2 * Copyright (C) 2016 Imagination Technologies
3 * Author: Paul Burton <paul.burton@mips.com>
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
11 #define pr_fmt(fmt) "yamon-dt: " fmt
13 #include <linux/bug.h>
14 #include <linux/errno.h>
15 #include <linux/kernel.h>
16 #include <linux/libfdt.h>
17 #include <linux/printk.h>
19 #include <asm/fw/fw.h>
20 #include <asm/yamon-dt.h>
22 #define MAX_MEM_ARRAY_ENTRIES 2
24 __init int yamon_dt_append_cmdline(void *fdt)
28 /* find or add chosen node */
29 chosen_off = fdt_path_offset(fdt, "/chosen");
30 if (chosen_off == -FDT_ERR_NOTFOUND)
31 chosen_off = fdt_path_offset(fdt, "/chosen@0");
32 if (chosen_off == -FDT_ERR_NOTFOUND)
33 chosen_off = fdt_add_subnode(fdt, 0, "chosen");
35 pr_err("Unable to find or add DT chosen node: %d\n",
40 err = fdt_setprop_string(fdt, chosen_off, "bootargs", fw_getcmdline());
42 pr_err("Unable to set bootargs property: %d\n", err);
49 static unsigned int __init gen_fdt_mem_array(
50 const struct yamon_mem_region *regions,
52 unsigned int max_entries,
53 unsigned long memsize)
55 const struct yamon_mem_region *mr;
57 unsigned int entries = 0;
59 for (mr = regions; mr->size && memsize; ++mr) {
60 if (entries >= max_entries) {
61 pr_warn("Number of regions exceeds max %u\n",
66 /* How much of the remaining RAM fits in the next region? */
67 size = min_t(unsigned long, memsize, mr->size);
70 /* Emit a memory region */
71 *(mem_array++) = cpu_to_be32(mr->start);
72 *(mem_array++) = cpu_to_be32(size);
75 /* Discard the next mr->discard bytes */
76 memsize -= min_t(unsigned long, memsize, mr->discard);
81 __init int yamon_dt_append_memory(void *fdt,
82 const struct yamon_mem_region *regions)
84 unsigned long phys_memsize = 0, memsize;
85 __be32 mem_array[2 * MAX_MEM_ARRAY_ENTRIES];
86 unsigned int mem_entries;
88 char *var, param_name[10], *var_names[] = {
89 "ememsize", "memsize",
92 /* find memory size from the bootloader environment */
93 for (i = 0; i < ARRAY_SIZE(var_names); i++) {
94 var = fw_getenv(var_names[i]);
98 err = kstrtoul(var, 0, &phys_memsize);
102 pr_warn("Failed to read the '%s' env variable '%s'\n",
107 pr_warn("The bootloader didn't provide memsize: defaulting to 32MB\n");
108 phys_memsize = 32 << 20;
111 /* default to using all available RAM */
112 memsize = phys_memsize;
114 /* allow the user to override the usable memory */
115 for (i = 0; i < ARRAY_SIZE(var_names); i++) {
116 snprintf(param_name, sizeof(param_name), "%s=", var_names[i]);
117 var = strstr(arcs_cmdline, param_name);
121 memsize = memparse(var + strlen(param_name), NULL);
124 /* if the user says there's more RAM than we thought, believe them */
125 phys_memsize = max_t(unsigned long, phys_memsize, memsize);
127 /* find or add a memory node */
128 mem_off = fdt_path_offset(fdt, "/memory");
129 if (mem_off == -FDT_ERR_NOTFOUND)
130 mem_off = fdt_add_subnode(fdt, 0, "memory");
132 pr_err("Unable to find or add memory DT node: %d\n", mem_off);
136 err = fdt_setprop_string(fdt, mem_off, "device_type", "memory");
138 pr_err("Unable to set memory node device_type: %d\n", err);
142 mem_entries = gen_fdt_mem_array(regions, mem_array,
143 MAX_MEM_ARRAY_ENTRIES, phys_memsize);
144 err = fdt_setprop(fdt, mem_off, "reg",
145 mem_array, mem_entries * 2 * sizeof(mem_array[0]));
147 pr_err("Unable to set memory regs property: %d\n", err);
151 mem_entries = gen_fdt_mem_array(regions, mem_array,
152 MAX_MEM_ARRAY_ENTRIES, memsize);
153 err = fdt_setprop(fdt, mem_off, "linux,usable-memory",
154 mem_array, mem_entries * 2 * sizeof(mem_array[0]));
156 pr_err("Unable to set linux,usable-memory property: %d\n", err);
163 __init int yamon_dt_serial_config(void *fdt)
165 const char *yamontty, *mode_var;
166 char mode_var_name[9], path[20], parity;
167 unsigned int uart, baud, stop_bits;
171 yamontty = fw_getenv("yamontty");
172 if (!yamontty || !strcmp(yamontty, "tty0")) {
174 } else if (!strcmp(yamontty, "tty1")) {
177 pr_warn("yamontty environment variable '%s' invalid\n",
182 baud = stop_bits = 0;
186 snprintf(mode_var_name, sizeof(mode_var_name), "modetty%u", uart);
187 mode_var = fw_getenv(mode_var_name);
189 while (mode_var[0] >= '0' && mode_var[0] <= '9') {
191 baud += mode_var[0] - '0';
194 if (mode_var[0] == ',')
197 parity = mode_var[0];
198 if (mode_var[0] == ',')
201 stop_bits = mode_var[0] - '0';
202 if (mode_var[0] == ',')
204 if (!strcmp(mode_var, "hw"))
211 if (parity != 'e' && parity != 'n' && parity != 'o')
214 if (stop_bits != 7 && stop_bits != 8)
217 WARN_ON(snprintf(path, sizeof(path), "serial%u:%u%c%u%s",
218 uart, baud, parity, stop_bits,
219 hw_flow ? "r" : "") >= sizeof(path));
221 /* find or add chosen node */
222 chosen_off = fdt_path_offset(fdt, "/chosen");
223 if (chosen_off == -FDT_ERR_NOTFOUND)
224 chosen_off = fdt_path_offset(fdt, "/chosen@0");
225 if (chosen_off == -FDT_ERR_NOTFOUND)
226 chosen_off = fdt_add_subnode(fdt, 0, "chosen");
227 if (chosen_off < 0) {
228 pr_err("Unable to find or add DT chosen node: %d\n",
233 err = fdt_setprop_string(fdt, chosen_off, "stdout-path", path);
235 pr_err("Unable to set stdout-path property: %d\n", err);