arch/mips/ar7/prom.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Carsten Langgaard, carstenl@mips.com
   4  * Copyright (C) 1999,2000 MIPS Technologies, Inc.  All rights reserved.
   5  *
   6  * Putting things on the screen/serial line using YAMONs facilities.
   7  */
   8 #include <linux/init.h>
   9 #include <linux/kernel.h>
  10 #include <linux/serial_reg.h>
  11 #include <linux/spinlock.h>
  12 #include <linux/export.h>
  13 #include <linux/string.h>
  14 #include <linux/io.h>
  15 #include <asm/bootinfo.h>
  16 #include <asm/setup.h>
  17
  18 #include <asm/mach-ar7/ar7.h>
  19 #include <asm/mach-ar7/prom.h>
  20
  21 #define MAX_ENTRY 80
  22
  23 struct env_var {
  24         char    *name;
  25         char    *value;
  26 };
  27
  28 static struct env_var adam2_env[MAX_ENTRY];
  29
  30 char *prom_getenv(const char *name)
  31 {
  32         int i;
  33
  34         for (i = 0; (i < MAX_ENTRY) && adam2_env[i].name; i++)
  35                 if (!strcmp(name, adam2_env[i].name))
  36                         return adam2_env[i].value;
  37
  38         return NULL;
  39 }
  40 EXPORT_SYMBOL(prom_getenv);
  41
  42 static void  __init ar7_init_cmdline(int argc, char *argv[])
  43 {
  44         int i;
  45
  46         for (i = 1; i < argc; i++) {
  47                 strlcat(arcs_cmdline, argv[i], COMMAND_LINE_SIZE);
  48                 if (i < (argc - 1))
  49                         strlcat(arcs_cmdline, " ", COMMAND_LINE_SIZE);
  50         }
  51 }
  52
  53 struct psbl_rec {
  54         u32     psbl_size;
  55         u32     env_base;
  56         u32     env_size;
  57         u32     ffs_base;
  58         u32     ffs_size;
  59 };
  60
  61 static const char psp_env_version[] __initconst = "TIENV0.8";
  62
  63 struct psp_env_chunk {
  64         u8      num;
  65         u8      ctrl;
  66         u16     csum;
  67         u8      len;
  68         char    data[11];
  69 } __packed;
  70
  71 struct psp_var_map_entry {
  72         u8      num;
  73         char    *value;
  74 };
  75
  76 static const struct psp_var_map_entry psp_var_map[] = {
  77         {  1,   "cpufrequency" },
  78         {  2,   "memsize" },
  79         {  3,   "flashsize" },
  80         {  4,   "modetty0" },
  81         {  5,   "modetty1" },
  82         {  8,   "maca" },
  83         {  9,   "macb" },
  84         { 28,   "sysfrequency" },
  85         { 38,   "mipsfrequency" },
  86 };
  87
  88 /*
  89
  90 Well-known variable (num is looked up in table above for matching variable name)
  91 Example: cpufrequency=211968000
  92 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
  93 | 01 |CTRL|CHECKSUM | 01 | _2 | _1 | _1 | _9 | _6 | _8 | _0 | _0 | _0 | \0 | FF
  94 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
  95
  96 Name=Value pair in a single chunk
  97 Example: NAME=VALUE
  98 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
  99 | 00 |CTRL|CHECKSUM | 01 | _N | _A | _M | _E | _0 | _V | _A | _L | _U | _E | \0
 100 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
 101
 102 Name=Value pair in 2 chunks (len is the number of chunks)
 103 Example: bootloaderVersion=1.3.7.15
 104 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
 105 | 00 |CTRL|CHECKSUM | 02 | _b | _o | _o | _t | _l | _o | _a | _d | _e | _r | _V
 106 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
 107 | _e | _r | _s | _i | _o | _n | \0 | _1 | _. | _3 | _. | _7 | _. | _1 | _5 | \0
 108 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
 109
 110 Data is padded with 0xFF
 111
 112 */
 113
 114 #define PSP_ENV_SIZE  4096
 115
 116 static char psp_env_data[PSP_ENV_SIZE] = { 0, };
 117
 118 static char * __init lookup_psp_var_map(u8 num)
 119 {
 120         int i;
 121
 122         for (i = 0; i < ARRAY_SIZE(psp_var_map); i++)
 123                 if (psp_var_map[i].num == num)
 124                         return psp_var_map[i].value;
 125
 126         return NULL;
 127 }
 128
 129 static void __init add_adam2_var(char *name, char *value)
 130 {
 131         int i;
 132
 133         for (i = 0; i < MAX_ENTRY; i++) {
 134                 if (!adam2_env[i].name) {
