Re: [PATCH v2 05/28] spi: dt-bindings: samsung: add samsung,spi-fifosize property

From: Rob Herring
Date: Tue Jan 30 2024 - 17:25:51 EST


On Thu, Jan 25, 2024 at 07:01:10PM +0000, Tudor Ambarus wrote:
>
>
> On 1/25/24 17:45, Mark Brown wrote:
> > On Thu, Jan 25, 2024 at 05:30:53PM +0000, Tudor Ambarus wrote:
> >> On 1/25/24 17:26, Mark Brown wrote:
> >
> >>> OK, so just the compatible is enough information then?
> >
> >> For gs101, yes. All the gs101 SPI instances are configured with 64 bytes
> >> FIFO depths. So instead of specifying the FIFO depth for each SPI node,
> >> we can infer the FIFO depth from the compatible.
> >
> > But this is needed for other SoCs? This change is scattered through a
>
> There are SoCs that have multiple instances of the SPI IP, and they
> configure them with different FIFO depths. See
> "samsung,exynosautov9-spi" for example: SPI0, SPI1, and SPI6 are
> configured by the SoC to use 256 bytes FIFO depths, while all the other
> 8 SPI instances use 64 bytes FIFOs. I tried to explain the entire logic
> of the series in another reply, see it here:
> https://lore.kernel.org/linux-arm-kernel/40ba9481-4aea-4a72-87bd-c2db319be069@xxxxxxxxxx/T/#u

We have some common properties for fifo size. In fact, there was just a
discussion recently on Samsung UART (Is that the same block?) about
this. So if you do use a property here, use a common one.

Rob