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
  18 #include <mach/dma.h>
  19
  20 static inline bool pl330_filter(struct dma_chan *chan, void *param)
  21 {
  22         struct dma_pl330_peri *peri = chan->private;
  23         return peri->peri_id == (unsigned)param;
  24 }
  25
  26 static unsigned samsung_dmadev_request(enum dma_ch dma_ch,
  27                                 struct samsung_dma_info *info)
  28 {
  29         struct dma_chan *chan;
  30         dma_cap_mask_t mask;
  31         struct dma_slave_config slave_config;
  32
  33         dma_cap_zero(mask);
  34         dma_cap_set(info->cap, mask);
  35
  36         chan = dma_request_channel(mask, pl330_filter, (void *)dma_ch);
  37
  38         if (info->direction == DMA_DEV_TO_MEM) {
  39                 memset(&slave_config, 0, sizeof(struct dma_slave_config));
  40                 slave_config.direction = info->direction;
  41                 slave_config.src_addr = info->fifo;
  42                 slave_config.src_addr_width = info->width;
  43                 slave_config.src_maxburst = 1;
  44                 dmaengine_slave_config(chan, &slave_config);
  45         } else if (info->direction == DMA_MEM_TO_DEV) {
  46                 memset(&slave_config, 0, sizeof(struct dma_slave_config));
  47                 slave_config.direction = info->direction;
  48                 slave_config.dst_addr = info->fifo;
  49                 slave_config.dst_addr_width = info->width;
  50                 slave_config.dst_maxburst = 1;
  51                 dmaengine_slave_config(chan, &slave_config);
  52         }
  53
  54         return (unsigned)chan;
  55 }
  56
  57 static int samsung_dmadev_release(unsigned ch,
  58                         struct s3c2410_dma_client *client)
  59 {
  60         dma_release_channel((struct dma_chan *)ch);
  61
  62         return 0;
  63 }
  64
  65 static int samsung_dmadev_prepare(unsigned ch,
  66                         struct samsung_dma_prep_info *info)
  67 {
  68         struct scatterlist sg;
  69         struct dma_chan *chan = (struct dma_chan *)ch;
  70         struct dma_async_tx_descriptor *desc;
  71
  72         switch (info->cap) {
  73         case DMA_SLAVE:
  74                 sg_init_table(&sg, 1);
  75                 sg_dma_len(&sg) = info->len;
  76                 sg_set_page(&sg, pfn_to_page(PFN_DOWN(info->buf)),
  77                             info->len, offset_in_page(info->buf));
  78                 sg_dma_address(&sg) = info->buf;
  79
  80                 desc = chan->device->device_prep_slave_sg(chan,
  81                         &sg, 1, info->direction, DMA_PREP_INTERRUPT);
  82                 break;
  83         case DMA_CYCLIC:
  84                 desc = chan->device->device_prep_dma_cyclic(chan,
  85                         info->buf, info->len, info->period, info->direction);
  86                 break;
  87         default:
  88                 dev_err(&chan->dev->device, "unsupported format\n");
  89                 return -EFAULT;
  90         }
  91
  92         if (!desc) {
  93                 dev_err(&chan->dev->device, "cannot prepare cyclic dma\n");
  94                 return -EFAULT;
  95         }
  96
  97         desc->callback = info->fp;
  98         desc->callback_param = info->fp_param;
  99
 100         dmaengine_submit((struct dma_async_tx_descriptor *)desc);
 101
 102         return 0;
 103 }
 104
 105 static inline int samsung_dmadev_trigger(unsigned ch)
 106 {
 107         dma_async_issue_pending((struct dma_chan *)ch);
 108
 109         return 0;
 110 }
 111
 112 static inline int samsung_dmadev_flush(unsigned ch)
 113 {
 114         return dmaengine_terminate_all((struct dma_chan *)ch);
 115 }
 116
 117 struct samsung_dma_ops dmadev_ops = {
 118         .request        = samsung_dmadev_request,
 119         .release        = samsung_dmadev_release,
 120         .prepare        = samsung_dmadev_prepare,
 121         .trigger        = samsung_dmadev_trigger,
 122         .started        = NULL,
 123         .flush          = samsung_dmadev_flush,
 124         .stop           = samsung_dmadev_flush,
 125 };
 126
 127 void *samsung_dmadev_get_ops(void)
 128 {
 129         return &dmadev_ops;
 130 }
 131 EXPORT_SYMBOL(samsung_dmadev_get_ops);