arch/nios2/kernel/prom.c

   1 /*
   2  * Device tree support
   3  *
   4  * Copyright (C) 2013, 2015 Altera Corporation
   5  * Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw>
   6  *
   7  * Based on MIPS support for CONFIG_OF device tree support
   8  *
   9  * Copyright (C) 2010 Cisco Systems Inc. <dediao@cisco.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23  *
  24  */
  25
  26 #include <linux/init.h>
  27 #include <linux/types.h>
  28 #include <linux/bootmem.h>
  29 #include <linux/of.h>
  30 #include <linux/of_fdt.h>
  31 #include <linux/io.h>
  32
  33 #include <asm/prom.h>
  34 #include <asm/sections.h>
  35
  36 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
  37 {
  38         u64 kernel_start = (u64)virt_to_phys(_text);
  39
  40         if (!memory_size &&
  41             (kernel_start >= base) && (kernel_start < (base + size)))
  42                 memory_size = size;
  43
  44 }
  45
  46 void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
  47 {
  48         return alloc_bootmem_align(size, align);
  49 }
  50
  51 void __init early_init_devtree(void *params)
  52 {
  53         __be32 *dtb = (u32 *)__dtb_start;
  54 #if defined(CONFIG_NIOS2_DTB_AT_PHYS_ADDR)
  55         if (be32_to_cpup((__be32 *)CONFIG_NIOS2_DTB_PHYS_ADDR) ==
  56                  OF_DT_HEADER) {
  57                 params = (void *)CONFIG_NIOS2_DTB_PHYS_ADDR;
  58                 early_init_dt_scan(params);
  59                 return;
  60         }
  61 #endif
  62         if (be32_to_cpu((__be32) *dtb) == OF_DT_HEADER)
  63                 params = (void *)__dtb_start;
  64
  65         early_init_dt_scan(params);
  66 }
  67
  68 #ifdef CONFIG_EARLY_PRINTK
  69 static int __init early_init_dt_scan_serial(unsigned long node,
  70                         const char *uname, int depth, void *data)
  71 {
  72         u64 *addr64 = (u64 *) data;
  73         const char *p;
  74
  75         /* only consider serial nodes */
  76         if (strncmp(uname, "serial", 6) != 0)
  77                 return 0;
  78
  79         p = of_get_flat_dt_prop(node, "compatible", NULL);
  80         if (!p)
  81                 return 0;
  82
  83         /*
  84          * We found an altera_jtaguart but it wasn't configured for console, so
  85          * skip it.
  86          */
  87 #ifndef CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE
  88         if (strncmp(p, "altr,juart", 10) == 0)
  89                 return 0;
  90 #endif
  91
  92         /*
  93          * Same for altera_uart.
  94          */
  95 #ifndef CONFIG_SERIAL_ALTERA_UART_CONSOLE
  96         if (strncmp(p, "altr,uart", 9) == 0)
  97                 return 0;
  98 #endif
  99
 100         *addr64 = of_flat_dt_translate_address(node);
 101
 102         return *addr64 == OF_BAD_ADDR ? 0 : 1;
 103 }
 104
 105 unsigned long __init of_early_console(void)
 106 {
 107         u64 base = 0;
 108
 109         if (of_scan_flat_dt(early_init_dt_scan_serial, &base))
 110                 return (u32)ioremap(base, 32);
 111         else
 112                 return 0;
 113 }
 114 #endif /* CONFIG_EARLY_PRINTK */