1 /***************************************************************************/
4 * timers.c -- generic ColdFire hardware timer support.
6 * Copyright (C) 1999-2007, Greg Ungerer (gerg@snapgear.com)
9 /***************************************************************************/
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 <linux/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>
24 /***************************************************************************/
27 * By default use timer1 as the system clock timer.
29 #define TA(a) (MCF_MBAR + MCFTIMER_BASE1 + (a))
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.
36 unsigned int mcf_timervector = 29;
37 unsigned int mcf_profilevector = 31;
38 unsigned int mcf_timerlevel = 5;
41 * These provide the underlying interrupt vector support.
42 * Unfortunately it is a little different on each ColdFire.
44 extern void mcf_settimericr(int timer, int level);
45 extern int mcf_timerirqpending(int timer);
47 #if defined(CONFIG_M532x)
48 #define __raw_readtrr __raw_readl
49 #define __raw_writetrr __raw_writel
51 #define __raw_readtrr __raw_readw
52 #define __raw_writetrr __raw_writew
55 /***************************************************************************/
57 void coldfire_tick(void)
59 /* Reset the ColdFire timer */
60 __raw_writeb(MCFTIMER_TER_CAP | MCFTIMER_TER_REF, TA(MCFTIMER_TER));
63 /***************************************************************************/
65 static struct irqaction coldfire_timer_irq = {
67 .flags = IRQF_DISABLED | IRQF_TIMER,
70 static int ticks_per_intr;
72 void coldfire_timer_init(irq_handler_t handler)
74 coldfire_timer_irq.handler = handler;
75 setup_irq(mcf_timervector, &coldfire_timer_irq);
77 __raw_writew(MCFTIMER_TMR_DISABLE, TA(MCFTIMER_TMR));
78 ticks_per_intr = (MCF_BUSCLK / 16) / HZ;
79 __raw_writetrr(ticks_per_intr - 1, TA(MCFTIMER_TRR));
80 __raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 |
81 MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, TA(MCFTIMER_TMR));
83 mcf_settimericr(1, mcf_timerlevel);
85 #ifdef CONFIG_HIGHPROFILE
86 coldfire_profile_init();
90 /***************************************************************************/
92 unsigned long coldfire_timer_offset(void)
94 unsigned long tcn, offset;
96 tcn = __raw_readw(TA(MCFTIMER_TCN));
97 offset = ((tcn + 1) * (1000000 / HZ)) / ticks_per_intr;
99 /* Check if we just wrapped the counters and maybe missed a tick */
100 if ((offset < (1000000 / HZ / 2)) && mcf_timerirqpending(1))
101 offset += 1000000 / HZ;
105 /***************************************************************************/
106 #ifdef CONFIG_HIGHPROFILE
107 /***************************************************************************/
110 * By default use timer2 as the profiler clock timer.
112 #define PA(a) (MCF_MBAR + MCFTIMER_BASE2 + (a))
115 * Choose a reasonably fast profile timer. Make it an odd value to
116 * try and get good coverage of kernel operations.
118 #define PROFILEHZ 1013
121 * Use the other timer to provide high accuracy profiling info.
123 irqreturn_t coldfire_profile_tick(int irq, void *dummy)
125 /* Reset ColdFire timer2 */
126 __raw_writeb(MCFTIMER_TER_CAP | MCFTIMER_TER_REF, PA(MCFTIMER_TER));
128 profile_tick(CPU_PROFILING, regs);
132 /***************************************************************************/
134 void coldfire_profile_init(void)
136 printk(KERN_INFO "PROFILE: lodging TIMER2 @ %dHz as profile timer\n", PROFILEHZ);
138 /* Set up TIMER 2 as high speed profile clock */
139 __raw_writew(MCFTIMER_TMR_DISABLE, PA(MCFTIMER_TMR));
141 __raw_writetrr(((MCF_CLK / 16) / PROFILEHZ), PA(MCFTIMER_TRR));
142 __raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 |
143 MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, PA(MCFTIMER_TMR));
145 request_irq(mcf_profilevector, coldfire_profile_tick,
146 (IRQF_DISABLED | IRQ_FLG_FAST), "profile timer", NULL);
147 mcf_settimericr(2, 7);
150 /***************************************************************************/
151 #endif /* CONFIG_HIGHPROFILE */
152 /***************************************************************************/