time.c 791 B

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * Cobalt time initialization.
  4. *
  5. * Copyright (C) 2007 Yoichi Yuasa <[email protected]>
  6. */
  7. #include <linux/i8253.h>
  8. #include <linux/init.h>
  9. #include <asm/gt64120.h>
  10. #include <asm/time.h>
  11. #define GT641XX_BASE_CLOCK 50000000 /* 50MHz */
  12. void __init plat_time_init(void)
  13. {
  14. u32 start, end;
  15. int i = HZ / 10;
  16. setup_pit_timer();
  17. gt641xx_set_base_clock(GT641XX_BASE_CLOCK);
  18. /*
  19. * MIPS counter frequency is measured during a 100msec interval
  20. * using GT64111 timer0.
  21. */
  22. while (!gt641xx_timer0_state())
  23. ;
  24. start = read_c0_count();
  25. while (i--)
  26. while (!gt641xx_timer0_state())
  27. ;
  28. end = read_c0_count();
  29. mips_hpt_frequency = (end - start) * 10;
  30. printk(KERN_INFO "MIPS counter frequency %dHz\n", mips_hpt_frequency);
  31. }