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

   1 /* linux/arch/arm/plat-samsung/dma-ops.c
   2  *
   3  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
   4  *              http://www.samsung.com
   5  *
   6  * Samsung 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/amba/pl330.h>
  16 #include <linux/scatterlist.h>
  17 #include <linux/export.h>
  18
  19 #include <mach/dma.h>
  20
  21 #if defined(CONFIG_PL330_DMA)
  22 #define dma_filter pl330_filter
  23 #elif defined(CONFIG_S3C64XX_PL080)
  24 #define dma_filter pl08x_filter_id
  25 #endif
  26
  27 static unsigned samsung_dmadev_request(enum dma_ch dma_ch,
  28                                 struct samsung_dma_req *param,
  29                                 struct device *dev, char *ch_name)
  30 {
  31         dma_cap_mask_t mask;
  32
  33         dma_cap_zero(mask);
  34         dma_cap_set(param->cap, mask);
  35
  36         if (dev->of_node)
  37                 return (unsigned)dma_request_slave_channel(dev, ch_name);
  38         else
  39                 return (unsigned)dma_request_channel(mask, dma_filter,
  40                                                         (void *)dma_ch);
  41 }
  42
  43 static int samsung_dmadev_release(unsigned ch, void *param)
  44 {
  45         dma_release_channel((struct dma_chan *)ch);
  46
  47         return 0;
  48 }
  49
  50 static int samsung_dmadev_config(unsigned ch,
  51                                 struct samsung_dma_config *param)
  52 {
  53         struct dma_chan *chan = (struct dma_chan *)ch;
  54         struct dma_slave_config slave_config;
  55
  56         if (param->direction == DMA_DEV_TO_MEM) {
  57                 memset(&slave_config, 0, sizeof(struct dma_slave_config));
  58                 slave_config.direction = param->direction;
  59                 slave_config.src_addr = param->fifo;
  60                 slave_config.src_addr_width = param->width;
  61                 slave_config.src_maxburst = 1;
  62                 dmaengine_slave_config(chan, &slave_config);
  63         } else if (param->direction == DMA_MEM_TO_DEV) {
  64                 memset(&slave_config, 0, sizeof(struct dma_slave_config));
  65                 slave_config.direction = param->direction;
  66                 slave_config.dst_addr = param->fifo;
  67                 slave_config.dst_addr_width = param->width;
  68                 slave_config.dst_maxburst = 1;
  69                 dmaengine_slave_config(chan, &slave_config);
  70         } else {
  71                 pr_warn("unsupported direction\n");
  72                 return -EINVAL;
  73         }
  74
  75         return 0;
  76 }
  77
  78 static int samsung_dmadev_prepare(unsigned ch,
  79                         struct samsung_dma_prep *param)
  80 {
  81         struct scatterlist sg;
  82         struct dma_chan *chan = (struct dma_chan *)ch;
  83         struct dma_async_tx_descriptor *desc;
  84
  85         switch (param->cap) {
  86         case DMA_SLAVE:
  87                 sg_init_table(&sg, 1);
  88                 sg_dma_len(&sg) = param->len;
  89                 sg_set_page(&sg, pfn_to_page(PFN_DOWN(param->buf)),
  90                             param->len, offset_in_page(param->buf));
  91                 sg_dma_address(&sg) = param->buf;
  92
  93                 desc = dmaengine_prep_slave_sg(chan,
  94                         &sg, 1, param->direction, DMA_PREP_INTERRUPT);
  95                 break;
  96         case DMA_CYCLIC:
  97                 desc = dmaengine_prep_dma_cyclic(chan, param->buf,
  98                         param->len, param->period, param->direction,
  99                         DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 100                 break;
 101         default:
 102                 dev_err(&chan->dev->device, "unsupported format\n");
 103                 return -EFAULT;
 104         }
 105
 106         if (!desc) {
 107                 dev_err(&chan->dev->device, "cannot prepare cyclic dma\n");
 108                 return -EFAULT;
 109         }
 110
 111         desc->callback = param->fp;
 112         desc->callback_param = param->fp_param;
 113
 114         dmaengine_submit((struct dma_async_tx_descriptor *)desc);
 115
 116         return 0;
 117 }
 118
 119 static inline int samsung_dmadev_trigger(unsigned ch)
 120 {
 121         dma_async_issue_pending((struct dma_chan *)ch);
 122
 123         return 0;
 124 }
 125
 126 static inline int samsung_dmadev_flush(unsigned ch)
 127 {
 128         return dmaengine_terminate_all((struct dma_chan *)ch);
 129 }
 130
 131 static struct samsung_dma_ops dmadev_ops = {
 132         .request        = samsung_dmadev_request,
 133         .release        = samsung_dmadev_release,
 134         .config         = samsung_dmadev_config,
 135         .prepare        = samsung_dmadev_prepare,
 136         .trigger        = samsung_dmadev_trigger,
 137         .started        = NULL,
 138         .flush          = samsung_dmadev_flush,
 139         .stop           = samsung_dmadev_flush,
 140 };
 141
 142 void *samsung_dmadev_get_ops(void)
 143 {
 144         return &dmadev_ops;
 145 }
 146 EXPORT_SYMBOL(samsung_dmadev_get_ops);