This code was based on:
"arch/microblaze/kernel/prom_parse.c"
"arch/powerpc/kernel/prom_parse.c"
Can be promoted as a global function for general use.
Signed-off-by: Hiroshi DOYU <[email protected]>
---
Based on the discussion:
http://marc.info/?l=linux-tegra&m=133732046606458&w=2
---
drivers/iommu/tegra-smmu.c | 50 ++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 50 insertions(+), 0 deletions(-)
diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 192fc4a..7fc444b 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -874,6 +874,56 @@ static struct iommu_ops smmu_iommu_ops = {
.pgsize_bitmap = SMMU_IOMMU_PGSIZES,
};
+static int of_get_dma_window(struct device_node *dn,
+ const char *propname, int index,
+ unsigned long *busno,
+ dma_addr_t *addr, size_t *size)
+{
+ const __be32 *dma_window, *end;
+ int bytes, cur_index = 0;
+
+ if (!dn || !addr || !size)
+ return -EINVAL;
+
+ if (!propname)
+ propname = "dma-window";
+
+ 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 always one cell */
+ if (busno)
+ *busno = be32_to_cpup(dma_window++);
+
+ prop = of_get_property(dn, "#dma-address-cells", 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, "#dma-size-cells", 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;
+}
+
static int tegra_smmu_suspend(struct device *dev)
{
struct smmu_device *smmu = dev_get_drvdata(dev);
--
1.7.5.4
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