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_req *param)
  40 {
  41         struct cb_data *data;
  42
  43         if (s3c2410_dma_request(dma_ch, param->client, NULL) < 0) {
  44                 s3c2410_dma_free(dma_ch, param->client);
  45                 return 0;
  46         }
  47
  48         if (param->cap == DMA_CYCLIC)
  49                 s3c2410_dma_setflags(dma_ch, S3C2410_DMAF_CIRCULAR);
  50
  51         data = kzalloc(sizeof(struct cb_data), GFP_KERNEL);
  52         data->ch = dma_ch;
  53         list_add_tail(&data->node, &dma_list);
  54
  55         return (unsigned)dma_ch;
  56 }
  57
  58 static int s3c_dma_release(unsigned ch, void *param)
  59 {
  60         struct cb_data *data;
  61
  62         list_for_each_entry(data, &dma_list, node)
  63                 if (data->ch == ch)
  64                         break;
  65         list_del(&data->node);
  66
  67         s3c2410_dma_free(ch, param);
  68         kfree(data);
  69
  70         return 0;
  71 }
  72
  73 static int s3c_dma_config(unsigned ch, struct samsung_dma_config *param)
  74 {
  75         s3c2410_dma_devconfig(ch, param->direction, param->fifo);
  76         s3c2410_dma_config(ch, param->width);
  77
  78         return 0;
  79 }
  80
  81 static int s3c_dma_prepare(unsigned ch, struct samsung_dma_prep *param)
  82 {
  83         struct cb_data *data;
  84         int len = (param->cap == DMA_CYCLIC) ? param->period : param->len;
  85
  86         list_for_each_entry(data, &dma_list, node)
  87                 if (data->ch == ch)
  88                         break;
  89
  90         if (!data->fp) {
  91                 s3c2410_dma_set_buffdone_fn(ch, s3c_dma_cb);
  92                 data->fp = param->fp;
  93                 data->fp_param = param->fp_param;
  94         }
  95
  96         s3c2410_dma_enqueue(ch, (void *)data, param->buf, len);
  97
  98         return 0;
  99 }
 100
 101 static inline int s3c_dma_trigger(unsigned ch)
 102 {
 103         return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_START);
 104 }
 105
 106 static inline int s3c_dma_started(unsigned ch)
 107 {
 108         return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_STARTED);
 109 }
 110
 111 static inline int s3c_dma_flush(unsigned ch)
 112 {
 113         return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_FLUSH);
 114 }
 115
 116 static inline int s3c_dma_stop(unsigned ch)
 117 {
 118         return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_STOP);
 119 }
 120
 121 static struct samsung_dma_ops s3c_dma_ops = {
 122         .request        = s3c_dma_request,
 123         .release        = s3c_dma_release,
 124         .config         = s3c_dma_config,
 125         .prepare        = s3c_dma_prepare,
 126         .trigger        = s3c_dma_trigger,
 127         .started        = s3c_dma_started,
 128         .flush          = s3c_dma_flush,
 129         .stop           = s3c_dma_stop,
 130 };
 131
 132 void *s3c_dma_get_ops(void)
 133 {
 134         return &s3c_dma_ops;
 135 }
 136 EXPORT_SYMBOL(s3c_dma_get_ops);