@@ -404,14 +404,16 @@ enum dma_residue_granularity {
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
- * @dst_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
+/**
+ * struct dma_slave_caps - expose capabilities of a slave channel only
+ * @src_addr_widths: bit mask of src addr widths the channel supports.
+ * Width is specified in bytes, e.g. for a channel supporting
+ * a width of 4 the mask should have BIT(4) set.
+ * @dst_addr_widths: bit mask of dst addr widths the channel supports
+ * @directions: bit mask of slave directions the channel supports.
+ * Since the enum dma_transfer_direction is not defined as bit flag for
+ * each type, the dma controller should set BIT(<TYPE>) and same
+ * should be checked by controller as well
* @max_burst: max burst capability per-transfer
* @cmd_pause: true, if pause and thereby resume is supported
* @cmd_terminate: true, if terminate cmd is supported
@@ -678,11 +680,13 @@ struct dma_filter {
* @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
+ * Width is specified in bytes, e.g. for a device supporting
+ * a width of 4 the mask should have BIT(4) set.
* @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
+ * @directions: bit mask of slave directions the device supports.
+ * Since the enum dma_transfer_direction is not defined as bit flag for
+ * each type, the dma controller should set BIT(<TYPE>) and same
+ * should be checked by controller as well
* @max_burst: max burst capability per-transfer
* @residue_granularity: granularity of the transfer residue reported
* by tx_status
struct dma_slave_caps documentation omitted the correct kernel-doc opening comment mark. Document byte granularity and interpretation of the src/dst_addr_widths bit flag fields used by struct dma_slave_caps and struct dma_device. Add punctuation to their "directions" member documentations, and cleanup wording of the description. Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de> --- include/linux/dmaengine.h | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-)