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