| /* SPDX-License-Identifier: GPL-2.0-or-later */ |
| |
| #ifndef _SPI_GENERIC_H_ |
| #define _SPI_GENERIC_H_ |
| |
| /* Common parameters -- kind of high, but they should only occur when there |
| * is a problem (and well your system already is broken), so err on the side |
| * of caution in case we're dealing with slower SPI buses and/or processors. |
| */ |
| #define SPI_FLASH_PROG_TIMEOUT_MS 200 |
| #define SPI_FLASH_PAGE_ERASE_TIMEOUT_MS 500 |
| |
| #include <commonlib/region.h> |
| #include <stdint.h> |
| #include <stddef.h> |
| |
| /* SPI vendor IDs */ |
| #define VENDOR_ID_ADESTO 0x1f |
| #define VENDOR_ID_AMIC 0x37 |
| #define VENDOR_ID_ATMEL 0x1f |
| #define VENDOR_ID_EON 0x1c |
| #define VENDOR_ID_GIGADEVICE 0xc8 |
| #define VENDOR_ID_MACRONIX 0xc2 |
| #define VENDOR_ID_SPANSION 0x01 |
| #define VENDOR_ID_SST 0xbf |
| #define VENDOR_ID_STMICRO 0x20 |
| #define VENDOR_ID_WINBOND 0xef |
| |
| /* Controller-specific definitions: */ |
| |
| struct spi_ctrlr; |
| |
| /*----------------------------------------------------------------------- |
| * Representation of a SPI slave, i.e. what we're communicating with. |
| * |
| * bus: ID of the bus that the slave is attached to. |
| * cs: ID of the chip select connected to the slave. |
| * ctrlr: Pointer to SPI controller structure. |
| */ |
| struct spi_slave { |
| unsigned int bus; |
| unsigned int cs; |
| const struct spi_ctrlr *ctrlr; |
| }; |
| |
| /* Representation of SPI operation status. */ |
| enum spi_op_status { |
| SPI_OP_NOT_EXECUTED = 0, |
| SPI_OP_SUCCESS = 1, |
| SPI_OP_FAILURE = 2, |
| }; |
| |
| /* |
| * Representation of a SPI operation. |
| * |
| * dout: Pointer to data to send. |
| * bytesout: Count of data in bytes to send. |
| * din: Pointer to store received data. |
| * bytesin: Count of data in bytes to receive. |
| */ |
| struct spi_op { |
| const void *dout; |
| size_t bytesout; |
| void *din; |
| size_t bytesin; |
| enum spi_op_status status; |
| }; |
| |
| enum spi_clock_phase { |
| SPI_CLOCK_PHASE_FIRST, |
| SPI_CLOCK_PHASE_SECOND |
| }; |
| |
| enum spi_wire_mode { |
| SPI_4_WIRE_MODE, |
| SPI_3_WIRE_MODE |
| }; |
| |
| enum spi_polarity { |
| SPI_POLARITY_LOW, |
| SPI_POLARITY_HIGH |
| }; |
| |
| struct spi_cfg { |
| /* CLK phase - 0: Phase first, 1: Phase second */ |
| enum spi_clock_phase clk_phase; |
| /* CLK polarity - 0: Low, 1: High */ |
| enum spi_polarity clk_polarity; |
| /* CS polarity - 0: Low, 1: High */ |
| enum spi_polarity cs_polarity; |
| /* Wire mode - 0: 4-wire, 1: 3-wire */ |
| enum spi_wire_mode wire_mode; |
| /* Data bit length. */ |
| unsigned int data_bit_length; |
| }; |
| |
| /* |
| * If there is no limit on the maximum transfer size for the controller, |
| * max_xfer_size can be set to SPI_CTRLR_DEFAULT_MAX_XFER_SIZE which is equal to |
| * UINT32_MAX. |
| */ |
| #define SPI_CTRLR_DEFAULT_MAX_XFER_SIZE (UINT32_MAX) |
| |
| struct spi_flash; |
| |
| enum ctrlr_prot_type { |
| READ_PROTECT = 1, |
| WRITE_PROTECT = 2, |
| READ_WRITE_PROTECT = 3, |
| }; |
| |
| enum { |
| /* Deduct the command length from the spi_crop_chunk() calculation for |
| sizing a transaction. If SPI_CNTRLR_DEDUCT_OPCODE_LEN is set, only |
| the bytes after the command byte will be deducted. */ |
| SPI_CNTRLR_DEDUCT_CMD_LEN = 1 << 0, |
| /* Remove the opcode size from the command length used in the |
| spi_crop_chunk() calculation. Controllers which have a dedicated |
| register for the command byte would set this flag which would |
| allow the use of the maximum transfer size. */ |
| SPI_CNTRLR_DEDUCT_OPCODE_LEN = 1 << 1, |
| }; |
| |
| /*----------------------------------------------------------------------- |
| * Representation of a SPI controller. Note the xfer() and xfer_vector() |
| * callbacks are meant to process full duplex transactions. If the |
| * controller cannot handle these transactions then return an error when |
| * din and dout are both set. See spi_xfer() below for more details. |
| * |
| * claim_bus: Claim SPI bus and prepare for communication. |
| * release_bus: Release SPI bus. |
| * setup: Setup given SPI device bus. |
| * xfer: Perform one SPI transfer operation. |
| * xfer_vector: Vector of SPI transfer operations. |
| * xfer_dual: (optional) Perform one SPI transfer in Dual SPI mode. |
| * max_xfer_size: Maximum transfer size supported by the controller |
| * (0 = invalid, |
| * SPI_CTRLR_DEFAULT_MAX_XFER_SIZE = unlimited) |
| * flags: See SPI_CNTRLR_* enums above. |
| * |
| * Following member is provided by specialized SPI controllers that are |
