diff options
| author | Nikita Kiryanov <nikita@compulab.co.il> | 2013-10-16 17:23:25 +0300 |
|---|---|---|
| committer | Anatolij Gustschin <agust@denx.de> | 2013-11-12 10:02:44 +0100 |
| commit | 5753d09b1064a669e3be8f27e0f1fd008b96934a (patch) | |
| tree | 03eb9c4427faed627d41802960f0c7c516e35203 /include | |
| parent | 54a759c880a11a6dd93704f0adba40139b595e87 (diff) | |
spi: omap3: add support for more word lengths
Current implementation only supports 8 bit word lengths, even though
omap3 can handle anything between 4 and 32.
Update the spi interface to support changing the SPI word length,
and implement it in omap3_spi driver to support the full range of
possible word lengths.
This implementation is backwards compatible by defaulting to the old
behavior of 8 bit word lengths.
Also, it required a change to the omap3_spi non static I/O functions,
but since they are not used anywhere else, no collateral changes are required.
Cc: Tom Rini <trini@ti.com>
Cc: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
Cc: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
Diffstat (limited to 'include')
| -rw-r--r-- | include/spi.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/include/spi.h b/include/spi.h index ad9248bee0..67da75cb59 100644 --- a/include/spi.h +++ b/include/spi.h @@ -33,6 +33,8 @@ /* Header byte that marks the start of the message */ #define SPI_PREAMBLE_END_BYTE 0xec +#define SPI_DEFAULT_WORDLEN 8 + /** * struct spi_slave - Representation of a SPI slave * @@ -40,6 +42,7 @@ * * @bus: ID of the bus that the slave is attached to. * @cs: ID of the chip select connected to the slave. + * @wordlen: Size of SPI word in number of bits * @max_write_size: If non-zero, the maximum number of bytes which can * be written at once, excluding command bytes. * @memory_map: Address of read-only SPI flash access. @@ -47,6 +50,7 @@ struct spi_slave { unsigned int bus; unsigned int cs; + unsigned int wordlen; unsigned int max_write_size; void *memory_map; }; @@ -153,6 +157,18 @@ int spi_claim_bus(struct spi_slave *slave); void spi_release_bus(struct spi_slave *slave); /** + * Set the word length for SPI transactions + * + * Set the word length (number of bits per word) for SPI transactions. + * + * @slave: The SPI slave + * @wordlen: The number of bits in a word + * + * Returns: 0 on success, -1 on failure. + */ +int spi_set_wordlen(struct spi_slave *slave, unsigned int wordlen); + +/** * SPI transfer * * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks |