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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright 2001 MontaVista Software Inc.
3 * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
4 * Copyright (c) 2003, 2004 Maciej W. Rozycki
5 *
Atsushi Nemotod9eec1a2007-10-31 01:21:03 +09006 * Common time service routines for MIPS machines.
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 *
Ralf Baechle70342282013-01-22 12:59:30 +01008 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
12 */
Ralf Baechle656db502007-10-26 13:24:06 +010013#include <linux/bug.h>
Ralf Baechle7bcf7712007-10-11 23:46:09 +010014#include <linux/clockchips.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/types.h>
16#include <linux/kernel.h>
17#include <linux/init.h>
18#include <linux/sched.h>
19#include <linux/param.h>
20#include <linux/time.h>
21#include <linux/timex.h>
22#include <linux/smp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/spinlock.h>
Paul Gortmaker73bc2562011-07-23 16:30:40 -040024#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <asm/cpu-features.h>
Ralf Baechle69f24d12013-09-17 10:25:47 +020027#include <asm/cpu-type.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <asm/div64.h>
Ralf Baechleea580402007-10-11 23:46:09 +010029#include <asm/smtc_ipi.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <asm/time.h>
31
32/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070033 * forward reference
34 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070035DEFINE_SPINLOCK(rtc_lock);
Ralf Baechle4b550482007-10-11 23:46:08 +010036EXPORT_SYMBOL(rtc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
Ralf Baechle4b550482007-10-11 23:46:08 +010038int __weak rtc_mips_set_time(unsigned long sec)
Linus Torvalds1da177e2005-04-16 15:20:36 -070039{
40 return 0;
41}
42
Ralf Baechle4b550482007-10-11 23:46:08 +010043int __weak rtc_mips_set_mmss(unsigned long nowtime)
44{
45 return rtc_mips_set_time(nowtime);
46}
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
Ralf Baechlef5ff0a22007-08-13 15:26:12 +010048int update_persistent_clock(struct timespec now)
49{
50 return rtc_mips_set_mmss(now.tv_sec);
51}
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
Dmitri Vorobiev46684732008-04-02 03:58:38 +040053static int null_perf_irq(void)
Ralf Baechleba339c02005-12-09 12:29:38 +000054{
55 return 0;
56}
57
David Howells7d12e782006-10-05 14:55:46 +010058int (*perf_irq)(void) = null_perf_irq;
Ralf Baechleba339c02005-12-09 12:29:38 +000059
Ralf Baechleba339c02005-12-09 12:29:38 +000060EXPORT_SYMBOL(perf_irq);
61
Chris Dearmanffe9ee42007-05-24 22:24:20 +010062/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 * time_init() - it does the following things.
64 *
Ralf Baechle4b550482007-10-11 23:46:08 +010065 * 1) plat_time_init() -
Ralf Baechle70342282013-01-22 12:59:30 +010066 * a) (optional) set up RTC routines,
67 * b) (optional) calibrate and set the mips_hpt_frequency
Atsushi Nemoto16b7b2a2006-10-24 00:21:27 +090068 * (only needed if you intended to use cpu counter as timer interrupt
69 * source)
Ralf Baechle4b550482007-10-11 23:46:08 +010070 * 2) calculate a couple of cached variables for later usage
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 */
72
Linus Torvalds1da177e2005-04-16 15:20:36 -070073unsigned int mips_hpt_frequency;
74
Ralf Baechle656db502007-10-26 13:24:06 +010075/*
76 * This function exists in order to cause an error due to a duplicate
77 * definition if platform code should have its own implementation. The hook
78 * to use instead is plat_time_init. plat_time_init does not receive the
Ralf Baechle70342282013-01-22 12:59:30 +010079 * irqaction pointer argument anymore. This is because any function which
Ralf Baechle656db502007-10-26 13:24:06 +010080 * initializes an interrupt timer now takes care of its own request_irq rsp.
81 * setup_irq calls and each clock_event_device should use its own
82 * struct irqrequest.
83 */
Atsushi Nemotod9eec1a2007-10-31 01:21:03 +090084void __init plat_timer_setup(void)
Ralf Baechle7bcf7712007-10-11 23:46:09 +010085{
Ralf Baechle656db502007-10-26 13:24:06 +010086 BUG();
Ralf Baechle7bcf7712007-10-11 23:46:09 +010087}
88
Ralf Baechle5aa85c92007-11-21 16:39:44 +000089static __init int cpu_has_mfc0_count_bug(void)
90{
91 switch (current_cpu_type()) {
92 case CPU_R4000PC:
93 case CPU_R4000SC:
94 case CPU_R4000MC:
95 /*
96 * V3.0 is documented as suffering from the mfc0 from count bug.
Ralf Baechle70342282013-01-22 12:59:30 +010097 * Afaik this is the last version of the R4000. Later versions
Ralf Baechle5aa85c92007-11-21 16:39:44 +000098 * were marketed as R4400.
99 */
100 return 1;
101
102 case CPU_R4400PC:
103 case CPU_R4400SC:
104 case CPU_R4400MC:
105 /*
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300106 * The published errata for the R4400 up to 3.0 say the CPU
Ralf Baechle5aa85c92007-11-21 16:39:44 +0000107 * has the mfc0 from count bug.
108 */
109 if ((current_cpu_data.processor_id & 0xff) <= 0x30)
110 return 1;
111
112 /*
Thomas Bogendoerferce202cb2008-01-04 23:38:31 +0100113 * we assume newer revisions are ok
Ralf Baechle5aa85c92007-11-21 16:39:44 +0000114 */
Thomas Bogendoerferce202cb2008-01-04 23:38:31 +0100115 return 0;
Ralf Baechle5aa85c92007-11-21 16:39:44 +0000116 }
117
118 return 0;
119}
120
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121void __init time_init(void)
122{
Ralf Baechle4b550482007-10-11 23:46:08 +0100123 plat_time_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
Maciej W. Rozyckiafddce02013-09-03 01:29:58 +0100125 /*
126 * The use of the R4k timer as a clock event takes precedence;
127 * if reading the Count register might interfere with the timer
128 * interrupt, then we don't use the timer as a clock source.
129 * We may still use the timer as a clock source though if the
130 * timer interrupt isn't reliable; the interference doesn't
131 * matter then, because we don't use the interrupt.
132 */
133 if (mips_clockevent_init() != 0 || !cpu_has_mfc0_count_bug())
Atsushi Nemotod9eec1a2007-10-31 01:21:03 +0900134 init_mips_clocksource();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135}