drivers/spi/mvebu_a3700_spi.c - filogic/uboot - Gitiles

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (C) 2015 Marvell International Ltd.
  *
  * Copyright (C) 2016 Stefan Roese <sr@denx.de>
  */

 #include <dm.h>
 #include <log.h>
 #include <malloc.h>
 #include <spi.h>
 #include <clk.h>
 #include <wait_bit.h>
 #include <asm/global_data.h>
 #include <asm/io.h>
 #include <dm/device_compat.h>
 #include <linux/bitops.h>
 #include <asm/gpio.h>

 DECLARE_GLOBAL_DATA_PTR;

 #define MVEBU_SPI_A3700_XFER_RDY		BIT(1)
 #define MVEBU_SPI_A3700_FIFO_FLUSH		BIT(9)
 #define MVEBU_SPI_A3700_BYTE_LEN		BIT(5)
 #define MVEBU_SPI_A3700_CLK_PHA			BIT(6)
 #define MVEBU_SPI_A3700_CLK_POL			BIT(7)
 #define MVEBU_SPI_A3700_FIFO_EN			BIT(17)
 #define MVEBU_SPI_A3700_SPI_EN_0		BIT(16)
 #define MVEBU_SPI_A3700_CLK_PRESCALE_MASK	0x1f

 #define MAX_CS_COUNT	4

 /* SPI registers */
 struct spi_reg {
 	u32 ctrl;	/* 0x10600 */
 	u32 cfg;	/* 0x10604 */
 	u32 dout;	/* 0x10608 */
 	u32 din;	/* 0x1060c */
 };

 struct mvebu_spi_plat {
 	struct spi_reg *spireg;
 	struct clk clk;
 	struct gpio_desc cs_gpios[MAX_CS_COUNT];
 };

 static void spi_cs_activate(struct mvebu_spi_plat *plat, int cs)
 {
 	if (CONFIG_IS_ENABLED(DM_GPIO) && dm_gpio_is_valid(&plat->cs_gpios[cs]))
 		dm_gpio_set_value(&plat->cs_gpios[cs], 1);
 	else
 		setbits_le32(&plat->spireg->ctrl, MVEBU_SPI_A3700_SPI_EN_0 << cs);
 }

 static void spi_cs_deactivate(struct mvebu_spi_plat *plat, int cs)
 {
 	if (CONFIG_IS_ENABLED(DM_GPIO) && dm_gpio_is_valid(&plat->cs_gpios[cs]))
 		dm_gpio_set_value(&plat->cs_gpios[cs], 0);
 	else
 		clrbits_le32(&plat->spireg->ctrl, MVEBU_SPI_A3700_SPI_EN_0 << cs);
 }

 /**
  * spi_legacy_shift_byte() - triggers the real SPI transfer
  * @bytelen:	Indicate how many bytes to transfer.
  * @dout:	Buffer address of what to send.
  * @din:	Buffer address of where to receive.
  *
  * This function triggers the real SPI transfer in legacy mode. It
  * will shift out char buffer from @dout, and shift in char buffer to
  * @din, if necessary.
  *
  * This function assumes that only one byte is shifted at one time.
  * However, it is not its responisbility to set the transfer type to
  * one-byte. Also, it does not guarantee that it will work if transfer
  * type becomes two-byte. See spi_set_legacy() for details.
  *
  * In legacy mode, simply write to the SPI_DOUT register will trigger
  * the transfer.
  *
  * If @dout == NULL, which means no actual data needs to be sent out,
  * then the function will shift out 0x00 in order to shift in data.
  * The XFER_RDY flag is checked every time before accessing SPI_DOUT
  * and SPI_DIN register.
  *
  * The number of transfers to be triggered is decided by @bytelen.
  *
  * Return:	0 - cool
  *		-ETIMEDOUT - XFER_RDY flag timeout
  */
 static int spi_legacy_shift_byte(struct spi_reg *reg, unsigned int bytelen,
 				 const void *dout, void *din)
 {
 	const u8 *dout_8;
 	u8 *din_8;
 	int ret;

 	/* Use 0x00 as dummy dout */
 	const u8 dummy_dout = 0x0;
 	u32 pending_dout = 0x0;

 	/* dout_8: pointer of current dout */
 	dout_8 = dout;
 	/* din_8: pointer of current din */
 	din_8 = din;

 	while (bytelen) {
 		ret = wait_for_bit_le32(&reg->ctrl,
 					MVEBU_SPI_A3700_XFER_RDY,
 					true,100, false);
 		if (ret)
 			return ret;

 		if (dout)
 			pending_dout = (u32)*dout_8;
 		else
 			pending_dout = (u32)dummy_dout;

