of: Simplify of_dma_set_restricted_buffer() to use of_for_each_phandle()

Simplify of_dma_set_restricted_buffer() by using of_property_present()
and of_for_each_phandle() iterator.

Acked-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Link: https://lore.kernel.org/r/20250423-dt-memory-region-v2-v2-2-2fbd6ebd3c88@kernel.org
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

diff --git a/drivers/of/device.c b/drivers/of/device.c
index 5053e5d532cc385e91c4230da17166191422bd52..c80426510ec2c0ddb1434b649edc9c1b8e661d19 100644 (file)
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -35,44 +35,35 @@ EXPORT_SYMBOL(of_match_device);
 static void
 of_dma_set_restricted_buffer(struct device *dev, struct device_node *np)
 {
-       struct device_node *node, *of_node = dev->of_node;
-       int count, i;
+       struct device_node *of_node = dev->of_node;
+       struct of_phandle_iterator it;
+       int rc, i = 0;
 
        if (!IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL))
                return;
 
-       count = of_property_count_elems_of_size(of_node, "memory-region",
-                                               sizeof(u32));
        /*
         * If dev->of_node doesn't exist or doesn't contain memory-region, try
         * the OF node having DMA configuration.
         */
-       if (count <= 0) {
+       if (!of_property_present(of_node, "memory-region"))
                of_node = np;
-               count = of_property_count_elems_of_size(
-                       of_node, "memory-region", sizeof(u32));
-       }
 
-       for (i = 0; i < count; i++) {
-               node = of_parse_phandle(of_node, "memory-region", i);
+       of_for_each_phandle(&it, rc, of_node, "memory-region", NULL, 0) {
                /*
                 * There might be multiple memory regions, but only one
                 * restricted-dma-pool region is allowed.
                 */
-               if (of_device_is_compatible(node, "restricted-dma-pool") &&
-                   of_device_is_available(node)) {
-                       of_node_put(node);
+               if (of_device_is_compatible(it.node, "restricted-dma-pool") &&
+                   of_device_is_available(it.node)) {
+                       if (of_reserved_mem_device_init_by_idx(dev, of_node, i))
+                               dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n");
+                       of_node_put(it.node);
                        break;
                }
-               of_node_put(node);
+               i++;
        }
 
-       /*
-        * Attempt to initialize a restricted-dma-pool region if one was found.
-        * Note that count can hold a negative error code.
-        */
-       if (i < count && of_reserved_mem_device_init_by_idx(dev, of_node, i))
-               dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n");
 }
 
 /**