diff options
author | Peng Fan <van.freenix@gmail.com> | 2016-05-03 10:02:22 +0800 |
---|---|---|
committer | Simon Glass <sjg@chromium.org> | 2016-05-17 09:54:43 -0600 |
commit | 7a3eff4ce962de50bd9a1d83a9fce178c04999d3 (patch) | |
tree | 269d284659e51ef795fb669089eef2f32f526db5 /include/spi.h | |
parent | 102412c415b5e51b01ed5797c965d0feaa065439 (diff) |
dm: spi: introduce dm api
Introduce dm_spi_claim_bus, dm_spi_release_bus and dm_spi_xfer
Convert spi_claim_bus, spi_release_bus and spi_xfer to use
the new API.
Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Jagan Teki <jteki@openedev.com>
Acked-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'include/spi.h')
-rw-r--r-- | include/spi.h | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/include/spi.h b/include/spi.h index 4b88d3986e..ca96fa4b31 100644 --- a/include/spi.h +++ b/include/spi.h @@ -612,6 +612,58 @@ int sandbox_spi_get_emul(struct sandbox_state *state, struct udevice *bus, struct udevice *slave, struct udevice **emulp); +/** + * Claim the bus and prepare it for communication with a given slave. + * + * This must be called before doing any transfers with a SPI slave. It + * will enable and initialize any SPI hardware as necessary, and make + * sure that the SCK line is in the correct idle state. It is not + * allowed to claim the same bus for several slaves without releasing + * the bus in between. + * + * @dev: The SPI slave device + * + * Returns: 0 if the bus was claimed successfully, or a negative value + * if it wasn't. + */ +int dm_spi_claim_bus(struct udevice *dev); + +/** + * Release the SPI bus + * + * This must be called once for every call to dm_spi_claim_bus() after + * all transfers have finished. It may disable any SPI hardware as + * appropriate. + * + * @slave: The SPI slave device + */ +void dm_spi_release_bus(struct udevice *dev); + +/** + * SPI transfer + * + * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks + * "bitlen" bits in the SPI MISO port. That's just the way SPI works. + * + * The source of the outgoing bits is the "dout" parameter and the + * destination of the input bits is the "din" parameter. Note that "dout" + * and "din" can point to the same memory location, in which case the + * input data overwrites the output data (since both are buffered by + * temporary variables, this is OK). + * + * dm_spi_xfer() interface: + * @dev: The SPI slave device which will be sending/receiving the data. + * @bitlen: How many bits to write and read. + * @dout: Pointer to a string of bits to send out. The bits are + * held in a byte array and are sent MSB first. + * @din: Pointer to a string of bits that will be filled in. + * @flags: A bitwise combination of SPI_XFER_* flags. + * + * Returns: 0 on success, not 0 on failure + */ +int dm_spi_xfer(struct udevice *dev, unsigned int bitlen, + const void *dout, void *din, unsigned long flags); + /* Access the operations for a SPI device */ #define spi_get_ops(dev) ((struct dm_spi_ops *)(dev)->driver->ops) #define spi_emul_get_ops(dev) ((struct dm_spi_emul_ops *)(dev)->driver->ops) |