Hello all, I've submitted a V3 following a KBuild warning. You can thus drop this V2. Thanks and sorry for the spamming. Have a nice weekend. Regards On 09/28/2018 10:36 AM, Pierre-Yves MORDRET wrote: > This serie adds support for M2M transfer triggered by STM32 DMA in order to > transfer data from/to SRAM to/from DDR. > > Normally, this mode should not be needed as transferring data from/to DDR > is supported by the STM32 DMA. > However, the STM32 DMA don't have the ability to generate burst transfer > on the DDR as it only embeds only a 4-word FIFO although the minimal burst > length on the DDR is 8 words. > Due to this constraint, the STM32 DMA transfers data from/to DDR in a > single way and could lead to pollute the DDR. > To avoid this, we have to use SRAM for all transfers where STM32 DMA is > involved. > > An Hw design has been specially put in place to allow this chaining where DMA > interrupt is connected on GIC and MDMA request line as well. This grants the > possibility to trigger an MDMA transfer from the completion of DMA. > At the same time MDMA has the ability to acknowlege DMA. The aim is to have an > self refreching mechanism to transfer from/to device to/from DDR with minimal > sw support. > For instance the DMA is set in cyclic double buffering to feed SRAM and MDMA > transfer to DDR thanks to LLI. > > M'boumba Cedric Madianga (7): > dt-bindings: stm32-dma: Add DMA/MDMA chaining support bindings > dt-bindings: stm32-dmamux: Add one cell to support DMA/MDMA chain > dt-bindings: stm32-mdma: Add DMA/MDMA chaining support bindings > dmaengine: stm32-dma: Add DMA/MDMA chaining support > dmaengine: stm32-mdma: Add DMA/MDMA chaining support > dmaengine: stm32-dma: enable descriptor_reuse > dmaengine: stm32-mdma: enable descriptor_reuse > > .../devicetree/bindings/dma/stm32-dma.txt | 27 +- > .../devicetree/bindings/dma/stm32-dmamux.txt | 6 +- > .../devicetree/bindings/dma/stm32-mdma.txt | 12 +- > drivers/dma/stm32-dma.c | 903 ++++++++++++++++++--- > drivers/dma/stm32-mdma.c | 133 ++- > 5 files changed, 949 insertions(+), 132 deletions(-) >
