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
18 #undef DEBUG_TIMER
19
20 #include <linux/errno.h>
21 #include <linux/init.h>
22 #include <linux/module.h>
23 #include <linux/sched.h>
24 #include <linux/kernel.h>
25 #include <linux/param.h>
26 #include <linux/string.h>
27 #include <linux/mm.h>
28 #include <linux/interrupt.h>
29 #include <linux/profile.h>
30
31 #include <asm/io.h>
32 #include <asm/m32r.h>
33
34 #include <asm/hw_irq.h>
35
36 #if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE)
37 /* this needs a better home */
38 DEFINE_SPINLOCK(rtc_lock);
39
40 #ifdef CONFIG_RTC_DRV_CMOS_MODULE
41 EXPORT_SYMBOL(rtc_lock);
42 #endif
43 #endif /* pc-style 'CMOS' RTC support */
44
45 #ifdef CONFIG_SMP
46 extern void smp_local_timer_interrupt(void);
47 #endif
48
49 #define TICK_SIZE (tick_nsec / 1000)
50
51 /*
52 * Change this if you have some constant time drift
53 */
54
55 /* This is for machines which generate the exact clock. */
56 #define USECS_PER_JIFFY (1000000/HZ)
57
58 static unsigned long latch;
59
arch_gettimeoffset(void)60 u32 arch_gettimeoffset(void)
61 {
62 unsigned long elapsed_time = 0; /* [us] */
63
64 #if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) \
65 || defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) \
66 || defined(CONFIG_CHIP_OPSP) || defined(CONFIG_CHIP_M32104)
67 #ifndef CONFIG_SMP
68
69 unsigned long count;
70
71 /* timer count may underflow right here */
72 count = inl(M32R_MFT2CUT_PORTL);
73
74 if (inl(M32R_ICU_CR18_PORTL) & 0x00000100) /* underflow check */
75 count = 0;
76
77 count = (latch - count) * TICK_SIZE;
78 elapsed_time = DIV_ROUND_CLOSEST(count, latch);
79 /* NOTE: LATCH is equal to the "interval" value (= reload count). */
80
81 #else /* CONFIG_SMP */
82 unsigned long count;
83 static unsigned long p_jiffies = -1;
84 static unsigned long p_count = 0;
85
86 /* timer count may underflow right here */
87 count = inl(M32R_MFT2CUT_PORTL);
88
89 if (jiffies == p_jiffies && count > p_count)
90 count = 0;
91
92 p_jiffies = jiffies;
93 p_count = count;
94
95 count = (latch - count) * TICK_SIZE;
96 elapsed_time = DIV_ROUND_CLOSEST(count, latch);
97 /* NOTE: LATCH is equal to the "interval" value (= reload count). */
98 #endif /* CONFIG_SMP */
99 #elif defined(CONFIG_CHIP_M32310)
100 #warning do_gettimeoffse not implemented
101 #else
102 #error no chip configuration
103 #endif
104
105 return elapsed_time * 1000;
106 }
107
108 /*
109 * timer_interrupt() needs to keep up the real-time clock,
110 * as well as call the "xtime_update()" routine every clocktick
111 */
timer_interrupt(int irq,void * dev_id)112 static irqreturn_t timer_interrupt(int irq, void *dev_id)
113 {
114 #ifndef CONFIG_SMP
115 profile_tick(CPU_PROFILING);
116 #endif
117 xtime_update(1);
118
119 #ifndef CONFIG_SMP
120 update_process_times(user_mode(get_irq_regs()));
121 #endif
122 /* As we return to user mode fire off the other CPU schedulers..
123 this is basically because we don't yet share IRQ's around.
124 This message is rigged to be safe on the 386 - basically it's
125 a hack, so don't look closely for now.. */
126
127 #ifdef CONFIG_SMP
128 smp_local_timer_interrupt();
129 smp_send_timer();
130 #endif
131
132 return IRQ_HANDLED;
133 }
134
135 static struct irqaction irq0 = {
136 .handler = timer_interrupt,
137 .flags = IRQF_DISABLED,
138 .name = "MFT2",
139 };
140
read_persistent_clock(struct timespec * ts)141 void read_persistent_clock(struct timespec *ts)
142 {
143 unsigned int epoch, year, mon, day, hour, min, sec;
144
145 sec = min = hour = day = mon = year = 0;
146 epoch = 0;
147
148 year = 23;
149 mon = 4;
150 day = 17;
151
152 /* Attempt to guess the epoch. This is the same heuristic as in rtc.c
153 so no stupid things will happen to timekeeping. Who knows, maybe
154 Ultrix also uses 1952 as epoch ... */
155 if (year > 10 && year < 44)
156 epoch = 1980;
157 else if (year < 96)
158 epoch = 1952;
159 year += epoch;
160
161 ts->tv_sec = mktime(year, mon, day, hour, min, sec);
162 ts->tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
163 }
164
165
time_init(void)166 void __init time_init(void)
167 {
168 #if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) \
169 || defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) \
170 || defined(CONFIG_CHIP_OPSP) || defined(CONFIG_CHIP_M32104)
171
172 /* M32102 MFT setup */
173 setup_irq(M32R_IRQ_MFT2, &irq0);
174 {
175 unsigned long bus_clock;
176 unsigned short divide;
177
178 bus_clock = boot_cpu_data.bus_clock;
179 divide = boot_cpu_data.timer_divide;
180 latch = DIV_ROUND_CLOSEST(bus_clock/divide, HZ);
181
182 printk("Timer start : latch = %ld\n", latch);
183
184 outl((M32R_MFTMOD_CC_MASK | M32R_MFTMOD_TCCR \
185 |M32R_MFTMOD_CSSEL011), M32R_MFT2MOD_PORTL);
186 outl(latch, M32R_MFT2RLD_PORTL);
187 outl(latch, M32R_MFT2CUT_PORTL);
188 outl(0, M32R_MFT2CMPRLD_PORTL);
189 outl((M32R_MFTCR_MFT2MSK|M32R_MFTCR_MFT2EN), M32R_MFTCR_PORTL);
190 }
191
192 #elif defined(CONFIG_CHIP_M32310)
193 #warning time_init not implemented
194 #else
195 #error no chip configuration
196 #endif
197 }
198