linux/arch/arm/plat-samsung/s3c-dma-ops.c
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   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
  21struct cb_data {
  22        void (*fp) (void *);
  23        void *fp_param;
  24        unsigned ch;
  25        struct list_head node;
  26};
  27
  28static LIST_HEAD(dma_list);
  29
  30static 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
  38static unsigned s3c_dma_request(enum dma_ch dma_ch,
  39                                struct samsung_dma_req *param,
  40                                struct device *dev, char *ch_name)
  41{
  42        struct cb_data *data;
  43
  44        if (s3c2410_dma_request(dma_ch, param->client, NULL) < 0) {
  45                s3c2410_dma_free(dma_ch, param->client);
  46                return 0;
  47        }
  48
  49        if (param->cap == DMA_CYCLIC)
  50                s3c2410_dma_setflags(dma_ch, S3C2410_DMAF_CIRCULAR);
  51
  52        data = kzalloc(sizeof(struct cb_data), GFP_KERNEL);
  53        data->ch = dma_ch;
  54        list_add_tail(&data->node, &dma_list);
  55
  56        return (unsigned)dma_ch;
  57}
  58
  59static int s3c_dma_release(unsigned ch, void *param)
  60{
  61        struct cb_data *data;
  62
  63        list_for_each_entry(data, &dma_list, node)
  64                if (data->ch == ch)
  65                        break;
  66        list_del(&data->node);
  67
  68        s3c2410_dma_free(ch, param);
  69        kfree(data);
  70
  71        return 0;
  72}
  73
  74static int s3c_dma_config(unsigned ch, struct samsung_dma_config *param)
  75{
  76        s3c2410_dma_devconfig(ch, param->direction, param->fifo);
  77        s3c2410_dma_config(ch, param->width);
  78
  79        return 0;
  80}
  81
  82static int s3c_dma_prepare(unsigned ch, struct samsung_dma_prep *param)
  83{
  84        struct cb_data *data;
  85        int len = (param->cap == DMA_CYCLIC) ? param->period : param->len;
  86
  87        list_for_each_entry(data, &dma_list, node)
  88                if (data->ch == ch)
  89                        break;
  90
  91        if (!data->fp) {
  92                s3c2410_dma_set_buffdone_fn(ch, s3c_dma_cb);
  93                data->fp = param->fp;
  94                data->fp_param = param->fp_param;
  95        }
  96
  97        s3c2410_dma_enqueue(ch, (void *)data, param->buf, len);
  98
  99        return 0;
 100}
 101
 102static inline int s3c_dma_trigger(unsigned ch)
 103{
 104        return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_START);
 105}
 106
 107static inline int s3c_dma_started(unsigned ch)
 108{
 109        return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_STARTED);
 110}
 111
 112static inline int s3c_dma_flush(unsigned ch)
 113{
 114        return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_FLUSH);
 115}
 116
 117static inline int s3c_dma_stop(unsigned ch)
 118{
 119        return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_STOP);
 120}
 121
 122static struct samsung_dma_ops s3c_dma_ops = {
 123        .request        = s3c_dma_request,
 124        .release        = s3c_dma_release,
 125        .config         = s3c_dma_config,
 126        .prepare        = s3c_dma_prepare,
 127        .trigger        = s3c_dma_trigger,
 128        .started        = s3c_dma_started,
 129        .flush          = s3c_dma_flush,
 130        .stop           = s3c_dma_stop,
 131};
 132
 133void *s3c_dma_get_ops(void)
 134{
 135        return &s3c_dma_ops;
 136}
 137EXPORT_SYMBOL(s3c_dma_get_ops);
 138