linux/arch/mips/kernel/csrc-bcm1480.c
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   1/*
   2 * Copyright (C) 2000,2001,2004 Broadcom Corporation
   3 *
   4 * This program is free software; you can redistribute it and/or
   5 * modify it under the terms of the GNU General Public License
   6 * as published by the Free Software Foundation; either version 2
   7 * of the License, or (at your option) any later version.
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write to the Free Software
  16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17 */
  18#include <linux/clocksource.h>
  19
  20#include <asm/addrspace.h>
  21#include <asm/io.h>
  22#include <asm/time.h>
  23
  24#include <asm/sibyte/bcm1480_regs.h>
  25#include <asm/sibyte/sb1250_regs.h>
  26#include <asm/sibyte/bcm1480_int.h>
  27#include <asm/sibyte/bcm1480_scd.h>
  28
  29#include <asm/sibyte/sb1250.h>
  30
  31static cycle_t bcm1480_hpt_read(struct clocksource *cs)
  32{
  33        return (cycle_t) __raw_readq(IOADDR(A_SCD_ZBBUS_CYCLE_COUNT));
  34}
  35
  36struct clocksource bcm1480_clocksource = {
  37        .name   = "zbbus-cycles",
  38        .rating = 200,
  39        .read   = bcm1480_hpt_read,
  40        .mask   = CLOCKSOURCE_MASK(64),
  41        .flags  = CLOCK_SOURCE_IS_CONTINUOUS,
  42};
  43
  44void __init sb1480_clocksource_init(void)
  45{
  46        struct clocksource *cs = &bcm1480_clocksource;
  47        unsigned int plldiv;
  48        unsigned long zbbus;
  49
  50        plldiv = G_BCM1480_SYS_PLL_DIV(__raw_readq(IOADDR(A_SCD_SYSTEM_CFG)));
  51        zbbus = ((plldiv >> 1) * 50000000) + ((plldiv & 1) * 25000000);
  52        clocksource_set_clock(cs, zbbus);
  53        clocksource_register(cs);
  54}
  55