Now struct spi_master is used for both SPI master and slave controllers,
it makes sense to rename it to struct spi_controller, and replace
"master" by "controller" where appropriate.
For now this conversion is done for SPI core infrastructure only.
Wrappers are provided for backwards compatibility, until all SPI drivers
have been converted.
Noteworthy details:
- SPI_MASTER_GPIO_SS is retained, as it only makes sense for SPI
master controllers,
- spi_busnum_to_master() is retained, as it looks up masters only,
- A new field spi_device.controller is added, but spi_device.master is
retained for compatibility (both are always initialized by
spi_alloc_device()),
- spi_flash_read() is used by SPI masters only.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
The loops which SPI controller drivers use to process the list of transfers
in a spi_message are typically very similar and have some error prone areas
such as the handling of /CS. Help simplify drivers by factoring this code
out into the core - if drivers provide a transfer_one() function instead
of a transfer_one_message() function the core will handle processing at the
message level.
/CS can be controlled by either setting cs_gpio or providing a set_cs
function. If this is not possible for hardware reasons then both can be
omitted and the driver should continue to implement manual /CS handling.
This is a first step in refactoring and it is expected that there will be
further enhancements, for example factoring out of the mapping of transfers
for DMA and the initiation and completion of interrupt driven transfers.
Signed-off-by: Mark Brown <broonie@linaro.org>
Provide tracepoints for the lifecycle of a message from submission to
completion and for the active time for masters to help with performance
analysis of SPI I/O.
Signed-off-by: Mark Brown <broonie@linaro.org>
Geert Uytterhoeven