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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - drivers/iommu/of_iommu.c
4 * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
20 #include <linux/export.h>
21 #include <linux/limits.h>
25 * of_get_dma_window - Parse *dma-window property and returns 0 if found.
28 * @prefix: prefix for property name if any
29 * @index: index to start to parse
30 * @busno: Returns busno if supported. Otherwise pass NULL
31 * @addr: Returns address that DMA starts
32 * @size: Returns the range that DMA can handle
34 * This supports different formats flexibly. "prefix" can be
35 * configured if any. "busno" and "index" are optionally
36 * specified. Set 0(or NULL) if not used.
38 int of_get_dma_window(struct device_node
*dn
, const char *prefix
, int index
,
39 unsigned long *busno
, dma_addr_t
*addr
, size_t *size
)
41 const __be32
*dma_window
, *end
;
42 int bytes
, cur_index
= 0;
43 char propname
[NAME_MAX
], addrname
[NAME_MAX
], sizename
[NAME_MAX
];
45 if (!dn
|| !addr
|| !size
)
51 snprintf(propname
, sizeof(propname
), "%sdma-window", prefix
);
52 snprintf(addrname
, sizeof(addrname
), "%s#dma-address-cells", prefix
);
53 snprintf(sizename
, sizeof(sizename
), "%s#dma-size-cells", prefix
);
55 dma_window
= of_get_property(dn
, propname
, &bytes
);
58 end
= dma_window
+ bytes
/ sizeof(*dma_window
);
60 while (dma_window
< end
) {
64 /* busno is one cell if supported */
66 *busno
= be32_to_cpup(dma_window
++);
68 prop
= of_get_property(dn
, addrname
, NULL
);
70 prop
= of_get_property(dn
, "#address-cells", NULL
);
72 cells
= prop
? be32_to_cpup(prop
) : of_n_addr_cells(dn
);
75 *addr
= of_read_number(dma_window
, cells
);
78 prop
= of_get_property(dn
, sizename
, NULL
);
79 cells
= prop
? be32_to_cpup(prop
) : of_n_size_cells(dn
);
82 *size
= of_read_number(dma_window
, cells
);
85 if (cur_index
++ == index
)
90 EXPORT_SYMBOL_GPL(of_get_dma_window
);