arch/microblaze/kernel/prom.c

   1 /*
   2  * Procedures for creating, accessing and interpreting the device tree.
   3  *
   4  * Paul Mackerras       August 1996.
   5  * Copyright (C) 1996-2005 Paul Mackerras.
   6  *
   7  *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
   8  *    {engebret|bergner}@us.ibm.com
   9  *
  10  *      This program is free software; you can redistribute it and/or
  11  *      modify it under the terms of the GNU General Public License
  12  *      as published by the Free Software Foundation; either version
  13  *      2 of the License, or (at your option) any later version.
  14  */
  15
  16 #include <stdarg.h>
  17 #include <linux/export.h>
  18 #include <linux/kernel.h>
  19 #include <linux/string.h>
  20 #include <linux/init.h>
  21 #include <linux/threads.h>
  22 #include <linux/spinlock.h>
  23 #include <linux/types.h>
  24 #include <linux/pci.h>
  25 #include <linux/stringify.h>
  26 #include <linux/delay.h>
  27 #include <linux/initrd.h>
  28 #include <linux/bitops.h>
  29 #include <linux/kexec.h>
  30 #include <linux/debugfs.h>
  31 #include <linux/irq.h>
  32 #include <linux/memblock.h>
  33 #include <linux/of_fdt.h>
  34
  35 #include <asm/prom.h>
  36 #include <asm/page.h>
  37 #include <asm/processor.h>
  38 #include <asm/irq.h>
  39 #include <linux/io.h>
  40 #include <asm/mmu.h>
  41 #include <asm/pgtable.h>
  42 #include <asm/sections.h>
  43 #include <asm/pci-bridge.h>
  44
  45 #ifdef CONFIG_EARLY_PRINTK
  46 static const char *stdout;
  47
  48 static int __init early_init_dt_scan_chosen_serial(unsigned long node,
  49                                 const char *uname, int depth, void *data)
  50 {
  51         int l;
  52         const char *p;
  53
  54         pr_debug("%s: depth: %d, uname: %s\n", __func__, depth, uname);
  55
  56         if (depth == 1 && (strcmp(uname, "chosen") == 0 ||
  57                                 strcmp(uname, "chosen@0") == 0)) {
  58                 p = of_get_flat_dt_prop(node, "linux,stdout-path", &l);
  59                 if (p != NULL && l > 0)
  60                         stdout = p; /* store pointer to stdout-path */
  61         }
  62
  63         if (stdout && strstr(stdout, uname)) {
  64                 p = of_get_flat_dt_prop(node, "compatible", &l);
  65                 pr_debug("Compatible string: %s\n", p);
  66
  67                 if ((strncmp(p, "xlnx,xps-uart16550", 18) == 0) ||
  68                         (strncmp(p, "xlnx,axi-uart16550", 18) == 0)) {
  69                         unsigned int addr;
  70
  71                         *(u32 *)data = UART16550;
  72
  73                         addr = *(u32 *)of_get_flat_dt_prop(node, "reg", &l);
  74                         addr += *(u32 *)of_get_flat_dt_prop(node,
  75                                                         "reg-offset", &l);
  76                         /* clear register offset */
  77                         return be32_to_cpu(addr) & ~3;
  78                 }
  79                 if ((strncmp(p, "xlnx,xps-uartlite", 17) == 0) ||
  80                                 (strncmp(p, "xlnx,opb-uartlite", 17) == 0) ||
  81                                 (strncmp(p, "xlnx,axi-uartlite", 17) == 0) ||
  82                                 (strncmp(p, "xlnx,mdm", 8) == 0)) {
  83                         const unsigned int *addrp;
  84
  85                         *(u32 *)data = UARTLITE;
  86
  87                         addrp = of_get_flat_dt_prop(node, "reg", &l);
  88                         return be32_to_cpup(addrp); /* return address */
  89                 }
  90         }
  91         return 0;
  92 }
  93
  94 /* this function is looking for early console - Microblaze specific */
  95 int __init of_early_console(void *version)
  96 {
  97         return of_scan_flat_dt(early_init_dt_scan_chosen_serial, version);
  98 }
  99 #endif
 100
 101 void __init early_init_devtree(void *params)
 102 {
 103         pr_debug(" -> early_init_devtree(%p)\n", params);
 104
 105         early_init_dt_scan(params);
 106         if (!strlen(boot_command_line))
 107                 strlcpy(boot_command_line, cmd_line, COMMAND_LINE_SIZE);
 108
 109         parse_early_param();
 110
 111         memblock_allow_resize();
 112
 113         pr_debug("Phys. mem: %lx\n", (unsigned long) memblock_phys_mem_size());
 114
 115         pr_debug(" <- early_init_devtree()\n");
 116 }