Commit Graph

2 Commits

Author SHA1 Message Date
Ruslan Bukin
3d5b3b0a44 Tune xDMA interface slightly:
o Move descriptors allocation to DMA engine driver
o Add generic xdma_request() routine
o Add less-generic scatter-gather application based on xdma interface

Typical operation flow in peripheral device driver is:

1. Get xDMA controller
sc->xdma_tx = xdma_ofw_get(sc->dev, "tx");

2. Allocate virtual channel
sc->xchan_tx = xdma_channel_alloc(sc->xdma_tx, caps);

3. Setup transfer status callback
xdma_setup_intr(sc->xchan_tx, my_tx_intr, sc, &sc->ih_tx);

4. Request a transfer(s)
ret = xdma_request(sc->xchan_tx, &req);

5. Free the channel
xdma_channel_free(sc->xdma_tx);

6. Free the controller
xdma_put(sc->xdma_tx);

Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D14971
2018-04-12 15:36:24 +00:00
Ruslan Bukin
85debf7f6e Add xDMA -- the DMA abstraction layer, initial verison.
xDMA is a DMA framework designed to abstract the interaction
between device drivers and DMA engines.

Project wiki: https://wiki.freebsd.org/xdma

Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D8807
2016-12-20 18:02:07 +00:00