[Minios-devel] [UNIKRAFT PATCHv5 1/8] plat/common: Introduce fdt_getprop_u32_by_offset helper

[Jia He <justin.he@xxxxxxx>]

From: Jianyong Wu <jianyong.wu@xxxxxxx>

This helper will be used very frequently to u32 from properties.
So we provide this helper here to avoid using fdt_getprop 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>
---
v4->v5:
        1.call fdt_get_property_namelen directly
        2.use UK_ASSERT to check the input parameter

 plat/drivers/include/ofw/fdt.h | 59 +++++++++++++++++++++++++++++++++
 plat/drivers/ofw/fdt.c         | 60 ++++++++++++++++++++++++++++++++++
 2 files changed, 119 insertions(+)
 create mode 100644 plat/drivers/include/ofw/fdt.h
 create mode 100644 plat/drivers/ofw/fdt.c

diff --git a/plat/drivers/include/ofw/fdt.h b/plat/drivers/include/ofw/fdt.h
new file mode 100644
index 0000000..c202671
--- /dev/null
+++ b/plat/drivers/include/ofw/fdt.h
@@ -0,0 +1,59 @@
+/* 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.
+ */
+#ifndef _PLAT_DRIVER_OFW_FDT_H
+#define _PLAT_DRIVER_OFW_FDT_H
+
+/**
+ * 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);
+
+#endif
diff --git a/plat/drivers/ofw/fdt.c b/plat/drivers/ofw/fdt.c
new file mode 100644
index 0000000..e23b7a3
--- /dev/null
+++ b/plat/drivers/ofw/fdt.c
@@ -0,0 +1,60 @@
+/* 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>
+
+#include <uk/print.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;
+
+       UK_ASSERT(out);
+
+       prop = fdt_get_property_namelen(fdt, offset, name, strlen(name),
+                                       &prop_len);
+       if (!prop)
+               return prop_len;
+
+       if (prop_len >= (int)sizeof(fdt32_t)) {
+               *out = fdt32_to_cpu(*(fdt32_t *)prop->data);
+               return 0;
+       }
+
+       return -FDT_ERR_NOTFOUND;
+}
-- 
2.17.1


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