[Minios-devel] [UNIKRAFT PATCHv10 1/7] lib/fdt: Introduce fdt_getprop_u32_by_offset helper

[Jia He <justin.he@xxxxxxx>]

This helper will be used very frequently to u32 from properties.
So we provide this helper here to avoid using fdt_get_property_namelen
and fdt32_to_cpu everywhere.

Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
Signed-off-by: Jianyong Wu <jianyong.wu@xxxxxxx>
Signed-off-by: Jia He <justin.he@xxxxxxx>
---
 lib/fdt/Makefile.uk      |  1 +
 lib/fdt/exportsyms.uk    |  1 +
 lib/fdt/include/libfdt.h | 21 +++++++++++++++
 lib/fdt/uk_fdt.c         | 57 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 80 insertions(+)
 create mode 100644 lib/fdt/uk_fdt.c

diff --git a/lib/fdt/Makefile.uk b/lib/fdt/Makefile.uk
index 03251f6..d4d85a0 100644
--- a/lib/fdt/Makefile.uk
+++ b/lib/fdt/Makefile.uk
@@ -14,3 +14,4 @@ LIBFDT_SRCS-y += $(LIBFDT_BASE)/fdt_rw.c
 LIBFDT_SRCS-y += $(LIBFDT_BASE)/fdt_strerror.c
 LIBFDT_SRCS-y += $(LIBFDT_BASE)/fdt_sw.c
 LIBFDT_SRCS-y += $(LIBFDT_BASE)/fdt_wip.c
+LIBFDT_SRCS-y += $(LIBFDT_BASE)/uk_fdt.c
diff --git a/lib/fdt/exportsyms.uk b/lib/fdt/exportsyms.uk
index 2fe4c32..d64d9dc 100644
--- a/lib/fdt/exportsyms.uk
+++ b/lib/fdt/exportsyms.uk
@@ -60,3 +60,4 @@ fdt_size_cells
 fdt_stringlist_contains
 fdt_resize
 fdt_overlay_apply
+fdt_getprop_u32_by_offset
diff --git a/lib/fdt/include/libfdt.h b/lib/fdt/include/libfdt.h
index 05dedbd..e75f0bb 100644
--- a/lib/fdt/include/libfdt.h
+++ b/lib/fdt/include/libfdt.h
@@ -1863,6 +1863,27 @@ int fdt_del_node(void *fdt, int nodeoffset);
  */
 int fdt_overlay_apply(void *fdt, void *fdto);
 
+/**
+ * fdt_getprop_u32_by_offset - retrieve u32 of a given property
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to find
+ * @name: name of the property to find
+ * @out: pointer to u32 variable (will be overwritten) or NULL
+ *
+ * fdt_getprop_u32_by_offset() retrieves u32 to the value of the property
+ * named 'name' of the node at offset nodeoffset (this will be a
+ * pointer to within the device blob itself, not a copy of the value).
+ * If out is non-NULL, the u32 of the property value is returned.
+ *
+ * returns:
+ *     0, on success
+ *             out contains the u32 of a given property at nodeoffset.
+ *     -FDT_ERR_NOTFOUND, node does not have named property
+ *     -FDT_ERR_BADNCELLS,
+ */
+int fdt_getprop_u32_by_offset(const void *fdt, int nodeoffset,
+               const char *name, uint32_t *out);
+
 /**********************************************************************/
 /* Debugging / informational functions                                */
 /**********************************************************************/
diff --git a/lib/fdt/uk_fdt.c b/lib/fdt/uk_fdt.c
new file mode 100644
index 0000000..e7f30cd
--- /dev/null
+++ b/lib/fdt/uk_fdt.c
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Authors: Wei Chen <Wei.Chen@xxxxxxx>
+ *          Jianyong Wu <Jianyong.Wu@xxxxxxx>
+ *
+ * Copyright (c) 2018, Arm Ltd. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
+ */
+#include <libfdt_env.h>
+#include <fdt.h>
+#include <libfdt.h>
+
+int fdt_getprop_u32_by_offset(const void *fdt, int offset,
+               const char *name, uint32_t *out)
+{
+       const struct fdt_property *prop;
+       int prop_len;
+       fdt32_t result;
+
+       prop = fdt_get_property_namelen(fdt, offset, name, strlen(name),
+                                       &prop_len);
+       if (!prop)
+               return prop_len;
+
+       memcpy(&result, prop->data, sizeof(result));
+
+       if (out)
+               *out = fdt32_to_cpu(result);
+
+       return 0;
+}
-- 
2.17.1


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