On 09-12-19, 11:43, Peter Ujfalusi wrote: > New binding document for > Texas Instruments K3 NAVSS Unified DMA – Peripheral Root Complex (UDMA-P). > > UDMA-P is introduced as part of the K3 architecture and can be found in > AM654 and j721e. > > Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx> > Reviewed-by: Rob Herring <robh@xxxxxxxxxx> > --- > .../devicetree/bindings/dma/ti/k3-udma.yaml | 185 ++++++++++++++++++ > 1 file changed, 185 insertions(+) > create mode 100644 Documentation/devicetree/bindings/dma/ti/k3-udma.yaml > > diff --git a/Documentation/devicetree/bindings/dma/ti/k3-udma.yaml b/Documentation/devicetree/bindings/dma/ti/k3-udma.yaml > new file mode 100644 > index 000000000000..77aef4a4abce > --- /dev/null > +++ b/Documentation/devicetree/bindings/dma/ti/k3-udma.yaml > @@ -0,0 +1,185 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/dma/ti/k3-udma.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Texas Instruments K3 NAVSS Unified DMA Device Tree Bindings > + > +maintainers: > + - Peter Ujfalusi <peter.ujfalusi@xxxxxx> > + > +description: | > + 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 is architected to facilitate the segmentation and reassembly of How about: The UDMA-P architecture facilitates the segmentation... > + SoC DMA data structure compliant packets to/from smaller data blocks that are > + natively compatible with the specific requirements of each connected > + peripheral. > + Multiple Tx and Rx channels are provided within the DMA which allow multiple > + segmentation or reassembly operations to be ongoing. The DMA controller > + maintains state information for each of the channels which allows packet > + segmentation and reassembly operations to be time division multiplexed between > + channels in order to share the underlying DMA hardware. An external DMA > + scheduler is used to control the ordering and rate at which this multiplexing > + occurs for Transmit operations. The ordering and rate of Receive operations > + is indirectly controlled by the order in which blocks are pushed into the DMA > + on the Rx PSI-L interface. > + > + 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. > + > + All transfers within NAVSS is done between PSI-L source and destination > + threads. > + The peripherals serviced by UDMA can be PSI-L native (sa2ul, cpsw, etc) or > + legacy, non PSI-L native peripherals. In the later case a special, small PDMA > + is tasked to act as a bridge between the PSI-L fabric and the legacy > + peripheral. > + > + PDMAs can be configured via UDMAP peer registers to match with the > + configuration of the legacy peripheral. > + > +allOf: > + - $ref: "../dma-controller.yaml#" > + > +properties: > + "#dma-cells": > + const: 1 > + description: | > + The cell is the PSI-L thread ID of the remote (to UDMAP) end. > + Valid ranges for thread ID depends on the data movement direction: > + for source thread IDs (rx): 0 - 0x7fff > + for destination thread IDs (tx): 0x8000 - 0xffff > + > + PLease refer to the device documentation for the PSI-L thread map and also s/PLease/Please -- ~Vinod
