mips/ar7/prom.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Carsten Langgaard, carstenl@mips.com
0004  * Copyright (C) 1999,2000 MIPS Technologies, Inc.  All rights reserved.
0005  *
0006  * Putting things on the screen/serial line using YAMONs facilities.
0007  */
0008 #include <linux/init.h>
0009 #include <linux/kernel.h>
0010 #include <linux/serial_reg.h>
0011 #include <linux/spinlock.h>
0012 #include <linux/export.h>
0013 #include <linux/string.h>
0014 #include <linux/io.h>
0015 #include <asm/bootinfo.h>
0016 #include <asm/setup.h>
0017
0018 #include <asm/mach-ar7/ar7.h>
0019 #include <asm/mach-ar7/prom.h>
0020
0021 #define MAX_ENTRY 80
0022
0023 struct env_var {
0024     char    *name;
0025     char    *value;
0026 };
0027
0028 static struct env_var adam2_env[MAX_ENTRY];
0029
0030 char *prom_getenv(const char *name)
0031 {
0032     int i;
0033
0034     for (i = 0; (i < MAX_ENTRY) && adam2_env[i].name; i++)
0035         if (!strcmp(name, adam2_env[i].name))
0036             return adam2_env[i].value;
0037
0038     return NULL;
0039 }
0040 EXPORT_SYMBOL(prom_getenv);
0041
0042 static void  __init ar7_init_cmdline(int argc, char *argv[])
0043 {
0044     int i;
0045
0046     for (i = 1; i < argc; i++) {
0047         strlcat(arcs_cmdline, argv[i], COMMAND_LINE_SIZE);
0048         if (i < (argc - 1))
0049             strlcat(arcs_cmdline, " ", COMMAND_LINE_SIZE);
0050     }
0051 }
0052
0053 struct psbl_rec {
0054     u32 psbl_size;
0055     u32 env_base;
0056     u32 env_size;
0057     u32 ffs_base;
0058     u32 ffs_size;
0059 };
0060
0061 static const char psp_env_version[] __initconst = "TIENV0.8";
0062
0063 struct psp_env_chunk {
0064     u8  num;
0065     u8  ctrl;
0066     u16 csum;
0067     u8  len;
0068     char    data[11];
0069 } __packed;
0070
0071 struct psp_var_map_entry {
0072     u8  num;
0073     char    *value;
0074 };
0075
0076 static const struct psp_var_map_entry psp_var_map[] = {
0077     {  1,   "cpufrequency" },
0078     {  2,   "memsize" },
0079     {  3,   "flashsize" },
0080     {  4,   "modetty0" },
0081     {  5,   "modetty1" },
0082     {  8,   "maca" },
0083     {  9,   "macb" },
0084     { 28,   "sysfrequency" },
0085     { 38,   "mipsfrequency" },
0086 };
0087
0088 /*
0089
0090 Well-known variable (num is looked up in table above for matching variable name)
0091 Example: cpufrequency=211968000
0092 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
0093 | 01 |CTRL|CHECKSUM | 01 | _2 | _1 | _1 | _9 | _6 | _8 | _0 | _0 | _0 | \0 | FF
0094 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
0095
0096 Name=Value pair in a single chunk
0097 Example: NAME=VALUE
0098 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
0099 | 00 |CTRL|CHECKSUM | 01 | _N | _A | _M | _E | _0 | _V | _A | _L | _U | _E | \0
0100 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
0101
0102 Name=Value pair in 2 chunks (len is the number of chunks)
0103 Example: bootloaderVersion=1.3.7.15
0104 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
0105 | 00 |CTRL|CHECKSUM | 02 | _b | _o | _o | _t | _l | _o | _a | _d | _e | _r | _V
0106 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
0107 | _e | _r | _s | _i | _o | _n | \0 | _1 | _. | _3 | _. | _7 | _. | _1 | _5 | \0
0108 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
0109
0110 Data is padded with 0xFF
0111
0112 */
0113
0114 #define PSP_ENV_SIZE  4096
0115
0116 static char psp_env_data[PSP_ENV_SIZE] = { 0, };
0117
0118 static char * __init lookup_psp_var_map(u8 num)
0119 {
0120     int i;
0121
0122     for (i = 0; i < ARRAY_SIZE(psp_var_map); i++)
0123         if (psp_var_map[i].num == num)
0124             return psp_var_map[i].value;
0125
0126     return NULL;
0127 }
0128
