dm: core: Add a function to decode a memory region

Add a way to decode a memory region, including the memory type (sram or
sdram) and its start address and size.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/core/of_extra.c b/drivers/core/of_extra.c
index 3243caa5d127c8ea161f20ea3dd7d085e110d3d2..aa48917dddf40b13aa0949851018e45a1930fba7 100644 (file)
--- a/drivers/core/of_extra.c
+++ b/drivers/core/of_extra.c
@@ -34,3 +34,84 @@ int ofnode_read_fmap_entry(ofnode node, struct fmap_entry *entry)
 
        return 0;
 }
+
+int ofnode_decode_region(ofnode node, const char *prop_name, fdt_addr_t *basep,
+                        fdt_size_t *sizep)
+{
+       const fdt_addr_t *cell;
+       int len;
+
+       debug("%s: %s: %s\n", __func__, ofnode_get_name(node), prop_name);
+       cell = ofnode_get_property(node, prop_name, &len);
+       if (!cell || (len < sizeof(fdt_addr_t) * 2)) {
+               debug("cell=%p, len=%d\n", cell, len);
+               return -1;
+       }
+
+       *basep = fdt_addr_to_cpu(*cell);
+       *sizep = fdt_size_to_cpu(cell[1]);
+       debug("%s: base=%08lx, size=%lx\n", __func__, (ulong)*basep,
+             (ulong)*sizep);
+
+       return 0;
+}
+
+int ofnode_decode_memory_region(ofnode config_node, const char *mem_type,
+                               const char *suffix, fdt_addr_t *basep,
+                               fdt_size_t *sizep)
+{
+       char prop_name[50];
+       const char *mem;
+       fdt_size_t size, offset_size;
+       fdt_addr_t base, offset;
+       ofnode node;
+
+       if (!ofnode_valid(config_node)) {
+               config_node = ofnode_path("/config");
+               if (!ofnode_valid(config_node)) {
+                       debug("%s: Cannot find /config node\n", __func__);
+                       return -ENOENT;
+               }
+       }
+       if (!suffix)
+               suffix = "";
+
+       snprintf(prop_name, sizeof(prop_name), "%s-memory%s", mem_type,
+                suffix);
+       mem = ofnode_read_string(config_node, prop_name);
+       if (!mem) {
+               debug("%s: No memory type for '%s', using /memory\n", __func__,
+                     prop_name);
+               mem = "/memory";
+       }
+
+       node = ofnode_path(mem);
+       if (!ofnode_valid(node)) {
+               debug("%s: Failed to find node '%s'\n", __func__, mem);
+               return -ENOENT;
+       }
+
+       /*
+        * Not strictly correct - the memory may have multiple banks. We just
+        * use the first
+        */
+       if (ofnode_decode_region(node, "reg", &base, &size)) {
+               debug("%s: Failed to decode memory region %s\n", __func__,
+                     mem);
+               return -EINVAL;
+       }
+
+       snprintf(prop_name, sizeof(prop_name), "%s-offset%s", mem_type,
+                suffix);
+       if (ofnode_decode_region(config_node, prop_name, &offset,
+                                &offset_size)) {
+               debug("%s: Failed to decode memory region '%s'\n", __func__,
+                     prop_name);
+               return -EINVAL;
+       }
+
+       *basep = base + offset;
+       *sizep = offset_size;
+
+       return 0;
+}

diff --git a/include/dm/of_extra.h b/include/dm/of_extra.h
index e1540c1fbdc3fd7df88bef518a67587fc219d69c..97988b666324d42afd3c634fc8b030dc31baa479 100644 (file)
--- a/include/dm/of_extra.h
+++ b/include/dm/of_extra.h
@@ -40,4 +40,49 @@ struct fmap_entry {
  */
 int ofnode_read_fmap_entry(ofnode node, struct fmap_entry *entry);
 
+/**
+ * ofnode_decode_region() - Decode a memory region from a node
+ *
+ * Look up a property in a node which contains a memory region address and
+ * size. Then return a pointer to this address.
+ *
+ * The property must hold one address with a length. This is only tested on
+ * 32-bit machines.
+ *
+ * @param node         ofnode to examine
+ * @param prop_name    name of property to find
+ * @param basep                Returns base address of region
+ * @param size         Returns size of region
+ * @return 0 if ok, -1 on error (property not found)
+ */
+int ofnode_decode_region(ofnode node, const char *prop_name, fdt_addr_t *basep,
+                        fdt_size_t *sizep);
+
+/**
+ * ofnode_decode_memory_region()- Decode a named region within a memory bank
+ *
+ * This function handles selection of a memory region. The region is
+ * specified as an offset/size within a particular type of memory.
+ *
+ * The properties used are:
+ *
+ *     <mem_type>-memory<suffix> for the name of the memory bank
+ *     <mem_type>-offset<suffix> for the offset in that bank
+ *
+ * The property value must have an offset and a size. The function checks
+ * that the region is entirely within the memory bank.5
+ *
+ * @param node         ofnode containing the properties (-1 for /config)
+ * @param mem_type     Type of memory to use, which is a name, such as
+ *                     "u-boot" or "kernel".
+ * @param suffix       String to append to the memory/offset
+ *                     property names
+ * @param basep                Returns base of region
+ * @param sizep                Returns size of region
+ * @return 0 if OK, -ive on error
+ */
+int ofnode_decode_memory_region(ofnode config_node, const char *mem_type,
+                               const char *suffix, fdt_addr_t *basep,
+                               fdt_size_t *sizep);
+
 #endif