From de705fa1f470683b9ea4ad91c1a9ae5a98942612 Mon Sep 17 00:00:00 2001 From: Furquan Shaikh Date: Wed, 19 Apr 2017 19:27:28 -0700 Subject: drivers/spi: Re-factor spi_crop_chunk spi_crop_chunk is a property of the SPI controller since it depends upon the maximum transfer size that is supported by the controller. Also, it is possible to implement this within spi-generic layer by obtaining following parameters from the controller: 1. max_xfer_size: Maximum transfer size supported by the controller (Size of 0 indicates invalid size, and unlimited transfer size is indicated by UINT32_MAX.) 2. deduct_cmd_len: Whether cmd_len needs to be deducted from the max_xfer_size to determine max data size that can be transferred. (This is used by the amd boards.) Change-Id: I81c199413f879c664682088e93bfa3f91c6a46e5 Signed-off-by: Furquan Shaikh Reviewed-on: https://review.coreboot.org/19386 Reviewed-by: Aaron Durbin Tested-by: build bot (Jenkins) Tested-by: coreboot org --- src/include/spi-generic.h | 36 +++++++++++++++++++++++++++++------- 1 file changed, 29 insertions(+), 7 deletions(-) (limited to 'src/include/spi-generic.h') 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. -- cgit v1.2.3