arch/mips/loongson32/common/prom.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (c) 2011 Zhang, Keguang <keguang.zhang@gmail.com>
   4  *
   5  * Modified from arch/mips/pnx833x/common/prom.c.
   6  */
   7
   8 #include <linux/serial_reg.h>
   9 #include <asm/bootinfo.h>
  10
  11 #include <loongson1.h>
  12 #include <prom.h>
  13
  14 int prom_argc;
  15 char **prom_argv, **prom_envp;
  16 unsigned long memsize, highmemsize;
  17
  18 char *prom_getenv(char *envname)
  19 {
  20         char **env = prom_envp;
  21         int i;
  22
  23         i = strlen(envname);
  24
  25         while (*env) {
  26                 if (strncmp(envname, *env, i) == 0 && *(*env + i) == '=')
  27                         return *env + i + 1;
  28                 env++;
  29         }
  30
  31         return 0;
  32 }
  33
  34 static inline unsigned long env_or_default(char *env, unsigned long dfl)
  35 {
  36         char *str = prom_getenv(env);
  37         return str ? simple_strtol(str, 0, 0) : dfl;
  38 }
  39
  40 void __init prom_init_cmdline(void)
  41 {
  42         char *c = &(arcs_cmdline[0]);
  43         int i;
  44
  45         for (i = 1; i < prom_argc; i++) {
  46                 strcpy(c, prom_argv[i]);
  47                 c += strlen(prom_argv[i]);
  48                 if (i < prom_argc - 1)
  49                         *c++ = ' ';
  50         }
  51         *c = 0;
  52 }
  53
  54 void __init prom_init(void)
  55 {
  56         void __iomem *uart_base;
  57         prom_argc = fw_arg0;
  58         prom_argv = (char **)fw_arg1;
  59         prom_envp = (char **)fw_arg2;
  60
  61         prom_init_cmdline();
  62
  63         memsize = env_or_default("memsize", DEFAULT_MEMSIZE);
  64         highmemsize = env_or_default("highmemsize", 0x0);
  65
  66         if (strstr(arcs_cmdline, "console=ttyS3"))
  67                 uart_base = ioremap_nocache(LS1X_UART3_BASE, 0x0f);
  68         else if (strstr(arcs_cmdline, "console=ttyS2"))
  69                 uart_base = ioremap_nocache(LS1X_UART2_BASE, 0x0f);
  70         else if (strstr(arcs_cmdline, "console=ttyS1"))
  71                 uart_base = ioremap_nocache(LS1X_UART1_BASE, 0x0f);
  72         else
  73                 uart_base = ioremap_nocache(LS1X_UART0_BASE, 0x0f);
  74         setup_8250_early_printk_port((unsigned long)uart_base, 0, 0);
  75 }
  76
  77 void __init prom_free_prom_memory(void)
  78 {
  79 }