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  */
  31 enum shdma_pm_state {
  32         SHDMA_PM_ESTABLISHED,
  33         SHDMA_PM_BUSY,
  34         SHDMA_PM_PENDING,
  35 };
  36
  37 struct 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
  45 struct shdma_slave {
  46         int slave_id;
  47 };
  48
  49 struct shdma_desc {
  50         struct list_head node;
  51         struct dma_async_tx_descriptor async_tx;
  52         enum dma_transfer_direction direction;
  53         dma_cookie_t cookie;
  54         int chunks;
  55         int mark;
  56 };
  57
  58 struct shdma_chan {
  59         spinlock_t chan_lock;           /* Channel operation lock */
  60         struct list_head ld_queue;      /* Link descriptors queue */
  61         struct list_head ld_free;       /* Free link descriptors */
  62         struct dma_chan dma_chan;       /* DMA channel */
  63         struct device *dev;             /* Channel device */
  64         void *desc;                     /* buffer for descriptor array */
  65         int desc_num;                   /* desc count */
  66         size_t max_xfer_len;            /* max transfer length */
  67         int id;                         /* Raw id of this channel */
  68         int irq;                        /* Channel IRQ */
  69         int slave_id;                   /* Client ID for slave DMA */
  70         enum shdma_pm_state pm_state;
  71 };
  72
  73 /**
  74  * struct shdma_ops - simple DMA driver operations
  75  * desc_completed:      return true, if this is the descriptor, that just has
  76  *                      completed (atomic)
  77  * halt_channel:        stop DMA channel operation (atomic)
  78  * channel_busy:        return true, if the channel is busy (atomic)
  79  * slave_addr:          return slave DMA address
  80  * desc_setup:          set up the hardware specific descriptor portion (atomic)
  81  * set_slave:           bind channel to a slave
  82  * setup_xfer:          configure channel hardware for operation (atomic)
  83  * start_xfer:          start the DMA transfer (atomic)
  84  * embedded_desc:       return Nth struct shdma_desc pointer from the
  85  *                      descriptor array
  86  * chan_irq:            process channel IRQ, return true if a transfer has
  87  *                      completed (atomic)
  88  */
  89 struct shdma_ops {
  90         bool (*desc_completed)(struct shdma_chan *, struct shdma_desc *);
  91         void (*halt_channel)(struct shdma_chan *);
  92         bool (*channel_busy)(struct shdma_chan *);
  93         dma_addr_t (*slave_addr)(struct shdma_chan *);
  94         int (*desc_setup)(struct shdma_chan *, struct shdma_desc *,
  95                           dma_addr_t, dma_addr_t, size_t *);
  96         int (*set_slave)(struct shdma_chan *, int, bool);
  97         void (*setup_xfer)(struct shdma_chan *, int);
  98         void (*start_xfer)(struct shdma_chan *, struct shdma_desc *);
  99         struct shdma_desc *(*embedded_desc)(void *, int);
 100         bool (*chan_irq)(struct shdma_chan *, int);
 101 };
 102
 103 struct shdma_dev {
 104         struct dma_device dma_dev;
 105         struct shdma_chan **schan;
 106         const struct shdma_ops *ops;
 107         size_t desc_size;
 108 };
 109
 110 #define shdma_for_each_chan(c, d, i) for (i = 0, c = (d)->schan[0]; \
 111                                 i < (d)->dma_dev.chancnt; c = (d)->schan[++i])
 112
 113 int shdma_request_irq(struct shdma_chan *, int,
 114                            unsigned long, const char *);
 115 void shdma_free_irq(struct shdma_chan *);
 116 bool shdma_reset(struct shdma_dev *sdev);
 117 void shdma_chan_probe(struct shdma_dev *sdev,
 118                            struct shdma_chan *schan, int id);
 119 void shdma_chan_remove(struct shdma_chan *schan);
 120 int shdma_init(struct device *dev, struct shdma_dev *sdev,
 121                     int chan_num);
 122 void shdma_cleanup(struct shdma_dev *sdev);
 123
 124 #endif