */
 struct ftssp010_regs {
 	uint32_t cr[3];/* control register */
 	uint32_t sr;   /* status register */
 	uint32_t icr;  /* interrupt control register */
 	uint32_t isr;  /* interrupt status register */
 	uint32_t dr;   /* data register */
 	uint32_t rsvd[17];
 	uint32_t revr; /* revision register */
 	uint32_t fear; /* feature register */
 };

 /* Control Register 0  */
 #define CR0_FFMT_MASK       (7 << 12)
 #define CR0_FFMT_SSP        (0 << 12)
 #define CR0_FFMT_SPI        (1 << 12)
 #define CR0_FFMT_MICROWIRE  (2 << 12)
 #define CR0_FFMT_I2S        (3 << 12)
 #define CR0_FFMT_AC97       (4 << 12)
 #define CR0_FLASH           (1 << 11)
 #define CR0_FSDIST(x)       (((x) & 0x03) << 8)
 #define CR0_LOOP            (1 << 7)  /* loopback mode */
 #define CR0_LSB             (1 << 6)  /* LSB */
 #define CR0_FSPO            (1 << 5)  /* fs atcive low (I2S only) */
 #define CR0_FSJUSTIFY       (1 << 4)
 #define CR0_OPM_SLAVE       (0 << 2)
 #define CR0_OPM_MASTER      (3 << 2)
 #define CR0_OPM_I2S_MSST    (3 << 2)  /* master stereo mode */
 #define CR0_OPM_I2S_MSMO    (2 << 2)  /* master mono mode */
 #define CR0_OPM_I2S_SLST    (1 << 2)  /* slave stereo mode */
 #define CR0_OPM_I2S_SLMO    (0 << 2)  /* slave mono mode */
 #define CR0_SCLKPO          (1 << 1)  /* clock polarity */
 #define CR0_SCLKPH          (1 << 0)  /* clock phase */

 /* Control Register 1 */
 #define CR1_PDL(x)   (((x) & 0xff) << 24) /* padding length */
 #define CR1_SDL(x)   ((((x) - 1) & 0x1f) << 16) /* data length */
 #define CR1_DIV(x)   (((x) - 1) & 0xffff) /* clock divider */

 /* Control Register 2 */
 #define CR2_CS(x)    (((x) & 3) << 10) /* CS/FS select */
 #define CR2_FS       (1 << 9) /* CS/FS signal level */
 #define CR2_TXEN     (1 << 8) /* tx enable */
 #define CR2_RXEN     (1 << 7) /* rx enable */
 #define CR2_RESET    (1 << 6) /* chip reset */
 #define CR2_TXFC     (1 << 3) /* tx fifo Clear */
 #define CR2_RXFC     (1 << 2) /* rx fifo Clear */
 #define CR2_TXDOE    (1 << 1) /* tx data output enable */
 #define CR2_EN       (1 << 0) /* chip enable */

 /* Status Register */
 #define SR_RFF       (1 << 0) /* rx fifo full */
 #define SR_TFNF      (1 << 1) /* tx fifo not full */
 #define SR_BUSY      (1 << 2) /* chip busy */
 #define SR_RFVE(reg) (((reg) >> 4) & 0x1f)  /* rx fifo valid entries */
 #define SR_TFVE(reg) (((reg) >> 12) & 0x1f) /* tx fifo valid entries */

 /* Feature Register */
 #define FEAR_BITS(reg)   ((((reg) >>  0) & 0xff) + 1) /* data width */
 #define FEAR_RFSZ(reg)   ((((reg) >>  8) & 0xff) + 1) /* rx fifo size */
 #define FEAR_TFSZ(reg)   ((((reg) >> 16) & 0xff) + 1) /* tx fifo size */
 #define FEAR_AC97        (1 << 24)
 #define FEAR_I2S         (1 << 25)
 #define FEAR_SPI_MWR     (1 << 26)
 #define FEAR_SSP         (1 << 27)
 #define FEAR_SPDIF       (1 << 28)

