diff options
Diffstat (limited to 'src/include/spi-generic.h')
| -rw-r--r-- | src/include/spi-generic.h | 36 |
1 files changed, 29 insertions, 7 deletions
diff --git a/src/include/spi-generic.h b/src/include/spi-generic.h index 7d957a0d9c..56353bb692 100644 --- a/src/include/spi-generic.h +++ b/src/include/spi-generic.h @@ -87,14 +87,27 @@ struct spi_cfg { 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) + /*----------------------------------------------------------------------- - * Representation of a SPI contoller. + * Representation of a SPI controller. + * + * 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. + * max_xfer_size: Maximum transfer size supported by the controller + * (0 = invalid, + * SPI_CTRLR_DEFAULT_MAX_XFER_SIZE = unlimited) + * deduct_cmd_len: Whether cmd_len should be deducted from max_xfer_size + * when calculating max_data_size * - * 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. */ struct spi_ctrlr { int (*claim_bus)(const struct spi_slave *slave); @@ -104,6 +117,8 @@ struct spi_ctrlr { size_t bytesout, void *din, size_t bytesin); int (*xfer_vector)(const struct spi_slave *slave, struct spi_op vectors[], size_t count); + uint32_t max_xfer_size; + bool deduct_cmd_len; }; /*----------------------------------------------------------------------- @@ -212,7 +227,14 @@ int spi_xfer(const struct spi_slave *slave, const void *dout, size_t bytesout, 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); +/*----------------------------------------------------------------------- + * 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. |