Re: [PATCH v4 2/4] drivers: dma: sh: Add DMAC driver for RZ/G2L SoC

Hi Biju,

On 27-07-21, 13:45, Biju Das wrote:

quoted

quoted

+
+	if (config->peripheral_config) {
+		ch_cfg = config->peripheral_config;
+		channel->chcfg = *ch_cfg;
+	}

can you explain what this the ch_cfg here and what does it represent?

It is a 32 bit value represent channel config value which supplied by each client driver during slave config.
It contains information like transfer mode,src/destination data size, Ack mode, Level type, DMA request on rising edge or falling
Edge, request direction etc...

For eg:- The channel config for SSI tx is (0x11228).
An example usage can be found here [1]

[1] https://patchwork.kernel.org/project/linux-renesas-soc/patch/20210719134040.7964-8-biju.das.jz@bp.renesas.com/

Sorry I dont like passing numbers like this :(

Can you explain what is meant by each of the above values and looks like
some (if not all) can be derived (slave config as well as transaction
properties)

-- 
~Vinod