1 /* 2 * Copyright (C) 2016 Imagination Technologies 3 * Author: Paul Burton <paul.burton@mips.com> 4 * 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. 9 */ 10 11 #define pr_fmt(fmt) "yamon-dt: " fmt 12 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> 18 19 #include <asm/fw/fw.h> 20 #include <asm/yamon-dt.h> 21 22 #define MAX_MEM_ARRAY_ENTRIES 2 23 24 __init int yamon_dt_append_cmdline(void *fdt) 25 { 26 int err, chosen_off; 27 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"); 34 if (chosen_off < 0) { 35 pr_err("Unable to find or add DT chosen node: %d\n", 36 chosen_off); 37 return chosen_off; 38 } 39 40 err = fdt_setprop_string(fdt, chosen_off, "bootargs", fw_getcmdline()); 41 if (err) { 42 pr_err("Unable to set bootargs property: %d\n", err); 43 return err; 44 } 45 46 return 0; 47 } 48 49 static unsigned int __init gen_fdt_mem_array( 50 const struct yamon_mem_region *regions, 51 __be32 *mem_array, 52 unsigned int max_entries, 53 unsigned long memsize) 54 { 55 const struct yamon_mem_region *mr; 56 unsigned long size; 57 unsigned int entries = 0; 58 59 for (mr = regions; mr->size && memsize; ++mr) { 60 if (entries >= max_entries) { 61 pr_warn("Number of regions exceeds max %u\n", 62 max_entries); 63 break; 64 } 65 66 /* How much of the remaining RAM fits in the next region? */ 67 size = min_t(unsigned long, memsize, mr->size); 68 memsize -= size; 69 70 /* Emit a memory region */ 71 *(mem_array++) = cpu_to_be32(mr->start); 72 *(mem_array++) = cpu_to_be32(size); 73 ++entries; 74 75 /* Discard the next mr->discard bytes */ 76 memsize -= min_t(unsigned long, memsize, mr->discard); 77 } 78 return entries; 79 } 80 81 __init int yamon_dt_append_memory(void *fdt, 82 const struct yamon_mem_region *regions) 83 { 84 unsigned long phys_memsize, memsize; 85 __be32 mem_array[2 * MAX_MEM_ARRAY_ENTRIES]; 86 unsigned int mem_entries; 87 int i, err, mem_off; 88 char *var, param_name[10], *var_names[] = { 89 "ememsize", "memsize", 90 }; 91 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]); 95 if (!var) 96 continue; 97 98 err = kstrtoul(var, 0, &phys_memsize); 99 if (!err) 100 break; 101 102 pr_warn("Failed to read the '%s' env variable '%s'\n", 103 var_names[i], var); 104 } 105 106 if (!phys_memsize) { 107 pr_warn("The bootloader didn't provide memsize: defaulting to 32MB\n"); 108 phys_memsize = 32 << 20; 109 } 110 111 /* default to using all available RAM */ 112 memsize = phys_memsize; 113 114 /* 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); 118 if (!var) 119 continue; 120 121 memsize = memparse(var + strlen(param_name), NULL); 122 } 123 124 /* if the user says there's more RAM than we thought, believe them */ 125 phys_memsize = max_t(unsigned long, phys_memsize, memsize); 126 127 /* 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"); 131 if (mem_off < 0) { 132 pr_err("Unable to find or add memory DT node: %d\n", mem_off); 133 return mem_off; 134 } 135 136 err = fdt_setprop_string(fdt, mem_off, "device_type", "memory"); 137 if (err) { 138 pr_err("Unable to set memory node device_type: %d\n", err); 139 return err; 140 } 141 142 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])); 146 if (err) { 147 pr_err("Unable to set memory regs property: %d\n", err); 148 return err; 149 } 150 151 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])); 155 if (err) { 156 pr_err("Unable to set linux,usable-memory property: %d\n", err); 157 return err; 158 } 159 160 return 0; 161 } 162 163 __init int yamon_dt_serial_config(void *fdt) 164 { 165 const char *yamontty, *mode_var; 166 char mode_var_name[9], path[20], parity; 167 unsigned int uart, baud, stop_bits; 168 bool hw_flow; 169 int chosen_off, err; 170 171 yamontty = fw_getenv("yamontty"); 172 if (!yamontty || !strcmp(yamontty, "tty0")) { 173 uart = 0; 174 } else if (!strcmp(yamontty, "tty1")) { 175 uart = 1; 176 } else { 177 pr_warn("yamontty environment variable '%s' invalid\n", 178 yamontty); 179 uart = 0; 180 } 181 182 baud = stop_bits = 0; 183 parity = 0; 184 hw_flow = false; 185 186 snprintf(mode_var_name, sizeof(mode_var_name), "modetty%u", uart); 187 mode_var = fw_getenv(mode_var_name); 188 if (mode_var) { 189 while (mode_var[0] >= '0' && mode_var[0] <= '9') { 190 baud *= 10; 191 baud += mode_var[0] - '0'; 192 mode_var++; 193 } 194 if (mode_var[0] == ',') 195 mode_var++; 196 if (mode_var[0]) 197 parity = mode_var[0]; 198 if (mode_var[0] == ',') 199 mode_var++; 200 if (mode_var[0]) 201 stop_bits = mode_var[0] - '0'; 202 if (mode_var[0] == ',') 203 mode_var++; 204 if (!strcmp(mode_var, "hw")) 205 hw_flow = true; 206 } 207 208 if (!baud) 209 baud = 38400; 210 211 if (parity != 'e' && parity != 'n' && parity != 'o') 212 parity = 'n'; 213 214 if (stop_bits != 7 && stop_bits != 8) 215 stop_bits = 8; 216 217 WARN_ON(snprintf(path, sizeof(path), "serial%u:%u%c%u%s", 218 uart, baud, parity, stop_bits, 219 hw_flow ? "r" : "") >= sizeof(path)); 220 221 /* 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", 229 chosen_off); 230 return chosen_off; 231 } 232 233 err = fdt_setprop_string(fdt, chosen_off, "stdout-path", path); 234 if (err) { 235 pr_err("Unable to set stdout-path property: %d\n", err); 236 return err; 237 } 238 239 return 0; 240 } 241