 /* FTGPIO010 chip registers */
 struct ftgpio010_regs {
 	uint32_t out;     /* 0x00: Data Output */
 	uint32_t in;      /* 0x04: Data Input */
 	uint32_t dir;     /* 0x08: Direction */
 	uint32_t bypass;  /* 0x0c: Bypass */
 	uint32_t set;     /* 0x10: Data Set */
 	uint32_t clr;     /* 0x14: Data Clear */
 	uint32_t pull_up; /* 0x18: Pull-Up Enabled */
 	uint32_t pull_st; /* 0x1c: Pull State (0=pull-down, 1=pull-up) */
 };

 struct ftssp010_gpio {
 	struct ftgpio010_regs *regs;
 	uint32_t pin;
 };

 struct ftssp010_spi {
 	struct spi_slave slave;
 	struct ftssp010_gpio gpio;
 	struct ftssp010_regs *regs;
 	uint32_t fifo;
 	uint32_t mode;
 	uint32_t div;
 	uint32_t clk;
 	uint32_t speed;
 	uint32_t revision;
 };

 static inline struct ftssp010_spi *to_ftssp010_spi(struct spi_slave *slave)
 {
 	return container_of(slave, struct ftssp010_spi, slave);
 }

 static int get_spi_chip(int bus, struct ftssp010_spi *chip)
 {
 	uint32_t fear, base[] = CONFIG_FTSSP010_BASE_LIST;

 	if (bus >= ARRAY_SIZE(base) || !base[bus])
 		return -1;

 	chip->regs = (struct ftssp010_regs *)base[bus];

 	chip->revision = readl(&chip->regs->revr);

 	fear = readl(&chip->regs->fear);
 	chip->fifo = min_t(uint32_t, FEAR_TFSZ(fear), FEAR_RFSZ(fear));

 	return 0;
 }

 static int get_spi_gpio(int bus, struct ftssp010_gpio *chip)
 {
 	uint32_t base[] = CONFIG_FTSSP010_GPIO_LIST;

 	if (bus >= ARRAY_SIZE(base) || !base[bus])
 		return -1;

 	chip->regs = (struct ftgpio010_regs *)(base[bus] & 0xfff00000);
 	chip->pin = base[bus] & 0x1f;

 	/* make it an output pin */
 	setbits_le32(&chip->regs->dir, 1 << chip->pin);

 	return 0;
 }

 static int ftssp010_wait(struct ftssp010_spi *chip)
 {
 	struct ftssp010_regs *regs = chip->regs;
 	ulong t;

 	/* wait until device idle */
 	for (t = get_timer(0); get_timer(t) < CONFIG_FTSSP010_TIMEOUT; ) {
 		if (!(readl(&regs->sr) & SR_BUSY))
 			return 0;
 	}

 	puts("ftspi010: busy timeout\n");

 	return -1;
 }

 static int ftssp010_wait_tx(struct ftssp010_spi *chip)
 {
 	struct ftssp010_regs *regs = chip->regs;
 	ulong t;

 	/* wait until tx fifo not full */
 	for (t = get_timer(0); get_timer(t) < CONFIG_FTSSP010_TIMEOUT; ) {
 		if (readl(&regs->sr) & SR_TFNF)
 			return 0;
 	}

 	puts("ftssp010: tx timeout\n");

 	return -1;
 }

 static int ftssp010_wait_rx(struct ftssp010_spi *chip)
 {
 	struct ftssp010_regs *regs = chip->regs;
 	ulong t;

 	/* wait until rx fifo not empty */
 	for (t = get_timer(0); get_timer(t) < CONFIG_FTSSP010_TIMEOUT; ) {
 		if (SR_RFVE(readl(&regs->sr)))
 			return 0;
 	}

 	puts("ftssp010: rx timeout\n");

 	return -1;
 }

 static int ftssp010_spi_work_transfer_v2(struct ftssp010_spi *chip,
 	const void *tx_buf, void *rx_buf, int len, uint flags)
 {
 	struct ftssp010_regs *regs = chip->regs;
 	const uint8_t *txb = tx_buf;
 	uint8_t       *rxb = rx_buf;

 	while (len > 0) {
 		int i, depth = min(chip->fifo >> 2, len);
 		uint32_t xmsk = 0;

 		if (tx_buf) {
 			for (i = 0; i < depth; ++i) {
 				ftssp010_wait_tx(chip);
 				writel(*txb++, &regs->dr);
 			}
 			xmsk |= CR2_TXEN | CR2_TXDOE;
 			if ((readl(&regs->cr[2]) & xmsk) != xmsk)
 				setbits_le32(&regs->cr[2], xmsk);
 		}
 		if (rx_buf) {
 			xmsk |= CR2_RXEN;
 			if ((readl(&regs->cr[2]) & xmsk) != xmsk)
 				setbits_le32(&regs->cr[2], xmsk);
 			for (i = 0; i < depth; ++i) {
 				ftssp010_wait_rx(chip);
 				*rxb++ = (uint8_t)readl(&regs->dr);
 			}
 		}

