src/soc/samsung/exynos5420/timer.c

   1 /*
   2  * This file is part of the coreboot project.
   3  *
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; version 2 of the License.
   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
  15 #include <device/mmio.h>
  16 #include <delay.h>
  17 #include <soc/clk.h>
  18 #include <stdint.h>
  19 #include <timer.h>
  20
  21 static const uint32_t clocks_per_usec = MCT_HZ/1000000;
  22
  23 static uint64_t mct_raw_value(void)
  24 {
  25         uint64_t upper = read32(&exynos_mct->g_cnt_u);
  26         uint64_t lower = read32(&exynos_mct->g_cnt_l);
  27
  28         return (upper << 32) | lower;
  29 }
  30
  31 void init_timer(void)
  32 {
  33         write32(&exynos_mct->g_tcon, read32(&exynos_mct->g_tcon) | (0x1 << 8));
  34 }
  35
  36 void timer_monotonic_get(struct mono_time *mt)
  37 {
  38         /* We don't have to call mct_start() here
  39          * because it was already called in the bootblock
  40          */
  41
  42         mono_time_set_usecs(mt, mct_raw_value() / clocks_per_usec);
  43 }