1 files changed, 108 insertions, 0 deletions
diff --git a/plat/arm/common/fconf/fconf_ethosn_getter.c b/plat/arm/common/fconf/fconf_ethosn_getter.c
new file mode 100644
index 000000000..1ba9f3a23
--- /dev/null
+++ b/plat/arm/common/fconf/fconf_ethosn_getter.c
@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2021, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <string.h>
+
+#include <common/debug.h>
+#include <common/fdt_wrappers.h>
+#include <libfdt.h>
+#include <plat/arm/common/fconf_ethosn_getter.h>
+
+struct ethosn_config_t ethosn_config;
+
+static uint8_t fdt_node_get_status(const void *fdt, int node)
+{
+	int len;
+	uint8_t status = ETHOSN_STATUS_DISABLED;
+	const char *node_status;
+
+	node_status = fdt_getprop(fdt, node, "status", &len);
+	if (node_status == NULL ||
+	    (len == 5 && /* Includes null character */
+	     strncmp(node_status, "okay", 4U) == 0)) {
+		status = ETHOSN_STATUS_ENABLED;
+	}
+
+	return status;
+}
+
+int fconf_populate_ethosn_config(uintptr_t config)
+{
+	int ethosn_node;
+	int sub_node;
+	uint8_t ethosn_status;
+	uint32_t core_count = 0U;
+	uint32_t core_addr_idx = 0U;
+	const void *hw_conf_dtb = (const void *)config;
+
+	/* Find offset to node with 'ethosn' compatible property */
+	ethosn_node = fdt_node_offset_by_compatible(hw_conf_dtb, -1, "ethosn");
+	if (ethosn_node < 0) {
+		ERROR("FCONF: Can't find 'ethosn' compatible node in dtb\n");
+		return ethosn_node;
+	}
+
+	/* If the Arm Ethos-N NPU is disabled the core check can be skipped */
+	ethosn_status = fdt_node_get_status(hw_conf_dtb, ethosn_node);
+	if (ethosn_status == ETHOSN_STATUS_DISABLED) {
+		return 0;
+	}
+
+	fdt_for_each_subnode(sub_node, hw_conf_dtb, ethosn_node) {
+		int err;
+		uintptr_t addr;
+		uint8_t status;
+
+		/* Check that the sub node is "ethosn-core" compatible */
+		if (fdt_node_check_compatible(hw_conf_dtb, sub_node,
+					      "ethosn-core") != 0) {
+			/* Ignore incompatible sub node */
+			continue;
+		}
+
+		/* Including disabled cores */
+		if (core_addr_idx >= ETHOSN_CORE_NUM_MAX) {
+			ERROR("FCONF: Reached max number of Arm Ethos-N NPU cores\n");
+			return -1;
+		}
+
+		status = fdt_node_get_status(hw_conf_dtb, ethosn_node);
+		if (status == ETHOSN_STATUS_DISABLED) {
+			++core_addr_idx;
+			continue;
+		}
+
+		err = fdt_get_reg_props_by_index(hw_conf_dtb, ethosn_node,
+						 core_addr_idx, &addr, NULL);
+		if (err < 0) {
+			ERROR("FCONF: Failed to read reg property for Arm Ethos-N NPU core %u\n",
+			      core_addr_idx);
+			return err;
+		}
+
+		ethosn_config.core_addr[core_count++] = addr;
+		++core_addr_idx;
+	}
+
+	if ((sub_node < 0) && (sub_node != -FDT_ERR_NOTFOUND)) {
+		ERROR("FCONF: Failed to parse sub nodes\n");
+		return sub_node;
+	}
+
+	/* The Arm Ethos-N NPU can't be used if no cores were found */
+	if (core_count == 0) {
+		ERROR("FCONF: No Arm Ethos-N NPU cores found\n");
+		return -1;
+	}
+
+	ethosn_config.num_cores = core_count;
+	ethosn_config.status = ethosn_status;
+
+	return 0;
+}
+
+FCONF_REGISTER_POPULATOR(HW_CONFIG, ethosn_config, fconf_populate_ethosn_config);