Merge series from Geert Uytterhoeven <geert+renesas@glider.be>:
This patch series (A) improves single transfer sizes in the MSIOF
driver, using two methods:
- By increasing the assumed FIFO sizes, impacting both PIO and DMA
transfers,
- By using two groups, impacting DMA transfers,
and (B) lets the recently-introduced MSIOF I2S drive reuse the SPI
driver's register definitions. All of this is covered with a thick
sauce of fixes for (harmless) bugs, cleanups, and refactorings.
Note that the driver uses the limitations as specified in the hardware
documentation. For discovering the actual FIFO sizes, I wrote some
crude test code that can be found at [2].
This is based on spi/for-next and sound-asoc/for-next, and has been
tested on a variery of R-Car SoCs.
[1] https://lore.kernel.org/cover.1746180072.git.geert+renesas@glider.be
[2] https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git/log/?h=topic/msiof-fifo
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