v4.19.13 snapshot.
diff --git a/arch/mips/generic/yamon-dt.c b/arch/mips/generic/yamon-dt.c
new file mode 100644
index 0000000..7ba4ad5
--- /dev/null
+++ b/arch/mips/generic/yamon-dt.c
@@ -0,0 +1,236 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ * Author: Paul Burton <paul.burton@mips.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#define pr_fmt(fmt) "yamon-dt: " fmt
+
+#include <linux/bug.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/libfdt.h>
+#include <linux/printk.h>
+
+#include <asm/fw/fw.h>
+#include <asm/yamon-dt.h>
+
+#define MAX_MEM_ARRAY_ENTRIES 2
+
+__init int yamon_dt_append_cmdline(void *fdt)
+{
+ int err, chosen_off;
+
+ /* find or add chosen node */
+ chosen_off = fdt_path_offset(fdt, "/chosen");
+ if (chosen_off == -FDT_ERR_NOTFOUND)
+ chosen_off = fdt_add_subnode(fdt, 0, "chosen");
+ if (chosen_off < 0) {
+ pr_err("Unable to find or add DT chosen node: %d\n",
+ chosen_off);
+ return chosen_off;
+ }
+
+ err = fdt_setprop_string(fdt, chosen_off, "bootargs", fw_getcmdline());
+ if (err) {
+ pr_err("Unable to set bootargs property: %d\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
+static unsigned int __init gen_fdt_mem_array(
+ const struct yamon_mem_region *regions,
+ __be32 *mem_array,
+ unsigned int max_entries,
+ unsigned long memsize)
+{
+ const struct yamon_mem_region *mr;
+ unsigned long size;
+ unsigned int entries = 0;
+
+ for (mr = regions; mr->size && memsize; ++mr) {
+ if (entries >= max_entries) {
+ pr_warn("Number of regions exceeds max %u\n",
+ max_entries);
+ break;
+ }
+
+ /* How much of the remaining RAM fits in the next region? */
+ size = min_t(unsigned long, memsize, mr->size);
+ memsize -= size;
+
+ /* Emit a memory region */
+ *(mem_array++) = cpu_to_be32(mr->start);
+ *(mem_array++) = cpu_to_be32(size);
+ ++entries;
+
+ /* Discard the next mr->discard bytes */
+ memsize -= min_t(unsigned long, memsize, mr->discard);
+ }
+ return entries;
+}
+
+__init int yamon_dt_append_memory(void *fdt,
+ const struct yamon_mem_region *regions)
+{
+ unsigned long phys_memsize, memsize;
+ __be32 mem_array[2 * MAX_MEM_ARRAY_ENTRIES];
+ unsigned int mem_entries;
+ int i, err, mem_off;
+ char *var, param_name[10], *var_names[] = {
+ "ememsize", "memsize",
+ };
+
+ /* find memory size from the bootloader environment */
+ for (i = 0; i < ARRAY_SIZE(var_names); i++) {
+ var = fw_getenv(var_names[i]);
+ if (!var)
+ continue;
+
+ err = kstrtoul(var, 0, &phys_memsize);
+ if (!err)
+ break;
+
+ pr_warn("Failed to read the '%s' env variable '%s'\n",
+ var_names[i], var);
+ }
+
+ if (!phys_memsize) {
+ pr_warn("The bootloader didn't provide memsize: defaulting to 32MB\n");
+ phys_memsize = 32 << 20;
+ }
+
+ /* default to using all available RAM */
+ memsize = phys_memsize;
+
+ /* allow the user to override the usable memory */
+ for (i = 0; i < ARRAY_SIZE(var_names); i++) {
+ snprintf(param_name, sizeof(param_name), "%s=", var_names[i]);
+ var = strstr(arcs_cmdline, param_name);
+ if (!var)
+ continue;
+
