linux_kernel/include/linux/platform_data/edma.h

/*
 *  TI EDMA definitions
 *
 *  Copyright (C) 2006-2013 Texas Instruments.
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 */

/*
 * This EDMA3 programming framework exposes two basic kinds of resource:
 *
 *  Channel	Triggers transfers, usually from a hardware event but
 *		also manually or by "chaining" from DMA completions.
 *		Each channel is coupled to a Parameter RAM (PaRAM) slot.
 *
 *  Slot	Each PaRAM slot holds a DMA transfer descriptor (PaRAM
 *		"set"), source and destination addresses, a link to a
 *		next PaRAM slot (if any), options for the transfer, and
 *		instructions for updating those addresses.  There are
 *		more than twice as many slots as event channels.
 *
 * Each PaRAM set describes a sequence of transfers, either for one large
 * buffer or for several discontiguous smaller buffers.  An EDMA transfer
 * is driven only from a channel, which performs the transfers specified
 * in its PaRAM slot until there are no more transfers.  When that last
 * transfer completes, the "link" field may be used to reload the channel's
 * PaRAM slot with a new transfer descriptor.
 *
 * The EDMA Channel Controller (CC) maps requests from channels into physical
 * Transfer Controller (TC) requests when the channel triggers (by hardware
 * or software events, or by chaining).  The two physical DMA channels provided
 * by the TCs are thus shared by many logical channels.
 *
 * DaVinci hardware also has a "QDMA" mechanism which is not currently
 * supported through this interface.  (DSP firmware uses it though.)
 */

#ifndef EDMA_H_
#define EDMA_H_

enum dma_event_q {
	EVENTQ_0 = 0,
	EVENTQ_1 = 1,
	EVENTQ_2 = 2,
	EVENTQ_3 = 3,
	EVENTQ_DEFAULT = -1
};

#define EDMA_CTLR_CHAN(ctlr, chan)	(((ctlr) << 16) | (chan))
#define EDMA_CTLR(i)			((i) >> 16)
#define EDMA_CHAN_SLOT(i)		((i) & 0xffff)

struct edma_rsv_info {

	const s16	(*rsv_chans)[2];
	const s16	(*rsv_slots)[2];
};

/* platform_data for EDMA driver */
struct edma_soc_info {
	/*
	 * Default queue is expected to be a low-priority queue.
	 * This way, long transfers on the default queue started
	 * by the codec engine will not cause audio defects.
	 */
	enum dma_event_q	default_queue;

	/* Resource reservation for other cores */
	struct edma_rsv_info	*rsv;

	/* List of channels allocated for memcpy, terminated with -1 */
	s32			*memcpy_channels;

	s8	(*queue_priority_mapping)[2];
	const s16	(*xbar_chans)[2];
};

#endif