arch/arm/plat-s3c/dma.c

   1 /* linux/arch/arm/plat-s3c/dma.c
   2  *
   3  * Copyright (c) 2003-2005,2006,2009 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 #include <plat/dma-plat.h>
  24
  25 /* dma channel state information */
  26 struct s3c2410_dma_chan s3c2410_chans[S3C_DMA_CHANNELS];
  27 struct s3c2410_dma_chan *s3c_dma_chan_map[DMACH_MAX];
  28
  29 /* s3c_dma_lookup_channel
  30  *
  31  * change the dma channel number given into a real dma channel id
  32 */
  33
  34 struct s3c2410_dma_chan *s3c_dma_lookup_channel(unsigned int channel)
  35 {
  36         if (channel & DMACH_LOW_LEVEL)
  37                 return &s3c2410_chans[channel & ~DMACH_LOW_LEVEL];
  38         else
  39                 return s3c_dma_chan_map[channel];
  40 }
  41
  42 /* do we need to protect the settings of the fields from
  43  * irq?
  44 */
  45
  46 int s3c2410_dma_set_opfn(unsigned int channel, s3c2410_dma_opfn_t rtn)
  47 {
  48         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
  49
  50         if (chan == NULL)
  51                 return -EINVAL;
  52
  53         pr_debug("%s: chan=%p, op rtn=%p\n", __func__, chan, rtn);
  54
  55         chan->op_fn = rtn;
  56
  57         return 0;
  58 }
  59 EXPORT_SYMBOL(s3c2410_dma_set_opfn);
  60
  61 int s3c2410_dma_set_buffdone_fn(unsigned int channel, s3c2410_dma_cbfn_t rtn)
  62 {
  63         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
  64
  65         if (chan == NULL)
  66                 return -EINVAL;
  67
  68         pr_debug("%s: chan=%p, callback rtn=%p\n", __func__, chan, rtn);
  69
  70         chan->callback_fn = rtn;
  71
  72         return 0;
  73 }
  74 EXPORT_SYMBOL(s3c2410_dma_set_buffdone_fn);
  75
  76 int s3c2410_dma_setflags(unsigned int channel, unsigned int flags)
  77 {
  78         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
  79
  80         if (chan == NULL)
  81                 return -EINVAL;
  82
  83         chan->flags = flags;
  84         return 0;
  85 }
  86 EXPORT_SYMBOL(s3c2410_dma_setflags);