diff options
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/plat-iop/Makefile | 2 | ||||
| -rw-r--r-- | arch/arm/plat-iop/time.c | 94 |
2 files changed, 95 insertions, 1 deletions
diff --git a/arch/arm/plat-iop/Makefile b/arch/arm/plat-iop/Makefile index efde7a513fb7..d20cdec3a944 100644 --- a/arch/arm/plat-iop/Makefile +++ b/arch/arm/plat-iop/Makefile @@ -2,7 +2,7 @@ # Makefile for the linux kernel. # -obj-y := i2c.o pci.o setup.o +obj-y := i2c.o pci.o setup.o time.o obj-m := obj-n := obj- := diff --git a/arch/arm/plat-iop/time.c b/arch/arm/plat-iop/time.c new file mode 100644 index 000000000000..5730a0d7ed67 --- /dev/null +++ b/arch/arm/plat-iop/time.c @@ -0,0 +1,94 @@ +/* + * arch/arm/plat-iop/time.c + * + * Timer code for IOP32x and IOP33x based systems + * + * Author: Deepak Saxena <dsaxena@mvista.com> + * + * Copyright 2002-2003 MontaVista Software Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#include <linux/kernel.h> +#include <linux/interrupt.h> +#include <linux/time.h> +#include <linux/init.h> +#include <linux/timex.h> +#include <asm/hardware.h> +#include <asm/io.h> +#include <asm/irq.h> +#include <asm/uaccess.h> +#include <asm/mach/irq.h> +#include <asm/mach/time.h> + +#ifdef CONFIG_ARCH_IOP32X +#define IRQ_IOP3XX_TIMER0 IRQ_IOP321_TIMER0 +#else +#ifdef CONFIG_ARCH_IOP33X +#define IRQ_IOP3XX_TIMER0 IRQ_IOP331_TIMER0 +#endif +#endif + +static unsigned long ticks_per_jiffy; +static unsigned long ticks_per_usec; +static unsigned long next_jiffy_time; + +unsigned long iop3xx_gettimeoffset(void) +{ + unsigned long offset; + + offset = next_jiffy_time - *IOP3XX_TU_TCR1; + + return offset / ticks_per_usec; +} + +static irqreturn_t +iop3xx_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) +{ + write_seqlock(&xtime_lock); + + asm volatile("mcr p6, 0, %0, c6, c1, 0" : : "r" (1)); + + while ((signed long)(next_jiffy_time - *IOP3XX_TU_TCR1) + >= ticks_per_jiffy) { + timer_tick(regs); + next_jiffy_time -= ticks_per_jiffy; + } + + write_sequnlock(&xtime_lock); + + return IRQ_HANDLED; +} + +static struct irqaction iop3xx_timer_irq = { + .name = "IOP3XX Timer Tick", + .handler = iop3xx_timer_interrupt, + .flags = IRQF_DISABLED | IRQF_TIMER, +}; + +void __init iop3xx_init_time(unsigned long tick_rate) +{ + u32 timer_ctl; + + ticks_per_jiffy = (tick_rate + HZ/2) / HZ; + ticks_per_usec = tick_rate / 1000000; + next_jiffy_time = 0xffffffff; + + timer_ctl = IOP3XX_TMR_EN | IOP3XX_TMR_PRIVILEGED | + IOP3XX_TMR_RELOAD | IOP3XX_TMR_RATIO_1_1; + + /* + * We use timer 0 for our timer interrupt, and timer 1 as + * monotonic counter for tracking missed jiffies. + */ + asm volatile("mcr p6, 0, %0, c4, c1, 0" : : "r" (ticks_per_jiffy - 1)); + asm volatile("mcr p6, 0, %0, c0, c1, 0" : : "r" (timer_ctl)); + asm volatile("mcr p6, 0, %0, c5, c1, 0" : : "r" (0xffffffff)); + asm volatile("mcr p6, 0, %0, c1, c1, 0" : : "r" (timer_ctl)); + + setup_irq(IRQ_IOP3XX_TIMER0, &iop3xx_timer_irq); +} |