On Wed, Jan 23, 2019 at 07:13:11PM +0530, Vignesh R wrote:
Tom,
On 23/01/19 4:05 PM, Peter Ujfalusi wrote:
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@ti.com Signed-off-by: Grygorii Strashko grygorii.strashko@ti.com Signed-off-by: Vignesh R vigneshr@ti.com
Reviewed-by: Tom Rini trini@konsulko.com
And the DT binding is common to Linux, and been reviewed there? Or?
As Peter pointed out DT bindings are not yet frozen and may change. Hence, I have added the nodes in -u-boot.dtsi. As and when DT bindings are accepted, these would be moved to base dtsi.
UDMA support in kernel is currently blocked due to on going discussions on how UDMA/ring interrupts needs to be modeled and supported (not a so important for U-Boot UDMA support). But, I submitted patches for U-Boot as UDMA is support is required to support networking on AM654 which is essential for ease of booting the platform with U-Boot.
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.
Will drop this as U-Boot driver does not use them either.
- 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
I plan to align above bindings with Linux as when bindings are accepted into kernel and then port it to U-Boot along with relevant TI-SCI driver code.
Meanwhile would it be acceptable to add these nodes in -u-boot.dtsi to get closer to enable tftp?
... I knew I should have read the whole thread first. So, how likely do we think the kernel bindings are to see big changes? I wonder if we should re-align things now, or not.