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drivers/spi: Re-factor spi_crop_chunk

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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 <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/19386
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Tested-by: coreboot org <coreboot.org@gmail.com>
This commit is contained in:
Furquan Shaikh
2017-04-19 19:27:28 -07:00
committed by Martin Roth
parent f1db5fdb4d
commit de705fa1f4
37 changed files with 92 additions and 119 deletions
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36
src/include/spi-generic.h
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@ -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.