/*

   * Common SPI Interface: Controller-specific definitions
   *

   * (C) Copyright 2001
   * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
   *

   * SPDX-License-Identifier:	GPL-2.0+

   */
  
  #ifndef _SPI_H_
  #define _SPI_H_

  /* SPI mode flags */

  #define SPI_CPHA	BIT(0)			/* clock phase */
  #define SPI_CPOL	BIT(1)			/* clock polarity */
  #define SPI_MODE_0	(0|0)			/* (original MicroWire) */
  #define SPI_MODE_1	(0|SPI_CPHA)
  #define SPI_MODE_2	(SPI_CPOL|0)
  #define SPI_MODE_3	(SPI_CPOL|SPI_CPHA)
  #define SPI_CS_HIGH	BIT(2)			/* CS active high */
  #define SPI_LSB_FIRST	BIT(3)			/* per-word bits-on-wire */
  #define SPI_3WIRE	BIT(4)			/* SI/SO signals shared */
  #define SPI_LOOP	BIT(5)			/* loopback mode */
  #define SPI_SLAVE	BIT(6)			/* slave mode */
  #define SPI_PREAMBLE	BIT(7)			/* Skip preamble bytes */

  #define SPI_TX_BYTE	BIT(8)			/* transmit with 1 wire byte */

  #define SPI_TX_DUAL	BIT(9)			/* transmit with 2 wires */
  #define SPI_TX_QUAD	BIT(10)			/* transmit with 4 wires */

  #define SPI_RX_SLOW	BIT(11)			/* receive with 1 wire slow */

  #define SPI_RX_DUAL	BIT(12)			/* receive with 2 wires */
  #define SPI_RX_QUAD	BIT(13)			/* receive with 4 wires */

  /* Header byte that marks the start of the message */

  #define SPI_PREAMBLE_END_BYTE	0xec

  #define SPI_DEFAULT_WORDLEN	8

  #ifdef CONFIG_DM_SPI

  /* TODO(sjg@chromium.org): Remove this and use max_hz from struct spi_slave */

  struct dm_spi_bus {
  	uint max_hz;
  };

  /**
   * struct dm_spi_platdata - platform data for all SPI slaves
   *
   * This describes a SPI slave, a child device of the SPI bus. To obtain this
   * struct from a spi_slave, use dev_get_parent_platdata(dev) or
   * dev_get_parent_platdata(slave->dev).
   *
   * This data is immuatable. Each time the device is probed, @max_hz and @mode
   * will be copied to struct spi_slave.
   *
   * @cs:		Chip select number (0..n-1)
   * @max_hz:	Maximum bus speed that this slave can tolerate
   * @mode:	SPI mode to use for this device (see SPI mode flags)
   */
  struct dm_spi_slave_platdata {
  	unsigned int cs;
  	uint max_hz;
  	uint mode;
  };

  #endif /* CONFIG_DM_SPI */

  /**

   * struct spi_slave - Representation of a SPI slave

   *

   * For driver model this is the per-child data used by the SPI bus. It can

   * be accessed using dev_get_parent_priv() on the slave device. The SPI uclass

   * sets uip per_child_auto_alloc_size to sizeof(struct spi_slave), and the
   * driver should not override it. Two platform data fields (max_hz and mode)
   * are copied into this structure to provide an initial value. This allows
   * them to be changed, since we should never change platform data in drivers.

   *

   * If not using driver model, drivers are expected to extend this with
   * controller-specific data.
   *
   * @dev:		SPI slave device
   * @max_hz:		Maximum speed for this slave

   * @speed:		Current bus speed. This is 0 until the bus is first
   *			claimed.

   * @bus:		ID of the bus that the slave is attached to. For
   *			driver model this is the sequence number of the SPI
   *			bus (bus->seq) so does not need to be stored

   * @cs:			ID of the chip select connected to the slave.

   * @mode:		SPI mode to use for this slave (see SPI mode flags)

   * @wordlen:		Size of SPI word in number of bits

   * @max_read_size:	If non-zero, the maximum number of bytes which can
   *			be read at once.

   * @max_write_size:	If non-zero, the maximum number of bytes which can

   *			be written at once.

   * @memory_map:		Address of read-only SPI flash access.

   * @flags:		Indication of SPI flags.

