sys/arch/arm/at91/at91pdc.c

   1 /*      $Id: at91pdc.c,v 1.2 2008/07/03 01:15:38 matt Exp $     */
   2
   3 #include <sys/types.h>
   4 #include <machine/bus.h>
   5 #include <arm/at91/at91pdcvar.h>
   6
   7 int at91pdc_alloc_fifo(bus_dma_tag_t dmat, at91pdc_fifo_t *fifo, int size,
   8                        int flags)
   9 {
  10         bus_dma_segment_t segs;
  11         int rsegs;
  12         int err;
  13         int f;
  14
  15         memset(fifo, 0, sizeof(*fifo));
  16
  17         /* allocate map: */
  18         f = flags & (BUS_DMA_BUS1 | BUS_DMA_BUS2 | BUS_DMA_BUS3 | BUS_DMA_BUS4);
  19         err = bus_dmamap_create(dmat, size, 1, size, 0,
  20                                 BUS_DMA_WAITOK | f,
  21                                 &fifo->f_dmamap);
  22         if (err)
  23                 goto fail_0;
  24
  25         /* allocate DMA safe memory: */
  26         f |= flags & BUS_DMA_STREAMING;
  27         err = bus_dmamem_alloc(dmat, size, 0, size, &segs, 1, &rsegs,
  28                                BUS_DMA_WAITOK | f);
  29         if (err)
  30                 goto fail_1;
  31
  32         /* allocate virtual memory: */
  33         f |= flags & (BUS_DMA_COHERENT | BUS_DMA_NOCACHE);
  34         err = bus_dmamem_map(dmat, &segs, 1, size, &fifo->f_buf,
  35                              BUS_DMA_WAITOK | f);
  36         if (err)
  37                 goto fail_2;
  38
  39         /* connect physical to virtual memory: */
  40         f |= flags & (BUS_DMA_READ | BUS_DMA_WRITE);
  41         f &= ~(BUS_DMA_COHERENT | BUS_DMA_NOCACHE);
  42         err = bus_dmamap_load(dmat, fifo->f_dmamap, fifo->f_buf, size, NULL,
  43                               BUS_DMA_NOWAIT | f);
  44         if (err)
  45                 goto fail_3;
  46
  47         /* initialize rest of the structure: */
  48         fifo->f_buf_size = size;
  49         fifo->f_ndx = fifo->f_length = 0;
  50
  51         fifo->f_buf_addr = fifo->f_dmamap->dm_segs[0].ds_addr;
  52         fifo->f_pdc_rd_ndx = fifo->f_pdc_wr_ndx = 0;
  53         fifo->f_pdc_space = fifo->f_buf_size;
  54
  55         return 0;
  56 fail_3:
  57         bus_dmamem_unmap(dmat, fifo->f_buf, size);
  58 fail_2:
  59         bus_dmamem_free(dmat, &segs, rsegs);
  60 fail_1:
  61         bus_dmamap_destroy(dmat, fifo->f_dmamap);
  62 fail_0:
  63         return err;
  64 }