+ memsize = memparse(var + strlen(param_name), NULL);
+ }
+
+ /* if the user says there's more RAM than we thought, believe them */
+ phys_memsize = max_t(unsigned long, phys_memsize, memsize);
+
+ /* find or add a memory node */
+ mem_off = fdt_path_offset(fdt, "/memory");
+ if (mem_off == -FDT_ERR_NOTFOUND)
+ mem_off = fdt_add_subnode(fdt, 0, "memory");
+ if (mem_off < 0) {
+ pr_err("Unable to find or add memory DT node: %d\n", mem_off);
+ return mem_off;
+ }
+
+ err = fdt_setprop_string(fdt, mem_off, "device_type", "memory");
+ if (err) {
+ pr_err("Unable to set memory node device_type: %d\n", err);
+ return err;
+ }
+
+ mem_entries = gen_fdt_mem_array(regions, mem_array,
+ MAX_MEM_ARRAY_ENTRIES, phys_memsize);
+ err = fdt_setprop(fdt, mem_off, "reg",
+ mem_array, mem_entries * 2 * sizeof(mem_array[0]));
+ if (err) {
+ pr_err("Unable to set memory regs property: %d\n", err);
+ return err;
+ }
+
+ mem_entries = gen_fdt_mem_array(regions, mem_array,
+ MAX_MEM_ARRAY_ENTRIES, memsize);
+ err = fdt_setprop(fdt, mem_off, "linux,usable-memory",
+ mem_array, mem_entries * 2 * sizeof(mem_array[0]));
+ if (err) {
+ pr_err("Unable to set linux,usable-memory property: %d\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
+__init int yamon_dt_serial_config(void *fdt)
+{
+ const char *yamontty, *mode_var;
+ char mode_var_name[9], path[20], parity;
+ unsigned int uart, baud, stop_bits;
+ bool hw_flow;
+ int chosen_off, err;
+
+ yamontty = fw_getenv("yamontty");
+ if (!yamontty || !strcmp(yamontty, "tty0")) {
+ uart = 0;
+ } else if (!strcmp(yamontty, "tty1")) {
+ uart = 1;
+ } else {
+ pr_warn("yamontty environment variable '%s' invalid\n",
+ yamontty);
+ uart = 0;
+ }
+
+ baud = stop_bits = 0;
+ parity = 0;
+ hw_flow = false;
+
+ snprintf(mode_var_name, sizeof(mode_var_name), "modetty%u", uart);
+ mode_var = fw_getenv(mode_var_name);
+ if (mode_var) {
+ while (mode_var[0] >= '0' && mode_var[0] <= '9') {
+ baud *= 10;
+ baud += mode_var[0] - '0';
+ mode_var++;
+ }
+ if (mode_var[0] == ',')
+ mode_var++;
+ if (mode_var[0])
+ parity = mode_var[0];
+ if (mode_var[0] == ',')
+ mode_var++;
+ if (mode_var[0])
+ stop_bits = mode_var[0] - '0';
+ if (mode_var[0] == ',')
+ mode_var++;
+ if (!strcmp(mode_var, "hw"))
+ hw_flow = true;
+ }
+
+ if (!baud)
+ baud = 38400;
+
+ if (parity != 'e' && parity != 'n' && parity != 'o')
+ parity = 'n';
+
+ if (stop_bits != 7 && stop_bits != 8)
+ stop_bits = 8;
+
+ WARN_ON(snprintf(path, sizeof(path), "serial%u:%u%c%u%s",
+ uart, baud, parity, stop_bits,
+ hw_flow ? "r" : "") >= sizeof(path));
+
+ /* find or add chosen node */
+ chosen_off = fdt_path_offset(fdt, "/chosen");
+ if (chosen_off == -FDT_ERR_NOTFOUND)
+ chosen_off = fdt_add_subnode(fdt, 0, "chosen");
+ if (chosen_off < 0) {
+ pr_err("Unable to find or add DT chosen node: %d\n",
+ chosen_off);
+ return chosen_off;
+ }
+
+ err = fdt_setprop_string(fdt, chosen_off, "stdout-path", path);
+ if (err) {
+ pr_err("Unable to set stdout-path property: %d\n", err);
+ return err;
+ }
+
+ return 0;
+}