92 строки
2.7 KiB
C
92 строки
2.7 KiB
C
/*
|
|
* OF helpers for IOMMU
|
|
*
|
|
* Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms and conditions of the GNU General Public License,
|
|
* version 2, as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope it will be useful, but WITHOUT
|
|
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
|
|
* more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along with
|
|
* this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*/
|
|
|
|
#include <linux/export.h>
|
|
#include <linux/limits.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_iommu.h>
|
|
|
|
/**
|
|
* of_get_dma_window - Parse *dma-window property and returns 0 if found.
|
|
*
|
|
* @dn: device node
|
|
* @prefix: prefix for property name if any
|
|
* @index: index to start to parse
|
|
* @busno: Returns busno if supported. Otherwise pass NULL
|
|
* @addr: Returns address that DMA starts
|
|
* @size: Returns the range that DMA can handle
|
|
*
|
|
* This supports different formats flexibly. "prefix" can be
|
|
* configured if any. "busno" and "index" are optionally
|
|
* specified. Set 0(or NULL) if not used.
|
|
*/
|
|
int of_get_dma_window(struct device_node *dn, const char *prefix, int index,
|
|
unsigned long *busno, dma_addr_t *addr, size_t *size)
|
|
{
|
|
const __be32 *dma_window, *end;
|
|
int bytes, cur_index = 0;
|
|
char propname[NAME_MAX], addrname[NAME_MAX], sizename[NAME_MAX];
|
|
|
|
if (!dn || !addr || !size)
|
|
return -EINVAL;
|
|
|
|
if (!prefix)
|
|
prefix = "";
|
|
|
|
snprintf(propname, sizeof(propname), "%sdma-window", prefix);
|
|
snprintf(addrname, sizeof(addrname), "%s#dma-address-cells", prefix);
|
|
snprintf(sizename, sizeof(sizename), "%s#dma-size-cells", prefix);
|
|
|
|
dma_window = of_get_property(dn, propname, &bytes);
|
|
if (!dma_window)
|
|
return -ENODEV;
|
|
end = dma_window + bytes / sizeof(*dma_window);
|
|
|
|
while (dma_window < end) {
|
|
u32 cells;
|
|
const void *prop;
|
|
|
|
/* busno is one cell if supported */
|
|
if (busno)
|
|
*busno = be32_to_cpup(dma_window++);
|
|
|
|
prop = of_get_property(dn, addrname, NULL);
|
|
if (!prop)
|
|
prop = of_get_property(dn, "#address-cells", NULL);
|
|
|
|
cells = prop ? be32_to_cpup(prop) : of_n_addr_cells(dn);
|
|
if (!cells)
|
|
return -EINVAL;
|
|
*addr = of_read_number(dma_window, cells);
|
|
dma_window += cells;
|
|
|
|
prop = of_get_property(dn, sizename, NULL);
|
|
cells = prop ? be32_to_cpup(prop) : of_n_size_cells(dn);
|
|
if (!cells)
|
|
return -EINVAL;
|
|
*size = of_read_number(dma_window, cells);
|
|
dma_window += cells;
|
|
|
|
if (cur_index++ == index)
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_get_dma_window);
|