 		len -= depth;
 	}

 	return 0;
 }

 static int ftssp010_spi_work_transfer_v1(struct ftssp010_spi *chip,
 	const void *tx_buf, void *rx_buf, int len, uint flags)
 {
 	struct ftssp010_regs *regs = chip->regs;
 	const uint8_t *txb = tx_buf;
 	uint8_t       *rxb = rx_buf;

 	while (len > 0) {
 		int i, depth = min(chip->fifo >> 2, len);
 		uint32_t tmp;

 		for (i = 0; i < depth; ++i) {
 			ftssp010_wait_tx(chip);
 			writel(txb ? (*txb++) : 0, &regs->dr);
 		}
 		for (i = 0; i < depth; ++i) {
 			ftssp010_wait_rx(chip);
 			tmp = readl(&regs->dr);
 			if (rxb)
 				*rxb++ = (uint8_t)tmp;
 		}

 		len -= depth;
 	}

 	return 0;
 }

 static void ftssp010_cs_set(struct ftssp010_spi *chip, int high)
 {
 	struct ftssp010_regs *regs = chip->regs;
 	struct ftssp010_gpio *gpio = &chip->gpio;
 	uint32_t mask;

 	/* cs pull high/low */
 	if (chip->revision >= 0x11900) {
 		mask = CR2_CS(chip->slave.cs) | (high ? CR2_FS : 0);
 		writel(mask, &regs->cr[2]);
 	} else if (gpio->regs) {
 		mask = 1 << gpio->pin;
 		if (high)
 			writel(mask, &gpio->regs->set);
 		else
 			writel(mask, &gpio->regs->clr);
 	}

 	/* extra delay for signal propagation */
 	udelay_masked(1);
 }

 /*
  * Determine if a SPI chipselect is valid.
  * This function is provided by the board if the low-level SPI driver
  * needs it to determine if a given chipselect is actually valid.
  *
  * Returns: 1 if bus:cs identifies a valid chip on this board, 0
  * otherwise.
  */
 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
 {
 	struct ftssp010_spi chip;

 	if (get_spi_chip(bus, &chip))
 		return 0;

 	if (!cs)
 		return 1;
 	else if ((cs < 4) && (chip.revision >= 0x11900))
 		return 1;

 	return 0;
 }

 /*
  * Activate a SPI chipselect.
  * This function is provided by the board code when using a driver
  * that can't control its chipselects automatically (e.g.
  * common/soft_spi.c). When called, it should activate the chip select
  * to the device identified by "slave".
  */
 void spi_cs_activate(struct spi_slave *slave)
 {
 	struct ftssp010_spi *chip = to_ftssp010_spi(slave);
 	struct ftssp010_regs *regs = chip->regs;

 	/* cs pull */
 	if (chip->mode & SPI_CS_HIGH)
 		ftssp010_cs_set(chip, 1);
 	else
 		ftssp010_cs_set(chip, 0);

 	/* chip enable + fifo clear */
 	setbits_le32(&regs->cr[2], CR2_EN | CR2_TXFC | CR2_RXFC);
 }

 /*
  * Deactivate a SPI chipselect.
  * This function is provided by the board code when using a driver
  * that can't control its chipselects automatically (e.g.
  * common/soft_spi.c). When called, it should deactivate the chip
  * select to the device identified by "slave".
  */
 void spi_cs_deactivate(struct spi_slave *slave)
 {
 	struct ftssp010_spi *chip = to_ftssp010_spi(slave);

 	/* wait until chip idle */
 	ftssp010_wait(chip);

