arch/mips/bcm47xx/prom.c

   1 /*
   2  *  Copyright (C) 2004 Florian Schirmer <jolt@tuxbox.org>
   3  *  Copyright (C) 2007 Aurelien Jarno <aurelien@aurel32.net>
   4  *  Copyright (C) 2010-2012 Hauke Mehrtens <hauke@hauke-m.de>
   5  *
   6  *  This program is free software; you can redistribute  it and/or modify it
   7  *  under  the terms of  the GNU General  Public License as published by the
   8  *  Free Software Foundation;  either version 2 of the  License, or (at your
   9  *  option) any later version.
  10  *
  11  *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
  12  *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
  13  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  14  *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
  15  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  16  *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
  17  *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  18  *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
  19  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  20  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  21  *
  22  *  You should have received a copy of the  GNU General Public License along
  23  *  with this program; if not, write  to the Free Software Foundation, Inc.,
  24  *  675 Mass Ave, Cambridge, MA 02139, USA.
  25  */
  26
  27 #include <linux/init.h>
  28 #include <linux/types.h>
  29 #include <linux/kernel.h>
  30 #include <linux/spinlock.h>
  31 #include <linux/ssb/ssb_driver_chipcommon.h>
  32 #include <linux/ssb/ssb_regs.h>
  33 #include <linux/smp.h>
  34 #include <asm/bootinfo.h>
  35 #include <bcm47xx.h>
  36 #include <bcm47xx_board.h>
  37
  38
  39 static char bcm47xx_system_type[20] = "Broadcom BCM47XX";
  40
  41 const char *get_system_type(void)
  42 {
  43         return bcm47xx_system_type;
  44 }
  45
  46 __init void bcm47xx_set_system_type(u16 chip_id)
  47 {
  48         snprintf(bcm47xx_system_type, sizeof(bcm47xx_system_type),
  49                  (chip_id > 0x9999) ? "Broadcom BCM%d" :
  50                                       "Broadcom BCM%04X",
  51                  chip_id);
  52 }
  53
  54 static __init void prom_init_mem(void)
  55 {
  56         unsigned long mem;
  57         unsigned long max;
  58         unsigned long off;
  59         struct cpuinfo_mips *c = &current_cpu_data;
  60
  61         /* Figure out memory size by finding aliases.
  62          *
  63          * We should theoretically use the mapping from CFE using cfe_enummem().
  64          * However as the BCM47XX is mostly used on low-memory systems, we
  65          * want to reuse the memory used by CFE (around 4MB). That means cfe_*
  66          * functions stop to work at some point during the boot, we should only
  67          * call them at the beginning of the boot.
  68          *
  69          * BCM47XX uses 128MB for addressing the ram, if the system contains
  70          * less that that amount of ram it remaps the ram more often into the
  71          * available space.
  72          * Accessing memory after 128MB will cause an exception.
  73          * max contains the biggest possible address supported by the platform.
  74          * If the method wants to try something above we assume 128MB ram.
  75          */
  76         off = (unsigned long)prom_init;
  77         max = off | ((128 << 20) - 1);
  78         for (mem = (1 << 20); mem < (128 << 20); mem += (1 << 20)) {
  79                 if ((off + mem) > max) {
  80                         mem = (128 << 20);
  81                         printk(KERN_DEBUG "assume 128MB RAM\n");
  82                         break;
  83                 }
  84                 if (!memcmp(prom_init, prom_init + mem, 32))
  85                         break;
  86         }
  87
  88         /* Ignoring the last page when ddr size is 128M. Cached
  89          * accesses to last page is causing the processor to prefetch
  90          * using address above 128M stepping out of the ddr address
  91          * space.
  92          */
  93         if (c->cputype == CPU_74K && (mem == (128  << 20)))
  94                 mem -= 0x1000;
  95
  96         add_memory_region(0, mem, BOOT_MEM_RAM);
  97 }
  98
  99 /*
 100  * This is the first serial on the chip common core, it is at this position
 101  * for sb (ssb) and ai (bcma) bus.
 102  */
 103 #define BCM47XX_SERIAL_ADDR (SSB_ENUM_BASE + SSB_CHIPCO_UART0_DATA)
 104
 105 void __init prom_init(void)
 106 {
 107         prom_init_mem();
 108         setup_8250_early_printk_port(CKSEG1ADDR(BCM47XX_SERIAL_ADDR), 0, 0);
 109 }
 110
 111 void __init prom_free_prom_memory(void)
 112 {
 113 }