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Diffstat (limited to 'arch/arm/mach-rpc/time.c')
| -rw-r--r-- | arch/arm/mach-rpc/time.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/arch/arm/mach-rpc/time.c b/arch/arm/mach-rpc/time.c new file mode 100644 index 00000000000..581fca934bb --- /dev/null +++ b/arch/arm/mach-rpc/time.c @@ -0,0 +1,95 @@ +/* + * linux/arch/arm/common/time-acorn.c + * + * Copyright (c) 1996-2000 Russell King. + * + * 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. + * + * Changelog: + * 24-Sep-1996 RMK Created + * 10-Oct-1996 RMK Brought up to date with arch-sa110eval + * 04-Dec-1997 RMK Updated for new arch/arm/time.c + * 13=Jun-2004 DS Moved to arch/arm/common b/c shared w/CLPS7500 + */ +#include <linux/timex.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/io.h> + +#include <mach/hardware.h> +#include <asm/hardware/ioc.h> + +#include <asm/mach/time.h> + +unsigned long ioc_timer_gettimeoffset(void) +{ + unsigned int count1, count2, status; + long offset; + + ioc_writeb (0, IOC_T0LATCH); + barrier (); + count1 = ioc_readb(IOC_T0CNTL) | (ioc_readb(IOC_T0CNTH) << 8); + barrier (); + status = ioc_readb(IOC_IRQREQA); + barrier (); + ioc_writeb (0, IOC_T0LATCH); + barrier (); + count2 = ioc_readb(IOC_T0CNTL) | (ioc_readb(IOC_T0CNTH) << 8); + + offset = count2; + if (count2 < count1) { + /* + * We have not had an interrupt between reading count1 + * and count2. + */ + if (status & (1 << 5)) + offset -= LATCH; + } else if (count2 > count1) { + /* + * We have just had another interrupt between reading + * count1 and count2. + */ + offset -= LATCH; + } + + offset = (LATCH - offset) * (tick_nsec / 1000); + return (offset + LATCH/2) / LATCH; +} + +void __init ioctime_init(void) +{ + ioc_writeb(LATCH & 255, IOC_T0LTCHL); + ioc_writeb(LATCH >> 8, IOC_T0LTCHH); + ioc_writeb(0, IOC_T0GO); +} + +static irqreturn_t +ioc_timer_interrupt(int irq, void *dev_id) +{ + timer_tick(); + return IRQ_HANDLED; +} + +static struct irqaction ioc_timer_irq = { + .name = "timer", + .flags = IRQF_DISABLED, + .handler = ioc_timer_interrupt +}; + +/* + * Set up timer interrupt. + */ +static void __init ioc_timer_init(void) +{ + ioctime_init(); + setup_irq(IRQ_TIMER0, &ioc_timer_irq); +} + +struct sys_timer ioc_timer = { + .init = ioc_timer_init, + .offset = ioc_timer_gettimeoffset, +}; + |