 		/* Trigger the xfer */
 		writel(pending_dout, &reg->dout);

 		if (din) {
 			ret = wait_for_bit_le32(&reg->ctrl,
 						MVEBU_SPI_A3700_XFER_RDY,
 						true, 100, false);
 			if (ret)
 				return ret;

 			/* Read what is transferred in */
 			*din_8 = (u8)readl(&reg->din);
 		}

 		/* Don't increment the current pointer if NULL */
 		if (dout)
 			dout_8++;
 		if (din)
 			din_8++;

 		bytelen--;
 	}

 	return 0;
 }

 static int mvebu_spi_xfer(struct udevice *dev, unsigned int bitlen,
 			  const void *dout, void *din, unsigned long flags)
 {
 	struct udevice *bus = dev->parent;
 	struct mvebu_spi_plat *plat = dev_get_plat(bus);
 	struct spi_reg *reg = plat->spireg;
 	unsigned int bytelen;
 	int ret;

 	bytelen = bitlen / 8;

 	if (dout && din)
 		debug("This is a duplex transfer.\n");

 	/* Activate CS */
 	if (flags & SPI_XFER_BEGIN) {
 		debug("SPI: activate cs.\n");
 		spi_cs_activate(plat, spi_chip_select(dev));
 	}

 	/* Send and/or receive */
 	if (dout || din) {
 		ret = spi_legacy_shift_byte(reg, bytelen, dout, din);
 		if (ret)
 			return ret;
 	}

 	/* Deactivate CS */
 	if (flags & SPI_XFER_END) {
 		ret = wait_for_bit_le32(&reg->ctrl,
 					MVEBU_SPI_A3700_XFER_RDY,
 					true, 100, false);
 		if (ret)
 			return ret;

 		debug("SPI: deactivate cs.\n");
 		spi_cs_deactivate(plat, spi_chip_select(dev));
 	}

 	return 0;
 }

 static int mvebu_spi_set_speed(struct udevice *bus, uint hz)
 {
 	struct mvebu_spi_plat *plat = dev_get_plat(bus);
 	struct spi_reg *reg = plat->spireg;
 	u32 data, prescale;

 	data = readl(&reg->cfg);

 	prescale = DIV_ROUND_UP(clk_get_rate(&plat->clk), hz);
 	if (prescale > 0xf)
 		prescale = 0x10 + (prescale + 1) / 2;
 	prescale = min(prescale, 0x1fu);

 	data &= ~MVEBU_SPI_A3700_CLK_PRESCALE_MASK;
 	data |= prescale & MVEBU_SPI_A3700_CLK_PRESCALE_MASK;

 	writel(data, &reg->cfg);

 	return 0;
 }

 static int mvebu_spi_set_mode(struct udevice *bus, uint mode)
 {
 	struct mvebu_spi_plat *plat = dev_get_plat(bus);
 	struct spi_reg *reg = plat->spireg;

 	/*
 	 * Set SPI polarity
 	 * 0: Serial interface clock is low when inactive
 	 * 1: Serial interface clock is high when inactive
 	 */
 	if (mode & SPI_CPOL)
 		setbits_le32(&reg->cfg, MVEBU_SPI_A3700_CLK_POL);
 	else
 		clrbits_le32(&reg->cfg, MVEBU_SPI_A3700_CLK_POL);
 	if (mode & SPI_CPHA)
 		setbits_le32(&reg->cfg, MVEBU_SPI_A3700_CLK_PHA);
 	else
 		clrbits_le32(&reg->cfg, MVEBU_SPI_A3700_CLK_PHA);

 	return 0;
 }

 static int mvebu_spi_probe(struct udevice *bus)
 {
 	struct mvebu_spi_plat *plat = dev_get_plat(bus);
 	struct spi_reg *reg = plat->spireg;
 	u32 data;
 	int ret;

 	/*
 	 * Settings SPI controller to be working in legacy mode, which
 	 * means use only DO pin (I/O 1) for Data Out, and DI pin (I/O 0)
 	 * for Data In.
 	 */

 	/* Flush read/write FIFO */
 	data = readl(&reg->cfg);
 	writel(data | MVEBU_SPI_A3700_FIFO_FLUSH, &reg->cfg);
 	ret = wait_for_bit_le32(&reg->cfg, MVEBU_SPI_A3700_FIFO_FLUSH,
 				false, 1000, false);
 	if (ret)
 		return ret;

