diff options
Diffstat (limited to 'include/linux/dmaengine.h')
| -rw-r--r-- | include/linux/dmaengine.h | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 96d3e4ab11a9..162242bd6f33 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -371,6 +371,61 @@ struct dma_slave_config { unsigned int slave_id; }; +/** + * enum dma_residue_granularity - Granularity of the reported transfer residue + * @DMA_RESIDUE_GRANULARITY_DESCRIPTOR: Residue reporting is not support. The + * DMA channel is only able to tell whether a descriptor has been completed or + * not, which means residue reporting is not supported by this channel. The + * residue field of the dma_tx_state field will always be 0. + * @DMA_RESIDUE_GRANULARITY_SEGMENT: Residue is updated after each successfully + * completed segment of the transfer (For cyclic transfers this is after each + * period). This is typically implemented by having the hardware generate an + * interrupt after each transferred segment and then the drivers updates the + * outstanding residue by the size of the segment. Another possibility is if + * the hardware supports scatter-gather and the segment descriptor has a field + * which gets set after the segment has been completed. The driver then counts + * the number of segments without the flag set to compute the residue. + * @DMA_RESIDUE_GRANULARITY_BURST: Residue is updated after each transferred + * burst. This is typically only supported if the hardware has a progress + * register of some sort (E.g. a register with the current read/write address + * or a register with the amount of bursts/beats/bytes that have been + * transferred or still need to be transferred). + */ +enum dma_residue_granularity { + DMA_RESIDUE_GRANULARITY_DESCRIPTOR = 0, + DMA_RESIDUE_GRANULARITY_SEGMENT = 1, + DMA_RESIDUE_GRANULARITY_BURST = 2, +}; + +/* struct dma_slave_caps - expose capabilities of a slave channel only + * + * @src_addr_widths: bit mask of src addr widths the channel supports + * @dstn_addr_widths: bit mask of dstn addr widths the channel supports + * @directions: bit mask of slave direction the channel supported + * 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 + * @cmd_pause: true, if pause and thereby resume is supported + * @cmd_terminate: true, if terminate cmd is supported + * + * @max_sg_nr: maximum number of SG segments supported + * 0 for no maximum + * @max_sg_len: maximum length of a SG segment supported + * 0 for no maximum + * @residue_granularity: granularity of the reported transfer residue + */ +struct dma_slave_caps { + u32 src_addr_widths; + u32 dstn_addr_widths; + u32 directions; + bool cmd_pause; + bool cmd_terminate; + + u32 max_sg_nr; + u32 max_sg_len; + enum dma_residue_granularity residue_granularity; +}; + static inline const char *dma_chan_name(struct dma_chan *chan) { return dev_name(&chan->dev->device); @@ -534,6 +589,7 @@ struct dma_tx_state { * struct with auxiliary transfer status information, otherwise the call * will just return a simple status code * @device_issue_pending: push pending transactions to hardware + * @device_slave_caps: return the slave channel capabilities */ struct dma_device { @@ -602,6 +658,7 @@ struct dma_device { dma_cookie_t cookie, struct dma_tx_state *txstate); void (*device_issue_pending)(struct dma_chan *chan); + int (*device_slave_caps)(struct dma_chan *chan, struct dma_slave_caps *caps); }; static inline int dmaengine_device_control(struct dma_chan *chan, @@ -675,6 +732,21 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_interleaved_dma( return chan->device->device_prep_interleaved_dma(chan, xt, flags); } +static inline int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps) +{ + if (!chan || !caps) + return -EINVAL; + + /* check if the channel supports slave transactions */ + if (!test_bit(DMA_SLAVE, chan->device->cap_mask.bits)) + return -ENXIO; + + if (chan->device->device_slave_caps) + return chan->device->device_slave_caps(chan, caps); + + return -ENXIO; +} + static inline int dmaengine_terminate_all(struct dma_chan *chan) { return dmaengine_device_control(chan, DMA_TERMINATE_ALL, 0); @@ -1000,6 +1072,7 @@ int dma_async_device_register(struct dma_device *device); void dma_async_device_unregister(struct dma_device *device); void dma_run_dependencies(struct dma_async_tx_descriptor *tx); struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type); +struct dma_chan *dma_get_slave_channel(struct dma_chan *chan); struct dma_chan *net_dma_find_channel(void); #define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y) #define dma_request_slave_channel_compat(mask, x, y, dev, name) \ |