diff options
| -rw-r--r-- | include/linux/dmaengine.h | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index cb286b1acdb6..5692bc3afd39 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -370,6 +370,33 @@ struct dma_slave_config { unsigned int slave_id; }; +/* 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 + */ +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; +}; + static inline const char *dma_chan_name(struct dma_chan *chan) { return dev_name(&chan->dev->device); @@ -532,6 +559,7 @@ 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 { @@ -597,6 +625,7 @@ 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, @@ -670,6 +699,21 @@ 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); |