Re: [PATCH v4 2/2] spi: cadence: add support for Cadence XSPI controller

[Pratyush Yadav <p.yadav@xxxxxx>]

On 13/09/21 02:06PM, Parshuram Thombare wrote:
> This patch adds driver for Cadence's XSPI controller.
> It supports 3 work modes.
> 1. ACMD (auto command) work mode
>     ACMD name is because it uses auto command engine in the controller.
>     It further has 2 modes PIO and CDMA (command DMA).
>     The CDMA work mode is dedicated for high-performance application
>     where very low software overhead is required. In this mode the
>     Command Engine is programmed by the series of linked descriptors
>     stored in system memory. These descriptors provide commands to execute
>     and store status information for finished commands.
>     The PIO mode work mode is dedicated for single operation where
>     constructing a linked list of descriptors would require too
>     much effort.
> 2. STIG (Software Triggered Instruction Generator) work mode
>     In STIG mode, controller sends low-level instructions to memory.
>     Each instruction is 128-bit width. There is special instruction
>     DataSequence which carries information about data phase.
>     Driver uses Slave DMA interface to transfer data as only this
>     interface can be used in STIG work mode.
> 3. Direct work mode
>     This work mode allows sending data without invoking any command through
>     the slave interface.
> Currently only STIG work mode is enabled, remaining work modes will
> be added later.

Acked-by: Pratyush Yadav <p.yadav@xxxxxx>

-- 
Regards,
Pratyush Yadav
Texas Instruments Inc.