Re: [PATCH v5 1/2] spi: dw: Add 32 bpw support to DW DMA Controller

From: Andy Shevchenko
Date: Tue Apr 11 2023 - 08:13:58 EST


On Thu, Mar 30, 2023 at 06:34:49AM +0000, Joy Chakraborty wrote:

First of all the Subject is wrong. You are not touching DMA controller.
Needs to be rephrased.

> Add Support for AxSize = 4 bytes configuration from dw dma driver if

SPI DMA driver

(or something like this, note capital letters for acronyms).

> n_bytes i.e. number of bytes per write to fifo is 3 or 4.
>
> Number of bytes written to fifo per write is depended on the bits/word
> configuration being used which the DW core driver translates to n_bytes.

...

> static enum dma_slave_buswidth dw_spi_dma_convert_width(u8 n_bytes)
> {
> - if (n_bytes == 1)
> + switch (n_bytes) {
> + case 1:
> return DMA_SLAVE_BUSWIDTH_1_BYTE;
> - else if (n_bytes == 2)
> + case 2:
> return DMA_SLAVE_BUSWIDTH_2_BYTES;
> -
> - return DMA_SLAVE_BUSWIDTH_UNDEFINED;

> + case 3:

I'm not sure about this.

> + case 4:
> + return DMA_SLAVE_BUSWIDTH_4_BYTES;
> + default:
> + return DMA_SLAVE_BUSWIDTH_UNDEFINED;
> + }
> }

--
With Best Regards,
Andy Shevchenko