dm: Introduce xxx_get_dma_range()

Add the following functions to get a specific device's DMA ranges:
 - dev_get_dma_range()
 - ofnode_get_dma_range()
 - of_get_dma_range()
 - fdt_get_dma_range()
They are specially useful in oder to be able validate a physical address
space range into a bus's and to convert addresses from and to address
spaces.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Peter Robinson <pbrobinson@gmail.com>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>

3 files changed, 93 insertions, 0 deletions

diff --git a/drivers/core/of_addr.c b/drivers/core/of_addr.c
index bbe80136ba..5bc6ca1de0 100644
--- a/drivers/core/of_addr.c
+++ b/drivers/core/of_addr.c
@@ -318,6 +318,84 @@ u64 of_translate_dma_address(const struct device_node *dev, const __be32 *in_add
 	return __of_translate_address(dev, in_addr, "dma-ranges");
 }
 
+int of_get_dma_range(const struct device_node *dev, phys_addr_t *cpu,
+		     dma_addr_t *bus, u64 *size)
+{
+	bool found_dma_ranges = false;
+	struct device_node *parent;
+	struct of_bus *bus_node;
+	int na, ns, pna, pns;
+	const __be32 *ranges;
+	int ret = 0;
+	int len;
+
+	/* Find the closest dma-ranges property */
+	dev = of_node_get(dev);
+	while (dev) {
+		ranges = of_get_property(dev, "dma-ranges", &len);
+
+		/* Ignore empty ranges, they imply no translation required */
+		if (ranges && len > 0)
+			break;
+
+		/* Once we find 'dma-ranges', then a missing one is an error */
+		if (found_dma_ranges && !ranges) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		if (ranges)
+			found_dma_ranges = true;
+
+		parent = of_get_parent(dev);
+		of_node_put(dev);
+		dev = parent;
+	}
+
+	if (!dev || !ranges) {
+		debug("no dma-ranges found for node %s\n",
+		      of_node_full_name(dev));
+		ret = -ENOENT;
+		goto out;
+	}
+
+	/* switch to that node */
+	parent = of_get_parent(dev);
+	if (!parent) {
+		printf("Found dma-ranges in root node, shoudln't happen\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Get the address sizes both for the bus and its parent */
+	bus_node = of_match_bus((struct device_node*)dev);
+	bus_node->count_cells(dev, &na, &ns);
+	if (!OF_CHECK_COUNTS(na, ns)) {
+		printf("Bad cell count for %s\n", of_node_full_name(dev));
+		return -EINVAL;
+		goto out_parent;
+	}
+
+	bus_node = of_match_bus(parent);
+	bus_node->count_cells(parent, &pna, &pns);
+	if (!OF_CHECK_COUNTS(pna, pns)) {
+		printf("Bad cell count for %s\n", of_node_full_name(parent));
+		return -EINVAL;
+		goto out_parent;
+	}
+
+	*bus = of_read_number(ranges, na);
+	*cpu = of_translate_dma_address(dev, ranges + na);
+	*size = of_read_number(ranges + na + pna, ns);
+
+out_parent:
+	of_node_put(parent);
+out:
+	of_node_put(dev);
+	return ret;
+}
+
+
 static int __of_address_to_resource(const struct device_node *dev,
 		const __be32 *addrp, u64 size, unsigned int flags,
 		const char *name, struct resource *r)
diff --git a/drivers/core/ofnode.c b/drivers/core/ofnode.c
index 26c9d04056..fa0bd2a9c4 100644
--- a/drivers/core/ofnode.c
+++ b/drivers/core/ofnode.c
@@ -927,6 +927,15 @@ u64 ofnode_translate_dma_address(ofnode node, const fdt32_t *in_addr)
 		return fdt_translate_dma_address(gd->fdt_blob, ofnode_to_offset(node), in_addr);
 }
 
+int ofnode_get_dma_range(ofnode node, phys_addr_t *cpu, dma_addr_t *bus, u64 *size)
+{
+	if (ofnode_is_np(node))
+		return of_get_dma_range(ofnode_to_np(node), cpu, bus, size);
+	else
+		return fdt_get_dma_range(gd->fdt_blob, ofnode_to_offset(node),
+					 cpu, bus, size);
+}
+
 int ofnode_device_is_compatible(ofnode node, const char *compat)
 {
 	if (ofnode_is_np(node))
diff --git a/drivers/core/read.c b/drivers/core/read.c
index 14fd1214d6..4307ca4579 100644
--- a/drivers/core/read.c
+++ b/drivers/core/read.c
@@ -341,6 +341,12 @@ u64 dev_translate_dma_address(const struct udevice *dev, const fdt32_t *in_addr)
 	return ofnode_translate_dma_address(dev_ofnode(dev), in_addr);
 }
 
+int dev_get_dma_range(const struct udevice *dev, phys_addr_t *cpu,
+		      dma_addr_t *bus, u64 *size)
+{
+	return ofnode_get_dma_range(dev_ofnode(dev), cpu, bus, size);
+}
+
 int dev_read_alias_highest_id(const char *stem)
 {
 	if (of_live_active())