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Diffstat (limited to 'include/spi.h')
| -rw-r--r-- | include/spi.h | 658 |
1 files changed, 658 insertions, 0 deletions
diff --git a/include/spi.h b/include/spi.h new file mode 100644 index 0000000..5eec0c4 --- /dev/null +++ b/include/spi.h @@ -0,0 +1,658 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Common SPI Interface: Controller-specific definitions + * + * (C) Copyright 2001 + * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com. + */ + +#ifndef _SPI_H_ +#define _SPI_H_ + +#include <common.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 */ +}; + +/** + * 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); + +/** + * spi_write_then_read - SPI synchronous write followed by read + * + * This performs a half duplex transaction in which the first transaction + * is to send the opcode and if the length of buf is non-zero then it start + * the second transaction as tx or rx based on the need from respective slave. + * + * @slave: The SPI slave device with which opcode/data will be exchanged + * @opcode: opcode used for specific transfer + * @n_opcode: size of opcode, in bytes + * @txbuf: buffer into which data to be written + * @rxbuf: buffer into which data will be read + * @n_buf: size of buf (whether it's [tx|rx]buf), in bytes + * + * Returns: 0 on success, not 0 on failure + */ +int spi_write_then_read(struct spi_slave *slave, const u8 *opcode, + size_t n_opcode, const u8 *txbuf, u8 *rxbuf, + size_t n_buf); + +/* 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); + + /** + * Optimized handlers for SPI memory-like operations. + * + * Optimized/dedicated operations for interactions with SPI memory. This + * field is optional and should only be implemented if the controller + * has native support for memory like operations. + */ + const struct spi_controller_mem_ops *mem_ops; + + /** + * 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 with requested speed and mode. + * + * Ths new slave device is probed ready for use with the speed and mode + * from platdata when available or the requested values. + * + * @busnum: SPI bus number + * @cs: Chip select to look for + * @speed: SPI speed to use for this slave when not available in platdata + * @mode: SPI mode to use for this slave when not available in platdata + * @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_ */ |