From: Hiroshi Doyu <hd...@nvidia.com>
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 to 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 <hd...@nvidia.com>
---
Based on the discussion:
http://marc.info/?l=linux-tegra&m=133732046606458&w=2
---
drivers/iommu/tegra-smmu.c | 70 ++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 70 insertions(+), 0 deletions(-)
diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index ecd6790..6f87ae4 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -30,6 +30,7 @@
#include <linux/sched.h>
#include <linux/iommu.h>
#include <linux/io.h>
+#include <linux/of.h>
#include <asm/page.h>
#include <asm/cacheflush.h>
@@ -858,6 +859,75 @@ static struct iommu_ops smmu_iommu_ops = {
.pgsize_bitmap = SMMU_IOMMU_PGSIZES,
};
+/**
+ * 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.
+ */
+static 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];
+ const char *s = "";
+
+ if (!dn || !addr || !size)
+ return -EINVAL;
+
+ if (prefix)
+ s = prefix;
+ snprintf(propname, sizeof(propname), "%sdma-window", s);
+ snprintf(addrname, sizeof(addrname), "%s#dma-address-cells", s);
+ snprintf(sizename, sizeof(sizename), "%s#dma-size-cells", s);
+
+ 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;
+}
+
static int tegra_smmu_suspend(struct device *dev)
{
struct smmu_device *smmu = dev_get_drvdata(dev);
--
1.7.5.4
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