 	/* Disable FIFO mode */
 	data &= ~MVEBU_SPI_A3700_FIFO_EN;

 	/* Always shift 1 byte at a time */
 	data &= ~MVEBU_SPI_A3700_BYTE_LEN;

 	writel(data, &reg->cfg);

 	/* Set up CS GPIOs in device tree, if any */
 	if (CONFIG_IS_ENABLED(DM_GPIO) && gpio_get_list_count(bus, "cs-gpios") > 0) {
 		int i;

 		for (i = 0; i < ARRAY_SIZE(plat->cs_gpios); i++) {
 			ret = gpio_request_by_name(bus, "cs-gpios", i, &plat->cs_gpios[i], 0);
 			if (ret < 0 || !dm_gpio_is_valid(&plat->cs_gpios[i])) {
 				/* Use the native CS function for this line */
 				continue;
 			}

 			ret = dm_gpio_set_dir_flags(&plat->cs_gpios[i],
 						    GPIOD_IS_OUT | GPIOD_ACTIVE_LOW);
 			if (ret) {
 				dev_err(bus, "Setting cs %d error\n", i);
 				return ret;
 			}
 		}
 	}

 	return 0;
 }

 static int mvebu_spi_of_to_plat(struct udevice *bus)
 {
 	struct mvebu_spi_plat *plat = dev_get_plat(bus);
 	int ret;

 	plat->spireg = dev_read_addr_ptr(bus);

 	ret = clk_get_by_index(bus, 0, &plat->clk);
 	if (ret) {
 		dev_err(bus, "cannot get clock\n");
 		return ret;
 	}

 	return 0;
 }

 static const struct dm_spi_ops mvebu_spi_ops = {
 	.xfer		= mvebu_spi_xfer,
 	.set_speed	= mvebu_spi_set_speed,
 	.set_mode	= mvebu_spi_set_mode,
 	/*
 	 * cs_info is not needed, since we require all chip selects to be
 	 * in the device tree explicitly
 	 */
 };

 static const struct udevice_id mvebu_spi_ids[] = {
 	{ .compatible = "marvell,armada-3700-spi" },
 	{ }
 };

 U_BOOT_DRIVER(mvebu_spi) = {
 	.name = "mvebu_spi",
 	.id = UCLASS_SPI,
 	.of_match = mvebu_spi_ids,
 	.ops = &mvebu_spi_ops,
 	.of_to_plat = mvebu_spi_of_to_plat,
 	.plat_auto	= sizeof(struct mvebu_spi_plat),
 	.probe = mvebu_spi_probe,
 };
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* Copyright (C) 2015 Marvell International Ltd.
	*
	* Copyright (C) 2016 Stefan Roese <sr@denx.de>
	*/

	#include <dm.h>
	#include <log.h>
	#include <malloc.h>
	#include <spi.h>
	#include <clk.h>
	#include <wait_bit.h>
	#include <asm/global_data.h>
	#include <asm/io.h>
	#include <dm/device_compat.h>
	#include <linux/bitops.h>
	#include <asm/gpio.h>

	DECLARE_GLOBAL_DATA_PTR;

	#define MVEBU_SPI_A3700_XFER_RDY BIT(1)
	#define MVEBU_SPI_A3700_FIFO_FLUSH BIT(9)
	#define MVEBU_SPI_A3700_BYTE_LEN BIT(5)
	#define MVEBU_SPI_A3700_CLK_PHA BIT(6)
	#define MVEBU_SPI_A3700_CLK_POL BIT(7)
	#define MVEBU_SPI_A3700_FIFO_EN BIT(17)
	#define MVEBU_SPI_A3700_SPI_EN_0 BIT(16)
	#define MVEBU_SPI_A3700_CLK_PRESCALE_MASK 0x1f

	#define MAX_CS_COUNT 4

	/* SPI registers */
	struct spi_reg {
	u32 ctrl; /* 0x10600 */
	u32 cfg; /* 0x10604 */
	u32 dout; /* 0x10608 */
	u32 din; /* 0x1060c */
	};

	struct mvebu_spi_plat {
	struct spi_reg *spireg;
	struct clk clk;
	struct gpio_desc cs_gpios[MAX_CS_COUNT];
	};

	static void spi_cs_activate(struct mvebu_spi_plat *plat, int cs)
	{
	if (CONFIG_IS_ENABLED(DM_GPIO) && dm_gpio_is_valid(&plat->cs_gpios[cs]))
	dm_gpio_set_value(&plat->cs_gpios[cs], 1);
	else
	setbits_le32(&plat->spireg->ctrl, MVEBU_SPI_A3700_SPI_EN_0 << cs);
	}

	static void spi_cs_deactivate(struct mvebu_spi_plat *plat, int cs)
	{
	if (CONFIG_IS_ENABLED(DM_GPIO) && dm_gpio_is_valid(&plat->cs_gpios[cs]))
	dm_gpio_set_value(&plat->cs_gpios[cs], 0);
	else
	clrbits_le32(&plat->spireg->ctrl, MVEBU_SPI_A3700_SPI_EN_0 << cs);
	}

