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 static unsigned samsung_dmadev_request(enum dma_ch dma_ch,
  22                                 struct samsung_dma_req *param)
  23 {
  24         dma_cap_mask_t mask;
  25         void *filter_param;
  26
  27         dma_cap_zero(mask);
  28         dma_cap_set(param->cap, mask);
  29
  30         /*
  31          * If a dma channel property of a device node from device tree is
  32          * specified, use that as the fliter parameter.
  33          */
  34         filter_param = (dma_ch == DMACH_DT_PROP) ?
  35                 (void *)param->dt_dmach_prop : (void *)dma_ch;
  36         return (unsigned)dma_request_channel(mask, pl330_filter, filter_param);
  37 }
  38
  39 static int samsung_dmadev_release(unsigned ch, void *param)
  40 {
  41         dma_release_channel((struct dma_chan *)ch);
  42
  43         return 0;
  44 }
  45
  46 static int samsung_dmadev_config(unsigned ch,
  47                                 struct samsung_dma_config *param)
  48 {
  49         struct dma_chan *chan = (struct dma_chan *)ch;
  50         struct dma_slave_config slave_config;
  51
  52         if (param->direction == DMA_DEV_TO_MEM) {
  53                 memset(&slave_config, 0, sizeof(struct dma_slave_config));
  54                 slave_config.direction = param->direction;
  55                 slave_config.src_addr = param->fifo;
  56                 slave_config.src_addr_width = param->width;
  57                 slave_config.src_maxburst = 1;
  58                 dmaengine_slave_config(chan, &slave_config);
  59         } else if (param->direction == DMA_MEM_TO_DEV) {
  60                 memset(&slave_config, 0, sizeof(struct dma_slave_config));
  61                 slave_config.direction = param->direction;
  62                 slave_config.dst_addr = param->fifo;
  63                 slave_config.dst_addr_width = param->width;
  64                 slave_config.dst_maxburst = 1;
  65                 dmaengine_slave_config(chan, &slave_config);
  66         } else {
  67                 pr_warn("unsupported direction\n");
  68                 return -EINVAL;
  69         }
  70
  71         return 0;
  72 }
  73
  74 static int samsung_dmadev_prepare(unsigned ch,
  75                         struct samsung_dma_prep *param)
  76 {
  77         struct scatterlist sg;
  78         struct dma_chan *chan = (struct dma_chan *)ch;
  79         struct dma_async_tx_descriptor *desc;
  80
  81         switch (param->cap) {
  82         case DMA_SLAVE:
  83                 sg_init_table(&sg, 1);
  84                 sg_dma_len(&sg) = param->len;
  85                 sg_set_page(&sg, pfn_to_page(PFN_DOWN(param->buf)),
  86                             param->len, offset_in_page(param->buf));
  87                 sg_dma_address(&sg) = param->buf;
  88
  89                 desc = dmaengine_prep_slave_sg(chan,
  90                         &sg, 1, param->direction, DMA_PREP_INTERRUPT);
  91                 break;
  92         case DMA_CYCLIC:
  93                 desc = dmaengine_prep_dma_cyclic(chan, param->buf,
  94                         param->len, param->period, param->direction);
  95                 break;
  96         default:
  97                 dev_err(&chan->dev->device, "unsupported format\n");
  98                 return -EFAULT;
  99         }
 100
 101         if (!desc) {
 102                 dev_err(&chan->dev->device, "cannot prepare cyclic dma\n");
 103                 return -EFAULT;
 104         }
 105
 106         desc->callback = param->fp;
 107         desc->callback_param = param->fp_param;
 108
 109         dmaengine_submit((struct dma_async_tx_descriptor *)desc);
 110
 111         return 0;
 112 }
 113
 114 static inline int samsung_dmadev_trigger(unsigned ch)
 115 {
 116         dma_async_issue_pending((struct dma_chan *)ch);
 117
 118         return 0;
 119 }
 120
 121 static inline int samsung_dmadev_flush(unsigned ch)
 122 {
 123         return dmaengine_terminate_all((struct dma_chan *)ch);
 124 }
 125
 126 static struct samsung_dma_ops dmadev_ops = {
 127         .request        = samsung_dmadev_request,
 128         .release        = samsung_dmadev_release,
 129         .config         = samsung_dmadev_config,
 130         .prepare        = samsung_dmadev_prepare,
 131         .trigger        = samsung_dmadev_trigger,
 132         .started        = NULL,
 133         .flush          = samsung_dmadev_flush,
 134         .stop           = samsung_dmadev_flush,
 135 };
 136
 137 void *samsung_dmadev_get_ops(void)
 138 {
 139         return &dmadev_ops;
 140 }
 141 EXPORT_SYMBOL(samsung_dmadev_get_ops);