   */
  struct spi_slave {

  #ifdef CONFIG_DM_SPI
  	struct udevice *dev;	/* struct spi_slave is dev->parentdata */
  	uint max_hz;

  	uint speed;

  #else

  	unsigned int bus;
  	unsigned int cs;

  #endif

  	uint mode;

  	unsigned int wordlen;

  	unsigned int max_read_size;

  	unsigned int max_write_size;

  	void *memory_map;

  	u8 flags;

  #define SPI_XFER_BEGIN		BIT(0)	/* Assert CS before transfer */
  #define SPI_XFER_END		BIT(1)	/* Deassert CS after transfer */

  #define SPI_XFER_ONCE		(SPI_XFER_BEGIN | SPI_XFER_END)

  #define SPI_XFER_MMAP		BIT(2)	/* Memory Mapped start */
  #define SPI_XFER_MMAP_END	BIT(3)	/* Memory Mapped End */

  };

  /**

   * Initialization, must be called once on start up.

   *
   * TODO: I don't think we really need this.

   */
  void spi_init(void);

  /**
   * spi_do_alloc_slave - Allocate a new SPI slave (internal)
   *
   * Allocate and zero all fields in the spi slave, and set the bus/chip
   * select. Use the helper macro spi_alloc_slave() to call this.
   *

   * @offset:	Offset of struct spi_slave within slave structure.
   * @size:	Size of slave structure.
   * @bus:	Bus ID of the slave chip.
   * @cs:		Chip select ID of the slave chip on the specified bus.

   */
  void *spi_do_alloc_slave(int offset, int size, unsigned int bus,
  			 unsigned int cs);
  
  /**
   * spi_alloc_slave - Allocate a new SPI slave
   *
   * Allocate and zero all fields in the spi slave, and set the bus/chip
   * select.
   *

   * @_struct:	Name of structure to allocate (e.g. struct tegra_spi).
   *		This structure must contain a member 'struct spi_slave *slave'.
   * @bus:	Bus ID of the slave chip.
   * @cs:		Chip select ID of the slave chip on the specified bus.

   */
  #define spi_alloc_slave(_struct, bus, cs) \
  	spi_do_alloc_slave(offsetof(_struct, slave), \
  			    sizeof(_struct), bus, cs)
  
  /**
   * spi_alloc_slave_base - Allocate a new SPI slave with no private data
   *
   * Allocate and zero all fields in the spi slave, and set the bus/chip
   * select.
   *

   * @bus:	Bus ID of the slave chip.
   * @cs:		Chip select ID of the slave chip on the specified bus.

   */
  #define spi_alloc_slave_base(bus, cs) \
  	spi_do_alloc_slave(0, sizeof(struct spi_slave), bus, cs)

  /**

   * Set up communications parameters for a SPI slave.
   *
   * This must be called once for each slave. Note that this function
   * usually doesn't touch any actual hardware, it only initializes the
   * contents of spi_slave so that the hardware can be easily
   * initialized later.
   *

   * @bus:	Bus ID of the slave chip.
   * @cs:		Chip select ID of the slave chip on the specified bus.
   * @max_hz:	Maximum SCK rate in Hz.
   * @mode:	Clock polarity, clock phase and other parameters.

   *
   * Returns: A spi_slave reference that can be used in subsequent SPI
   * calls, or NULL if one or more of the parameters are not supported.
   */
  struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
  		unsigned int max_hz, unsigned int mode);

  /**

   * Free any memory associated with a SPI slave.
   *

   * @slave:	The SPI slave

   */
  void spi_free_slave(struct spi_slave *slave);

  /**

   * Claim the bus and prepare it for communication with a given slave.
   *
   * This must be called before doing any transfers with a SPI slave. It
   * will enable and initialize any SPI hardware as necessary, and make
   * sure that the SCK line is in the correct idle state. It is not
   * allowed to claim the same bus for several slaves without releasing
   * the bus in between.
   *

   * @slave:	The SPI slave

   *
   * Returns: 0 if the bus was claimed successfully, or a negative value
   * if it wasn't.
   */
  int spi_claim_bus(struct spi_slave *slave);

  /**

   * Release the SPI bus
   *
   * This must be called once for every call to spi_claim_bus() after
   * all transfers have finished. It may disable any SPI hardware as
   * appropriate.
   *

   * @slave:	The SPI slave

   */
  void spi_release_bus(struct spi_slave *slave);

  /**

   * Set the word length for SPI transactions
   *
   * Set the word length (number of bits per word) for SPI transactions.
   *
   * @slave:	The SPI slave
   * @wordlen:	The number of bits in a word
   *
   * Returns: 0 on success, -1 on failure.
   */
  int spi_set_wordlen(struct spi_slave *slave, unsigned int wordlen);
  
