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1da177e4 LT |
1 | /***************************************************************************/ |
2 | ||
3 | /* | |
4 | * timers.c -- generic ColdFire hardware timer support. | |
5 | * | |
6 | * Copyright (C) 1999-2003, Greg Ungerer (gerg@snapgear.com) | |
7 | */ | |
8 | ||
9 | /***************************************************************************/ | |
10 | ||
11 | #include <linux/config.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/sched.h> | |
14 | #include <linux/param.h> | |
15 | #include <linux/interrupt.h> | |
16 | #include <linux/init.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 | * Default the timer and vector to use for ColdFire. Some ColdFire | |
28 | * CPU's and some boards may want different. Their sub-architecture | |
29 | * startup code (in config.c) can change these if they want. | |
30 | */ | |
31 | unsigned int mcf_timervector = 29; | |
32 | unsigned int mcf_profilevector = 31; | |
33 | unsigned int mcf_timerlevel = 5; | |
34 | ||
35 | static volatile struct mcftimer *mcf_timerp; | |
36 | ||
37 | /* | |
38 | * These provide the underlying interrupt vector support. | |
39 | * Unfortunately it is a little different on each ColdFire. | |
40 | */ | |
41 | extern void mcf_settimericr(int timer, int level); | |
42 | extern int mcf_timerirqpending(int timer); | |
43 | ||
44 | /***************************************************************************/ | |
45 | ||
46 | void coldfire_tick(void) | |
47 | { | |
48 | /* Reset the ColdFire timer */ | |
49 | mcf_timerp->ter = MCFTIMER_TER_CAP | MCFTIMER_TER_REF; | |
50 | } | |
51 | ||
52 | /***************************************************************************/ | |
53 | ||
54 | void coldfire_timer_init(irqreturn_t (*handler)(int, void *, struct pt_regs *)) | |
55 | { | |
56 | /* Set up an internal TIMER as poll clock */ | |
57 | mcf_timerp = (volatile struct mcftimer *) (MCF_MBAR + MCFTIMER_BASE1); | |
58 | mcf_timerp->tmr = MCFTIMER_TMR_DISABLE; | |
59 | ||
60 | mcf_timerp->trr = (unsigned short) ((MCF_BUSCLK / 16) / HZ); | |
61 | mcf_timerp->tmr = MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 | | |
62 | MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE; | |
63 | ||
64 | request_irq(mcf_timervector, handler, SA_INTERRUPT, "timer", NULL); | |
65 | mcf_settimericr(1, mcf_timerlevel); | |
66 | ||
67 | #ifdef CONFIG_HIGHPROFILE | |
68 | coldfire_profile_init(); | |
69 | #endif | |
70 | } | |
71 | ||
72 | /***************************************************************************/ | |
73 | ||
74 | unsigned long coldfire_timer_offset(void) | |
75 | { | |
76 | unsigned long trr, tcn, offset; | |
77 | ||
78 | /* | |
79 | * The change to pointer and de-reference is to force the compiler | |
80 | * to read the registers with a single 16bit access. Otherwise it | |
81 | * does some crazy 8bit read combining. | |
82 | */ | |
83 | tcn = *(&mcf_timerp->tcn); | |
84 | trr = *(&mcf_timerp->trr); | |
85 | offset = (tcn * (1000000 / HZ)) / trr; | |
86 | ||
87 | /* Check if we just wrapped the counters and maybe missed a tick */ | |
88 | if ((offset < (1000000 / HZ / 2)) && mcf_timerirqpending(1)) | |
89 | offset += 1000000 / HZ; | |
90 | return offset; | |
91 | } | |
92 | ||
93 | /***************************************************************************/ | |
94 | #ifdef CONFIG_HIGHPROFILE | |
95 | /***************************************************************************/ | |
96 | ||
97 | /* | |
98 | * Choose a reasonably fast profile timer. Make it an odd value to | |
99 | * try and get good coverage of kernal operations. | |
100 | */ | |
101 | #define PROFILEHZ 1013 | |
102 | ||
103 | static volatile struct mcftimer *mcf_proftp; | |
104 | ||
105 | /* | |
106 | * Use the other timer to provide high accuracy profiling info. | |
107 | */ | |
108 | ||
109 | void coldfire_profile_tick(int irq, void *dummy, struct pt_regs *regs) | |
110 | { | |
111 | /* Reset ColdFire timer2 */ | |
112 | mcf_proftp->ter = MCFTIMER_TER_CAP | MCFTIMER_TER_REF; | |
113 | if (current->pid) | |
114 | profile_tick(CPU_PROFILING, regs); | |
115 | } | |
116 | ||
117 | /***************************************************************************/ | |
118 | ||
119 | void coldfire_profile_init(void) | |
120 | { | |
121 | printk(KERN_INFO "PROFILE: lodging TIMER2 @ %dHz as profile timer\n", PROFILEHZ); | |
122 | ||
123 | /* Set up TIMER 2 as high speed profile clock */ | |
124 | mcf_proftp = (volatile struct mcftimer *) (MCF_MBAR + MCFTIMER_BASE2); | |
125 | mcf_proftp->tmr = MCFTIMER_TMR_DISABLE; | |
126 | ||
127 | mcf_proftp->trr = (unsigned short) ((MCF_CLK / 16) / PROFILEHZ); | |
128 | mcf_proftp->tmr = MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 | | |
129 | MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE; | |
130 | ||
131 | request_irq(mcf_profilevector, coldfire_profile_tick, | |
132 | (SA_INTERRUPT | IRQ_FLG_FAST), "profile timer", NULL); | |
133 | mcf_settimericr(2, 7); | |
134 | } | |
135 | ||
136 | /***************************************************************************/ | |
137 | #endif /* CONFIG_HIGHPROFILE */ | |
138 | /***************************************************************************/ |