diff options
Diffstat (limited to 'src/include')
| -rw-r--r-- | src/include/spi-generic.h | 62 |
1 files changed, 60 insertions, 2 deletions
diff --git a/src/include/spi-generic.h b/src/include/spi-generic.h index d28fefd026..7eb18a6ac8 100644 --- a/src/include/spi-generic.h +++ b/src/include/spi-generic.h @@ -36,20 +36,46 @@ struct spi_slave { 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; +}; + /*----------------------------------------------------------------------- * Representation of a SPI contoller. * * claim_bus: Claim SPI bus and prepare for communication. * release_bus: Release SPI bus. - * xfer: SPI transfer * setup: Setup given SPI device bus. + * xfer: Perform one SPI transfer operation. + * xfer_vector: Vector of SPI transfer operations. */ 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 (*setup)(const struct spi_slave *slave); + int (*xfer_vector)(const struct spi_slave *slave, + struct spi_op vectors[], size_t count); }; /*----------------------------------------------------------------------- @@ -134,6 +160,19 @@ void spi_release_bus(const struct spi_slave *slave); 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); + unsigned int spi_crop_chunk(unsigned int cmd_len, unsigned int buf_len); /*----------------------------------------------------------------------- @@ -158,4 +197,23 @@ static inline int spi_w8r8(const struct spi_slave *slave, unsigned char byte) return ret < 0 ? ret : din[1]; } +/* + * Helper function to allow chipsets to combine two vectors if possible. It can + * only handle upto 2 vectors. + * + * This function is provided to support command-response kind of transactions + * expected by users like flash. Some special SPI flash controllers can handle + * such command-response operations in a single transaction. For these special + * controllers, separate command and response vectors can be combined into a + * single operation. + * + * Two vectors are combined if first vector has a non-NULL dout and NULL din and + * second vector has a non-NULL din and NULL dout. Otherwise, each vector is + * operated upon one at a time. + * + * Returns 0 on success and non-zero on failure. + */ +int spi_xfer_two_vectors(const struct spi_slave *slave, + struct spi_op vectors[], size_t count); + #endif /* _SPI_GENERIC_H_ */ |