freebsd-dev/sys/dev/xdma/xdma_if.m
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

116 lines
2.8 KiB
Objective-C

#-
# Copyright (c) 2016-2018 Ruslan Bukin <br@bsdpad.com>
# All rights reserved.
#
# This software was developed by SRI International and the University of
# Cambridge Computer Laboratory under DARPA/AFRL contract FA8750-10-C-0237
# ("CTSRD"), as part of the DARPA CRASH research programme.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
# $FreeBSD$
#
#include <machine/bus.h>
#ifdef FDT
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#endif
#include <dev/xdma/xdma.h>
INTERFACE xdma;
#
# Request a transfer.
#
METHOD int channel_request {
device_t dev;
struct xdma_channel *xchan;
struct xdma_request *req;
};
#
# Prepare xDMA channel for a scatter-gather transfer.
#
METHOD int channel_prep_sg {
device_t dev;
struct xdma_channel *xchan;
};
#
# Query DMA engine driver for the amount of free entries
# (descriptors) are available.
#
METHOD int channel_capacity {
device_t dev;
struct xdma_channel *xchan;
uint32_t *capacity;
};
#
# Submit sglist list to DMA engine driver.
#
METHOD int channel_submit_sg {
device_t dev;
struct xdma_channel *xchan;
struct xdma_sglist *sg;
uint32_t sg_n;
};
#
# Notify driver we have machine-dependend data.
#
METHOD int ofw_md_data {
device_t dev;
pcell_t *cells;
int ncells;
void **data;
};
#
# Allocate both virtual and harware channels.
#
METHOD int channel_alloc {
device_t dev;
struct xdma_channel *xchan;
};
#
# Free the real hardware channel.
#
METHOD int channel_free {
device_t dev;
struct xdma_channel *xchan;
};
#
# Begin, pause or terminate the channel operation.
#
METHOD int channel_control {
device_t dev;
struct xdma_channel *xchan;
int cmd;
};