 135                         adam2_env[i].name = name;
 136                         adam2_env[i].value = value;
 137                         return;
 138                 } else if (!strcmp(adam2_env[i].name, name)) {
 139                         adam2_env[i].value = value;
 140                         return;
 141                 }
 142         }
 143 }
 144
 145 static int __init parse_psp_env(void *psp_env_base)
 146 {
 147         int i, n;
 148         char *name, *value;
 149         struct psp_env_chunk *chunks = (struct psp_env_chunk *)psp_env_data;
 150
 151         memcpy_fromio(chunks, psp_env_base, PSP_ENV_SIZE);
 152
 153         i = 1;
 154         n = PSP_ENV_SIZE / sizeof(struct psp_env_chunk);
 155         while (i < n) {
 156                 if ((chunks[i].num == 0xff) || ((i + chunks[i].len) > n))
 157                         break;
 158                 value = chunks[i].data;
 159                 if (chunks[i].num) {
 160                         name = lookup_psp_var_map(chunks[i].num);
 161                 } else {
 162                         name = value;
 163                         value += strlen(name) + 1;
 164                 }
 165                 if (name)
 166                         add_adam2_var(name, value);
 167                 i += chunks[i].len;
 168         }
 169         return 0;
 170 }
 171
 172 static void __init ar7_init_env(struct env_var *env)
 173 {
 174         int i;
 175         struct psbl_rec *psbl = (struct psbl_rec *)(KSEG1ADDR(0x14000300));
 176         void *psp_env = (void *)KSEG1ADDR(psbl->env_base);
 177
 178         if (strcmp(psp_env, psp_env_version) == 0) {
 179                 parse_psp_env(psp_env);
 180         } else {
 181                 for (i = 0; i < MAX_ENTRY; i++, env++)
 182                         if (env->name)
 183                                 add_adam2_var(env->name, env->value);
 184         }
 185 }
 186
 187 static void __init console_config(void)
 188 {
 189 #ifdef CONFIG_SERIAL_8250_CONSOLE
 190         char console_string[40];
 191         int baud = 0;
 192         char parity = '\0', bits = '\0', flow = '\0';
 193         char *s, *p;
 194
 195         if (strstr(arcs_cmdline, "console="))
 196                 return;
 197
 198         s = prom_getenv("modetty0");
 199         if (s) {
 200                 baud = simple_strtoul(s, &p, 10);
 201                 s = p;
 202                 if (*s == ',')
 203                         s++;
 204                 if (*s)
 205                         parity = *s++;
 206                 if (*s == ',')
 207                         s++;
 208                 if (*s)
 209                         bits = *s++;
 210                 if (*s == ',')
 211                         s++;
 212                 if (*s == 'h')
 213                         flow = 'r';
 214         }
 215
 216         if (baud == 0)
 217                 baud = 38400;
 218         if (parity != 'n' && parity != 'o' && parity != 'e')
 219                 parity = 'n';
 220         if (bits != '7' && bits != '8')
 221                 bits = '8';
 222
 223         if (flow == 'r')
 224                 sprintf(console_string, " console=ttyS0,%d%c%c%c", baud,
 225                         parity, bits, flow);
 226         else
 227                 sprintf(console_string, " console=ttyS0,%d%c%c", baud, parity,
 228                         bits);
 229         strlcat(arcs_cmdline, console_string, COMMAND_LINE_SIZE);
 230 #endif
 231 }
 232
 233 void __init prom_init(void)
 234 {
 235         ar7_init_cmdline(fw_arg0, (char **)fw_arg1);
 236         ar7_init_env((struct env_var *)fw_arg2);
 237         console_config();
 238 }
 239
 240 #define PORT(offset) (KSEG1ADDR(AR7_REGS_UART0 + (offset * 4)))
 241 static inline unsigned int serial_in(int offset)
 242 {
 243         return readl((void *)PORT(offset));
 244 }
 245
 246 static inline void serial_out(int offset, int value)
 247 {
 248         writel(value, (void *)PORT(offset));
 249 }
 250
 251 void prom_putchar(char c)
 252 {
 253         while ((serial_in(UART_LSR) & UART_LSR_TEMT) == 0)
 254                 ;
 255         serial_out(UART_TX, c);
 256 }