  /**

   * SPI transfer
   *
   * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
   * "bitlen" bits in the SPI MISO port.  That's just the way SPI works.
   *
   * The source of the outgoing bits is the "dout" parameter and the
   * destination of the input bits is the "din" parameter.  Note that "dout"
   * and "din" can point to the same memory location, in which case the
   * input data overwrites the output data (since both are buffered by
   * temporary variables, this is OK).
   *

   * spi_xfer() interface:

   * @slave:	The SPI slave which will be sending/receiving the data.
   * @bitlen:	How many bits to write and read.
   * @dout:	Pointer to a string of bits to send out.  The bits are

   *		held in a byte array and are sent MSB first.

   * @din:	Pointer to a string of bits that will be filled in.
   * @flags:	A bitwise combination of SPI_XFER_* flags.

   *

   * Returns: 0 on success, not 0 on failure

   */

  int  spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
  		void *din, unsigned long flags);

  /* Copy memory mapped data */
  void spi_flash_copy_mmap(void *data, void *offset, size_t len);

  /**

   * 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);

  #ifndef CONFIG_DM_SPI

  /**

   * 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);

  /**

   * 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);

  /**

   * Set transfer speed.
   * This sets a new speed to be applied for next spi_xfer().

   * @slave:	The SPI slave
   * @hz:		The transfer speed

   */
  void spi_set_speed(struct spi_slave *slave, uint hz);

  #endif

  /**

   * Write 8 bits, then read 8 bits.

   * @slave:	The SPI slave we're communicating with
   * @byte:	Byte to be written

   *
   * Returns: The value that was read, or a negative value on error.
   *
   * TODO: This function probably shouldn't be inlined.
   */
  static inline int spi_w8r8(struct spi_slave *slave, unsigned char byte)
  {
  	unsigned char dout[2];
  	unsigned char din[2];
  	int ret;
  
  	dout[0] = byte;
  	dout[1] = 0;

  	ret = spi_xfer(slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
  	return ret < 0 ? ret : din[1];
  }

  #ifdef CONFIG_DM_SPI
  
  /**
   * struct spi_cs_info - Information about a bus chip select
   *
   * @dev:	Connected device, or NULL if none
   */
  struct spi_cs_info {
  	struct udevice *dev;
  };
  
  /**
   * struct struct dm_spi_ops - Driver model SPI operations
   *
   * The uclass interface is implemented by all SPI devices which use
   * driver model.
   */
  struct dm_spi_ops {
  	/**
  	 * Claim the bus and prepare it for communication.
  	 *
  	 * The device provided is the slave device. It's parent controller
  	 * will be used to provide the communication.
  	 *
  	 * This must be called before doing any transfers with a SPI slave. It
  	 * will enable and initialize any SPI hardware as necessary, and make
  	 * sure that the SCK line is in the correct idle state. It is not
  	 * allowed to claim the same bus for several slaves without releasing
  	 * the bus in between.
  	 *

  	 * @dev:	The SPI slave

  	 *
  	 * Returns: 0 if the bus was claimed successfully, or a negative value
  	 * if it wasn't.
  	 */

  	int (*claim_bus)(struct udevice *dev);

  
  	/**
  	 * Release the SPI bus
  	 *
  	 * This must be called once for every call to spi_claim_bus() after
  	 * all transfers have finished. It may disable any SPI hardware as
  	 * appropriate.
  	 *

  	 * @dev:	The SPI slave

  	 */

  	int (*release_bus)(struct udevice *dev);

  
  	/**
  	 * Set the word length for SPI transactions
  	 *
  	 * Set the word length (number of bits per word) for SPI transactions.
  	 *
  	 * @bus:	The SPI slave
  	 * @wordlen:	The number of bits in a word
  	 *
  	 * Returns: 0 on success, -ve on failure.
  	 */

  	int (*set_wordlen)(struct udevice *dev, unsigned int wordlen);

