--- /dev/null
+* Firewall and privilege register settings in device tree
+
+Required properties:
+--------------------
+
+- compatible: should contain "intel,socfpga-dtreg"
+- reg: Physical base address and size of block register.
+- intel,offset-settings: 32-bit offset address of block register,
+ followed by 32-bit value settings and
+ the masking bits, only masking bit
+ set to 1 allows modification.
+
+The device tree node which describes secure and privilege register access
+configuration in compile time.
+
+Most of these registers are expected to work except for the case which some
+registers configuration are required for granting access to some other
+registers, for example CCU registers have to be properly configured before
+allowing register configuration access to fpga2sdram firewall as shown in
+below example.
+
+Some registers depend on runtime data for proper configuration are expected
+to be part of driver that generating these data for example configuration for
+soc_noc_fw_ddr_mpu_inst_0_ddr_scr block register depend on DDR size parsed from
+memory device tree node.
+
+Please refer details of tested examples below for both fpga2sdram and QoS
+configuration with default reset value and the comments.
+
+Example:
+--------
+
+Configuration for multiple dtreg node support in device tree:
+
+ socfpga_dtreg0: socfpga-dtreg0 {
+ compatible = "intel,socfpga-dtreg";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ bootph-all;
+
+ coh_cpu0_bypass_OC_Firewall_main_Firewall@f7100200 {
+ reg = <0xf7100200 0x00000014>;
+ intel,offset-settings =
+ /*
+ * Disable ocram security at CCU for
+ * non secure access
+ */
+ <0x0000004 0x8000ffff 0xe007ffff>,
+ <0x0000008 0x8000ffff 0xe007ffff>,
+ <0x000000c 0x8000ffff 0xe007ffff>,
+ <0x0000010 0x8000ffff 0xe007ffff>;
+ bootph-all;
+ };
+ };
+
+ socfpga_dtreg1: socfpga-dtreg1 {
+ compatible = "intel,socfpga-dtreg";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ bootph-all;
+
+ soc_noc_fw_mpfe_csr_inst_0_mpfe_scr@f8020000 {
+ reg = <0xf8020000 0x0000001c>;
+ intel,offset-settings =
+ /* Disable MPFE firewall for SMMU */
+ <0x00000000 0x00010101 0x00010101>,
+ /*
+ * Disable MPFE firewall for HMC
+ * adapter
+ */
+ <0x00000004 0x00000001 0x00010101>;
+ bootph-all;
+ };
+ };
+
+To call the nodes use:
+
+ ret = uclass_get_device_by_name(UCLASS_NOP, "socfpga-dtreg0", &dev);
+ ret = uclass_get_device_by_name(UCLASS_NOP, "socfpga-dtreg1", &dev);
+
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2024 Intel Corporation <www.intel.com>
+ */
+
+#include <dm.h>
+#include <errno.h>
+#include <asm/io.h>
+#include <linux/sizes.h>
+
+#define NUMBER_OF_ELEMENTS 3
+
+static int socfpga_dtreg_probe(struct udevice *dev)
+{
+ const fdt32_t *list;
+ fdt_addr_t offset, base;
+ fdt_val_t val, read_val, mask, set_mask;
+ int size, i;
+ u32 blk_sz, reg;
+ ofnode node;
+ const char *name = NULL;
+
+ debug("%s(dev=%p)\n", __func__, dev);
+
+ if (!dev_has_ofnode(dev))
+ return 0;
+
+ dev_for_each_subnode(node, dev) {
+ name = ofnode_get_name(node);
+ if (!name)
+ return -EINVAL;
+
+ if (ofnode_read_u32_index(node, "reg", 1, &blk_sz))
+ return -EINVAL;
+
+ base = ofnode_get_addr(node);
+ if (base == FDT_ADDR_T_NONE)
+ return -EINVAL;
+
+ debug("%s(node_offset 0x%lx node_name %s ", __func__,
+ node.of_offset, name);
+ debug("node addr 0x%llx blk sz 0x%x)\n", base, blk_sz);
+
+ list = ofnode_read_prop(node, "intel,offset-settings", &size);
+ if (!list)
+ return -EINVAL;
+
+ debug("%s(intel,offset-settings property size=%x)\n", __func__,
+ size);
+ size /= sizeof(*list) * NUMBER_OF_ELEMENTS;
+
+ /*
+ * First element: offset
+ * Second element: val
+ * Third element: mask
+ */
+ for (i = 0; i < size; i++) {
+ offset = fdt32_to_cpu(*list++);
+ val = fdt32_to_cpu(*list++);
+
+ /* Reads the masking bit value from the list */
+ mask = fdt32_to_cpu(*list++);
+
+ /*
+ * Reads out the offsets, value and masking bits
+ * Ex: <0x00000000 0x00000230 0xffffffff>
+ */
+ debug("%s(intel,offset-settings 0x%llx : 0x%llx : 0x%llx)\n",
+ __func__, offset, val, mask);
+
+ if (blk_sz < offset + SZ_4) {
+ printf("%s: Overflow as offset 0x%llx or reg",
+ __func__, offset);
+ printf(" write is more than block size 0x%x\n",
+ blk_sz);
+ return -EINVAL;
+ }
+
+ if (mask != 0) {
+ if (mask == 0xffffffff) {
+ reg = base + offset;
+ writel(val, (uintptr_t)reg);
+ } else {
+ /* Mask the value with the masking bits */
+ set_mask = val & mask;
+
+ reg = base + offset;
+
+ /* Clears and sets specific bits in the register */
+ clrsetbits_le32((uintptr_t)reg, mask, set_mask);
+ }
+ }
+
+ read_val = readl((uintptr_t)reg);
+
+ /* Reads out the register, masked value and the read value */
+ debug("%s(reg 0x%x = wr : 0x%llx rd : 0x%llx)\n",
+ __func__, reg, set_mask, read_val);
+ }
+ }
+
+ return 0;
+};
+
+static const struct udevice_id socfpga_dtreg_ids[] = {
+ {.compatible = "intel,socfpga-dtreg"},
+ { }
+};
+
+U_BOOT_DRIVER(socfpga_dtreg) = {
+ .name = "socfpga-dtreg",
+ .id = UCLASS_NOP,
+ .of_match = socfpga_dtreg_ids,
+ .probe = socfpga_dtreg_probe,
+};