 	/* cs pull */
 	if (chip->mode & SPI_CS_HIGH)
 		ftssp010_cs_set(chip, 0);
 	else
 		ftssp010_cs_set(chip, 1);
 }

 void spi_init(void)
 {
 	/* nothing to do */
 }

 struct spi_slave *spi_setup_slave(uint bus, uint cs, uint max_hz, uint mode)
 {
 	struct ftssp010_spi *chip;

 	if (mode & SPI_3WIRE) {
 		puts("ftssp010: can't do 3-wire\n");
 		return NULL;
 	}

 	if (mode & SPI_SLAVE) {
 		puts("ftssp010: can't do slave mode\n");
 		return NULL;
 	}

 	if (mode & SPI_PREAMBLE) {
 		puts("ftssp010: can't skip preamble bytes\n");
 		return NULL;
 	}

 	if (!spi_cs_is_valid(bus, cs)) {
 		puts("ftssp010: invalid (bus, cs)\n");
 		return NULL;
 	}

 	chip = spi_alloc_slave(struct ftssp010_spi, bus, cs);
 	if (!chip)
 		return NULL;

 	if (get_spi_chip(bus, chip))
 		goto free_out;

 	if (chip->revision < 0x11900 && get_spi_gpio(bus, &chip->gpio)) {
 		puts("ftssp010: Before revision 1.19.0, its clock & cs are\n"
 		"controlled by tx engine which is not synced with rx engine,\n"
 		"so the clock & cs might be shutdown before rx engine\n"
 		"finishs its jobs.\n"
 		"If possible, please add a dedicated gpio for it.\n");
 	}

 	chip->mode = mode;
 	chip->clk = CONFIG_FTSSP010_CLOCK;
 	chip->div = 2;
 	if (max_hz) {
 		while (chip->div < 0xffff) {
 			if ((chip->clk / (2 * chip->div)) <= max_hz)
 				break;
 			chip->div += 1;
 		}
 	}
 	chip->speed = chip->clk / (2 * chip->div);

 	return &chip->slave;

 free_out:
 	free(chip);
 	return NULL;
 }

 void spi_free_slave(struct spi_slave *slave)
 {
 	free(slave);
 }

 int spi_claim_bus(struct spi_slave *slave)
 {
 	struct ftssp010_spi *chip = to_ftssp010_spi(slave);
 	struct ftssp010_regs *regs = chip->regs;

 	writel(CR1_SDL(8) | CR1_DIV(chip->div), &regs->cr[1]);

 	if (chip->revision >= 0x11900) {
 		writel(CR0_OPM_MASTER | CR0_FFMT_SPI | CR0_FSPO | CR0_FLASH,
 		       &regs->cr[0]);
 		writel(CR2_TXFC | CR2_RXFC,
 		       &regs->cr[2]);
 	} else {
 		writel(CR0_OPM_MASTER | CR0_FFMT_SPI | CR0_FSPO,
 		       &regs->cr[0]);
 		writel(CR2_TXFC | CR2_RXFC | CR2_EN | CR2_TXDOE,
 		       &regs->cr[2]);
 	}

 	if (chip->mode & SPI_LOOP)
 		setbits_le32(&regs->cr[0], CR0_LOOP);

 	if (chip->mode & SPI_CPOL)
 		setbits_le32(&regs->cr[0], CR0_SCLKPO);

 	if (chip->mode & SPI_CPHA)
 		setbits_le32(&regs->cr[0], CR0_SCLKPH);

 	spi_cs_deactivate(slave);

 	return 0;
 }

 void spi_release_bus(struct spi_slave *slave)
 {
 	struct ftssp010_spi *chip = to_ftssp010_spi(slave);
 	struct ftssp010_regs *regs = chip->regs;

 	writel(0, &regs->cr[2]);
 }

 int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
 			 const void *dout, void *din, unsigned long flags)
 {
 	struct ftssp010_spi *chip = to_ftssp010_spi(slave);
 	uint32_t len = bitlen >> 3;

 	if (flags & SPI_XFER_BEGIN)
 		spi_cs_activate(slave);

 	if (chip->revision >= 0x11900)
 		ftssp010_spi_work_transfer_v2(chip, dout, din, len, flags);
 	else
 		ftssp010_spi_work_transfer_v1(chip, dout, din, len, flags);

 	if (flags & SPI_XFER_END)
 		spi_cs_deactivate(slave);

 	return 0;
 }
	/*
	* (C) Copyright 2013
	* Faraday Technology Corporation. <http://www.faraday-tech.com/tw/>
	* Kuo-Jung Su <dantesu@gmail.com>
	*
	* SPDX-License-Identifier: GPL-2.0+
	*/

