Add a function to lookup a property which is a phandle in a node, and
another to read a fixed-length integer array from an fdt property.
Also add a function to read boolean properties.
Signed-off-by: Simon Glass <s...@chromium.org>
---
include/fdtdec.h | 40 ++++++++++++++++++++++++++
lib/fdtdec.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 122 insertions(+), 0 deletions(-)
diff --git a/include/fdtdec.h b/include/fdtdec.h
index 9018181..9ecb6ab 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -126,3 +126,43 @@ int fdtdec_get_is_enabled(const void *blob, int node);
* if not.
*/
int fdtdec_check_fdt(void);
+
+/**
+ * Look up a phandle and follow it to its node. Then return the offset
+ * of that node.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @return node offset if found, -ve error code on error
+ */
+int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
+
+/**
+ * Look up a property in a node and return its contents in an integer
+ * array of given length. The property must have at least enough data for
+ * the array (4*count bytes). It may have more, but this will be ignored.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param array array to fill with data
+ * @param count number of array elements
+ * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
+ * or -FDT_ERR_BADLAYOUT if not enough data
+ */
+int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
+ int *array, int count);
+
+/**
+ * Look up a boolean property in a node and return it.
+ *
+ * A boolean properly is true if present in the device tree and false if not
+ * present, or present with a 0 value.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @return 1 if the properly is present; 0 if it isn't present or is 0
+ */
+int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index d1321a8..613547a 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -146,3 +146,85 @@ int fdtdec_check_fdt(void)
"binary or define CONFIG_OF_EMBED\n");
return 0;
}
+
+int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name)
+{
+ const u32 *phandle;
+ int lookup;
+
+ phandle = fdt_getprop(blob, node, prop_name, NULL);
+ if (!phandle)
+ return -FDT_ERR_NOTFOUND;
+
+ lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle));
+ return lookup;
+}
+
+/**
+ * Look up a property in a node and check that it has a minimum length.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param min_len minimum property length in bytes
+ * @param err 0 if ok, or -FDT_ERR_NOTFOUND if the property is not
+ found, or -FDT_ERR_BADLAYOUT if not enough data
+ * @return pointer to cell, which is only valid if err == 0
+ */
+static const void *get_prop_len(const void *blob, int node,
+ const char *prop_name, int min_len, int *err)
+{
+ const void *cell;
+ int len;
+
+ debug("%s: %s\n", __func__, prop_name);
+ cell = fdt_getprop(blob, node, prop_name, &len);
+ if (!cell)
+ *err = -FDT_ERR_NOTFOUND;
+ else if (len < min_len)
+ *err = -FDT_ERR_BADLAYOUT;
+ else
+ *err = 0;
+ return cell;
+}
+
+int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
+ int *array, int count)
+{
+ const s32 *cell;
+ int i, err = 0;
+
+ debug("%s: %s\n", __func__, prop_name);
+ cell = get_prop_len(blob, node, prop_name, sizeof(s32) * count, &err);
+ if (!err) {
+ for (i = 0; i < count; i++)
+ array[i] = fdt32_to_cpu(cell[i]);
+ }
+ return err;
+}
+
+/**
+ * Look up a boolean property in a node and return it.
+ *
+ * A boolean properly is true if present in the device tree and false if not
+ * present, or present with a 0 value.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @return 1 if the properly is present; 0 if it isn't present or is 0
+ */
+int fdtdec_get_bool(const void *blob, int node, const char *prop_name)
+{
+ const s32 *cell;
+ int len;
+
+ debug("%s: %s\n", __func__, prop_name);
+ cell = fdt_getprop(blob, node, prop_name, &len);
+ if (!cell)
+ return 0;
+ if (len >= sizeof(u32) && *cell == 0)
+ return 0;
+
+ return 1;
+}
--
1.7.3.1
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