text: /* linux/arch/arm/plat-samsung/s3c-dma-ops.c
   *
   * Copyright (c) 2011 Samsung Electronics Co., Ltd.
   *		http://www.samsung.com
   *
   * Samsung S3C-DMA Operations
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/slab.h>
  #include <linux/types.h>
  #include <linux/export.h>
  
  #include <mach/dma.h>
  
  struct cb_data {
  	void (*fp) (void *);
  	void *fp_param;
  	unsigned ch;
  	struct list_head node;
  };
  
  static LIST_HEAD(dma_list);
  
  static void s3c_dma_cb(struct s3c2410_dma_chan *channel, void *param,
  		       int size, enum s3c2410_dma_buffresult res)
  {
  	struct cb_data *data = param;
  
  	data->fp(data->fp_param);
  }
  
  static unsigned s3c_dma_request(enum dma_ch dma_ch,
  				 struct samsung_dma_info *info)
  {
  	struct cb_data *data;
  
  	if (s3c2410_dma_request(dma_ch, info->client, NULL) < 0) {
  		s3c2410_dma_free(dma_ch, info->client);
  		return 0;
  	}
  
  	data = kzalloc(sizeof(struct cb_data), GFP_KERNEL);
  	data->ch = dma_ch;
  	list_add_tail(&data->node, &dma_list);
  
  	s3c2410_dma_devconfig(dma_ch, info->direction, info->fifo);
  
  	if (info->cap == DMA_CYCLIC)
  		s3c2410_dma_setflags(dma_ch, S3C2410_DMAF_CIRCULAR);
  
  	s3c2410_dma_config(dma_ch, info->width);
  
  	return (unsigned)dma_ch;
  }
  
  static int s3c_dma_release(unsigned ch, struct s3c2410_dma_client *client)
  {
  	struct cb_data *data;
  
  	list_for_each_entry(data, &dma_list, node)
  		if (data->ch == ch)
  			break;
  	list_del(&data->node);
  
  	s3c2410_dma_free(ch, client);
  	kfree(data);
  
  	return 0;
  }
  
  static int s3c_dma_prepare(unsigned ch, struct samsung_dma_prep_info *info)
  {
  	struct cb_data *data;
  	int len = (info->cap == DMA_CYCLIC) ? info->period : info->len;
  
  	list_for_each_entry(data, &dma_list, node)
  		if (data->ch == ch)
  			break;
  
  	if (!data->fp) {
  		s3c2410_dma_set_buffdone_fn(ch, s3c_dma_cb);
  		data->fp = info->fp;
  		data->fp_param = info->fp_param;
  	}
  
  	s3c2410_dma_enqueue(ch, (void *)data, info->buf, len);
  
  	return 0;
  }
  
  static inline int s3c_dma_trigger(unsigned ch)
  {
  	return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_START);
  }
  
  static inline int s3c_dma_started(unsigned ch)
  {
  	return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_STARTED);
  }
  
  static inline int s3c_dma_flush(unsigned ch)
  {
  	return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_FLUSH);
  }
  
  static inline int s3c_dma_stop(unsigned ch)
  {
  	return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_STOP);
  }
  
  static struct samsung_dma_ops s3c_dma_ops = {
  	.request	= s3c_dma_request,
  	.release	= s3c_dma_release,
  	.prepare	= s3c_dma_prepare,
  	.trigger	= s3c_dma_trigger,
  	.started	= s3c_dma_started,
  	.flush		= s3c_dma_flush,
  	.stop		= s3c_dma_stop,
  };
  
  void *s3c_dma_get_ops(void)
  {
  	return &s3c_dma_ops;
  }
  EXPORT_SYMBOL(s3c_dma_get_ops);
  