From 4e0ee78f2af96676c9dca898c13250f62c513058 Mon Sep 17 00:00:00 2001 From: Hiroshi Doyu Date: Mon, 25 Jun 2012 14:23:54 +0300 Subject: iommu: Add DMA window parser, of_get_dma_window() This code was based on: "arch/microblaze/kernel/prom_parse.c" "arch/powerpc/kernel/prom_parse.c" Can replace "of_parse_dma_window()" in the above. This supports different formats flexibly. "prefix" can be configured if any. "busno" and "index" are optionally specified. Set NULL and 0 if not used. Signed-off-by: Hiroshi DOYU Acked-by: Stephen Warren Signed-off-by: Joerg Roedel --- drivers/iommu/of_iommu.c | 90 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 drivers/iommu/of_iommu.c (limited to 'drivers/iommu/of_iommu.c') diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c new file mode 100644 index 0000000..ee249bc --- /dev/null +++ b/drivers/iommu/of_iommu.c @@ -0,0 +1,90 @@ +/* + * 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 +#include +#include + +/** + * 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); -- cgit v1.1