	#include <common.h>
	#include <linux/compat.h>
	#include <asm/io.h>
	#include <malloc.h>
	#include <spi.h>

	#ifndef CONFIG_FTSSP010_BASE_LIST
	#define CONFIG_FTSSP010_BASE_LIST { CONFIG_FTSSP010_BASE }
	#endif

	#ifndef CONFIG_FTSSP010_GPIO_BASE
	#define CONFIG_FTSSP010_GPIO_BASE 0
	#endif

	#ifndef CONFIG_FTSSP010_GPIO_LIST
	#define CONFIG_FTSSP010_GPIO_LIST { CONFIG_FTSSP010_GPIO_BASE }
	#endif

	#ifndef CONFIG_FTSSP010_CLOCK
	#define CONFIG_FTSSP010_CLOCK clk_get_rate("SSP");
	#endif

	#ifndef CONFIG_FTSSP010_TIMEOUT
	#define CONFIG_FTSSP010_TIMEOUT 100
	#endif

	/* FTSSP010 chip registers */
	struct ftssp010_regs {
	uint32_t cr[3];/* control register */
	uint32_t sr; /* status register */
	uint32_t icr; /* interrupt control register */
	uint32_t isr; /* interrupt status register */
	uint32_t dr; /* data register */
	uint32_t rsvd[17];
	uint32_t revr; /* revision register */
	uint32_t fear; /* feature register */
	};

	/* Control Register 0 */
	#define CR0_FFMT_MASK (7 << 12)
	#define CR0_FFMT_SSP (0 << 12)
	#define CR0_FFMT_SPI (1 << 12)
	#define CR0_FFMT_MICROWIRE (2 << 12)
	#define CR0_FFMT_I2S (3 << 12)
	#define CR0_FFMT_AC97 (4 << 12)
	#define CR0_FLASH (1 << 11)
	#define CR0_FSDIST(x) (((x) & 0x03) << 8)
	#define CR0_LOOP (1 << 7) /* loopback mode */
	#define CR0_LSB (1 << 6) /* LSB */
	#define CR0_FSPO (1 << 5) /* fs atcive low (I2S only) */
	#define CR0_FSJUSTIFY (1 << 4)
	#define CR0_OPM_SLAVE (0 << 2)
	#define CR0_OPM_MASTER (3 << 2)
	#define CR0_OPM_I2S_MSST (3 << 2) /* master stereo mode */
	#define CR0_OPM_I2S_MSMO (2 << 2) /* master mono mode */
	#define CR0_OPM_I2S_SLST (1 << 2) /* slave stereo mode */
	#define CR0_OPM_I2S_SLMO (0 << 2) /* slave mono mode */
	#define CR0_SCLKPO (1 << 1) /* clock polarity */
	#define CR0_SCLKPH (1 << 0) /* clock phase */

	/* Control Register 1 */
	#define CR1_PDL(x) (((x) & 0xff) << 24) /* padding length */
	#define CR1_SDL(x) ((((x) - 1) & 0x1f) << 16) /* data length */
	#define CR1_DIV(x) (((x) - 1) & 0xffff) /* clock divider */

	/* Control Register 2 */
	#define CR2_CS(x) (((x) & 3) << 10) /* CS/FS select */
	#define CR2_FS (1 << 9) /* CS/FS signal level */
	#define CR2_TXEN (1 << 8) /* tx enable */
	#define CR2_RXEN (1 << 7) /* rx enable */
	#define CR2_RESET (1 << 6) /* chip reset */
	#define CR2_TXFC (1 << 3) /* tx fifo Clear */
	#define CR2_RXFC (1 << 2) /* rx fifo Clear */
	#define CR2_TXDOE (1 << 1) /* tx data output enable */
	#define CR2_EN (1 << 0) /* chip enable */

	/* Status Register */
	#define SR_RFF (1 << 0) /* rx fifo full */
	#define SR_TFNF (1 << 1) /* tx fifo not full */
	#define SR_BUSY (1 << 2) /* chip busy */
	#define SR_RFVE(reg) (((reg) >> 4) & 0x1f) /* rx fifo valid entries */
	#define SR_TFVE(reg) (((reg) >> 12) & 0x1f) /* tx fifo valid entries */

