Introduce fdtw_read_array() helper

fdtw_read_cells() can only read one or two cells, sometimes it may be
needed to read more cells from one property.

Change-Id: Ie70dc76d1540cd6a04787cde7cccb4d1bafc7282
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

diff --git a/common/fdt_wrappers.c b/common/fdt_wrappers.c
index 1715a6f0e124f6cd09d520302872d44c4ee8a4f1..31dafb2eb483640730f6cee4bcfa67c6d46813b0 100644 (file)
--- a/common/fdt_wrappers.c
+++ b/common/fdt_wrappers.c
@@ -40,7 +40,6 @@ int fdtw_read_cells(const void *dtb, int node, const char *prop,
                return -1;
        }
 
-
        /* Verify that property length accords with cell length */
        if (NCELLS((unsigned int)value_len) != cells) {
                WARN("Property length mismatch\n");
@@ -62,6 +61,45 @@ int fdtw_read_cells(const void *dtb, int node, const char *prop,
        return 0;
 }
 
+/*
+ * Read cells from a given property of the given node. Any number of 32-bit
+ * cells of the property can be read. The fdt pointer is updated. Returns 0 on
+ * success, and -1 on error.
+ */
+int fdtw_read_array(const void *dtb, int node, const char *prop,
+               unsigned int cells, void *value)
+{
+       const uint32_t *value_ptr;
+       int value_len;
+
+       assert(dtb != NULL);
+       assert(prop != NULL);
+       assert(value != NULL);
+       assert(node >= 0);
+
+       /* Access property and obtain its length (in bytes) */
+       value_ptr = fdt_getprop_namelen(dtb, node, prop, (int)strlen(prop),
+                       &value_len);
+       if (value_ptr == NULL) {
+               WARN("Couldn't find property %s in dtb\n", prop);
+               return -1;
+       }
+
+       /* Verify that property length accords with cell length */
+       if (NCELLS((unsigned int)value_len) != cells) {
+               WARN("Property length mismatch\n");
+               return -1;
+       }
+
+       uint32_t *dst = value;
+
+       for (unsigned int i = 0U; i < cells; i++) {
+               dst[i] = fdt32_to_cpu(value_ptr[i]);
+       }
+
+       return 0;
+}
+
 /*
  * Read string from a given property of the given node. Up to 'size - 1'
  * characters are read, and a NUL terminator is added. Returns 0 on success,

diff --git a/include/common/fdt_wrappers.h b/include/common/fdt_wrappers.h
index a0fe6b753098405b8738f520c63dbe6b7ae7deb0..c8d753f9ab7f7b5c96f9c906202eafa6ecdc61f7 100644 (file)
--- a/include/common/fdt_wrappers.h
+++ b/include/common/fdt_wrappers.h
@@ -14,6 +14,8 @@
 
 int fdtw_read_cells(const void *dtb, int node, const char *prop,
                unsigned int cells, void *value);
+int fdtw_read_array(const void *dtb, int node, const char *prop,
+               unsigned int cells, void *value);
 int fdtw_read_string(const void *dtb, int node, const char *prop,
                char *str, size_t size);
 int fdtw_write_inplace_cells(void *dtb, int node, const char *prop,