rapidio: add DMA engine support for RIO data transfers

Adds DMA Engine framework support into RapidIO subsystem.

Uses DMA Engine DMA_SLAVE interface to generate data transfers to/from
remote RapidIO target devices.

Introduces RapidIO-specific wrapper for prep_slave_sg() interface with an
extra parameter to pass target specific information.

Uses scatterlist to describe local data buffer.  Address flat data buffer
on a remote side.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Acked-by: Vinod Koul <vinod.koul@linux.intel.com>
Cc: Li Yang <leoli@freescale.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alexandre Bounine
2012-05-31 16:26:38 -07:00
committed by Linus Torvalds
parent ce2d52cc13
commit e42d98ebe7
5 changed files with 163 additions and 0 deletions

View File

@@ -377,6 +377,15 @@ void rio_unregister_driver(struct rio_driver *);
struct rio_dev *rio_dev_get(struct rio_dev *);
void rio_dev_put(struct rio_dev *);
#ifdef CONFIG_RAPIDIO_DMA_ENGINE
extern struct dma_chan *rio_request_dma(struct rio_dev *rdev);
extern void rio_release_dma(struct dma_chan *dchan);
extern struct dma_async_tx_descriptor *rio_dma_prep_slave_sg(
struct rio_dev *rdev, struct dma_chan *dchan,
struct rio_dma_data *data,
enum dma_transfer_direction direction, unsigned long flags);
#endif
/**
* rio_name - Get the unique RIO device identifier
* @rdev: RIO device