linux/include/linux/shdma-base.h

/* SPDX-License-Identifier: GPL-2.0
 *
 * Dmaengine driver base library for DMA controllers, found on SH-based SoCs
 *
 * extracted from shdma.c and headers
 *
 * Copyright (C) 2011-2012 Guennadi Liakhovetski <[email protected]>
 * Copyright (C) 2009 Nobuhiro Iwamatsu <[email protected]>
 * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved.
 * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
 */

#ifndef SHDMA_BASE_H
#define SHDMA_BASE_H

#include <linux/dmaengine.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/types.h>

/**
 * shdma_pm_state - DMA channel PM state
 * SHDMA_PM_ESTABLISHED:	either idle or during data transfer
 * SHDMA_PM_BUSY:		during the transfer preparation, when we have to
 *				drop the lock temporarily
 * SHDMA_PM_PENDING:	transfers pending
 */
enum shdma_pm_state { … };

struct device;

/*
 * Drivers, using this library are expected to embed struct shdma_dev,
 * struct shdma_chan, struct shdma_desc, and struct shdma_slave
 * in their respective device, channel, descriptor and slave objects.
 */

struct shdma_slave { … };

struct shdma_desc { … };

struct shdma_chan { … };

/**
 * struct shdma_ops - simple DMA driver operations
 * desc_completed:	return true, if this is the descriptor, that just has
 *			completed (atomic)
 * halt_channel:	stop DMA channel operation (atomic)
 * channel_busy:	return true, if the channel is busy (atomic)
 * slave_addr:		return slave DMA address
 * desc_setup:		set up the hardware specific descriptor portion (atomic)
 * set_slave:		bind channel to a slave
 * setup_xfer:		configure channel hardware for operation (atomic)
 * start_xfer:		start the DMA transfer (atomic)
 * embedded_desc:	return Nth struct shdma_desc pointer from the
 *			descriptor array
 * chan_irq:		process channel IRQ, return true if a transfer has
 *			completed (atomic)
 */
struct shdma_ops { … };

struct shdma_dev { … };

#define shdma_for_each_chan(c, d, i) …

int shdma_request_irq(struct shdma_chan *, int,
			   unsigned long, const char *);
bool shdma_reset(struct shdma_dev *sdev);
void shdma_chan_probe(struct shdma_dev *sdev,
			   struct shdma_chan *schan, int id);
void shdma_chan_remove(struct shdma_chan *schan);
int shdma_init(struct device *dev, struct shdma_dev *sdev,
		    int chan_num);
void shdma_cleanup(struct shdma_dev *sdev);
#if IS_ENABLED(CONFIG_SH_DMAE_BASE)
bool shdma_chan_filter(struct dma_chan *chan, void *arg);
#else
static inline bool shdma_chan_filter(struct dma_chan *chan, void *arg)
{
	return false;
}
#endif

#endif