1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * TI EDMA definitions
4 *
5 * Copyright (C) 2006-2013 Texas Instruments.
6 */
7
8/*
9 * This EDMA3 programming framework exposes two basic kinds of resource:
10 *
11 * Channel Triggers transfers, usually from a hardware event but
12 * also manually or by "chaining" from DMA completions.
13 * Each channel is coupled to a Parameter RAM (PaRAM) slot.
14 *
15 * Slot Each PaRAM slot holds a DMA transfer descriptor (PaRAM
16 * "set"), source and destination addresses, a link to a
17 * next PaRAM slot (if any), options for the transfer, and
18 * instructions for updating those addresses. There are
19 * more than twice as many slots as event channels.
20 *
21 * Each PaRAM set describes a sequence of transfers, either for one large
22 * buffer or for several discontiguous smaller buffers. An EDMA transfer
23 * is driven only from a channel, which performs the transfers specified
24 * in its PaRAM slot until there are no more transfers. When that last
25 * transfer completes, the "link" field may be used to reload the channel's
26 * PaRAM slot with a new transfer descriptor.
27 *
28 * The EDMA Channel Controller (CC) maps requests from channels into physical
29 * Transfer Controller (TC) requests when the channel triggers (by hardware
30 * or software events, or by chaining). The two physical DMA channels provided
31 * by the TCs are thus shared by many logical channels.
32 *
33 * DaVinci hardware also has a "QDMA" mechanism which is not currently
34 * supported through this interface. (DSP firmware uses it though.)
35 */
36
37#ifndef EDMA_H_
38#define EDMA_H_
39
40enum dma_event_q {
41 EVENTQ_0 = 0,
42 EVENTQ_1 = 1,
43 EVENTQ_2 = 2,
44 EVENTQ_3 = 3,
45 EVENTQ_DEFAULT = -1
46};
47
48#define EDMA_CTLR_CHAN(ctlr, chan) (((ctlr) << 16) | (chan))
49#define EDMA_CTLR(i) ((i) >> 16)
50#define EDMA_CHAN_SLOT(i) ((i) & 0xffff)
51
52#define EDMA_FILTER_PARAM(ctlr, chan) ((int[]) { EDMA_CTLR_CHAN(ctlr, chan) })
53
54struct edma_rsv_info {
55
56 const s16 (*rsv_chans)[2];
57 const s16 (*rsv_slots)[2];
58};
59
60struct dma_slave_map;
61
62/* platform_data for EDMA driver */
63struct edma_soc_info {
64 /*
65 * Default queue is expected to be a low-priority queue.
66 * This way, long transfers on the default queue started
67 * by the codec engine will not cause audio defects.
68 */
69 enum dma_event_q default_queue;
70
71 /* Resource reservation for other cores */
72 struct edma_rsv_info *rsv;
73
74 /* List of channels allocated for memcpy, terminated with -1 */
75 s32 *memcpy_channels;
76
77 s8 (*queue_priority_mapping)[2];
78 const s16 (*xbar_chans)[2];
79
80 const struct dma_slave_map *slave_map;
81 int slavecnt;
82};
83
84#endif
85

source code of linux/include/linux/platform_data/edma.h