LXR linux/include/linux/shdma-base.h

   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        bool cyclic;                    /* used as cyclic transfer */
  58};
  59
  60struct shdma_chan {
  61        spinlock_t chan_lock;           /* Channel operation lock */
  62        struct list_head ld_queue;      /* Link descriptors queue */
  63        struct list_head ld_free;       /* Free link descriptors */
  64        struct dma_chan dma_chan;       /* DMA channel */
  65        struct device *dev;             /* Channel device */
  66        void *desc;                     /* buffer for descriptor array */
  67        int desc_num;                   /* desc count */
  68        size_t max_xfer_len;            /* max transfer length */
  69        int id;                         /* Raw id of this channel */
  70        int irq;                        /* Channel IRQ */
  71        int slave_id;                   /* Client ID for slave DMA */
  72        int real_slave_id;              /* argument passed to filter function */
  73        int hw_req;                     /* DMA request line for slave DMA - same
  74                                         * as MID/RID, used with DT */
  75        enum shdma_pm_state pm_state;
  76};
  77
  78/**
  79 * struct shdma_ops - simple DMA driver operations
  80 * desc_completed:      return true, if this is the descriptor, that just has
  81 *                      completed (atomic)
  82 * halt_channel:        stop DMA channel operation (atomic)
  83 * channel_busy:        return true, if the channel is busy (atomic)
  84 * slave_addr:          return slave DMA address
  85 * desc_setup:          set up the hardware specific descriptor portion (atomic)
  86 * set_slave:           bind channel to a slave
  87 * setup_xfer:          configure channel hardware for operation (atomic)
  88 * start_xfer:          start the DMA transfer (atomic)
  89 * embedded_desc:       return Nth struct shdma_desc pointer from the
  90 *                      descriptor array
  91 * chan_irq:            process channel IRQ, return true if a transfer has
  92 *                      completed (atomic)
  93 */
  94struct shdma_ops {
  95        bool (*desc_completed)(struct shdma_chan *, struct shdma_desc *);
  96        void (*halt_channel)(struct shdma_chan *);
  97        bool (*channel_busy)(struct shdma_chan *);
  98        dma_addr_t (*slave_addr)(struct shdma_chan *);
  99        int (*desc_setup)(struct shdma_chan *, struct shdma_desc *,
 100                          dma_addr_t, dma_addr_t, size_t *);
 101        int (*set_slave)(struct shdma_chan *, int, dma_addr_t, bool);
 102        void (*setup_xfer)(struct shdma_chan *, int);
 103        void (*start_xfer)(struct shdma_chan *, struct shdma_desc *);
 104        struct shdma_desc *(*embedded_desc)(void *, int);
 105        bool (*chan_irq)(struct shdma_chan *, int);
 106        size_t (*get_partial)(struct shdma_chan *, struct shdma_desc *);
 107};
 108
 109struct shdma_dev {
 110        struct dma_device dma_dev;
 111        struct shdma_chan **schan;
 112        const struct shdma_ops *ops;
 113        size_t desc_size;
 114};
 115
 116#define shdma_for_each_chan(c, d, i) for (i = 0, c = (d)->schan[0]; \
 117                                i < (d)->dma_dev.chancnt; c = (d)->schan[++i])
 118
 119int shdma_request_irq(struct shdma_chan *, int,
 120                           unsigned long, const char *);
 121bool shdma_reset(struct shdma_dev *sdev);
 122void shdma_chan_probe(struct shdma_dev *sdev,
 123                           struct shdma_chan *schan, int id);
 124void shdma_chan_remove(struct shdma_chan *schan);
 125int shdma_init(struct device *dev, struct shdma_dev *sdev,
 126                    int chan_num);
 127void shdma_cleanup(struct shdma_dev *sdev);
 128#if IS_ENABLED(CONFIG_SH_DMAE_BASE)
 129bool shdma_chan_filter(struct dma_chan *chan, void *arg);
 130#else
 131static inline bool shdma_chan_filter(struct dma_chan *chan, void *arg)
 132{
 133        return false;
 134}
 135#endif
 136
 137#endif
 138