diff options
| author | Maxime Ripard <maxime.ripard@free-electrons.com> | 2014-11-17 16:42:04 +0300 |
|---|---|---|
| committer | Vinod Koul <vinod.koul@intel.com> | 2014-12-22 09:58:56 +0300 |
| commit | cb8cea513c80db1dfe2dce468d2d0772005bb9a1 (patch) | |
| tree | 44dcb2103f8b2023d0c6b1bab113bfeacdfd5165 /include/linux/dmaengine.h | |
| parent | 4f8ef9f4140cc286d7d1cf9237da7a7439e4fc0b (diff) | |
| download | linux-cb8cea513c80db1dfe2dce468d2d0772005bb9a1.tar.xz | |
dmaengine: Create a generic dma_slave_caps callback
dma_slave_caps is very important to the generic layers that might interact with
dmaengine, such as ASoC. Unfortunately, it has been added as yet another
dma_device callback, and most of the existing drivers haven't implemented it,
reducing its reliability.
Introduce a generic behaviour to implement this, that rely on both the split of
device_control to derive which functions are supported and on new variables to
be set in the dma_device structure.
These variables holds what used to be the capabilities, that were set
per-channel. However, this proved to be a bit overkill, since every driver
filling these so far were hardcoding it, disregarding which channel was
actually given.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'include/linux/dmaengine.h')
| -rw-r--r-- | include/linux/dmaengine.h | 41 |
1 files changed, 37 insertions, 4 deletions
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index ded5161653aa..adf22089cc93 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -594,6 +594,14 @@ struct dma_tx_state { * @fill_align: alignment shift for memset operations * @dev_id: unique device ID * @dev: struct device reference for dma mapping api + * @src_addr_widths: bit mask of src addr widths the device supports + * @dst_addr_widths: bit mask of dst addr widths the device supports + * @directions: bit mask of slave direction the device supports since + * the enum dma_transfer_direction is not defined as bits for + * each type of direction, the dma controller should fill (1 << + * <TYPE>) and same should be checked by controller as well + * @residue_granularity: granularity of the transfer residue reported + * by tx_status * @device_alloc_chan_resources: allocate resources and return the * number of allocated descriptors * @device_free_chan_resources: release DMA channel's resources @@ -643,6 +651,11 @@ struct dma_device { int dev_id; struct device *dev; + u32 src_addr_widths; + u32 dst_addr_widths; + u32 directions; + enum dma_residue_granularity residue_granularity; + int (*device_alloc_chan_resources)(struct dma_chan *chan); void (*device_free_chan_resources)(struct dma_chan *chan); @@ -784,17 +797,37 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_sg( static inline int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps) { + struct dma_device *device; + if (!chan || !caps) return -EINVAL; + device = chan->device; + /* check if the channel supports slave transactions */ - if (!test_bit(DMA_SLAVE, chan->device->cap_mask.bits)) + if (!test_bit(DMA_SLAVE, device->cap_mask.bits)) + return -ENXIO; + + if (device->device_slave_caps) + return device->device_slave_caps(chan, caps); + + /* + * Check whether it reports it uses the generic slave + * capabilities, if not, that means it doesn't support any + * kind of slave capabilities reporting. + */ + if (!device->directions) return -ENXIO; - if (chan->device->device_slave_caps) - return chan->device->device_slave_caps(chan, caps); + caps->src_addr_widths = device->src_addr_widths; + caps->dst_addr_widths = device->dst_addr_widths; + caps->directions = device->directions; + caps->residue_granularity = device->residue_granularity; + + caps->cmd_pause = !!device->device_pause; + caps->cmd_terminate = !!device->device_terminate_all; - return -ENXIO; + return 0; } static inline int dmaengine_terminate_all(struct dma_chan *chan) |