arch/arm/plat-samsung/dma.c

   1 /* linux/arch/arm/plat-samsung/dma.c
   2  *
   3  * Copyright (c) 2003-2009 Simtec Electronics
   4  *      Ben Dooks <ben@simtec.co.uk>
   5  *      http://armlinux.simtec.co.uk/
   6  *
   7  * S3C DMA core
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12 */
  13
  14 struct s3c2410_dma_buf;
  15
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/errno.h>
  19
  20 #include <mach/dma.h>
  21 #include <mach/irqs.h>
  22
  23 /* dma channel state information */
  24 struct s3c2410_dma_chan s3c2410_chans[S3C_DMA_CHANNELS];
  25 struct s3c2410_dma_chan *s3c_dma_chan_map[DMACH_MAX];
  26
  27 /* s3c_dma_lookup_channel
  28  *
  29  * change the dma channel number given into a real dma channel id
  30 */
  31
  32 struct s3c2410_dma_chan *s3c_dma_lookup_channel(unsigned int channel)
  33 {
  34         if (channel & DMACH_LOW_LEVEL)
  35                 return &s3c2410_chans[channel & ~DMACH_LOW_LEVEL];
  36         else
  37                 return s3c_dma_chan_map[channel];
  38 }
  39
  40 /* do we need to protect the settings of the fields from
  41  * irq?
  42 */
  43
  44 int s3c2410_dma_set_opfn(enum dma_ch channel, s3c2410_dma_opfn_t rtn)
  45 {
  46         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
  47
  48         if (chan == NULL)
  49                 return -EINVAL;
  50
  51         pr_debug("%s: chan=%p, op rtn=%p\n", __func__, chan, rtn);
  52
  53         chan->op_fn = rtn;
  54
  55         return 0;
  56 }
  57 EXPORT_SYMBOL(s3c2410_dma_set_opfn);
  58
  59 int s3c2410_dma_set_buffdone_fn(enum dma_ch channel, s3c2410_dma_cbfn_t rtn)
  60 {
  61         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
  62
  63         if (chan == NULL)
  64                 return -EINVAL;
  65
  66         pr_debug("%s: chan=%p, callback rtn=%p\n", __func__, chan, rtn);
  67
  68         chan->callback_fn = rtn;
  69
  70         return 0;
  71 }
  72 EXPORT_SYMBOL(s3c2410_dma_set_buffdone_fn);
  73
  74 int s3c2410_dma_setflags(enum dma_ch channel, unsigned int flags)
  75 {
  76         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
  77
  78         if (chan == NULL)
  79                 return -EINVAL;
  80
  81         chan->flags = flags;
  82         return 0;
  83 }
  84 EXPORT_SYMBOL(s3c2410_dma_setflags);