release/src-rt-6.x.4708/linux/linux-2.6.36/arch/mips/kernel/csrc-r4k.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2007 by Ralf Baechle
   7  */
   8 #include <linux/clocksource.h>
   9 #include <linux/init.h>
  10
  11 #include <asm/time.h>
  12
  13 static cycle_t c0_hpt_read(struct clocksource *cs)
  14 {
  15         return read_c0_count();
  16 }
  17
  18 static struct clocksource clocksource_mips = {
  19         .name           = "MIPS",
  20         .read           = c0_hpt_read,
  21         .mask           = CLOCKSOURCE_MASK(32),
  22         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
  23 };
  24
  25 int __init init_r4k_clocksource(void)
  26 {
  27         if (!cpu_has_counter || !mips_hpt_frequency)
  28                 return -ENXIO;
  29
  30         /* Calculate a somewhat reasonable rating value */
  31         clocksource_mips.rating = 200 + mips_hpt_frequency / 10000000;
  32
  33         clocksource_set_clock(&clocksource_mips, mips_hpt_frequency);
  34
  35         clocksource_register(&clocksource_mips);
  36
  37         return 0;
  38 }