From c511595390a373e19a774246c659b4f563a4c3f3 Mon Sep 17 00:00:00 2001 From: Nicolas Ferre Date: Mon, 17 Oct 2011 14:56:41 +0200 Subject: dmaengine: at_hdmac: add device tree support Add device tree probe support for atmel at_hdmac DMA driver. Bindings are added to specify DMA controller configuration. Signed-off-by: Nicolas Ferre Acked-by: Grant Likely Signed-off-by: Vinod Koul --- Documentation/devicetree/bindings/dma/atmel-dma.txt | 14 ++++++++++++++ 1 file changed, 14 insertions(+) create mode 100644 Documentation/devicetree/bindings/dma/atmel-dma.txt (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/dma/atmel-dma.txt b/Documentation/devicetree/bindings/dma/atmel-dma.txt new file mode 100644 index 0000000..3c046ee --- /dev/null +++ b/Documentation/devicetree/bindings/dma/atmel-dma.txt @@ -0,0 +1,14 @@ +* Atmel Direct Memory Access Controller (DMA) + +Required properties: +- compatible: Should be "atmel,-dma" +- reg: Should contain DMA registers location and length +- interrupts: Should contain DMA interrupt + +Examples: + +dma@ffffec00 { + compatible = "atmel,at91sam9g45-dma"; + reg = <0xffffec00 0x200>; + interrupts = <21>; +}; -- cgit v1.1 From b14dab792dee3245b628e046d80a7fad5573fea6 Mon Sep 17 00:00:00 2001 From: Jassi Brar Date: Thu, 13 Oct 2011 12:33:30 +0530 Subject: DMAEngine: Define interleaved transfer request api Define a new api that could be used for doing fancy data transfers like interleaved to contiguous copy and vice-versa. Traditional SG_list based transfers tend to be very inefficient in such cases as where the interleave and chunk are only a few bytes, which call for a very condensed api to convey pattern of the transfer. This api supports all 4 variants of scatter-gather and contiguous transfer. Of course, neither can this api help transfers that don't lend to DMA by nature, i.e, scattered tiny read/writes with no periodic pattern. Also since now we support SLAVE channels that might not provide device_prep_slave_sg callback but device_prep_interleaved_dma, remove the BUG_ON check. Signed-off-by: Jassi Brar Acked-by: Barry Song [renamed dmaxfer_template to dma_interleaved_template did fixup after the enum dma_transfer_merge] Signed-off-by: Vinod Koul --- Documentation/dmaengine.txt | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'Documentation') diff --git a/Documentation/dmaengine.txt b/Documentation/dmaengine.txt index 94b7e0f..bbe6cb3 100644 --- a/Documentation/dmaengine.txt +++ b/Documentation/dmaengine.txt @@ -75,6 +75,10 @@ The slave DMA usage consists of following steps: slave_sg - DMA a list of scatter gather buffers from/to a peripheral dma_cyclic - Perform a cyclic DMA operation from/to a peripheral till the operation is explicitly stopped. + interleaved_dma - This is common to Slave as well as M2M clients. For slave + address of devices' fifo could be already known to the driver. + Various types of operations could be expressed by setting + appropriate values to the 'dma_interleaved_template' members. A non-NULL return of this transfer API represents a "descriptor" for the given transaction. @@ -89,6 +93,10 @@ The slave DMA usage consists of following steps: struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, size_t period_len, enum dma_data_direction direction); + struct dma_async_tx_descriptor *(*device_prep_interleaved_dma)( + struct dma_chan *chan, struct dma_interleaved_template *xt, + unsigned long flags); + The peripheral driver is expected to have mapped the scatterlist for the DMA operation prior to calling device_prep_slave_sg, and must keep the scatterlist mapped until the DMA operation has completed. -- cgit v1.1