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 */
38DEFINE_SPINLOCK(rtc_lock);
39
40#ifdef CONFIG_RTC_DRV_CMOS_MODULE
41EXPORT_SYMBOL(rtc_lock);
42#endif
43#endif  /* pc-style 'CMOS' RTC support */
44
45#ifdef CONFIG_SMP
46extern 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
58static unsigned long latch;
59
60static u32 m32r_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 */
112static 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
135static struct irqaction irq0 = {
136	.handler = timer_interrupt,
137	.name = "MFT2",
138};
139
140void read_persistent_clock(struct timespec *ts)
141{
142	unsigned int epoch, year, mon, day, hour, min, sec;
143
144	sec = min = hour = day = mon = year = 0;
145	epoch = 0;
146
147	year = 23;
148	mon = 4;
149	day = 17;
150
151	/* Attempt to guess the epoch.  This is the same heuristic as in rtc.c
152	   so no stupid things will happen to timekeeping.  Who knows, maybe
153	   Ultrix also uses 1952 as epoch ...  */
154	if (year > 10 && year < 44)
155		epoch = 1980;
156	else if (year < 96)
157		epoch = 1952;
158	year += epoch;
159
160	ts->tv_sec = mktime(year, mon, day, hour, min, sec);
161	ts->tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
162}
163
164
165void __init time_init(void)
166{
167	arch_gettimeoffset = m32r_gettimeoffset;
168
169#if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) \
170	|| defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) \
171	|| defined(CONFIG_CHIP_OPSP) || defined(CONFIG_CHIP_M32104)
172
173	/* M32102 MFT setup */
174	setup_irq(M32R_IRQ_MFT2, &irq0);
175	{
176		unsigned long bus_clock;
177		unsigned short divide;
178
179		bus_clock = boot_cpu_data.bus_clock;
180		divide = boot_cpu_data.timer_divide;
181		latch = DIV_ROUND_CLOSEST(bus_clock/divide, HZ);
182
183		printk("Timer start : latch = %ld\n", latch);
184
185		outl((M32R_MFTMOD_CC_MASK | M32R_MFTMOD_TCCR \
186			|M32R_MFTMOD_CSSEL011), M32R_MFT2MOD_PORTL);
187		outl(latch, M32R_MFT2RLD_PORTL);
188		outl(latch, M32R_MFT2CUT_PORTL);
189		outl(0, M32R_MFT2CMPRLD_PORTL);
190		outl((M32R_MFTCR_MFT2MSK|M32R_MFTCR_MFT2EN), M32R_MFTCR_PORTL);
191	}
192
193#elif defined(CONFIG_CHIP_M32310)
194#warning time_init not implemented
195#else
196#error no chip configuration
197#endif
198}
199