	/* Feature Register */
	#define FEAR_BITS(reg) ((((reg) >> 0) & 0xff) + 1) /* data width */
	#define FEAR_RFSZ(reg) ((((reg) >> 8) & 0xff) + 1) /* rx fifo size */
	#define FEAR_TFSZ(reg) ((((reg) >> 16) & 0xff) + 1) /* tx fifo size */
	#define FEAR_AC97 (1 << 24)
	#define FEAR_I2S (1 << 25)
	#define FEAR_SPI_MWR (1 << 26)
	#define FEAR_SSP (1 << 27)
	#define FEAR_SPDIF (1 << 28)

	/* FTGPIO010 chip registers */
	struct ftgpio010_regs {
	uint32_t out; /* 0x00: Data Output */
	uint32_t in; /* 0x04: Data Input */
	uint32_t dir; /* 0x08: Direction */
	uint32_t bypass; /* 0x0c: Bypass */
	uint32_t set; /* 0x10: Data Set */
	uint32_t clr; /* 0x14: Data Clear */
	uint32_t pull_up; /* 0x18: Pull-Up Enabled */
	uint32_t pull_st; /* 0x1c: Pull State (0=pull-down, 1=pull-up) */
	};

	struct ftssp010_gpio {
	struct ftgpio010_regs *regs;
	uint32_t pin;
	};

	struct ftssp010_spi {
	struct spi_slave slave;
	struct ftssp010_gpio gpio;
	struct ftssp010_regs *regs;
	uint32_t fifo;
	uint32_t mode;
	uint32_t div;
	uint32_t clk;
	uint32_t speed;
	uint32_t revision;
	};

	static inline struct ftssp010_spi to_ftssp010_spi(struct spi_slave slave)
	{
	return container_of(slave, struct ftssp010_spi, slave);
	}

	static int get_spi_chip(int bus, struct ftssp010_spi *chip)
	{
	uint32_t fear, base[] = CONFIG_FTSSP010_BASE_LIST;

	if (bus >= ARRAY_SIZE(base) \|\| !base[bus])
	return -1;

	chip->regs = (struct ftssp010_regs *)base[bus];

	chip->revision = readl(&chip->regs->revr);

	fear = readl(&chip->regs->fear);
	chip->fifo = min_t(uint32_t, FEAR_TFSZ(fear), FEAR_RFSZ(fear));

	return 0;
	}

	static int get_spi_gpio(int bus, struct ftssp010_gpio *chip)
	{
	uint32_t base[] = CONFIG_FTSSP010_GPIO_LIST;

	if (bus >= ARRAY_SIZE(base) \|\| !base[bus])
	return -1;

	chip->regs = (struct ftgpio010_regs *)(base[bus] & 0xfff00000);
	chip->pin = base[bus] & 0x1f;

	/* make it an output pin */
	setbits_le32(&chip->regs->dir, 1 << chip->pin);

	return 0;
	}

	static int ftssp010_wait(struct ftssp010_spi *chip)
	{
	struct ftssp010_regs *regs = chip->regs;
	ulong t;

	/* wait until device idle */
	for (t = get_timer(0); get_timer(t) < CONFIG_FTSSP010_TIMEOUT; ) {
	if (!(readl(&regs->sr) & SR_BUSY))
	return 0;
	}

	puts("ftspi010: busy timeout\n");

	return -1;
	}

	static int ftssp010_wait_tx(struct ftssp010_spi *chip)
	{
	struct ftssp010_regs *regs = chip->regs;
	ulong t;

	/* wait until tx fifo not full */
	for (t = get_timer(0); get_timer(t) < CONFIG_FTSSP010_TIMEOUT; ) {
	if (readl(&regs->sr) & SR_TFNF)
	return 0;
	}

	puts("ftssp010: tx timeout\n");

	return -1;
	}

	static int ftssp010_wait_rx(struct ftssp010_spi *chip)
	{
	struct ftssp010_regs *regs = chip->regs;
	ulong t;

