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         void *filter_param;
  27
  28         dma_cap_zero(mask);
  29         dma_cap_set(param->cap, mask);
  30
  31         /*
  32          * If a dma channel property of a device node from device tree is
  33          * specified, use that as the fliter parameter.
  34          */
  35         filter_param = (dma_ch == DMACH_DT_PROP) ?
  36                 (void *)param->dt_dmach_prop : (void *)dma_ch;
  37
  38         if (dev->of_node)
  39                 return (unsigned)dma_request_slave_channel(dev, ch_name);
  40         else
  41                 return (unsigned)dma_request_channel(mask, pl330_filter,
  42                                                         filter_param);
  43 }
  44
  45 static int samsung_dmadev_release(unsigned ch, void *param)
  46 {
  47         dma_release_channel((struct dma_chan *)ch);
  48
  49         return 0;
  50 }
  51
  52 static int samsung_dmadev_config(unsigned ch,
  53                                 struct samsung_dma_config *param)
  54 {
  55         struct dma_chan *chan = (struct dma_chan *)ch;
  56         struct dma_slave_config slave_config;
  57
  58         if (param->direction == DMA_DEV_TO_MEM) {
  59                 memset(&slave_config, 0, sizeof(struct dma_slave_config));
  60                 slave_config.direction = param->direction;
  61                 slave_config.src_addr = param->fifo;
  62                 slave_config.src_addr_width = param->width;
  63                 slave_config.src_maxburst = 1;
  64                 dmaengine_slave_config(chan, &slave_config);
  65         } else if (param->direction == DMA_MEM_TO_DEV) {
  66                 memset(&slave_config, 0, sizeof(struct dma_slave_config));
  67                 slave_config.direction = param->direction;
  68                 slave_config.dst_addr = param->fifo;
  69                 slave_config.dst_addr_width = param->width;
  70                 slave_config.dst_maxburst = 1;
  71                 dmaengine_slave_config(chan, &slave_config);
  72         } else {
  73                 pr_warn("unsupported direction\n");
  74                 return -EINVAL;
  75         }
  76
  77         return 0;
  78 }
  79
  80 static int samsung_dmadev_prepare(unsigned ch,
  81                         struct samsung_dma_prep *param)
  82 {
  83         struct scatterlist sg;
  84         struct dma_chan *chan = (struct dma_chan *)ch;
  85         struct dma_async_tx_descriptor *desc;
  86
  87         switch (param->cap) {
  88         case DMA_SLAVE:
  89                 sg_init_table(&sg, 1);
  90                 sg_dma_len(&sg) = param->len;
  91                 sg_set_page(&sg, pfn_to_page(PFN_DOWN(param->buf)),
  92                             param->len, offset_in_page(param->buf));
  93                 sg_dma_address(&sg) = param->buf;
  94
  95                 desc = dmaengine_prep_slave_sg(chan,
  96                         &sg, 1, param->direction, DMA_PREP_INTERRUPT);
  97                 break;
  98         case DMA_CYCLIC:
  99                 desc = dmaengine_prep_dma_cyclic(chan, param->buf,
 100                         param->len, param->period, param->direction,
 101                         DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 102                 break;
 103         default:
 104                 dev_err(&chan->dev->device, "unsupported format\n");
 105                 return -EFAULT;
 106         }
 107
 108         if (!desc) {
 109                 dev_err(&chan->dev->device, "cannot prepare cyclic dma\n");
 110                 return -EFAULT;
 111         }
 112
 113         desc->callback = param->fp;
 114         desc->callback_param = param->fp_param;
 115
 116         dmaengine_submit((struct dma_async_tx_descriptor *)desc);
 117
 118         return 0;
 119 }
 120
 121 static inline int samsung_dmadev_trigger(unsigned ch)
 122 {
 123         dma_async_issue_pending((struct dma_chan *)ch);
 124
 125         return 0;
 126 }
 127
 128 static inline int samsung_dmadev_flush(unsigned ch)
 129 {
 130         return dmaengine_terminate_all((struct dma_chan *)ch);
 131 }
 132
 133 static struct samsung_dma_ops dmadev_ops = {
 134         .request        = samsung_dmadev_request,
 135         .release        = samsung_dmadev_release,
 136         .config         = samsung_dmadev_config,
 137         .prepare        = samsung_dmadev_prepare,
 138         .trigger        = samsung_dmadev_trigger,
 139         .started        = NULL,
 140         .flush          = samsung_dmadev_flush,
 141         .stop           = samsung_dmadev_flush,
 142 };
 143
 144 void *samsung_dmadev_get_ops(void)
 145 {
 146         return &dmadev_ops;
 147 }
 148 EXPORT_SYMBOL(samsung_dmadev_get_ops);