	/**
	* spi_legacy_shift_byte() - triggers the real SPI transfer
	* @bytelen: Indicate how many bytes to transfer.
	* @dout: Buffer address of what to send.
	* @din: Buffer address of where to receive.
	*
	* This function triggers the real SPI transfer in legacy mode. It
	* will shift out char buffer from @dout, and shift in char buffer to
	* @din, if necessary.
	*
	* This function assumes that only one byte is shifted at one time.
	* However, it is not its responisbility to set the transfer type to
	* one-byte. Also, it does not guarantee that it will work if transfer
	* type becomes two-byte. See spi_set_legacy() for details.
	*
	* In legacy mode, simply write to the SPI_DOUT register will trigger
	* the transfer.
	*
	* If @dout == NULL, which means no actual data needs to be sent out,
	* then the function will shift out 0x00 in order to shift in data.
	* The XFER_RDY flag is checked every time before accessing SPI_DOUT
	* and SPI_DIN register.
	*
	* The number of transfers to be triggered is decided by @bytelen.
	*
	* Return: 0 - cool
	* -ETIMEDOUT - XFER_RDY flag timeout
	*/
	static int spi_legacy_shift_byte(struct spi_reg *reg, unsigned int bytelen,
	const void dout, void din)
	{
	const u8 *dout_8;
	u8 *din_8;
	int ret;

	/* Use 0x00 as dummy dout */
	const u8 dummy_dout = 0x0;
	u32 pending_dout = 0x0;

	/* dout_8: pointer of current dout */
	dout_8 = dout;
	/* din_8: pointer of current din */
	din_8 = din;

	while (bytelen) {
	ret = wait_for_bit_le32(&reg->ctrl,
	MVEBU_SPI_A3700_XFER_RDY,
	true,100, false);
	if (ret)
	return ret;

	if (dout)
	pending_dout = (u32)*dout_8;
	else
	pending_dout = (u32)dummy_dout;

	/* Trigger the xfer */
	writel(pending_dout, &reg->dout);

	if (din) {
	ret = wait_for_bit_le32(&reg->ctrl,
	MVEBU_SPI_A3700_XFER_RDY,
	true, 100, false);
	if (ret)
	return ret;

	/* Read what is transferred in */
	*din_8 = (u8)readl(&reg->din);
	}

	/* Don't increment the current pointer if NULL */
	if (dout)
	dout_8++;
	if (din)
	din_8++;

	bytelen--;
	}

	return 0;
	}

	static int mvebu_spi_xfer(struct udevice *dev, unsigned int bitlen,
	const void dout, void din, unsigned long flags)
	{
	struct udevice *bus = dev->parent;
	struct mvebu_spi_plat *plat = dev_get_plat(bus);
	struct spi_reg *reg = plat->spireg;
	unsigned int bytelen;
	int ret;

	bytelen = bitlen / 8;

	if (dout && din)
	debug("This is a duplex transfer.\n");

	/* Activate CS */
	if (flags & SPI_XFER_BEGIN) {
	debug("SPI: activate cs.\n");
	spi_cs_activate(plat, spi_chip_select(dev));
	}

	/* Send and/or receive */
	if (dout \|\| din) {
	ret = spi_legacy_shift_byte(reg, bytelen, dout, din);
	if (ret)
	return ret;
	}

	/* Deactivate CS */
	if (flags & SPI_XFER_END) {
	ret = wait_for_bit_le32(&reg->ctrl,
	MVEBU_SPI_A3700_XFER_RDY,
	true, 100, false);
	if (ret)
	return ret;

	debug("SPI: deactivate cs.\n");
	spi_cs_deactivate(plat, spi_chip_select(dev));
	}

	return 0;
	}

	static int mvebu_spi_set_speed(struct udevice *bus, uint hz)
	{
	struct mvebu_spi_plat *plat = dev_get_plat(bus);
	struct spi_reg *reg = plat->spireg;
	u32 data, prescale;

	data = readl(&reg->cfg);

