diff options
| -rw-r--r-- | Documentation/driver-api/dmaengine/client.rst | 9 | ||||
| -rw-r--r-- | Documentation/driver-api/dmaengine/provider.rst | 10 | ||||
| -rw-r--r-- | drivers/dma/dma-axi-dmac.c | 40 | ||||
| -rw-r--r-- | include/linux/dmaengine.h | 33 |
4 files changed, 92 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 diff --git a/drivers/dma/dma-axi-dmac.c b/drivers/dma/dma-axi-dmac.c index bdb752f11869..36943b0c6d60 100644 --- a/drivers/dma/dma-axi-dmac.c +++ b/drivers/dma/dma-axi-dmac.c @@ -620,6 +620,45 @@ static struct axi_dmac_sg *axi_dmac_fill_linear_sg(struct axi_dmac_chan *chan, return sg; } +static struct dma_async_tx_descriptor * +axi_dmac_prep_peripheral_dma_vec(struct dma_chan *c, const struct dma_vec *vecs, + size_t nb, enum dma_transfer_direction direction, + unsigned long flags) +{ + struct axi_dmac_chan *chan = to_axi_dmac_chan(c); + struct axi_dmac_desc *desc; + unsigned int num_sgs = 0; + struct axi_dmac_sg *dsg; + size_t i; + + if (direction != chan->direction) + return NULL; + + for (i = 0; i < nb; i++) + num_sgs += DIV_ROUND_UP(vecs[i].len, chan->max_length); + + desc = axi_dmac_alloc_desc(chan, num_sgs); + if (!desc) + return NULL; + + dsg = desc->sg; + + for (i = 0; i < nb; i++) { + if (!axi_dmac_check_addr(chan, vecs[i].addr) || + !axi_dmac_check_len(chan, vecs[i].len)) { + kfree(desc); + return NULL; + } + + dsg = axi_dmac_fill_linear_sg(chan, direction, vecs[i].addr, 1, + vecs[i].len, dsg); + } + + desc->cyclic = false; + + return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags); +} + static struct dma_async_tx_descriptor *axi_dmac_prep_slave_sg( struct dma_chan *c, struct scatterlist *sgl, unsigned int sg_len, enum dma_transfer_direction direction, @@ -1061,6 +1100,7 @@ static int axi_dmac_probe(struct platform_device *pdev) dma_dev->device_tx_status = dma_cookie_status; dma_dev->device_issue_pending = axi_dmac_issue_pending; dma_dev->device_prep_slave_sg = axi_dmac_prep_slave_sg; + dma_dev->device_prep_peripheral_dma_vec = axi_dmac_prep_peripheral_dma_vec; dma_dev->device_prep_dma_cyclic = axi_dmac_prep_dma_cyclic; dma_dev->device_prep_interleaved_dma = axi_dmac_prep_interleaved; dma_dev->device_terminate_all = axi_dmac_terminate_all; diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 73537fddbb52..b137fdb56093 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -161,6 +161,16 @@ struct dma_interleaved_template { }; /** + * struct dma_vec - DMA vector + * @addr: Bus address of the start of the vector + * @len: Length in bytes of the DMA vector + */ +struct dma_vec { + dma_addr_t addr; + size_t len; +}; + +/** * enum dma_ctrl_flags - DMA flags to augment operation preparation, * control completion, and communicate status. * @DMA_PREP_INTERRUPT - trigger an interrupt (callback) upon completion of @@ -910,6 +920,10 @@ struct dma_device { struct dma_async_tx_descriptor *(*device_prep_dma_interrupt)( struct dma_chan *chan, unsigned long flags); + struct dma_async_tx_descriptor *(*device_prep_peripheral_dma_vec)( + struct dma_chan *chan, const struct dma_vec *vecs, + size_t nents, enum dma_transfer_direction direction, + unsigned long flags); struct dma_async_tx_descriptor *(*device_prep_slave_sg)( struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len, enum dma_transfer_direction direction, @@ -973,6 +987,25 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_single( dir, flags, NULL); } +/** + * dmaengine_prep_peripheral_dma_vec() - Prepare a DMA scatter-gather descriptor + * @chan: The channel to be used for this descriptor + * @vecs: The array of DMA vectors that should be transferred + * @nents: The number of DMA vectors in the array + * @dir: Specifies the direction of the data transfer + * @flags: DMA engine flags + */ +static inline struct dma_async_tx_descriptor *dmaengine_prep_peripheral_dma_vec( + struct dma_chan *chan, const struct dma_vec *vecs, size_t nents, + enum dma_transfer_direction dir, unsigned long flags) +{ + if (!chan || !chan->device || !chan->device->device_prep_peripheral_dma_vec) + return NULL; + + return chan->device->device_prep_peripheral_dma_vec(chan, vecs, nents, + dir, flags); +} + static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_sg( struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len, enum dma_transfer_direction dir, unsigned long flags) |