bsps/microblaze: Add device tree getter

This allows drivers to read configuration data from the device tree if
the BSP is built with device tree support.

4 files changed, 140 insertions, 23 deletions

diff --git a/bsps/microblaze/include/bsp/microblaze-fdt-support.h b/bsps/microblaze/include/bsp/microblaze-fdt-support.h
new file mode 100644
index 0000000000..d4430c5a3a
--- /dev/null
+++ b/bsps/microblaze/include/bsp/microblaze-fdt-support.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup RTEMSBSPsMicroblaze
+ *
+ * @brief This header file provides support for the device tree.
+ */
+
+/*
+ * Copyright (C) 2022 On-Line Applications Research Corporation (OAR)
+ *
+ * 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.
+ *
+ * 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 OWNER 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.
+ */
+
+#ifndef LIBBSP_MICROBLAZE_MICROBLAZE_FDT_SUPPORT_H
+#define LIBBSP_MICROBLAZE_MICROBLAZE_FDT_SUPPORT_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+
+/**
+ * @brief Get the value of a property from a compatible node in the device tree.
+ *
+ * @param[in] compatible The 'compatible' string to match against.
+ * @param[in] prop_name The property name.
+ * @param[in] default_value The default value to return if no compatible node
+ *                          was found or the property was not found.
+ *
+ * @return The value of the property or the default value.
+ */
+uint32_t try_get_prop_from_device_tree(
+  const char *compatible,
+  const char *prop_name,
+  uint32_t default_value
+);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* LIBBSP_MICROBLAZE_MICROBLAZE_FDT_SUPPORT_H */
diff --git a/bsps/microblaze/microblaze_fpga/fdt/bsp_fdt.c b/bsps/microblaze/microblaze_fpga/fdt/bsp_fdt.c
deleted file mode 100644
index 9eb92c5dc6..0000000000
--- a/bsps/microblaze/microblaze_fpga/fdt/bsp_fdt.c
+++ /dev/null
@@ -1,23 +0,0 @@
-/*
- *  COPYRIGHT (c) 2021.
- *  On-Line Applications Research Corporation (OAR).
- *
- *  The license and distribution terms for this file may be
- *  found in the file LICENSE in this distribution or at
- *  http://www.rtems.org/license/LICENSE.
- */
-
-#include <bsp.h>
-#include <bsp/fdt.h>
-
-#include BSP_MICROBLAZE_FPGA_DTB_HEADER_PATH
-
-const void *bsp_fdt_get(void)
-{
-  return system_dtb;
-}
-
-uint32_t bsp_fdt_map_intr(const uint32_t *intr, size_t icells)
-{
-  return intr[0];
-}
diff --git a/bsps/microblaze/microblaze_fpga/include/bsp.h b/bsps/microblaze/microblaze_fpga/include/bsp.h
index 93cf0e4b34..410d4483c6 100644
--- a/bsps/microblaze/microblaze_fpga/include/bsp.h
+++ b/bsps/microblaze/microblaze_fpga/include/bsp.h
@@ -43,12 +43,15 @@ extern "C" {
 
 #include <bspopts.h>
 #include <bsp/default-initial-extension.h>
+#include <bsp/microblaze-fdt-support.h>
 
 #include <rtems.h>
 
+#ifdef BSP_MICROBLAZE_FPGA_USE_FDT
 #define BSP_FDT_IS_SUPPORTED
 extern const unsigned char system_dtb[];
 extern const size_t system_dtb_size;
+#endif /* BSP_MICROBLAZE_FPGA_USE_FDT */
 
 void microblaze_enable_icache(void);
 void microblaze_enable_dcache(void);
diff --git a/bsps/microblaze/shared/fdt/microblaze-fdt-support.c b/bsps/microblaze/shared/fdt/microblaze-fdt-support.c
new file mode 100644
index 0000000000..d48b051ffd
--- /dev/null
+++ b/bsps/microblaze/shared/fdt/microblaze-fdt-support.c
@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/*
+ * Copyright (C) 2022 On-Line Applications Research Corporation (OAR)
+ *
+ * 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.
+ *
+ * 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 OWNER 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.
+ */
+
+#include <bspopts.h>
+#include <bsp/microblaze-fdt-support.h>
+#ifdef BSP_MICROBLAZE_FPGA_USE_FDT
+#include <bsp/fdt.h>
+
+#include <libfdt.h>
+
+#include BSP_MICROBLAZE_FPGA_DTB_HEADER_PATH
+
+const void *bsp_fdt_get(void)
+{
+  return system_dtb;
+}
+
+uint32_t bsp_fdt_map_intr(const uint32_t *intr, size_t icells)
+{
+  return intr[0];
+}
+#endif /* BSP_MICROBLAZE_FPGA_USE_FDT */
+
+uint32_t try_get_prop_from_device_tree(
+  const char *compatible,
+  const char *prop_name,
+  uint32_t default_value
+)
+{
+  uint32_t value = default_value;
+
+#ifdef BSP_MICROBLAZE_FPGA_USE_FDT
+  const void *fdt = bsp_fdt_get();
+  int node = fdt_node_offset_by_compatible( fdt, -1, compatible );
+  if ( node < 0 ) {
+    return default_value;
+  }
+
+  const uint32_t *prop = fdt_getprop( fdt, node, prop_name, NULL );
+  if ( prop == NULL ) {
+    return default_value;
+  }
+
+  value = fdt32_to_cpu( prop[0] );
+#endif /* BSP_MICROBLAZE_FPGA_USE_FDT */
+
+   return value;
+}