ip30-timer.c 1.6 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * ip30-timer.c: Clocksource/clockevent support for the
  4. * HEART chip in SGI Octane (IP30) systems.
  5. *
  6. * Copyright (C) 2004-2007 Stanislaw Skowronek <skylark@unaligned.org>
  7. * Copyright (C) 2009 Johannes Dickgreber <tanzy@gmx.de>
  8. * Copyright (C) 2011 Joshua Kinard <kumba@gentoo.org>
  9. */
  10. #include <linux/clocksource.h>
  11. #include <linux/cpumask.h>
  12. #include <linux/init.h>
  13. #include <linux/kernel.h>
  14. #include <linux/percpu.h>
  15. #include <linux/sched_clock.h>
  16. #include <asm/time.h>
  17. #include <asm/cevt-r4k.h>
  18. #include <asm/sgi/heart.h>
  19. static u64 ip30_heart_counter_read(struct clocksource *cs)
  20. {
  21. return heart_read(&heart_regs->count);
  22. }
  23. struct clocksource ip30_heart_clocksource = {
  24. .name = "HEART",
  25. .rating = 400,
  26. .read = ip30_heart_counter_read,
  27. .mask = CLOCKSOURCE_MASK(52),
  28. .flags = (CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_VALID_FOR_HRES),
  29. };
  30. static u64 notrace ip30_heart_read_sched_clock(void)
  31. {
  32. return heart_read(&heart_regs->count);
  33. }
  34. static void __init ip30_heart_clocksource_init(void)
  35. {
  36. struct clocksource *cs = &ip30_heart_clocksource;
  37. clocksource_register_hz(cs, HEART_CYCLES_PER_SEC);
  38. sched_clock_register(ip30_heart_read_sched_clock, 52,
  39. HEART_CYCLES_PER_SEC);
  40. }
  41. void __init plat_time_init(void)
  42. {
  43. int irq = get_c0_compare_int();
  44. cp0_timer_irq_installed = 1;
  45. c0_compare_irqaction.percpu_dev_id = &mips_clockevent_device;
  46. c0_compare_irqaction.flags &= ~IRQF_SHARED;
  47. irq_set_handler(irq, handle_percpu_devid_irq);
  48. irq_set_percpu_devid(irq);
  49. setup_percpu_irq(irq, &c0_compare_irqaction);
  50. enable_percpu_irq(irq, IRQ_TYPE_NONE);
  51. ip30_heart_clocksource_init();
  52. }