  
  	/**
  	 * SPI transfer
  	 *
  	 * This writes "bitlen" bits out the SPI MOSI port and simultaneously
  	 * clocks "bitlen" bits in the SPI MISO port.  That's just the way SPI
  	 * works.
  	 *
  	 * The source of the outgoing bits is the "dout" parameter and the
  	 * destination of the input bits is the "din" parameter.  Note that
  	 * "dout" and "din" can point to the same memory location, in which
  	 * case the input data overwrites the output data (since both are
  	 * buffered by temporary variables, this is OK).
  	 *
  	 * spi_xfer() interface:
  	 * @dev:	The slave device to communicate with
  	 * @bitlen:	How many bits to write and read.
  	 * @dout:	Pointer to a string of bits to send out.  The bits are
  	 *		held in a byte array and are sent MSB first.
  	 * @din:	Pointer to a string of bits that will be filled in.
  	 * @flags:	A bitwise combination of SPI_XFER_* flags.
  	 *
  	 * Returns: 0 on success, not -1 on failure
  	 */
  	int (*xfer)(struct udevice *dev, unsigned int bitlen, const void *dout,
  		    void *din, unsigned long flags);
  
  	/**
  	 * Set transfer speed.
  	 * This sets a new speed to be applied for next spi_xfer().
  	 * @bus:	The SPI bus
  	 * @hz:		The transfer speed
  	 * @return 0 if OK, -ve on error
  	 */
  	int (*set_speed)(struct udevice *bus, uint hz);
  
  	/**
  	 * Set the SPI mode/flags
  	 *
  	 * It is unclear if we want to set speed and mode together instead
  	 * of separately.
  	 *
  	 * @bus:	The SPI bus
  	 * @mode:	Requested SPI mode (SPI_... flags)
  	 * @return 0 if OK, -ve on error
  	 */
  	int (*set_mode)(struct udevice *bus, uint mode);
  
  	/**
  	 * Get information on a chip select
  	 *
  	 * This is only called when the SPI uclass does not know about a
  	 * chip select, i.e. it has no attached device. It gives the driver
  	 * a chance to allow activity on that chip select even so.
  	 *
  	 * @bus:	The SPI bus
  	 * @cs:		The chip select (0..n-1)
  	 * @info:	Returns information about the chip select, if valid.
  	 *		On entry info->dev is NULL
  	 * @return 0 if OK (and @info is set up), -ENODEV if the chip select
  	 *	   is invalid, other -ve value on error
  	 */
  	int (*cs_info)(struct udevice *bus, uint cs, struct spi_cs_info *info);
  };

  struct dm_spi_emul_ops {
  	/**
  	 * SPI transfer
  	 *
  	 * This writes "bitlen" bits out the SPI MOSI port and simultaneously
  	 * clocks "bitlen" bits in the SPI MISO port.  That's just the way SPI
  	 * works. Here the device is a slave.
  	 *
  	 * The source of the outgoing bits is the "dout" parameter and the
  	 * destination of the input bits is the "din" parameter.  Note that
  	 * "dout" and "din" can point to the same memory location, in which
  	 * case the input data overwrites the output data (since both are
  	 * buffered by temporary variables, this is OK).
  	 *
  	 * spi_xfer() interface:
  	 * @slave:	The SPI slave which will be sending/receiving the data.
  	 * @bitlen:	How many bits to write and read.
  	 * @dout:	Pointer to a string of bits sent to the device. The
  	 *		bits are held in a byte array and are sent MSB first.
  	 * @din:	Pointer to a string of bits that will be sent back to
  	 *		the master.
  	 * @flags:	A bitwise combination of SPI_XFER_* flags.
  	 *
  	 * Returns: 0 on success, not -1 on failure
  	 */
  	int (*xfer)(struct udevice *slave, unsigned int bitlen,
  		    const void *dout, void *din, unsigned long flags);
  };

  /**
   * spi_find_bus_and_cs() - Find bus and slave devices by number
   *
   * Given a bus number and chip select, this finds the corresponding bus
   * device and slave device. Neither device is activated by this function,
   * although they may have been activated previously.
   *
   * @busnum:	SPI bus number
   * @cs:		Chip select to look for
   * @busp:	Returns bus device
   * @devp:	Return slave device
   * @return 0 if found, -ENODEV on error
   */
  int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
  			struct udevice **devp);
  
  /**
   * spi_get_bus_and_cs() - Find and activate bus and slave devices by number
   *
   * Given a bus number and chip select, this finds the corresponding bus
   * device and slave device.
   *
   * If no such slave exists, and drv_name is not NULL, then a new slave device
   * is automatically bound on this chip select.
   *
   * Ths new slave device is probed ready for use with the given speed and mode.
   *
   * @busnum:	SPI bus number
   * @cs:		Chip select to look for
   * @speed:	SPI speed to use for this slave
   * @mode:	SPI mode to use for this slave
   * @drv_name:	Name of driver to attach to this chip select
   * @dev_name:	Name of the new device thus created
   * @busp:	Returns bus device
   * @devp:	Return slave device
   * @return 0 if found, -ve on error
   */
  int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
  			const char *drv_name, const char *dev_name,
  			struct udevice **busp, struct spi_slave **devp);
  
