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authorPaul Cercueil <paul@crapouillou.net>2024-06-20 14:27:26 +0200
committerVinod Koul <vkoul@kernel.org>2024-06-21 15:31:57 +0530
commit380afccc2a55e8015adae4266e8beff96ab620be (patch)
tree6e503fd27276cda622fbe57a1be6a6fd5da860bb
parent74609e5686701ed8e8adc3082d15f009e327286d (diff)
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 <paul@crapouillou.net> Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com> Link: https://lore.kernel.org/r/20240620122726.41232-8-paul@crapouillou.net Signed-off-by: Vinod Koul <vkoul@kernel.org>
-rw-r--r--Documentation/driver-api/dmaengine/client.rst9
-rw-r--r--Documentation/driver-api/dmaengine/provider.rst10
2 files changed, 19 insertions, 0 deletions
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