Re: [PATCH v1 2/3] dt-bindings: serial: samsung: add Exynos990 compatible

From: Tudor Ambarus
Date: Fri Feb 14 2025 - 01:42:28 EST




On 2/14/25 5:16 AM, Denzeel Oliva wrote:
> On Thu, Feb 13, 2025 at 07:20:22AM +0000, Tudor Ambarus wrote:
>> doesn't the 32 bit register restriction apply to uart as it applies to
>> SPI? If so, you shall probably fallback to gs101.
>
> Of course not, downstream of the UART serial driver there is nothing
> specified about 32-bit access restriction, nothing explicitly
> in the driver. [0]
>
> https://github.com/pascua28/android_kernel_samsung_s20fe/blob/3be539e9cd22b89ba3cc8282945a0c46ff27341d/drivers/tty/serial/samsung.c#L1543

that's very strange. uart and spi are part of the same USI IP, on the
same bus. I don't think you can have the same IP requiring 32 bit
accesses for SPI but allow 8-bit accesses for uart.

Maybe SPI can work with 8bit accesses? How did you test SPI and uart?