| * actually SPI flash controllers. |
| * |
| * flash_probe: Specialized probe function provided by SPI flash |
| * controllers. |
| * flash_protect: Protect a region of flash using the SPI flash controller. |
| */ |
| struct spi_ctrlr { |
| int (*claim_bus)(const struct spi_slave *slave); |
| void (*release_bus)(const struct spi_slave *slave); |
| int (*setup)(const struct spi_slave *slave); |
| int (*xfer)(const struct spi_slave *slave, const void *dout, |
| size_t bytesout, void *din, size_t bytesin); |
| int (*xfer_vector)(const struct spi_slave *slave, |
| struct spi_op vectors[], size_t count); |
| int (*xfer_dual)(const struct spi_slave *slave, const void *dout, |
| size_t bytesout, void *din, size_t bytesin); |
| uint32_t max_xfer_size; |
| uint32_t flags; |
| int (*flash_probe)(const struct spi_slave *slave, |
| struct spi_flash *flash); |
| int (*flash_protect)(const struct spi_flash *flash, |
| const struct region *region, |
| const enum ctrlr_prot_type type); |
| }; |
| |
| /*----------------------------------------------------------------------- |
| * Structure defining mapping of SPI buses to controller. |
| * |
| * ctrlr: Pointer to controller structure managing the given SPI buses. |
| * bus_start: Start bus number managed by the controller. |
| * bus_end: End bus number manager by the controller. |
| */ |
| struct spi_ctrlr_buses { |
| const struct spi_ctrlr *ctrlr; |
| unsigned int bus_start; |
| unsigned int bus_end; |
| }; |
| |
| /* Mapping of SPI buses to controllers - should be defined by platform. */ |
| extern const struct spi_ctrlr_buses spi_ctrlr_bus_map[]; |
| extern const size_t spi_ctrlr_bus_map_count; |
| |
| /*----------------------------------------------------------------------- |
| * Initialization, must be called once on start up. |
| * |
| */ |
| void spi_init(void); |
| |
| /* |
| * Get configuration of SPI bus. |
| * |
| * slave: Pointer to slave structure. |
| * cfg: Pointer to SPI configuration that needs to be filled. |
| * |
| * Returns: |
| * 0 on success, -1 on error |
| */ |
| int spi_get_config(const struct spi_slave *slave, struct spi_cfg *cfg); |
| |
| /*----------------------------------------------------------------------- |
| * 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. |
| * slave: Pointer to slave structure that needs to be initialized. |
| * |
| * Returns: |
| * 0 on success, -1 on error |
| */ |
| int spi_setup_slave(unsigned int bus, unsigned int cs, 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(const 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(const struct spi_slave *slave); |
| |
| /*----------------------------------------------------------------------- |
| * SPI transfer |
| * |
| * spi_xfer() interface: |
| * slave: The SPI slave which will be sending/receiving the data. |
| * dout: Pointer to a string of bytes to send out. |
| * bytesout: How many bytes to write. |
| * din: Pointer to a string of bytes that will be filled in. |
| * bytesin: How many bytes to read. |
| * |
| * Note that din and dout are transferred simultaneously in a full duplex |
| * transaction. The number of clocks within one transaction is calculated |
| * as: MAX(bytesout*8, bytesin*8). |
| * |
| * Returns: 0 on success, not 0 on failure |
| */ |
| int spi_xfer(const struct spi_slave *slave, const void *dout, size_t bytesout, |
| void *din, size_t bytesin); |
| |
| /*----------------------------------------------------------------------- |
| * Vector of SPI transfer operations |
| * |
| * spi_xfer_vector() interface: |
| * slave: The SPI slave which will be sending/receiving the data. |
| * vectors: Array of SPI op structures. |
| * count: Number of SPI op vectors. |
| * |
| * Returns: 0 on success, not 0 on failure |
| */ |
| int spi_xfer_vector(const struct spi_slave *slave, |
| struct spi_op vectors[], size_t count); |
| |
| /*----------------------------------------------------------------------- |
| * Given command length and length of remaining data, return the maximum data |
| * that can be transferred in next spi_xfer. |
| * |
| * Returns: 0 on error, non-zero data size that can be xfered on success. |
| */ |
| unsigned int spi_crop_chunk(const struct spi_slave *slave, unsigned int cmd_len, |
| unsigned int buf_len); |
| |
| /*----------------------------------------------------------------------- |
| * 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(const 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, dout, 2, din, 2); |
| return ret < 0 ? ret : din[1]; |
| } |
| |
| #endif /* _SPI_GENERIC_H_ */ |