[Minios-devel] [UNIKRAFT PATCHv6 6/8] plat/common: Introduce fdt_node_offset_by_compatible_list helper

[Jia He <justin.he@xxxxxxx>]

From: Jianyong Wu <jianyong.wu@xxxxxxx>

For most of devices that will use the device tree will have one
or more compatible strings. This helper will avoid implement a
function to match compatible list everywhere.
The valid compatible strings array should be ended with NULL.
E.g.
static const char * const gic_device_list[] = {
        "arm,cortex-a15-gic",
        "arm,cortex-a7-gic",
        "arm,cortex-a9-gic",
        NULL}

Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
Signed-off-by: Jianyong Wu <jianyong.wu@xxxxxxx>
Signed-off-by: Jia He <justin.he@xxxxxxx>
---
 plat/drivers/include/ofw/fdt.h | 26 ++++++++++++++++++++++++++
 plat/drivers/ofw/fdt.c         | 15 +++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/plat/drivers/include/ofw/fdt.h b/plat/drivers/include/ofw/fdt.h
index c9ae8e5..5e2eb63 100644
--- a/plat/drivers/include/ofw/fdt.h
+++ b/plat/drivers/include/ofw/fdt.h
@@ -96,4 +96,30 @@ int fdt_interrupt_cells(const void *fdt, int nodeoffset);
 int fdt_get_address(const void *fdt, int nodeoffset, uint32_t index,
                        uint64_t *addr, uint64_t *size);
 
+/**
+ * fdt_node_offset_by_compatible_list - find nodes with a given
+ *                                     'compatible' list value
+ * @fdt: pointer to the device tree blob
+ * @startoffset: only find nodes after this offset
+ * @compatibles: a list of 'compatible' string to match, should be ended
+ * with NULL string.
+ * fdt_node_offset_by_compatible_list() returns the offset of the
+ * first matched node after startoffset, which has a 'compatible'
+ * property which lists the given compatible string; or if
+ * startoffset is -1, the very first such node in the tree.
+ *
+ * returns:
+ *     structure block offset of the located node (>= 0, >startoffset),
+ *              on success
+ *     -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
+ *             tree after startoffset
+ *     -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
+ *     -FDT_ERR_BADMAGIC,
+ *     -FDT_ERR_BADVERSION,
+ *     -FDT_ERR_BADSTATE,
+ *     -FDT_ERR_BADSTRUCTURE, standard meanings
+ */
+int fdt_node_offset_by_compatible_list(const void *fdt, int startoffset,
+                                       const char * const compatibles[]);
+
 #endif
diff --git a/plat/drivers/ofw/fdt.c b/plat/drivers/ofw/fdt.c
index b72c1df..b4debb9 100644
--- a/plat/drivers/ofw/fdt.c
+++ b/plat/drivers/ofw/fdt.c
@@ -279,3 +279,18 @@ int fdt_get_address(const void *fdt, int nodeoffset, 
uint32_t index,
                return -FDT_ERR_NOTFOUND;
        return 0;
 }
+
+int fdt_node_offset_by_compatible_list(const void *fdt, int startoffset,
+                                 const char * const compatibles[])
+{
+       int idx, offset;
+
+       for (idx = 0; compatibles[idx] != NULL; idx++) {
+               offset = fdt_node_offset_by_compatible(fdt, startoffset,
+                                 compatibles[idx]);
+               if (offset >= 0)
+                       return offset;
+       }
+
+       return -FDT_ERR_NOTFOUND;
+}
-- 
2.17.1


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