  /**
   * spi_chip_select() - Get the chip select for a slave
   *
   * @return the chip select this slave is attached to
   */
  int spi_chip_select(struct udevice *slave);
  
  /**

   * spi_find_chip_select() - Find the slave attached to chip select
   *
   * @bus:	SPI bus to search
   * @cs:		Chip select to look for
   * @devp:	Returns the slave device if found
   * @return 0 if found, -ENODEV on error
   */
  int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp);
  
  /**

   * spi_slave_ofdata_to_platdata() - decode standard SPI platform data

   *

   * This decodes the speed and mode for a slave from a device tree node

   *
   * @blob:	Device tree blob
   * @node:	Node offset to read from

   * @plat:	Place to put the decoded information

   */

  int spi_slave_ofdata_to_platdata(struct udevice *dev,

  				 struct dm_spi_slave_platdata *plat);

  
  /**
   * spi_cs_info() - Check information on a chip select
   *
   * This checks a particular chip select on a bus to see if it has a device
   * attached, or is even valid.
   *
   * @bus:	The SPI bus
   * @cs:		The chip select (0..n-1)
   * @info:	Returns information about the chip select, if valid
   * @return 0 if OK (and @info is set up), -ENODEV if the chip select
   *	   is invalid, other -ve value on error
   */
  int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info);
  
  struct sandbox_state;

  
  /**
   * sandbox_spi_get_emul() - get an emulator for a SPI slave
   *
   * This provides a way to attach an emulated SPI device to a particular SPI
   * slave, so that xfer() operations on the slave will be handled by the
   * emulator. If a emulator already exists on that chip select it is returned.
   * Otherwise one is created.
   *
   * @state:	Sandbox state
   * @bus:	SPI bus requesting the emulator
   * @slave:	SPI slave device requesting the emulator
   * @emuip:	Returns pointer to emulator
   * @return 0 if OK, -ve on error
   */

  int sandbox_spi_get_emul(struct sandbox_state *state,
  			 struct udevice *bus, struct udevice *slave,
  			 struct udevice **emulp);

  /**
   * Claim the bus and prepare it for communication with a given slave.
   *
   * This must be called before doing any transfers with a SPI slave. It
   * will enable and initialize any SPI hardware as necessary, and make
   * sure that the SCK line is in the correct idle state. It is not
   * allowed to claim the same bus for several slaves without releasing
   * the bus in between.
   *
   * @dev:	The SPI slave device
   *
   * Returns: 0 if the bus was claimed successfully, or a negative value
   * if it wasn't.
   */
  int dm_spi_claim_bus(struct udevice *dev);
  
  /**
   * Release the SPI bus
   *
   * This must be called once for every call to dm_spi_claim_bus() after
   * all transfers have finished. It may disable any SPI hardware as
   * appropriate.
   *
   * @slave:	The SPI slave device
   */
  void dm_spi_release_bus(struct udevice *dev);
  
  /**
   * SPI transfer
   *
   * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
   * "bitlen" bits in the SPI MISO port.  That's just the way SPI works.
   *
   * The source of the outgoing bits is the "dout" parameter and the
   * destination of the input bits is the "din" parameter.  Note that "dout"
   * and "din" can point to the same memory location, in which case the
   * input data overwrites the output data (since both are buffered by
   * temporary variables, this is OK).
   *
   * dm_spi_xfer() interface:
   * @dev:	The SPI slave device which will be sending/receiving the data.
   * @bitlen:	How many bits to write and read.
   * @dout:	Pointer to a string of bits to send out.  The bits are
   *		held in a byte array and are sent MSB first.
   * @din:	Pointer to a string of bits that will be filled in.
   * @flags:	A bitwise combination of SPI_XFER_* flags.
   *
   * Returns: 0 on success, not 0 on failure
   */
  int dm_spi_xfer(struct udevice *dev, unsigned int bitlen,
  		const void *dout, void *din, unsigned long flags);

  /* Access the operations for a SPI device */

  #define spi_get_ops(dev)	((struct dm_spi_ops *)(dev)->driver->ops)

  #define spi_emul_get_ops(dev)	((struct dm_spi_emul_ops *)(dev)->driver->ops)

  #endif /* CONFIG_DM_SPI */

  #endif	/* _SPI_H_ */