Some SoCs have devices that are using a separate bus from the main bus to
perform DMA.
These buses might have some restrictions and/or different mapping than from
the CPU side, so we'd need to express those using the usual dma-ranges, but
using a different DT node than the node's parent.
Add support for a dma-parent property that links to the DMA bus used by the
device in such a case.
Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxx>
---
drivers/of/address.c | 34 +++++++++++++++++++++++++++++++---
1 file changed, 31 insertions(+), 3 deletions(-)
diff --git a/drivers/of/address.c b/drivers/of/address.c
index 4c5dc21c71ca..0e9d87a664f5 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -583,8 +583,8 @@ static u64 __of_translate_address(struct device_node *dev,
/* Increase refcount at current level */
of_node_get(dev);
+ *host = NULL;
if (!parent) {
- *host = NULL;
/* Get parent & match bus type */
parent = of_get_parent(dev);
if (parent == NULL)
@@ -678,12 +678,34 @@ u64 of_translate_address(struct device_node *dev, const __be32 *in_addr)
}
EXPORT_SYMBOL(of_translate_address);
+static struct device_node *__of_get_dma_parent(struct device_node *np)
+{
+ struct of_phandle_args args;
+ unsigned int index;
+ int ret;
+
+ ret = of_property_match_string(np, "interconnect-names", "dma");
+ if (ret < 0)
+ return of_get_parent(np);
+
+ ret = of_parse_phandle_with_args(np, "interconnects",
+ "#interconnect-cells",
+ index, &args);
+ if (ret < 0)
+ return of_get_parent(np);
+
+ return of_node_get(args.np);
+}
+
u64 of_translate_dma_address(struct device_node *dev, const __be32 *in_addr)
{
+ struct device_node *parent;
struct device_node *host;
u64 ret;
- ret = __of_translate_address(dev, NULL, in_addr, "dma-ranges", &host);
+ parent = __of_get_dma_parent(dev);
+ ret = __of_translate_address(dev, parent, in_addr, "dma-ranges", &host);
+ of_node_put(parent);
if (host) {
of_node_put(host);
@@ -911,9 +933,15 @@ int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *siz
return -EINVAL;
while (1) {
+ struct device_node *parent;
+
naddr = of_n_addr_cells(node);
nsize = of_n_size_cells(node);
- node = of_get_next_parent(node);
+
+ parent = __of_get_dma_parent(node);
+ of_node_put(node);
+
+ node = parent;
if (!node)
break;
--
git-series 0.9.1
