arch/arm/plat-samsung/s3c-dma-ops.c

   1 /* linux/arch/arm/plat-samsung/s3c-dma-ops.c
   2  *
   3  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
   4  *              http://www.samsung.com
   5  *
   6  * Samsung S3C-DMA Operations
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/errno.h>
  15 #include <linux/slab.h>
  16 #include <linux/types.h>
  17 #include <linux/export.h>
  18
  19 #include <mach/dma.h>
  20
  21 struct cb_data {
  22         void (*fp) (void *);
  23         void *fp_param;
  24         unsigned ch;
  25         struct list_head node;
  26 };
  27
  28 static LIST_HEAD(dma_list);
  29
  30 static void s3c_dma_cb(struct s3c2410_dma_chan *channel, void *param,
  31                        int size, enum s3c2410_dma_buffresult res)
  32 {
  33         struct cb_data *data = param;
  34
  35         data->fp(data->fp_param);
  36 }
  37
  38 static unsigned s3c_dma_request(enum dma_ch dma_ch,
  39                                  struct samsung_dma_info *info)
  40 {
  41         struct cb_data *data;
  42
  43         if (s3c2410_dma_request(dma_ch, info->client, NULL) < 0) {
  44                 s3c2410_dma_free(dma_ch, info->client);
  45                 return 0;
  46         }
  47
  48         data = kzalloc(sizeof(struct cb_data), GFP_KERNEL);
  49         data->ch = dma_ch;
  50         list_add_tail(&data->node, &dma_list);
  51
  52         s3c2410_dma_devconfig(dma_ch, info->direction, info->fifo);
  53
  54         if (info->cap == DMA_CYCLIC)
  55                 s3c2410_dma_setflags(dma_ch, S3C2410_DMAF_CIRCULAR);
  56
  57         s3c2410_dma_config(dma_ch, info->width);
  58
  59         return (unsigned)dma_ch;
  60 }
  61
  62 static int s3c_dma_release(unsigned ch, struct s3c2410_dma_client *client)
  63 {
  64         struct cb_data *data;
  65
  66         list_for_each_entry(data, &dma_list, node)
  67                 if (data->ch == ch)
  68                         break;
  69         list_del(&data->node);
  70
  71         s3c2410_dma_free(ch, client);
  72         kfree(data);
  73
  74         return 0;
  75 }
  76
  77 static int s3c_dma_prepare(unsigned ch, struct samsung_dma_prep_info *info)
  78 {
  79         struct cb_data *data;
  80         int len = (info->cap == DMA_CYCLIC) ? info->period : info->len;
  81
  82         list_for_each_entry(data, &dma_list, node)
  83                 if (data->ch == ch)
  84                         break;
  85
  86         if (!data->fp) {
  87                 s3c2410_dma_set_buffdone_fn(ch, s3c_dma_cb);
  88                 data->fp = info->fp;
  89                 data->fp_param = info->fp_param;
  90         }
  91
  92         s3c2410_dma_enqueue(ch, (void *)data, info->buf, len);
  93
  94         return 0;
  95 }
  96
  97 static inline int s3c_dma_trigger(unsigned ch)
  98 {
  99         return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_START);
 100 }
 101
 102 static inline int s3c_dma_started(unsigned ch)
 103 {
 104         return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_STARTED);
 105 }
 106
 107 static inline int s3c_dma_flush(unsigned ch)
 108 {
 109         return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_FLUSH);
 110 }
 111
 112 static inline int s3c_dma_stop(unsigned ch)
 113 {
 114         return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_STOP);
 115 }
 116
 117 static struct samsung_dma_ops s3c_dma_ops = {
 118         .request        = s3c_dma_request,
 119         .release        = s3c_dma_release,
 120         .prepare        = s3c_dma_prepare,
 121         .trigger        = s3c_dma_trigger,
 122         .started        = s3c_dma_started,
 123         .flush          = s3c_dma_flush,
 124         .stop           = s3c_dma_stop,
 125 };
 126
 127 void *s3c_dma_get_ops(void)
 128 {
 129         return &s3c_dma_ops;
 130 }
 131 EXPORT_SYMBOL(s3c_dma_get_ops);