From 380afccc2a55e8015adae4266e8beff96ab620be Mon Sep 17 00:00:00 2001 From: Paul Cercueil Date: Thu, 20 Jun 2024 14:27:26 +0200 Subject: Documentation: dmaengine: Document new dma_vec API Document the dmaengine_prep_peripheral_dma_vec() API function, the device_prep_peripheral_dma_vec() backend function, and the dma_vec struct. Signed-off-by: Paul Cercueil Reviewed-by: Bagas Sanjaya Link: https://lore.kernel.org/r/20240620122726.41232-8-paul@crapouillou.net Signed-off-by: Vinod Koul --- Documentation/driver-api/dmaengine/client.rst | 9 +++++++++ Documentation/driver-api/dmaengine/provider.rst | 10 ++++++++++ 2 files changed, 19 insertions(+) (limited to 'Documentation/driver-api') diff --git a/Documentation/driver-api/dmaengine/client.rst b/Documentation/driver-api/dmaengine/client.rst index ecf139f73da4..d491e385d61a 100644 --- a/Documentation/driver-api/dmaengine/client.rst +++ b/Documentation/driver-api/dmaengine/client.rst @@ -80,6 +80,10 @@ The details of these operations are: - slave_sg: DMA a list of scatter gather buffers from/to a peripheral + - peripheral_dma_vec: DMA an array of scatter gather buffers from/to a + peripheral. Similar to slave_sg, but uses an array of dma_vec + structures instead of a scatterlist. + - dma_cyclic: Perform a cyclic DMA operation from/to a peripheral till the operation is explicitly stopped. @@ -102,6 +106,11 @@ The details of these operations are: unsigned int sg_len, enum dma_data_direction direction, unsigned long flags); + struct dma_async_tx_descriptor *dmaengine_prep_peripheral_dma_vec( + struct dma_chan *chan, const struct dma_vec *vecs, + size_t nents, enum dma_data_direction direction, + unsigned long flags); + struct dma_async_tx_descriptor *dmaengine_prep_dma_cyclic( struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, size_t period_len, enum dma_data_direction direction); diff --git a/Documentation/driver-api/dmaengine/provider.rst b/Documentation/driver-api/dmaengine/provider.rst index ceac2a300e32..3085f8b460fa 100644 --- a/Documentation/driver-api/dmaengine/provider.rst +++ b/Documentation/driver-api/dmaengine/provider.rst @@ -433,6 +433,12 @@ supported. - residue: Provides the residue bytes of the transfer for those that support residue. +- ``device_prep_peripheral_dma_vec`` + + - Similar to ``device_prep_slave_sg``, but it takes a pointer to a + array of ``dma_vec`` structures, which (in the long run) will replace + scatterlists. + - ``device_issue_pending`` - Takes the first transaction descriptor in the pending queue, @@ -544,6 +550,10 @@ dma_cookie_t - Not really relevant any more since the introduction of ``virt-dma`` that abstracts it away. +dma_vec + +- A small structure that contains a DMA address and length. + DMA_CTRL_ACK - If clear, the descriptor cannot be reused by provider until the -- cgit v1.2.3