0129 static void __init add_adam2_var(char *name, char *value)
0130 {
0131     int i;
0132
0133     for (i = 0; i < MAX_ENTRY; i++) {
0134         if (!adam2_env[i].name) {
0135             adam2_env[i].name = name;
0136             adam2_env[i].value = value;
0137             return;
0138         } else if (!strcmp(adam2_env[i].name, name)) {
0139             adam2_env[i].value = value;
0140             return;
0141         }
0142     }
0143 }
0144
0145 static int __init parse_psp_env(void *psp_env_base)
0146 {
0147     int i, n;
0148     char *name, *value;
0149     struct psp_env_chunk *chunks = (struct psp_env_chunk *)psp_env_data;
0150
0151     memcpy_fromio(chunks, psp_env_base, PSP_ENV_SIZE);
0152
0153     i = 1;
0154     n = PSP_ENV_SIZE / sizeof(struct psp_env_chunk);
0155     while (i < n) {
0156         if ((chunks[i].num == 0xff) || ((i + chunks[i].len) > n))
0157             break;
0158         value = chunks[i].data;
0159         if (chunks[i].num) {
0160             name = lookup_psp_var_map(chunks[i].num);
0161         } else {
0162             name = value;
0163             value += strlen(name) + 1;
0164         }
0165         if (name)
0166             add_adam2_var(name, value);
0167         i += chunks[i].len;
0168     }
0169     return 0;
0170 }
0171
0172 static void __init ar7_init_env(struct env_var *env)
0173 {
0174     int i;
0175     struct psbl_rec *psbl = (struct psbl_rec *)(KSEG1ADDR(0x14000300));
0176     void *psp_env = (void *)KSEG1ADDR(psbl->env_base);
0177
0178     if (strcmp(psp_env, psp_env_version) == 0) {
0179         parse_psp_env(psp_env);
0180     } else {
0181         for (i = 0; i < MAX_ENTRY; i++, env++)
0182             if (env->name)
0183                 add_adam2_var(env->name, env->value);
0184     }
0185 }
0186
0187 static void __init console_config(void)
0188 {
0189 #ifdef CONFIG_SERIAL_8250_CONSOLE
0190     char console_string[40];
0191     int baud = 0;
0192     char parity = '\0', bits = '\0', flow = '\0';
0193     char *s, *p;
0194
0195     if (strstr(arcs_cmdline, "console="))
0196         return;
0197
0198     s = prom_getenv("modetty0");
0199     if (s) {
0200         baud = simple_strtoul(s, &p, 10);
0201         s = p;
0202         if (*s == ',')
0203             s++;
0204         if (*s)
0205             parity = *s++;
0206         if (*s == ',')
0207             s++;
0208         if (*s)
0209             bits = *s++;
0210         if (*s == ',')
0211             s++;
0212         if (*s == 'h')
0213             flow = 'r';
0214     }
0215
0216     if (baud == 0)
0217         baud = 38400;
0218     if (parity != 'n' && parity != 'o' && parity != 'e')
0219         parity = 'n';
0220     if (bits != '7' && bits != '8')
0221         bits = '8';
0222
0223     if (flow == 'r')
0224         sprintf(console_string, " console=ttyS0,%d%c%c%c", baud,
0225             parity, bits, flow);
0226     else
0227         sprintf(console_string, " console=ttyS0,%d%c%c", baud, parity,
0228             bits);
0229     strlcat(arcs_cmdline, console_string, COMMAND_LINE_SIZE);
0230 #endif
0231 }
0232
0233 void __init prom_init(void)
0234 {
0235     ar7_init_cmdline(fw_arg0, (char **)fw_arg1);
0236     ar7_init_env((struct env_var *)fw_arg2);
0237     console_config();
0238 }
0239
0240 #define PORT(offset) (KSEG1ADDR(AR7_REGS_UART0 + (offset * 4)))
0241 static inline unsigned int serial_in(int offset)
0242 {
0243     return readl((void *)PORT(offset));
0244 }
0245
0246 static inline void serial_out(int offset, int value)
0247 {
0248     writel(value, (void *)PORT(offset));
0249 }
0250
0251 void prom_putchar(char c)
0252 {
0253     while ((serial_in(UART_LSR) & UART_LSR_TEMT) == 0)
0254         ;
0255     serial_out(UART_TX, c);
0256 }