Re: [PATCH v2 0/4] spi: dw: Auto-detect number of native CS
From: Andy Shevchenko
Date: Thu Feb 22 2024 - 12:53:17 EST
On Thu, Feb 22, 2024 at 7:28 PM Serge Semin <fancer.lancer@xxxxxxxxx> wrote:
>
> The main goal of the short series is to provide a procedure implementing
> the auto-detection of the number of native Chip-Select signals supported
> by the controller. The suggested algorithm is straightforward. It relies
> on the fact that the SER register writable flags reflects the actual
> number of available native chip-select signals. So the DW APB/AHB SSI
> driver now tests the SER register for having the writable bits,
> calculates the number of CS signals based on the number of set flags and
> then initializes the num_cs private data field based on that, which then
> will be passed to the SPI-core subsystem indicating the number of
> supported hardware chip-selects. The implemented procedure will be useful
> for the DW SSI device nodes not having the explicitly set "num-cs"
> property. In case if the property is specified it will be utilized instead
> of the auto-detection procedure.
>
> Besides of that a small cleanup patch is introduced in the head of the
> series. It converts the driver to using the BITS_TO_BYTES() macro instead
> of the hard-coded DIV_ROUND_UP()-based calculation of the number of
> bytes-per-transfer-word.
>
> Link: https://lore.kernel.org/linux-spi/20240215180102.13887-1-fancer.lancer@xxxxxxxxx
> Changelog v2:
> - Add a new patch:
> [PATCH v2 3/4] spi: dw: Convert dw_spi::num_cs to u32
> - Fix some spelling notes (@Andy).
For all untagged,
Reviewed-by: Andy Shevchenko <andy@xxxxxxxxxx>
Thank you!
--
With Best Regards,
Andy Shevchenko