	prescale = DIV_ROUND_UP(clk_get_rate(&plat->clk), hz);
	if (prescale > 0xf)
	prescale = 0x10 + (prescale + 1) / 2;
	prescale = min(prescale, 0x1fu);

	data &= ~MVEBU_SPI_A3700_CLK_PRESCALE_MASK;
	data \|= prescale & MVEBU_SPI_A3700_CLK_PRESCALE_MASK;

	writel(data, &reg->cfg);

	return 0;
	}

	static int mvebu_spi_set_mode(struct udevice *bus, uint mode)
	{
	struct mvebu_spi_plat *plat = dev_get_plat(bus);
	struct spi_reg *reg = plat->spireg;

	/*
	* Set SPI polarity
	* 0: Serial interface clock is low when inactive
	* 1: Serial interface clock is high when inactive
	*/
	if (mode & SPI_CPOL)
	setbits_le32(&reg->cfg, MVEBU_SPI_A3700_CLK_POL);
	else
	clrbits_le32(&reg->cfg, MVEBU_SPI_A3700_CLK_POL);
	if (mode & SPI_CPHA)
	setbits_le32(&reg->cfg, MVEBU_SPI_A3700_CLK_PHA);
	else
	clrbits_le32(&reg->cfg, MVEBU_SPI_A3700_CLK_PHA);

	return 0;
	}

	static int mvebu_spi_probe(struct udevice *bus)
	{
	struct mvebu_spi_plat *plat = dev_get_plat(bus);
	struct spi_reg *reg = plat->spireg;
	u32 data;
	int ret;

	/*
	* Settings SPI controller to be working in legacy mode, which
	* means use only DO pin (I/O 1) for Data Out, and DI pin (I/O 0)
	* for Data In.
	*/

	/* Flush read/write FIFO */
	data = readl(&reg->cfg);
	writel(data \| MVEBU_SPI_A3700_FIFO_FLUSH, &reg->cfg);
	ret = wait_for_bit_le32(&reg->cfg, MVEBU_SPI_A3700_FIFO_FLUSH,
	false, 1000, false);
	if (ret)
	return ret;

	/* Disable FIFO mode */
	data &= ~MVEBU_SPI_A3700_FIFO_EN;

	/* Always shift 1 byte at a time */
	data &= ~MVEBU_SPI_A3700_BYTE_LEN;

	writel(data, &reg->cfg);

	/* Set up CS GPIOs in device tree, if any */
	if (CONFIG_IS_ENABLED(DM_GPIO) && gpio_get_list_count(bus, "cs-gpios") > 0) {
	int i;

	for (i = 0; i < ARRAY_SIZE(plat->cs_gpios); i++) {
	ret = gpio_request_by_name(bus, "cs-gpios", i, &plat->cs_gpios[i], 0);
	if (ret < 0 \|\| !dm_gpio_is_valid(&plat->cs_gpios[i])) {
	/* Use the native CS function for this line */
	continue;
	}

	ret = dm_gpio_set_dir_flags(&plat->cs_gpios[i],
	GPIOD_IS_OUT \| GPIOD_ACTIVE_LOW);
	if (ret) {
	dev_err(bus, "Setting cs %d error\n", i);
	return ret;
	}
	}
	}

	return 0;
	}

	static int mvebu_spi_of_to_plat(struct udevice *bus)
	{
	struct mvebu_spi_plat *plat = dev_get_plat(bus);
	int ret;

	plat->spireg = dev_read_addr_ptr(bus);

	ret = clk_get_by_index(bus, 0, &plat->clk);
	if (ret) {
	dev_err(bus, "cannot get clock\n");
	return ret;
	}

	return 0;
	}

	static const struct dm_spi_ops mvebu_spi_ops = {
	.xfer = mvebu_spi_xfer,
	.set_speed = mvebu_spi_set_speed,
	.set_mode = mvebu_spi_set_mode,
	/*
	* cs_info is not needed, since we require all chip selects to be
	* in the device tree explicitly
	*/
	};

	static const struct udevice_id mvebu_spi_ids[] = {
	{ .compatible = "marvell,armada-3700-spi" },
	{ }
	};

	U_BOOT_DRIVER(mvebu_spi) = {
	.name = "mvebu_spi",
	.id = UCLASS_SPI,
	.of_match = mvebu_spi_ids,
	.ops = &mvebu_spi_ops,
	.of_to_plat = mvebu_spi_of_to_plat,
	.plat_auto = sizeof(struct mvebu_spi_plat),
	.probe = mvebu_spi_probe,
	};