diff options
author | Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de> | 2007-02-16 15:36:55 +0100 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2007-02-17 20:05:45 +0000 |
commit | 9918cda52368ec3df5bb6bc1630ba8c070ad9fdd (patch) | |
tree | 4b0a6b5df2c8d5f27b3c945eaec0966d8bcf67d8 /arch/arm/mach-ns9xxx/time.c | |
parent | ae0a846e411dc0b568e8ccda584896310ee5f369 (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.c | 88 |
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 00000000000..eec05f18714 --- /dev/null +++ b/arch/arm/mach-ns9xxx/time.c @@ -0,0 +1,88 @@ +/* + * arch/arm/mach-ns9xxx/time.c + * + * Copyright (C) 2006 by Digi International Inc. + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ +#include <linux/jiffies.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <asm/arch-ns9xxx/regs-sys.h> +#include <asm/arch-ns9xxx/clock.h> +#include <asm/arch-ns9xxx/irqs.h> +#include <asm/arch/system.h> +#include "generic.h" + +#define TIMERCLOCKSELECT 64 + +static u32 usecs_per_tick; + +static irqreturn_t +ns9xxx_timer_interrupt(int irq, void *dev_id) +{ + write_seqlock(&xtime_lock); + timer_tick(); + write_sequnlock(&xtime_lock); + + return IRQ_HANDLED; +} + +static unsigned long ns9xxx_timer_gettimeoffset(void) +{ + /* return the microseconds which have passed since the last interrupt + * was _serviced_. That is, if an interrupt is pending or the counter + * reloads, return one periode more. */ + + u32 counter1 = SYS_TR(0); + int pending = SYS_ISR & (1 << IRQ_TIMER0); + u32 counter2 = SYS_TR(0); + u32 elapsed; + + if (pending || counter2 > counter1) + elapsed = 2 * SYS_TRC(0) - counter2; + else + elapsed = SYS_TRC(0) - counter1; + + return (elapsed * usecs_per_tick) >> 16; + +} + +static struct irqaction ns9xxx_timer_irq = { + .name = "NS9xxx Timer Tick", + .flags = IRQF_DISABLED | IRQF_TIMER, + .handler = ns9xxx_timer_interrupt, +}; + +static void __init ns9xxx_timer_init(void) +{ + int tc; + + usecs_per_tick = + SH_DIV(1000000 * TIMERCLOCKSELECT, ns9xxx_cpuclock(), 16); + + /* disable timer */ + if ((tc = SYS_TC(0)) & SYS_TCx_TEN) + SYS_TC(0) = tc & ~SYS_TCx_TEN; + + SYS_TRC(0) = SH_DIV(ns9xxx_cpuclock(), (TIMERCLOCKSELECT * HZ), 0); + + REGSET(tc, SYS_TCx, TEN, EN); + REGSET(tc, SYS_TCx, TLCS, DIV64); /* This must match TIMERCLOCKSELECT */ + REGSET(tc, SYS_TCx, INTS, EN); + REGSET(tc, SYS_TCx, UDS, DOWN); + REGSET(tc, SYS_TCx, TDBG, STOP); + REGSET(tc, SYS_TCx, TSZ, 32); + REGSET(tc, SYS_TCx, REN, EN); + SYS_TC(0) = tc; + + setup_irq(IRQ_TIMER0, &ns9xxx_timer_irq); +} + +struct sys_timer ns9xxx_timer = { + .init = ns9xxx_timer_init, + .offset = ns9xxx_timer_gettimeoffset, +}; |