linux/include/linux/shdma-base.h
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   1/*
   2 * Dmaengine driver base library for DMA controllers, found on SH-based SoCs
   3 *
   4 * extracted from shdma.c and headers
   5 *
   6 * Copyright (C) 2011-2012 Guennadi Liakhovetski <g.liakhovetski@gmx.de>
   7 * Copyright (C) 2009 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
   8 * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved.
   9 * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
  10 *
  11 * This is free software; you can redistribute it and/or modify
  12 * it under the terms of version 2 of the GNU General Public License as
  13 * published by the Free Software Foundation.
  14 */
  15
  16#ifndef SHDMA_BASE_H
  17#define SHDMA_BASE_H
  18
  19#include <linux/dmaengine.h>
  20#include <linux/interrupt.h>
  21#include <linux/list.h>
  22#include <linux/types.h>
  23
  24/**
  25 * shdma_pm_state - DMA channel PM state
  26 * SHDMA_PM_ESTABLISHED:        either idle or during data transfer
  27 * SHDMA_PM_BUSY:               during the transfer preparation, when we have to
  28 *                              drop the lock temporarily
  29 * SHDMA_PM_PENDING:    transfers pending
  30 */
  31enum shdma_pm_state {
  32        SHDMA_PM_ESTABLISHED,
  33        SHDMA_PM_BUSY,
  34        SHDMA_PM_PENDING,
  35};
  36
  37struct device;
  38
  39/*
  40 * Drivers, using this library are expected to embed struct shdma_dev,
  41 * struct shdma_chan, struct shdma_desc, and struct shdma_slave
  42 * in their respective device, channel, descriptor and slave objects.
  43 */
  44
  45struct shdma_slave {
  46        int slave_id;
  47};
  48
  49struct shdma_desc {
  50        struct list_head node;
  51        struct dma_async_tx_descriptor async_tx;
  52        enum dma_transfer_direction direction;
  53        size_t partial;
  54        dma_cookie_t cookie;
  55        int chunks;
  56        int mark;
  57};
  58
  59struct shdma_chan {
  60        spinlock_t chan_lock;           /* Channel operation lock */
  61        struct list_head ld_queue;      /* Link descriptors queue */
  62        struct list_head ld_free;       /* Free link descriptors */
  63        struct dma_chan dma_chan;       /* DMA channel */
  64        struct device *dev;             /* Channel device */
  65        void *desc;                     /* buffer for descriptor array */
  66        int desc_num;                   /* desc count */
  67        size_t max_xfer_len;            /* max transfer length */
  68        int id;                         /* Raw id of this channel */
  69        int irq;                        /* Channel IRQ */
  70        int slave_id;                   /* Client ID for slave DMA */
  71        enum shdma_pm_state pm_state;
  72};
  73
  74/**
  75 * struct shdma_ops - simple DMA driver operations
  76 * desc_completed:      return true, if this is the descriptor, that just has
  77 *                      completed (atomic)
  78 * halt_channel:        stop DMA channel operation (atomic)
  79 * channel_busy:        return true, if the channel is busy (atomic)
  80 * slave_addr:          return slave DMA address
  81 * desc_setup:          set up the hardware specific descriptor portion (atomic)
  82 * set_slave:           bind channel to a slave
  83 * setup_xfer:          configure channel hardware for operation (atomic)
  84 * start_xfer:          start the DMA transfer (atomic)
  85 * embedded_desc:       return Nth struct shdma_desc pointer from the
  86 *                      descriptor array
  87 * chan_irq:            process channel IRQ, return true if a transfer has
  88 *                      completed (atomic)
  89 */
  90struct shdma_ops {
  91        bool (*desc_completed)(struct shdma_chan *, struct shdma_desc *);
  92        void (*halt_channel)(struct shdma_chan *);
  93        bool (*channel_busy)(struct shdma_chan *);
  94        dma_addr_t (*slave_addr)(struct shdma_chan *);
  95        int (*desc_setup)(struct shdma_chan *, struct shdma_desc *,
  96                          dma_addr_t, dma_addr_t, size_t *);
  97        int (*set_slave)(struct shdma_chan *, int, bool);
  98        void (*setup_xfer)(struct shdma_chan *, int);
  99        void (*start_xfer)(struct shdma_chan *, struct shdma_desc *);
 100        struct shdma_desc *(*embedded_desc)(void *, int);
 101        bool (*chan_irq)(struct shdma_chan *, int);
 102        size_t (*get_partial)(struct shdma_chan *, struct shdma_desc *);
 103};
 104
 105struct shdma_dev {
 106        struct dma_device dma_dev;
 107        struct shdma_chan **schan;
 108        const struct shdma_ops *ops;
 109        size_t desc_size;
 110};
 111
 112#define shdma_for_each_chan(c, d, i) for (i = 0, c = (d)->schan[0]; \
 113                                i < (d)->dma_dev.chancnt; c = (d)->schan[++i])
 114
 115int shdma_request_irq(struct shdma_chan *, int,
 116                           unsigned long, const char *);
 117void shdma_free_irq(struct shdma_chan *);
 118bool shdma_reset(struct shdma_dev *sdev);
 119void shdma_chan_probe(struct shdma_dev *sdev,
 120                           struct shdma_chan *schan, int id);
 121void shdma_chan_remove(struct shdma_chan *schan);
 122int shdma_init(struct device *dev, struct shdma_dev *sdev,
 123                    int chan_num);
 124void shdma_cleanup(struct shdma_dev *sdev);
 125
 126#endif
 127
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