arch/m68knommu/platform/5307/timers.c

   1 /***************************************************************************/
   2
   3 /*
   4  *      timers.c -- generic ColdFire hardware timer support.
   5  *
   6  *      Copyright (C) 1999-2006, Greg Ungerer (gerg@snapgear.com)
   7  */
   8
   9 /***************************************************************************/
  10
  11 #include <linux/kernel.h>
  12 #include <linux/sched.h>
  13 #include <linux/param.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/init.h>
  16 #include <asm/io.h>
  17 #include <asm/irq.h>
  18 #include <asm/traps.h>
  19 #include <asm/machdep.h>
  20 #include <asm/coldfire.h>
  21 #include <asm/mcftimer.h>
  22 #include <asm/mcfsim.h>
  23
  24 /***************************************************************************/
  25
  26 /*
  27  *      By default use timer1 as the system clock timer.
  28  */
  29 #define TA(a)   (MCF_MBAR + MCFTIMER_BASE1 + (a))
  30
  31 /*
  32  *      Default the timer and vector to use for ColdFire. Some ColdFire
  33  *      CPU's and some boards may want different. Their sub-architecture
  34  *      startup code (in config.c) can change these if they want.
  35  */
  36 unsigned int    mcf_timervector = 29;
  37 unsigned int    mcf_profilevector = 31;
  38 unsigned int    mcf_timerlevel = 5;
  39
  40 /*
  41  *      These provide the underlying interrupt vector support.
  42  *      Unfortunately it is a little different on each ColdFire.
  43  */
  44 extern void mcf_settimericr(int timer, int level);
  45 extern int mcf_timerirqpending(int timer);
  46
  47 #if defined(CONFIG_M532x)
  48 #define __raw_readtrr   __raw_readl
  49 #define __raw_writetrr  __raw_writel
  50 #else
  51 #define __raw_readtrr   __raw_readw
  52 #define __raw_writetrr  __raw_writew
  53 #endif
  54
  55 /***************************************************************************/
  56
  57 void coldfire_tick(void)
  58 {
  59         /* Reset the ColdFire timer */
  60         __raw_writeb(MCFTIMER_TER_CAP | MCFTIMER_TER_REF, TA(MCFTIMER_TER));
  61 }
  62
  63 /***************************************************************************/
  64
  65 void coldfire_timer_init(irqreturn_t (*handler)(int, void *, struct pt_regs *))
  66 {
  67         __raw_writew(MCFTIMER_TMR_DISABLE, TA(MCFTIMER_TMR));
  68         __raw_writetrr(((MCF_BUSCLK / 16) / HZ), TA(MCFTIMER_TRR));
  69         __raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 |
  70                 MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, TA(MCFTIMER_TMR));
  71
  72         request_irq(mcf_timervector, handler, IRQF_DISABLED, "timer", NULL);
  73         mcf_settimericr(1, mcf_timerlevel);
  74
  75 #ifdef CONFIG_HIGHPROFILE
  76         coldfire_profile_init();
  77 #endif
  78 }
  79
  80 /***************************************************************************/
  81
  82 unsigned long coldfire_timer_offset(void)
  83 {
  84         unsigned long trr, tcn, offset;
  85
  86         tcn = __raw_readw(TA(MCFTIMER_TCN));
  87         trr = __raw_readtrr(TA(MCFTIMER_TRR));
  88         offset = (tcn * (1000000 / HZ)) / trr;
  89
  90         /* Check if we just wrapped the counters and maybe missed a tick */
  91         if ((offset < (1000000 / HZ / 2)) && mcf_timerirqpending(1))
  92                 offset += 1000000 / HZ;
  93         return offset;
  94 }
  95
  96 /***************************************************************************/
  97 #ifdef CONFIG_HIGHPROFILE
  98 /***************************************************************************/
  99
 100 /*
 101  *      By default use timer2 as the profiler clock timer.
 102  */
 103 #define PA(a)   (MCF_MBAR + MCFTIMER_BASE2 + (a))
 104
 105 /*
 106  *      Choose a reasonably fast profile timer. Make it an odd value to
 107  *      try and get good coverage of kernal operations.
 108  */
 109 #define PROFILEHZ       1013
 110
 111 /*
 112  *      Use the other timer to provide high accuracy profiling info.
 113  */
 114 void coldfire_profile_tick(int irq, void *dummy, struct pt_regs *regs)
 115 {
 116         /* Reset ColdFire timer2 */
 117         __raw_writeb(MCFTIMER_TER_CAP | MCFTIMER_TER_REF, PA(MCFTIMER_TER));
 118         if (current->pid)
 119                 profile_tick(CPU_PROFILING, regs);
 120 }
 121
 122 /***************************************************************************/
 123
 124 void coldfire_profile_init(void)
 125 {
 126         printk(KERN_INFO "PROFILE: lodging TIMER2 @ %dHz as profile timer\n", PROFILEHZ);
 127
 128         /* Set up TIMER 2 as high speed profile clock */
 129         __raw_writew(MCFTIMER_TMR_DISABLE, PA(MCFTIMER_TMR));
 130
 131         __raw_writetrr(((MCF_CLK / 16) / PROFILEHZ), PA(MCFTIMER_TRR));
 132         __raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 |
 133                 MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, PA(MCFTIMER_TMR));
 134
 135         request_irq(mcf_profilevector, coldfire_profile_tick,
 136                 (IRQF_DISABLED | IRQ_FLG_FAST), "profile timer", NULL);
 137         mcf_settimericr(2, 7);
 138 }
 139
 140 /***************************************************************************/
 141 #endif  /* CONFIG_HIGHPROFILE */
 142 /***************************************************************************/