	/* wait until rx fifo not empty */
	for (t = get_timer(0); get_timer(t) < CONFIG_FTSSP010_TIMEOUT; ) {
	if (SR_RFVE(readl(&regs->sr)))
	return 0;
	}

	puts("ftssp010: rx timeout\n");

	return -1;
	}

	static int ftssp010_spi_work_transfer_v2(struct ftssp010_spi *chip,
	const void tx_buf, void rx_buf, int len, uint flags)
	{
	struct ftssp010_regs *regs = chip->regs;
	const uint8_t *txb = tx_buf;
	uint8_t *rxb = rx_buf;

	while (len > 0) {
	int i, depth = min(chip->fifo >> 2, len);
	uint32_t xmsk = 0;

	if (tx_buf) {
	for (i = 0; i < depth; ++i) {
	ftssp010_wait_tx(chip);
	writel(*txb++, &regs->dr);
	}
	xmsk \|= CR2_TXEN \| CR2_TXDOE;
	if ((readl(&regs->cr[2]) & xmsk) != xmsk)
	setbits_le32(&regs->cr[2], xmsk);
	}
	if (rx_buf) {
	xmsk \|= CR2_RXEN;
	if ((readl(&regs->cr[2]) & xmsk) != xmsk)
	setbits_le32(&regs->cr[2], xmsk);
	for (i = 0; i < depth; ++i) {
	ftssp010_wait_rx(chip);
	*rxb++ = (uint8_t)readl(&regs->dr);
	}
	}

	len -= depth;
	}

	return 0;
	}

	static int ftssp010_spi_work_transfer_v1(struct ftssp010_spi *chip,
	const void tx_buf, void rx_buf, int len, uint flags)
	{
	struct ftssp010_regs *regs = chip->regs;
	const uint8_t *txb = tx_buf;
	uint8_t *rxb = rx_buf;

	while (len > 0) {
	int i, depth = min(chip->fifo >> 2, len);
	uint32_t tmp;

	for (i = 0; i < depth; ++i) {
	ftssp010_wait_tx(chip);
	writel(txb ? (*txb++) : 0, &regs->dr);
	}
	for (i = 0; i < depth; ++i) {
	ftssp010_wait_rx(chip);
	tmp = readl(&regs->dr);
	if (rxb)
	*rxb++ = (uint8_t)tmp;
	}

	len -= depth;
	}

	return 0;
	}

	static void ftssp010_cs_set(struct ftssp010_spi *chip, int high)
	{
	struct ftssp010_regs *regs = chip->regs;
	struct ftssp010_gpio *gpio = &chip->gpio;
	uint32_t mask;

	/* cs pull high/low */
	if (chip->revision >= 0x11900) {
	mask = CR2_CS(chip->slave.cs) \| (high ? CR2_FS : 0);
	writel(mask, &regs->cr[2]);
	} else if (gpio->regs) {
	mask = 1 << gpio->pin;
	if (high)
	writel(mask, &gpio->regs->set);
	else
	writel(mask, &gpio->regs->clr);
	}

	/* extra delay for signal propagation */
	udelay_masked(1);
	}

	/*
	* Determine if a SPI chipselect is valid.
	* This function is provided by the board if the low-level SPI driver
	* needs it to determine if a given chipselect is actually valid.
	*
	* Returns: 1 if bus:cs identifies a valid chip on this board, 0
	* otherwise.
	*/
	int spi_cs_is_valid(unsigned int bus, unsigned int cs)
	{
	struct ftssp010_spi chip;

	if (get_spi_chip(bus, &chip))
	return 0;

	if (!cs)
	return 1;
	else if ((cs < 4) && (chip.revision >= 0x11900))
	return 1;

	return 0;
	}

	/*
	* Activate a SPI chipselect.
	* This function is provided by the board code when using a driver
	* that can't control its chipselects automatically (e.g.
	* common/soft_spi.c). When called, it should activate the chip select
	* to the device identified by "slave".
	*/
	void spi_cs_activate(struct spi_slave *slave)
	{
	struct ftssp010_spi *chip = to_ftssp010_spi(slave);
	struct ftssp010_regs *regs = chip->regs;

	/* cs pull */
	if (chip->mode & SPI_CS_HIGH)
	ftssp010_cs_set(chip, 1);
	else
	ftssp010_cs_set(chip, 0);

	/* chip enable + fifo clear */
	setbits_le32(&regs->cr[2], CR2_EN \| CR2_TXFC \| CR2_RXFC);
	}

	/*
	* Deactivate a SPI chipselect.
	* This function is provided by the board code when using a driver
	* that can't control its chipselects automatically (e.g.
	* common/soft_spi.c). When called, it should deactivate the chip
	* select to the device identified by "slave".
	*/
	void spi_cs_deactivate(struct spi_slave *slave)
	{
	struct ftssp010_spi *chip = to_ftssp010_spi(slave);

