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authorUwe Kleine-König <ukleinek@informatik.uni-freiburg.de>2007-02-16 09:36:55 -0500
committerRussell King <rmk+kernel@arm.linux.org.uk>2007-02-17 15:05:45 -0500
commit9918cda52368ec3df5bb6bc1630ba8c070ad9fdd (patch)
tree4b0a6b5df2c8d5f27b3c945eaec0966d8bcf67d8 /arch/arm/mach-ns9xxx/time.c
parentae0a846e411dc0b568e8ccda584896310ee5f369 (diff)
[ARM] 4210/1: base for new machine type "NetSilicon NS9360"
Signed-off-by: Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mach-ns9xxx/time.c')
-rw-r--r--arch/arm/mach-ns9xxx/time.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/arch/arm/mach-ns9xxx/time.c b/arch/arm/mach-ns9xxx/time.c
new file mode 100644
index 000000000000..eec05f18714a
--- /dev/null
+++ b/arch/arm/mach-ns9xxx/time.c
@@ -0,0 +1,88 @@
1/*
2 * arch/arm/mach-ns9xxx/time.c
3 *
4 * Copyright (C) 2006 by Digi International Inc.
5 * All rights reserved.
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as published by
9 * the Free Software Foundation.
10 */
11#include <linux/jiffies.h>
12#include <linux/interrupt.h>
13#include <linux/irq.h>
14#include <asm/arch-ns9xxx/regs-sys.h>
15#include <asm/arch-ns9xxx/clock.h>
16#include <asm/arch-ns9xxx/irqs.h>
17#include <asm/arch/system.h>
18#include "generic.h"
19
20#define TIMERCLOCKSELECT 64
21
22static u32 usecs_per_tick;
23
24static irqreturn_t
25ns9xxx_timer_interrupt(int irq, void *dev_id)
26{
27 write_seqlock(&xtime_lock);
28 timer_tick();
29 write_sequnlock(&xtime_lock);
30
31 return IRQ_HANDLED;
32}
33
34static unsigned long ns9xxx_timer_gettimeoffset(void)
35{
36 /* return the microseconds which have passed since the last interrupt
37 * was _serviced_. That is, if an interrupt is pending or the counter
38 * reloads, return one periode more. */
39
40 u32 counter1 = SYS_TR(0);
41 int pending = SYS_ISR & (1 << IRQ_TIMER0);
42 u32 counter2 = SYS_TR(0);
43 u32 elapsed;
44
45 if (pending || counter2 > counter1)
46 elapsed = 2 * SYS_TRC(0) - counter2;
47 else
48 elapsed = SYS_TRC(0) - counter1;
49
50 return (elapsed * usecs_per_tick) >> 16;
51
52}
53
54static struct irqaction ns9xxx_timer_irq = {
55 .name = "NS9xxx Timer Tick",
56 .flags = IRQF_DISABLED | IRQF_TIMER,
57 .handler = ns9xxx_timer_interrupt,
58};
59
60static void __init ns9xxx_timer_init(void)
61{
62 int tc;
63
64 usecs_per_tick =
65 SH_DIV(1000000 * TIMERCLOCKSELECT, ns9xxx_cpuclock(), 16);
66
67 /* disable timer */
68 if ((tc = SYS_TC(0)) & SYS_TCx_TEN)
69 SYS_TC(0) = tc & ~SYS_TCx_TEN;
70
71 SYS_TRC(0) = SH_DIV(ns9xxx_cpuclock(), (TIMERCLOCKSELECT * HZ), 0);
72
73 REGSET(tc, SYS_TCx, TEN, EN);
74 REGSET(tc, SYS_TCx, TLCS, DIV64); /* This must match TIMERCLOCKSELECT */
75 REGSET(tc, SYS_TCx, INTS, EN);
76 REGSET(tc, SYS_TCx, UDS, DOWN);
77 REGSET(tc, SYS_TCx, TDBG, STOP);
78 REGSET(tc, SYS_TCx, TSZ, 32);
79 REGSET(tc, SYS_TCx, REN, EN);
80 SYS_TC(0) = tc;
81
82 setup_irq(IRQ_TIMER0, &ns9xxx_timer_irq);
83}
84
85struct sys_timer ns9xxx_timer = {
86 .init = ns9xxx_timer_init,
87 .offset = ns9xxx_timer_gettimeoffset,
88};