From 5753d09b1064a669e3be8f27e0f1fd008b96934a Mon Sep 17 00:00:00 2001 From: Nikita Kiryanov Date: Wed, 16 Oct 2013 17:23:25 +0300 Subject: 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 Cc: Jagannadha Sutradharudu Teki Cc: Igor Grinberg Signed-off-by: Nikita Kiryanov --- include/spi.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'include/spi.h') 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; }; @@ -152,6 +156,18 @@ 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 * -- cgit v1.2.3