1 /* $Id: at91pdc.c,v 1.3 2011/07/01 19:31:17 dyoung Exp $ */
2
3 #include <sys/types.h>
4 #include <sys/bus.h>
5 #include <arm/at91/at91pdcvar.h>
6
at91pdc_alloc_fifo(bus_dma_tag_t dmat,at91pdc_fifo_t * fifo,int size,int flags)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 }
65