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    SubjectRe: [PATCH 10/16] dmaengine: ti: New driver for K3 UDMA - split#1: defines, structs, io func
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    Rob,

    On 13/06/2019 21.43, Rob Herring wrote:
    > On Mon, May 06, 2019 at 03:34:50PM +0300, Peter Ujfalusi wrote:
    >> Split patch for review containing: defines, structs, io and low level
    >> functions and interrupt callbacks.
    >
    > Not a useful comment for upstream.

    Vinod asked me to split the patch to smaller pieces for review. This is
    just a short note on what this part covers. The real commit message
    follows under.

    >> DMA driver for
    >> Texas Instruments K3 NAVSS Unified DMA – Peripheral Root Complex (UDMA-P)
    >>
    >> 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 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.
    >>
    >> The initial driver supports:
    >> - MEM_TO_MEM (TR mode)
    >> - DEV_TO_MEM (Packet / TR mode)
    >> - MEM_TO_DEV (Packet / TR mode)
    >> - Cyclic (Packet / TR mode)
    >> - Metadata for descriptors
    >>
    >> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
    >> ---
    >> drivers/dma/ti/k3-udma.c | 1008 +++++++++++++++++++++++++++++
    >> drivers/dma/ti/k3-udma.h | 129 ++++
    >> include/dt-bindings/dma/k3-udma.h | 26 +
    >
    > This belongs in the binding patch.

    OK, I'll move it.

    >
    >> 3 files changed, 1163 insertions(+)
    >> create mode 100644 drivers/dma/ti/k3-udma.c
    >> create mode 100644 drivers/dma/ti/k3-udma.h
    >> create mode 100644 include/dt-bindings/dma/k3-udma.h
    >
    >> diff --git a/include/dt-bindings/dma/k3-udma.h b/include/dt-bindings/dma/k3-udma.h
    >> new file mode 100644
    >> index 000000000000..89ba6a9d4a8f
    >> --- /dev/null
    >> +++ b/include/dt-bindings/dma/k3-udma.h
    >> @@ -0,0 +1,26 @@
    >> +#ifndef __DT_TI_UDMA_H
    >> +#define __DT_TI_UDMA_H
    >> +
    >> +#define UDMA_TR_MODE 0
    >> +#define UDMA_PKT_MODE 1
    >> +
    >> +#define UDMA_DIR_TX 0
    >> +#define UDMA_DIR_RX 1
    >> +
    >> +#define PSIL_STATIC_TR_NONE 0
    >> +#define PSIL_STATIC_TR_XY 1
    >> +#define PSIL_STATIC_TR_MCAN 2
    >> +
    >> +#define UDMA_PDMA_TR_XY(id) \
    >> + ti,psil-config##id { \
    >> + linux,udma-mode = <UDMA_TR_MODE>; \
    >> + statictr-type = <PSIL_STATIC_TR_XY>; \
    >> + }
    >
    > We don't accept this kind of complex macros in dts files. It obfuscates
    > reading dts files.

    I see. I agree that it obfuscates things as you need to look it up in
    the header, but as I mentioned regarding to patch 9 we have PDMAs with
    22 threads needing 22 psil-config section for the threads. It makes the
    reading of the DT a bit hard and also error prone when you populate things.

    But I can drop the macro and write all psil-config0...22

    Hrm, so we have 23 threads in some PDMA...

    Thanks,
    - Péter

    Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
    Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

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