Linux Kernel  3.7.1
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dma.c
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1 /* linux/arch/arm/plat-samsung/dma.c
2  *
3  * Copyright (c) 2003-2009 Simtec Electronics
4  * Ben Dooks <[email protected]>
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 */
26 
27 /* s3c_dma_lookup_channel
28  *
29  * change the dma channel number given into a real dma channel id
30 */
31 
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 
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 }
58 
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 }
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 }