of/flattree: Add non-boottime device tree functions

In preparation for providing run-time handling of device trees, factor
out some of the basic functions so that they take an arbitrary blob,
rather than relying on the single boot-time tree.

V2:
- functions have of_fdt_* names
- removed find_flat_dt_string
- blob argument is first

Signed-off-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 79 insertions, 54 deletions

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 2ebacf14e7de..10eab21076ea 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -22,6 +22,82 @@
 
 #include <asm/page.h>
 
+char *of_fdt_get_string(struct boot_param_header *blob, u32 offset)
+{
+        return ((char *)blob) +
+                be32_to_cpu(blob->off_dt_strings) + offset;
+}
+
+/**
+ * of_fdt_get_property - Given a node in the given flat blob, return
+ * the property ptr
+ */
+void *of_fdt_get_property(struct boot_param_header *blob,
+                       unsigned long node, const char *name,
+                       unsigned long *size)
+{
+        unsigned long p = node;
+
+        do {
+                u32 tag = be32_to_cpup((__be32 *)p);
+                u32 sz, noff;
+                const char *nstr;
+
+                p += 4;
+                if (tag == OF_DT_NOP)
+                        continue;
+                if (tag != OF_DT_PROP)
+                        return NULL;
+
+                sz = be32_to_cpup((__be32 *)p);
+                noff = be32_to_cpup((__be32 *)(p + 4));
+                p += 8;
+                if (be32_to_cpu(blob->version) < 0x10)
+                        p = ALIGN(p, sz >= 8 ? 8 : 4);
+
+                nstr = of_fdt_get_string(blob, noff);
+                if (nstr == NULL) {
+                        pr_warning("Can't find property index name !\n");
+                        return NULL;
+                }
+                if (strcmp(name, nstr) == 0) {
+                        if (size)
+                                *size = sz;
+                        return (void *)p;
+                }
+                p += sz;
+                p = ALIGN(p, 4);
+        } while (1);
+}
+
+/**
+ * of_fdt_is_compatible - Return true if given node from the given blob has
+ * compat in its compatible list
+ * @blob: A device tree blob
+ * @node: node to test
+ * @compat: compatible string to compare with compatible list.
+ */
+int of_fdt_is_compatible(struct boot_param_header *blob,
+                      unsigned long node, const char *compat)
+{
+        const char *cp;
+        unsigned long cplen, l;
+
+        cp = of_fdt_get_property(blob, node, "compatible", &cplen);
+        if (cp == NULL)
+                return 0;
+        while (cplen > 0) {
+                if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
+                        return 1;
+                l = strlen(cp) + 1;
+                cp += l;
+                cplen -= l;
+        }
+
+        return 0;
+}
+
+/* Everything below here references initial_boot_params directly. */
 int __initdata dt_root_addr_cells;
 int __initdata dt_root_size_cells;
 
@@ -29,12 +105,6 @@ struct boot_param_header *initial_boot_params;
 
 #ifdef CONFIG_OF_EARLY_FLATTREE
 
-char *find_flat_dt_string(u32 offset)
-{
-        return ((char *)initial_boot_params) +
-                be32_to_cpu(initial_boot_params->off_dt_strings) + offset;
-}
-
 /**
  * of_scan_flat_dt - scan flattened tree blob and call callback on each.
  * @it: callback function
@@ -123,38 +193,7 @@ unsigned long __init of_get_flat_dt_root(void)
 void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
                                  unsigned long *size)
 {
-        unsigned long p = node;
-
-        do {
-                u32 tag = be32_to_cpup((__be32 *)p);
-                u32 sz, noff;
-                const char *nstr;
-
-                p += 4;
-                if (tag == OF_DT_NOP)
-                        continue;
-                if (tag != OF_DT_PROP)
-                        return NULL;
-
-                sz = be32_to_cpup((__be32 *)p);
-                noff = be32_to_cpup((__be32 *)(p + 4));
-                p += 8;
-                if (be32_to_cpu(initial_boot_params->version) < 0x10)
-                        p = ALIGN(p, sz >= 8 ? 8 : 4);
-
-                nstr = find_flat_dt_string(noff);
-                if (nstr == NULL) {
-                        pr_warning("Can't find property index name !\n");
-                        return NULL;
-                }
-                if (strcmp(name, nstr) == 0) {
-                        if (size)
-                                *size = sz;
-                        return (void *)p;
-                }
-                p += sz;
-                p = ALIGN(p, 4);
-        } while (1);
+        return of_fdt_get_property(initial_boot_params, node, name, size);
 }
 
 /**
@@ -164,21 +203,7 @@ void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
  */
 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
 {
-        const char *cp;
-        unsigned long cplen, l;
-
-        cp = of_get_flat_dt_prop(node, "compatible", &cplen);
-        if (cp == NULL)
-                return 0;
-        while (cplen > 0) {
-                if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
-                        return 1;
-                l = strlen(cp) + 1;
-                cp += l;
-                cplen -= l;
-        }
-
-        return 0;
+        return of_fdt_is_compatible(initial_boot_params, node, compat);
 }
 
 static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size,
@@ -303,7 +328,7 @@ unsigned long __init unflatten_dt_node(unsigned long mem,
                 if (be32_to_cpu(initial_boot_params->version) < 0x10)
                         *p = ALIGN(*p, sz >= 8 ? 8 : 4);
 
-                pname = find_flat_dt_string(noff);
+                pname = of_fdt_get_string(initial_boot_params, noff);
                 if (pname == NULL) {
                         pr_info("Can't find property name in list !\n");
                         break;