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Release 4.12 include/linux/shdma-base.h

Directory: include/linux
 * Dmaengine driver base library for DMA controllers, found on SH-based SoCs
 * extracted from shdma.c and headers
 * Copyright (C) 2011-2012 Guennadi Liakhovetski <>
 * Copyright (C) 2009 Nobuhiro Iwamatsu <>
 * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved.
 * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
 * This is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.

#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 {
int slave_id;

struct shdma_desc {
struct list_head node;
struct dma_async_tx_descriptor async_tx;
enum dma_transfer_direction direction;
size_t partial;
dma_cookie_t cookie;
int chunks;
int mark;
bool cyclic;			/* used as cyclic transfer */

struct shdma_chan {
spinlock_t chan_lock;		/* Channel operation lock */
struct list_head ld_queue;	/* Link descriptors queue */
struct list_head ld_free;	/* Free link descriptors */
struct dma_chan dma_chan;	/* DMA channel */
struct device *dev;		/* Channel device */
void *desc;			/* buffer for descriptor array */
int desc_num;			/* desc count */
size_t max_xfer_len;		/* max transfer length */
int id;				/* Raw id of this channel */
int irq;			/* Channel IRQ */
int slave_id;			/* Client ID for slave DMA */
int real_slave_id;		/* argument passed to filter function */
int hw_req;			/* DMA request line for slave DMA - same
                                         * as MID/RID, used with DT */
enum shdma_pm_state pm_state;

 * 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 {
bool (*desc_completed)(struct shdma_chan *, struct shdma_desc *);
void (*halt_channel)(struct shdma_chan *);
bool (*channel_busy)(struct shdma_chan *);
dma_addr_t (*slave_addr)(struct shdma_chan *);
int (*desc_setup)(struct shdma_chan *, struct shdma_desc *,
			  dma_addr_t, dma_addr_t, size_t *);
int (*set_slave)(struct shdma_chan *, int, dma_addr_t, bool);
void (*setup_xfer)(struct shdma_chan *, int);
void (*start_xfer)(struct shdma_chan *, struct shdma_desc *);
struct shdma_desc *(*embedded_desc)(void *, int);
bool (*chan_irq)(struct shdma_chan *, int);
size_t (*get_partial)(struct shdma_chan *, struct shdma_desc *);

struct shdma_dev {
struct dma_device dma_dev;
struct shdma_chan **schan;
const struct shdma_ops *ops;
size_t desc_size;

#define shdma_for_each_chan(c, d, i) for (i = 0, c = (d)->schan[0]; \
                                i < (d)->dma_dev.chancnt; c = (d)->schan[++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);
bool shdma_chan_filter(struct dma_chan *chan, void *arg);

static inline bool shdma_chan_filter(struct dma_chan *chan, void *arg) { return false; }


Geert Uytterhoeven1894.74%150.00%
Guennadi Liakhovetski15.26%150.00%

#endif #endif

Overall Contributors

Guennadi Liakhovetski43694.37%975.00%
Geert Uytterhoeven183.90%18.33%
Kuninori Morimoto40.87%18.33%
Arnd Bergmann40.87%18.33%
Directory: include/linux
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