[PATCH 2/4] spi: sun6i: Support A523's SPI controllers
Jernej Škrabec
jernej.skrabec at gmail.com
Sun Dec 21 07:50:54 PST 2025
Dne nedelja, 21. december 2025 ob 12:05:09 Srednjeevropski standardni čas je Chen-Yu Tsai napisal(a):
> The A523 has four SPI controllers. One of them supports MIPI DBI mode
> in addition to standard SPI.
>
> Compared to older generations, this newer controller now has a combined
> counter for the RX FIFO ad buffer levels. In older generations, the
> RX buffer level was a separate bitfield in the FIFO status register.
>
> In practice this difference is negligible. The buffer is mostly
> invisible to the implementation. If programmed I/O transfers are limited
> to the FIFO size, then the contents of the buffer seem to always be
> flushed over to the FIFO. For DMA, the DRQ trigger levels are only tied
> to the FIFO levels. In all other aspects, the controller is the same as
> the one in the R329.
>
> Support the standard SPI mode controllers using the settings for R329.
> DBI is left out as there currently is no infrastructure for enabling a
> DBI host controller, as was the case for the R329.
>
> Also fold the entry for the R329 to make the style consistent.
>
> Signed-off-by: Chen-Yu Tsai <wens at kernel.org>
Reviewed-by: Jernej Skrabec <jernej.skrabec at gmail.com>
Best regards,
Jernej
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