[U-Boot] [PATCH 4/6] dma: ti: add driver to K3 UDMA

[Peter Ujfalusi]

Tom,

On 22/01/2019 20.56, Tom Rini wrote:
> On Tue, Jan 22, 2019 at 08:33:57PM +0530, Vignesh R wrote:
> 
>> The UDMA-P is intended to perform similar (but significantly upgraded) functions
>> as the packet-oriented DMA used on previous SoC devices. The UDMA-P module
>> supports the transmission and reception of various packet types.
>> The UDMA-P also supports acting as both a UTC and UDMA-C for its internal
>> channels. Channels in the UDMA-P can be configured to be either Packet-Based or
>> Third-Party channels on a channel by channel basis.
>>
>> The initial driver supports:
>> - MEM_TO_MEM (TR mode)
>> - DEV_TO_MEM (Packet mode)
>> - MEM_TO_DEV (Packet mode)
>>
>> Signed-off-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
>> Signed-off-by: Grygorii Strashko <grygorii.strashko at ti.com>
>> Signed-off-by: Vignesh R <vigneshr at ti.com>
> 
> Reviewed-by: Tom Rini <trini at konsulko.com>
> 
> And the DT binding is common to Linux, and been reviewed there?  Or?

The binding is the same for Linux but unfortunately it has not went
through a proper review yet due to the fact that I need to wait for the
interrupt support to arrive to mainline.

However I have sent an earlier version as RFC:
https://www.spinics.net/lists/dmaengine/msg16661.html

As for the bindings (and code):
The linux bindings are different:

- there is no ti,psi-proxy anymore.
- ringacc uses tisci to get GP ring range and we need
  ti,sci-rm-range-gp-rings property in DT for it
- UDMA also uses tisci to get resource ranges and needs:
  ti,sci-rm-range-tchan, ti,sci-rm-range-rchan, ti,sci-rm-range-rflow in DT
- UDMA does not have/need dma-channels property
- properties needed for interrupts (currently msi-parent)

FWIW this is how the MCU NAVSS looks like in Linux atm:
https://github.com/omap-audio/linux-audio/blob/peter/linux-next-wip/arch/arm64/boot/dts/ti/k3-am65-mcu.dtsi

and the binding documentation for UDMA:
https://github.com/omap-audio/linux-audio/blob/peter/linux-next-wip/Documentation/devicetree/bindings/dma/ti/k3-udma.txt

- Péter

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