time.c 4.9 KB

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  1. /*
  2. * linux/arch/m32r/kernel/time.c
  3. *
  4. * Copyright (c) 2001, 2002 Hiroyuki Kondo, Hirokazu Takata,
  5. * Hitoshi Yamamoto
  6. * Taken from i386 version.
  7. * Copyright (C) 1991, 1992, 1995 Linus Torvalds
  8. * Copyright (C) 1996, 1997, 1998 Ralf Baechle
  9. *
  10. * This file contains the time handling details for PC-style clocks as
  11. * found in some MIPS systems.
  12. *
  13. * Some code taken from sh version.
  14. * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
  15. * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
  16. */
  17. #undef DEBUG_TIMER
  18. #include <linux/errno.h>
  19. #include <linux/init.h>
  20. #include <linux/module.h>
  21. #include <linux/sched.h>
  22. #include <linux/kernel.h>
  23. #include <linux/param.h>
  24. #include <linux/string.h>
  25. #include <linux/mm.h>
  26. #include <linux/interrupt.h>
  27. #include <linux/profile.h>
  28. #include <asm/io.h>
  29. #include <asm/m32r.h>
  30. #include <asm/hw_irq.h>
  31. #if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE)
  32. /* this needs a better home */
  33. DEFINE_SPINLOCK(rtc_lock);
  34. #ifdef CONFIG_RTC_DRV_CMOS_MODULE
  35. EXPORT_SYMBOL(rtc_lock);
  36. #endif
  37. #endif /* pc-style 'CMOS' RTC support */
  38. #ifdef CONFIG_SMP
  39. extern void smp_local_timer_interrupt(void);
  40. #endif
  41. #define TICK_SIZE (tick_nsec / 1000)
  42. /*
  43. * Change this if you have some constant time drift
  44. */
  45. /* This is for machines which generate the exact clock. */
  46. #define USECS_PER_JIFFY (1000000/HZ)
  47. static unsigned long latch;
  48. static u32 m32r_gettimeoffset(void)
  49. {
  50. unsigned long elapsed_time = 0; /* [us] */
  51. #if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) \
  52. || defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) \
  53. || defined(CONFIG_CHIP_OPSP) || defined(CONFIG_CHIP_M32104)
  54. #ifndef CONFIG_SMP
  55. unsigned long count;
  56. /* timer count may underflow right here */
  57. count = inl(M32R_MFT2CUT_PORTL);
  58. if (inl(M32R_ICU_CR18_PORTL) & 0x00000100) /* underflow check */
  59. count = 0;
  60. count = (latch - count) * TICK_SIZE;
  61. elapsed_time = DIV_ROUND_CLOSEST(count, latch);
  62. /* NOTE: LATCH is equal to the "interval" value (= reload count). */
  63. #else /* CONFIG_SMP */
  64. unsigned long count;
  65. static unsigned long p_jiffies = -1;
  66. static unsigned long p_count = 0;
  67. /* timer count may underflow right here */
  68. count = inl(M32R_MFT2CUT_PORTL);
  69. if (jiffies == p_jiffies && count > p_count)
  70. count = 0;
  71. p_jiffies = jiffies;
  72. p_count = count;
  73. count = (latch - count) * TICK_SIZE;
  74. elapsed_time = DIV_ROUND_CLOSEST(count, latch);
  75. /* NOTE: LATCH is equal to the "interval" value (= reload count). */
  76. #endif /* CONFIG_SMP */
  77. #elif defined(CONFIG_CHIP_M32310)
  78. #warning do_gettimeoffse not implemented
  79. #else
  80. #error no chip configuration
  81. #endif
  82. return elapsed_time * 1000;
  83. }
  84. /*
  85. * timer_interrupt() needs to keep up the real-time clock,
  86. * as well as call the "xtime_update()" routine every clocktick
  87. */
  88. static irqreturn_t timer_interrupt(int irq, void *dev_id)
  89. {
  90. #ifndef CONFIG_SMP
  91. profile_tick(CPU_PROFILING);
  92. #endif
  93. xtime_update(1);
  94. #ifndef CONFIG_SMP
  95. update_process_times(user_mode(get_irq_regs()));
  96. #endif
  97. /* As we return to user mode fire off the other CPU schedulers..
  98. this is basically because we don't yet share IRQ's around.
  99. This message is rigged to be safe on the 386 - basically it's
  100. a hack, so don't look closely for now.. */
  101. #ifdef CONFIG_SMP
  102. smp_local_timer_interrupt();
  103. smp_send_timer();
  104. #endif
  105. return IRQ_HANDLED;
  106. }
  107. static struct irqaction irq0 = {
  108. .handler = timer_interrupt,
  109. .name = "MFT2",
  110. };
  111. void read_persistent_clock(struct timespec *ts)
  112. {
  113. unsigned int epoch, year, mon, day, hour, min, sec;
  114. sec = min = hour = day = mon = year = 0;
  115. epoch = 0;
  116. year = 23;
  117. mon = 4;
  118. day = 17;
  119. /* Attempt to guess the epoch. This is the same heuristic as in rtc.c
  120. so no stupid things will happen to timekeeping. Who knows, maybe
  121. Ultrix also uses 1952 as epoch ... */
  122. if (year > 10 && year < 44)
  123. epoch = 1980;
  124. else if (year < 96)
  125. epoch = 1952;
  126. year += epoch;
  127. ts->tv_sec = mktime(year, mon, day, hour, min, sec);
  128. ts->tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
  129. }
  130. void __init time_init(void)
  131. {
  132. arch_gettimeoffset = m32r_gettimeoffset;
  133. #if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) \
  134. || defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) \
  135. || defined(CONFIG_CHIP_OPSP) || defined(CONFIG_CHIP_M32104)
  136. /* M32102 MFT setup */
  137. setup_irq(M32R_IRQ_MFT2, &irq0);
  138. {
  139. unsigned long bus_clock;
  140. unsigned short divide;
  141. bus_clock = boot_cpu_data.bus_clock;
  142. divide = boot_cpu_data.timer_divide;
  143. latch = DIV_ROUND_CLOSEST(bus_clock/divide, HZ);
  144. printk("Timer start : latch = %ld\n", latch);
  145. outl((M32R_MFTMOD_CC_MASK | M32R_MFTMOD_TCCR \
  146. |M32R_MFTMOD_CSSEL011), M32R_MFT2MOD_PORTL);
  147. outl(latch, M32R_MFT2RLD_PORTL);
  148. outl(latch, M32R_MFT2CUT_PORTL);
  149. outl(0, M32R_MFT2CMPRLD_PORTL);
  150. outl((M32R_MFTCR_MFT2MSK|M32R_MFTCR_MFT2EN), M32R_MFTCR_PORTL);
  151. }
  152. #elif defined(CONFIG_CHIP_M32310)
  153. #warning time_init not implemented
  154. #else
  155. #error no chip configuration
  156. #endif
  157. }