	/* wait until chip idle */
	ftssp010_wait(chip);

	/* cs pull */
	if (chip->mode & SPI_CS_HIGH)
	ftssp010_cs_set(chip, 0);
	else
	ftssp010_cs_set(chip, 1);
	}

	void spi_init(void)
	{
	/* nothing to do */
	}

	struct spi_slave *spi_setup_slave(uint bus, uint cs, uint max_hz, uint mode)
	{
	struct ftssp010_spi *chip;

	if (mode & SPI_3WIRE) {
	puts("ftssp010: can't do 3-wire\n");
	return NULL;
	}

	if (mode & SPI_SLAVE) {
	puts("ftssp010: can't do slave mode\n");
	return NULL;
	}

	if (mode & SPI_PREAMBLE) {
	puts("ftssp010: can't skip preamble bytes\n");
	return NULL;
	}

	if (!spi_cs_is_valid(bus, cs)) {
	puts("ftssp010: invalid (bus, cs)\n");
	return NULL;
	}

	chip = spi_alloc_slave(struct ftssp010_spi, bus, cs);
	if (!chip)
	return NULL;

	if (get_spi_chip(bus, chip))
	goto free_out;

	if (chip->revision < 0x11900 && get_spi_gpio(bus, &chip->gpio)) {
	puts("ftssp010: Before revision 1.19.0, its clock & cs are\n"
	"controlled by tx engine which is not synced with rx engine,\n"
	"so the clock & cs might be shutdown before rx engine\n"
	"finishs its jobs.\n"
	"If possible, please add a dedicated gpio for it.\n");
	}

	chip->mode = mode;
	chip->clk = CONFIG_FTSSP010_CLOCK;
	chip->div = 2;
	if (max_hz) {
	while (chip->div < 0xffff) {
	if ((chip->clk / (2 * chip->div)) <= max_hz)
	break;
	chip->div += 1;
	}
	}
	chip->speed = chip->clk / (2 * chip->div);

	return &chip->slave;

	free_out:
	free(chip);
	return NULL;
	}

	void spi_free_slave(struct spi_slave *slave)
	{
	free(slave);
	}

	int spi_claim_bus(struct spi_slave *slave)
	{
	struct ftssp010_spi *chip = to_ftssp010_spi(slave);
	struct ftssp010_regs *regs = chip->regs;

	writel(CR1_SDL(8) \| CR1_DIV(chip->div), &regs->cr[1]);

	if (chip->revision >= 0x11900) {
	writel(CR0_OPM_MASTER \| CR0_FFMT_SPI \| CR0_FSPO \| CR0_FLASH,
	&regs->cr[0]);
	writel(CR2_TXFC \| CR2_RXFC,
	&regs->cr[2]);
	} else {
	writel(CR0_OPM_MASTER \| CR0_FFMT_SPI \| CR0_FSPO,
	&regs->cr[0]);
	writel(CR2_TXFC \| CR2_RXFC \| CR2_EN \| CR2_TXDOE,
	&regs->cr[2]);
	}

	if (chip->mode & SPI_LOOP)
	setbits_le32(&regs->cr[0], CR0_LOOP);

	if (chip->mode & SPI_CPOL)
	setbits_le32(&regs->cr[0], CR0_SCLKPO);

	if (chip->mode & SPI_CPHA)
	setbits_le32(&regs->cr[0], CR0_SCLKPH);

	spi_cs_deactivate(slave);

	return 0;
	}

	void spi_release_bus(struct spi_slave *slave)
	{
	struct ftssp010_spi *chip = to_ftssp010_spi(slave);
	struct ftssp010_regs *regs = chip->regs;

	writel(0, &regs->cr[2]);
	}

	int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
	const void dout, void din, unsigned long flags)
	{
	struct ftssp010_spi *chip = to_ftssp010_spi(slave);
	uint32_t len = bitlen >> 3;

	if (flags & SPI_XFER_BEGIN)
	spi_cs_activate(slave);

	if (chip->revision >= 0x11900)
	ftssp010_spi_work_transfer_v2(chip, dout, din, len, flags);
	else
	ftssp010_spi_work_transfer_v1(chip, dout, din, len, flags);

	if (flags & SPI_XFER_END)
	spi_cs_deactivate(slave);

	return 0;
	}